中文   |   English   |   Email Alert
Fig/Tab
Advanced Search
image

Quasi-Solid-State Conversion Mechanism for Sulfur Cathodes

Xumin Wang , Shuping Li , Renjie He , Chuang Yu , Jia Xie , Shijie Cheng

Progress in Chemistry ›› 2022, Vol. 34 ›› Issue (4) : 909 -925.

PDF
Progress in Chemistry ›› 2022, Vol. 34 ›› Issue (4) : 909-925 DOI: 10.7536/PC210635
research-article
Scan to read & Share
Quasi-Solid-State Conversion Mechanism for Sulfur Cathodes
Author information +
History +
PDF

Abstract

With the rapid development of electric vehicles and portable electronic products, the demand for high-energy-density battery systems is becoming more and more urgent. However, the energy density of traditional lithium-ion battery cathode materials is approaching the theoretical limit, thus it is urgent to develop the next-generation battery system with higher energy density. Sulfur cathodes possess lots of advantages, such as high energy density, natural abundance, and low cost, achieving extensive research attention. For the conventional dissolution-deposition mechanism, sulfur cathodes suffer from “shuttle effect”, resulting in irreversible loss of active material, low coulomb efficiency, and poor cycle life. To alleviate the “shuttle effect”, a series of strategies are usually adopted, for instance, physical confinement, chemical adsorption, and reaction accelerators, but none of them can fundamentally solve these problems. Recently, the quasi-solid-state conversion reaction of sulfur cathodes has attracted wide attention. This review discusses these approaches for constructing quasi-solid-state conversion reaction of sulfur cathodes, including the designs of microporous carbon structure, the formation of a solid electrolyte interface (SEI) on the sulfur surface, and electrolyte engineering. The research significance is highlighted and electrochemical behaviors of the quasi-solid-state conversion reaction of sulfur cathodes are summarized. Enhancing the reactivity of sulfur cathode is an effective strategy to alleviate the intrinsic sluggish kinetics of sulfur cathodes. These strategies for quasi-solid-state conversion mechanism of sulfur cathodes are beneficial to cyclability, enabling the practical development of high-performance Li-S batteries.

Contents

1 Introduction

2 Microporous carbon structure

2.1 Electrochemical reaction characteristics

2.2 Building strategy

3 Solid electrolyte interface on the sulfur cathode

3.1 In-situ SEI

3.2 Ex-situ SEI

4 Electrolyte engineering

4.1 Concentrated electrolyte

4.2 Diluted concentrated electrolyte

5 Conclusion and outlook

Graphical abstract

Keywords

sulfur cathode / quasi-solid-state conversion reaction / microporous carbon structure / solid electrolyte interface (SEI) on the sulfur surface / electrolyte engineering

Cite this article

Download citation ▾
Xumin Wang, Shuping Li, Renjie He, Chuang Yu, Jia Xie, Shijie Cheng. Quasi-Solid-State Conversion Mechanism for Sulfur Cathodes. Progress in Chemistry, 2022, 34(4): 909-925 DOI:10.7536/PC210635

登录浏览全文

4963

注册一个新账户 忘记密码

1 Introduction

With the increasing consumption of fossil energy and environmental problems, it is more and more urgent to develop environmentally friendly, clean and renewable secondary energy[1⇓⇓~4]. After decades of development, the specific capacity of electrode materials based on embedded reaction mechanism is approaching the theoretical limit, which limits the development and practical application of lithium-ion batteries[5,6]. Sulfur cathode based on conversion-type reaction mechanism has the advantages of high theoretical specific capacity (1675 mAh·g-1), abundant resources, and environmental friendliness, making Li-S battery one of the most potential secondary batteries for new energy[7⇓~9].
At present, there are two reaction mechanisms of sulfur cathode in liquid electrolyte, which are dissolution-deposition mechanism and quasi-solid phase transformation mechanism[10]. As shown in Figure 1, lithium-sulfur batteries were first proposed in 1970, laying the foundation for research[11]. In 2008, it was found that LiNO3 could form a SEI passivation layer on the surface of lithium anode and significantly improve the coulombic efficiency[12]. In 2009, Nazar et al. Found that the long cycle performance of ordered carbon CMK-3 was improved after it was combined with sulfur by melting and diffusion, which opened the era of sulfur loading on porous conductive carbon, which was mainly a dissolution-deposition mechanism[13]. In order to alleviate the "shuttle effect", scientists have mainly improved the research from physical confinement, chemical adsorption and reaction accelerator[14⇓⇓~17][18⇓⇓~21][22,23]. In 2012, the microporous carbon-sulfur cathode developed by Guo et al. Showed a single platform charge and discharge, and the quasi-solid phase conversion mechanism of sulfur cathode attracted the attention of researchers[24]. In addition, electrolyte regulation and SEI film on the surface of the cathode can also construct a quasi-solid phase conversion mechanism[25][26].
The charge-discharge cycle of sulfur cathode in conventional ether electrolyte 1,3-dioxolane/1,2-dimethoxyethane (DOL/DME) is a "dissolution-deposition" mechanism. As shown in Figure 2A, the battery shows two discharge plateaus during cycling. At the high potential discharge plateau of 2.3 V, the cyclic S8 is converted into soluble high-order polysulfide Li2Sn(8≤n≤4); Subsequently, at the second discharge plateau of 2.1 V, the high-order polysulfides were further reduced to Li2S2/Li2S[27]. The sulfur cathode in the "dissolution-deposition" mechanism undergoes a solid-liquid-solid conversion process, and there is uneven deposition of Li2S2/Li2S and elemental sulfur during repeated charge-discharge, which easily leads to pore blockage and loss of electrochemical activity of sulfur. At the same time, polysulfides dissolve and diffuse in the electrolyte, resulting in a "shuttle effect", which leads to the loss of active materials and rapid capacity decay[28][29]. The conversion of sulfur to lithium sulfide is a multi-step concomitant multi-electron conversion reaction, and a series of disproportionation reactions occur between the intermediate products of high-order/low-order polysulfides, sulfur and lithium sulfide[30,31]. In the "dissolution-deposition" mechanism, in order to improve the active material utilization and cycle stability of sulfur cathode, the main strategy is to inhibit the dissolution and loss of polysulfides in the electrolyte. At present, the widely used methods (physical confinement, chemical adsorption and reaction accelerator) can not fundamentally eliminate the "shuttle effect", and the effect is limited[14⇓⇓~17][18⇓⇓~21][22,23]. Therefore, it is still very challenging to improve the cycle stability of sulfur cathode[32,33].
In order to fundamentally solve the problem of "shuttle effect" and improve the long cycle performance of sulfur cathode, researchers have proposed a new scheme to construct a quasi-solid phase conversion sulfur cathode. As shown in Figure 2B, the lithium-sulfur battery is charged and discharged at a single plateau of about 2.0 V during cycling, that is, sulfur is directly converted into the solid product Li2S2/Li2S. Only a pair of redox peaks appear in the cyclic voltammetry (CV) curve, which is a solid-solid transformation process, and there is no problem of dissolution and diffusion of polysulfides. This single-stage electrochemical reaction in liquid electrolyte, similar to the charge-discharge curve of solid-state batteries, was defined by Wang et al as a "quasi-solid phase conversion" reaction mechanism[34,35]. The sulfur anode of quasi-solid phase conversion can fundamentally eliminate the generation of polysulfides or inhibit the dissolution of polysulfides, effectively solve the problem of "shuttle effect", and is conducive to obtaining stable long-term cycle performance[36].
According to the characteristics of single platform charge and discharge of sulfur cathode, the strategy of constructing sulfur cathode with quasi-solid phase conversion mechanism is proposed as follows: microporous carbon-sulfur cathode, SEI (solid electrolyte interface) membrane on the surface of cathode and electrolyte regulation. Small molecular sulfur (S2-4) is confined in the microporous carbon, producing only insoluble short-chain polysulfides[37]. However, microporous carbon-sulfur cathodes are limited by low sulfur content (generally less than 40%) and slow mass transfer. A SEI film is constructed on the surface of the carbon-sulfur positive electrode to effectively prevent solvent molecules from passing through and allow lithium ions to freely pass in and out, so as to construct the sulfur positive electrode with a quasi-solid phase conversion mechanism. In this way, the sulfur content in the cathode is not limited, which is beneficial to the design of the cathode with high sulfur content, but the SEI film is required to be dense enough and have certain mechanical properties to adapt to the volume change of the sulfur cathode. Electrolyte control refers to the use of lithium ion complex electrolyte to reduce free solvent molecules and reduce their solvating ability for polysulfides, thus preventing the dissolution of polysulfides[38]. At present, high-concentration electrolyte is usually used, but its high viscosity leads to slow mass transfer in the electrolyte, and at the same time, the large demand for lithium salt leads to high price and other problems. Diluting high-concentration or local high-concentration electrolyte can solve the related problems well[39]. Although these three ways are facing certain challenges, the sulfur positive electrode with quasi-solid phase conversion mechanism can effectively solve the problem of polysulfide dissolution, which is conducive to obtaining stable long-term cycle performance and promoting the practical process of lithium-sulfur batteries.

2 Fabrication of microporous carbon-sulfur cathode

2.1 Electrochemical reaction characteristics of microporous carbon-sulfur cathode

As early as 2010, Gao et al. Obtained a microporous carbon-sulfur cathode by loading sulfur into microporous carbon spheres with a size of 0. 7 nm through melt diffusion[40]. The first cycle of the positive electrode has a low ramp and a discharge plateau of 1. 8 V, followed by a single plateau charge and discharge, and the cycle performance is stable. The explanation for the low discharge plateau is that the elemental sulfur is confined in the narrow micropores of the carbon spheres in a highly dispersed state, and the microporous carbon has a strong adsorption capacity, thus limiting the electrochemical reaction. It is worth noting that the microporous carbon-sulfur cathode can operate reversibly in carbonate electrolyte, breaking the recognition that lithium-sulfur batteries and carbonate electrolyte are not suitable. In the follow-up study, the analysis of microporous carbon and sulfur by thermogravimetric (TG) test shows that the mass loss occurs at temperatures above 300 ℃, which is different from the weight loss of conventional S8 at 155 ℃. Combined with theoretical calculation, the sulfur molecules with different configurations were simulated, and it was found that the sulfur cathode in microporous carbon existed in the form of small sulfur molecules. Guo et al. Selected carbon nanotubes (CNTs) to coat microporous carbon (MPC) by solution method to prepare a coaxial core-shell structure, in which the pore size of MPC was 0. 5 nm, so as to prepare a microporous carbon-sulfur cathode[24]. The charge-discharge curve of the sulfur cathode is a single plateau, indicating that the sulfur exists in the form of S2-4, thus avoiding the formation of soluble polysulfides during the reaction.
Sulfur in the microporous carbon-sulfur cathode exists in the form of S2-4 due to the space limitation, and it is a single platform in charge and discharge, which is essentially a reversible conversion from S2-4 to Li2S2/Li2S[41]. During the charge-discharge process of microporous carbon-sulfur cathode, solid-solid conversion occurs, and the single plateau charge-discharge is a significant sign of the quasi-solid phase conversion mechanism of sulfur cathode.

2.2 Strategy for the construction of microporous carbon-sulfur cathode

The sulfur cathode with quasi-solid phase conversion mechanism can be constructed by using microporous carbon materials with pore size less than 2 nm to carry sulfur. The conventional preparation methods of microporous carbon materials include carbonized metal organic frameworks (MOFs) derivative materials, high temperature pyrolysis of organic compounds, template method and carbonized aerogel, etc. Next, the microporous carbon-sulfur cathode is introduced from these aspects[42,43][44][45][46].

2.2.1 Preparation of Microporous Carbon-Sulfur Cathode from Derivatives of Carbonized MOFs

Metal-organic frameworks (MOFs) are three-dimensional network frameworks formed by the self-assembly of inorganic metal centers and organic ligands[47,48]. MOFs have unique three-dimensional porous structures, which are easy to design, assemble and regulate, and have promising applications in gas storage, adsorption separation, catalysis and drug delivery[49,50]. MOFs as electrode materials have rich and adjustable pore structure to store active materials, which can effectively buffer the volume change of sulfur cathode and accelerate ion conduction, and improve electrochemical performance. Yin et al. Used 0.5 nm microporous supported S2-4 and 22 nm mesoporous supported S8 in N-doped MOFs materials[51]. N element doping is generally divided into three forms: pyridine N, pyrrole N and graphitized N. The nitrogen in the six-membered ring is called pyridine N, and the nitrogen in the five-membered ring is called pyrrole N, both of which can improve the adsorption of the material on sulfur and polysulfides; Doping into graphitized N in the plane of graphitic carbon can improve the conductivity and contribute to the rapid transfer of charge. As shown in fig. 3A, the S8 in the mesopores is removed by heating so that only S2-4 exists, and the sulfur cathode shows a quasi-solid phase conversion mechanism, and the charge-discharge reaction process is a solid-solid conversion of sulfur and Li2S2/Li2S, which effectively avoids the formation of soluble polysulfides and the loss of active sulfur substances. Under the condition of 335 mA·g-1, the specific capacity 936.5 mAh·g-1 was retained after 100 cycles in carbonate electrolyte (Fig. 3 B). Cai et al. Synthesized flower-like microporous N-doped carbon nanosheets with a pore size of 0.6 nm by carbonizing N-rich MOF (Zn-TDPAT), which is an ideal carrier for small molecule S2-4[52]. The type and content of N changed with the carbonization temperature. FMNCN-800 has the highest content of pyridine N and pyrrole N, which is helpful to provide binding sites for polysulfides and enhance the interaction between carbon materials and polysulfides. However, FMNCN-900 has a moderate content of pyridine N and pyrrole N, and the highest content of graphitized N, which is helpful to improve the conductivity and reaction kinetics of carbon materials. Therefore, FMNCN-900 is the best porous carbon. The electrochemical performance is shown in Figure 3C, and the specific capacity of S @ FMNCN-900 is 727 mAh·g-1 after 1000 cycles at 2 C in carbonate. Teng et al. Used a nitrogen-containing porous organic framework JUC-Z2-900 as the host material, and 0.5 nm pores were used to carry the S2-4. Nitrogen doping promoted the adsorption of sulfur, which was beneficial to improving the electrochemical performance[53]. Yang et al. Used MOF framework ZIF-8 as precursor, carbonized and sulfur-loaded, compared the reaction process in different electrolytes, and the CV curve showed that the mechanism was dissolution-deposition in ether electrolytes[54]. In carbonate electrolyte, it is a quasi-solid state reaction mechanism. MOFs have the advantages of rich pore structure and easy introduction of doping elements, which are conducive to loading small sulfur molecules into S2-4 and increasing electrochemical reaction active sites, thus improving battery performance.

2.2.2 Preparation of Microporous Carbon-Sulfur Cathode by High Temperature Pyrolysis of Organic Matter

The preparation of microporous carbon materials by high temperature pyrolysis is direct, simple and efficient. With the increase of heating temperature, the weaker bonds in the organic matter are gradually broken to form gas to be released, and finally the required porous conductive carbon material is obtained[55,56]. Xu et al. carbonized polyvinylidene fluoride (PVDF) powder at 800 ℃ to obtain ultramicroporous carbon material (UMC) with a pore size of 0.55 nm, and prepared microporous carbon-sulfur cathode with sulfur in different proportions (Fig. 4A)[57]. As shown in Fig. 4B, the sulfur loading of S/UMC-3 is too high, not only small sulfur molecules exist in the ultramicropores, but also S8 exist in the mesopores or the surface layer, so side reactions with polysulfides will occur in carbonate electrolyte, and shuttle effect will occur in ethers; However, the sulfur in S/UMC-1 and S/UMC-2 existed in the form of S2-4, which showed excellent electrochemical performance in both types of electrolytes. Subsequently, they used ultra-light three-dimensional melamine-formaldehyde carbon foam (MFC) as a current collector, and MFC as a network for rapid transmission of electronic and Li+ to load the above S 2 - 4/UMC composite[58]. The surface loading of sulfur can be increased to 4.2 mg·cm2,100 and the specific capacity is 839.8 mAh·g-1 after cycles. Feng et al. selected a macadamia shell (MNS) as the precursor, and obtained a carbon scaffold with a size of less than 0.6 nm by alkali washing and calcination at 800 ℃, and then prepared C/S materials with sulfur in different proportions (Fig. 4C)[59]. As shown in Figure 4D, the optimum sulfur loading ratio of the material is 40%, that is, the maximum reversible specific capacity of C-MNS/S40 is 80% after 1254 mAh·g-1,100 cycles at 0.1 C rate. Zhu et al. Prepared microporous carbon with different pore sizes to carry sulfur by calcining potassium and sodium composite precursors at 800 ℃[60]. KNC/S has the largest specific surface area, but it is mainly submicroporous (0.7 ~ 2 nm). KC/S has the largest proportion of mesoporous carbon (< 0.7 nm), which has good electrochemical kinetic performance and low electrode polarization. This indicates that the smaller the pore size of the conductive carbon is, the more helpful it is to improve the performance of the quasi-solid phase conversion sulfur cathode. Zhang et al. Synthesized a novel ultramicroporous carbon with uniform pore size of 0.54 nm by using the biomass material commercial housefly larvae as the precursor, and obtained a nitrogen-doped microporous carbon similar to Tremella fuciformis, which showed excellent electrochemical performance and high cycle stability as the host material for S2-4, with a coulombic efficiency of 100%[61]. The pore size and shape of microporous carbon materials prepared by high temperature pyrolysis are not easy to control, and the calcination temperature has a great influence on the structure of the materials.

2.2.3 Preparation of microporous carbon-sulfur cathode by template method

The template method is to use the self-assembly of the template and the precursor to arrange them into a uniform and orderly structure, and then remove the template to obtain a uniform and orderly porous carbon material[45]. Huang et al. First synthesized phenolic resin, used surfactant triblock polymer F127 as a template, fully stirred, then carbonized at 700 ℃, and decomposed the surfactant to form pores, thus preparing highly ordered microporous carbon (FDU)[62]. Microporous carbon FDU was loaded with different sulfur contents, and the reaction mechanism and performance of the sulfur cathode material in carbonate and ether electrolytes were compared. The experimental results show that S8 can only cycle stably in ether electrolytes, and S2-4 can reversibly deintercalate lithium in both electrolytes. DFT theoretical calculation shows that the size of microporous carbon is smaller than the diameter of solvent molecules ethylene carbonate (EC) and dimethyl carbonate (DMC), so lithium ions must be desolvated into the cathode to react with sulfur, while solvent molecules will not directly contact with sulfur. As shown in Fig. 5A, the S — S bonds of the S2-4 in the micropore are rearranged during the charge-discharge cycle. In the first cycle of discharge, the interaction between carbon atom and sulfur atom is weak and disconnected, so the discharge plateau is low, and the subsequent reaction is completely reversible. As shown in the figure, when the 5b,S2-4/S8 material circulates in the ester electrolyte, the surface S8 will have a nucleophilic reaction with carbonate and lose its electrochemical activity, and the final stable capacity is contributed by the S2-4 in the micropores. Ye et al. Selected sodium dodecyl sulfonate as a template to prepare a series of sulfur-loaded nanospheres ranging from 5 nm to 40 nm. Due to the coexistence of micropores smaller than 2 nm and pores with 5 nm, three reduction peaks appeared in the CV curve, which were the conversion of S to Li2S6/Li2S4, Li2S6/Li2S4 to Li2S, and S2-4 to Li2S, respectively. Two reaction mechanisms coexisted in this carbon-sulfur cathode, including dissolution-deposition and quasi-solid phase conversion[63].
Microporous carbon materials prepared by template method have the advantages of ordered structure, uniform pore channels and rich types of templates. However, only the volatilization of the template can form a pore structure, which may cause volume shrinkage and lead to macroscopic fracture of the material.

2.2.4 Preparation of microporous carbon-sulfur anode from carbonized aerogel

Aerogel is a kind of porous material with three-dimensional network structure, which has the advantages of good conductivity and large specific surface area, and has been widely used in energy, chemical and environmental research[64]. Aerogels are usually synthesized using the sol method, and during drying and carbonization, the properties and microstructure of the material can be tailored as needed, such as to produce different pore size distributions. Nojabaee and Sievert et al. Prepare carbon aerogels with ultramicropores for sulfur loading[65]. As shown in fig. 5C, the aerogel is pyrolyzed and carbonized in an Ar or N2/CO2 atmosphere, and then sulfur is loaded by a melt diffusion method. With the increase of temperature, the chain length of S8 decreases, and when the temperature rises to 600 ℃, the S2 is the main form, which is conducive to the loading of sulfur into the hierarchical pore structure of aerogel. As shown in Fig. 5d, in carbonate electrolyte, the long cycle performance of carbon aerogel sulfur cathode and mesoporous carbon KB sulfur cathode obtained by mechanical mixing is not good, while the aerogel prepared in Ar or N2/CO2 atmosphere shows a quasi-solid state reaction mechanism after loading into S2, and the long cycle performance is stable. Li et al. Synthesized sulfur-loaded carbon aerogels with micropores accounting for more than 66% of the total pore volume. Due to the limitation of less than 3 nm pores, sulfur exists in the form of S2-4 after the first cycle of charge and discharge[66]. Compared with the common carbon material acetylene black supported sulfur, the aerogel supported sulfur can show better electrochemical performance.
The quasi-solid phase conversion mechanism was constructed by the strategy of preparing microporous carbon-sulfur cathode from carbonized aerogel, which showed excellent compatibility in both ester and ether electrolytes. However, due to the characteristics of micropore size, the content of sulfur is limited, generally 40 wt%. In addition, the quasi-solid phase reaction mechanism has the characteristics of slow mass transfer and slow reaction kinetics, and the electrochemical performance of the microporous carbon-sulfur cathode can be improved and enhanced by using heteroatom doped carbon materials, aerogel supported sulfur, metal compound catalysts and the like[67].

3 Construction of Sulfur Cathode with SEI Film on Cathode Surface

In the lithium metal battery system, the lithium metal anode has a low potential and reacts with the electrolyte to form a solid electrolyte interface (SEI) film with a thickness of about 10 nm on the surface of the anode. The concept of SEI was proposed in 1979 and was first discovered on the surface of graphite anode[68,69]. The quality of SEI film directly affects the electrochemical performance of battery, such as cycle performance, safety and self-discharge[70,71]. The SEI film is required to have the following characteristics: (1) conducting lithium ions but not electrons; (2) sufficiently dense to avoid uneven deposition of lithium dendrites; (3) good thermal stability; And (4) that chemical stability is good, the further reaction between the electrolyte and the negative electrode is avoid, and the co-intercalation of solvent molecules is prevent. Inspired by this, in the lithium-sulfur battery system, the SEI film is constructed on the surface of the sulfur positive electrode, which has enough mechanical properties to accommodate the volume change of sulfur, prevent the solvent from penetrating into the positive electrode, prevent the "shuttle effect", and construct the quasi-solid phase conversion sulfur positive electrode. According to the construction method of SEI film, it can be divided into in-situ SEI film and artificial SEI film[72⇓~74].

3.1 Pseudo-solid phase conversion sulfur cathode fabricated by in situ SEI

In 2016, Aurbach et al. proposed a quasi-solid phase conversion mechanism for sulfur cathode: the use of microporous carbon less than 1 nm is not a necessary condition, but the SEI film on the surface of the cathode material plays an indispensable role, so that the construction of quasi-solid phase sulfur cathode no longer depends solely on the microporous carbon structure[75]. Sulfur was encapsulated in microporous carbon, as shown in fig. 6a, and SEI was generated in situ on the surface of the sulfur cathode during the first cycle discharge of the carbonate-based electrolyte to construct a quasi-solid phase conversion mechanism. The electrochemical performance of sulfur supported on microporous carbon (S-AC) in ionic liquid was investigated, and the important role of SEI generated at the first cycle discharge to 1. 5 V in the quasi-solid phase conversion mechanism was verified[76]. The SEI film can prevent the direct contact between sulfur and electrolyte and promote the quasi-solid phase reaction between lithium ion and sulfur. S-AC and S-PAN (polyacrylonitrile supported sulfur) were used as sulfur cathode materials respectively, and ester or fluoroethylene carbonate (FEC) electrolyte was used. It was found that the battery had higher specific capacity and longer cycle stability in FEC-based electrolyte. This may be due to the formation of a denser SEI film on the surface of the sulfur cathode, or due to the lower energy required for the desolvation of lithium ions into the cathode in FEC[77]. In addition, polyvinylidene chloride (PVDC) materials were directly carbonized to prepare microporous carbon with pore size less than 1 nm. The CV curve of the lithium-sulfur battery prepared based on the micropore is a single redox peak, the charge and discharge is a single platform, and the lithium-sulfur battery can maintain more than 2000 ultra-long cycles under the protection of the SEI film[78].
When carbonate is used as electrolyte, polysulfides will react with carbonate to form insoluble solid substances, resulting in pore blockage of the positive electrode and deactivation of the sulfur positive electrode. Therefore, ether electrolyte is mostly used for lithium-sulfur batteries, and sulfur anode is the dissolution-deposition mechanism. Ai et al. Used this property to add a proper amount of carbonate as a co-solvent in ether-based electrolyte[26]. As shown in Fig. 6B, the intermediate polysulfide formed in DOL/DME at the initial stage of sulfur cathode discharge is immediately captured by carbonate, forming a layer of SEI on the cathode surface in situ. The properties of four carbonate solvents, DMC, FEC, propylene carbonate (PC) and vinylene carbonate (VC), were compared. The results showed that the reaction rate of DMC and PC with polysulfide was too slow, and the products might be dissolved in the electrolyte and could not exist stably on the surface of sulfur cathode. FEC can form SEI, but it is not dense enough, and the cycle performance of the battery is not good. The reaction rate of VC is the fastest, which is beneficial to the conduction of lithium ions, and the SEI film formed is dense. Therefore, VC is the most ideal film-forming additive. As shown in Fig. 6C, the BP2000/S cathode in ether electrolyte with VC showed a quasi-solid state reaction mechanism, and could cycle stably for 400 cycles, and the specific capacity reached 1000 mAh·g-1.
In addition to using carbonate electrolyte, it can also promote the decomposition of salt and solvent through deep discharge, and form SEI film on the surface of sulfur cathode. Yushin et al. Synthesized S-AC materials by melt impregnation with FEC as an additive[79]. By deep lithiation, the cathode was first discharged to 0. 1 V at 0. 1 C, and the sulfur was converted to Li2S, and the electrolyte was reduced and polymerized to form SEI in situ on the sulfur cathode. The SEI film can cover all the pores and prevent the dissolution and diffusion of polysulfides in the electrolyte. As shown in Figure 7 a, the specific capacity of the control group without SEI decreased significantly within 200 cycles. As shown in Fig. 7B, Huang et al. Found that SEI could be generated in situ at the initial cycle in a high-concentration two-salt electrolyte[80]. In particular, when the positive electrode with a SEI film is placed in a carbonate or ether electrolyte, the charge and discharge is still a single platform.
Te and Se, the main group elements of S, have similar physicochemical and electrochemical properties and can reversibly deintercalate lithium. It is worth noting that Te (conductivity 5×102S·cm-1) and Se (conductivity 1×10-3S·cm-1) are more conductive and can form eutectic with S (conductivity 5×10-30S·cm-1) in any proportion, which can be used as eutectic accelerator to enhance the conductivity of materials and upgrade the reaction kinetics of sulfur cathode[81][29][82]. In 2019, Amine et al. Explored the effects of Se-S ratio and types of carbon materials on battery performance[83]. As shown in Figure 8 a, taking advantage of the film-forming property of 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (HFE), the sulfur cathode forms a stable SEI in situ during cycling, constructing a quasi-solid phase transformation. The pore size of host carbon materials expands from micropores to mesopores and even macropores, which promotes the development of lithium-sulfur batteries towards high loading and high energy density. As shown in Fig. 8 B, the reversible specific capacity of the S5Se2/KB cathode exceeded that of 800 mAh·g-1 after 3 times of activation. Due to its quasi-solid state reaction mechanism, the formation of soluble polysulfides/polyselenides can be avoided during cycling. In 2020, Xie et al. Explored the promotion effect of Te on the electrochemical reaction rate under the quasi-solid state reaction mechanism[84]. As shown in Fig. 8 C and d, the SEI was formed on the surface of the sulfur cathode after the first discharge using the high concentrated ether electrolyte with VC addition. The sulfur cathode with 1 wt% Te addition has a more excellent rate performance, providing a high reversible specific capacity (1150.2 mAh·g-1) at 0.1 C. Through XPS and EIS analysis, Te doping can effectively reduce the reaction resistance, form a SEI film with fast lithium ion conduction and low impedance, and improve the reaction kinetics of the quasi-solid phase conversion mechanism. In 2021, Huang et al. Designed a cathode material structure with porous nanoscale sulfur as the core and PAN/S7Se as the shell, FEC was used as an electrolyte additive, and the SEI formed after cycling prevented the reaction between electrolyte and polysulfide (Figure 8E)[85].
With an E/S ratio of 10μL·mg-1 and a loading of 5 mg·cm-2, this cathode exerted a very stable specific capacity (881 mAh·g-1) (Fig. 8f).

3.2 Pseudo-solid phase conversion sulfur cathode constructed by artificial SEI film

The ideal SEI film should have the characteristics of conducting lithium ions, not conducting electrons, good mechanical properties and electrochemical stability, and people can form an artificial SEI film on the surface of sulfur cathode through ingenious experimental design.
By adjusting the composition and structure, a dense and uniform SEI film was prepared to construct a sulfur anode with a quasi-solid phase conversion mechanism. Molecular layer deposition (MLD) can realize the precise control and design of chemical composition at the molecular scale, which is helpful to obtain a uniform and dense surface coating and improve the electrochemical performance, and is widely used in solid electrolytes, electrode materials and other aspects.
As shown in Figure 9a, Sun et al. Used MLD to form an alumina composite coating on the surface of C/S cathode as an artificial SEI film[86]. The SEI membrane can prevent a series of reactions between polysulfides and carbonate solvents, and achieve the design purpose of quasi-solid phase reaction. Due to the low boiling point and flash point of ether-based electrolyte, it is not conducive to the realization of safe high-temperature lithium-sulfur batteries. As shown in Fig. 9b, the material coated with MLD can be stably cycled in carbonate electrolyte for 300 cycles at a high temperature of 55 ℃. Subsequently, the effects of the type of sulfur-loaded carbon materials and the proportion of electrolyte on the performance of the battery in carbonate electrolyte were discussed, and it was found that the addition of appropriate amount of FEC could effectively improve the performance of the battery. FEC can enhance the solubility of lithium ions and promote the transport; The lithium ion desolvation process at the positive electrode is accelerated, and the polarization of the battery is reduced, so that the electrochemical performance is improved. As shown in Figure 9C, at a sulfur loading of 1.2 mg·cm2, the MLD-coated sulfur cathode retained a specific capacity of 870 mAh·g-1 after 300 turns, further increasing the sulfur loading to a specific capacity of 705 mAh · G after 4.0 mg·cm2,300 turns-1[87]. Blzquez et al. Coated S/C particles with aluminum oxide atomic layer deposition (ALD), a 3D spray treatment, in a fluidized bed reactor (FBR), and then made into pole pieces[88]. As shown in Fig. 9 (d), the material coated by FBR-ALD for 5 times is denser than the untreated surface, and the specific capacity of the C/S cathode of 3.6 mg·cm2 is improved by 165% compared with the untreated electrode sheet with a loading of only 1.8 mg·cm2.
In addition to the above MLD and ALD methods, it is found that the stability of polysulfides in lithium-sulfur batteries is related to the DN (donor number) of the solvent. The larger the DN is, the more stable the long-chain polysulfides ( S 8 2 -/ S 6 2 -) are, such as dimethyl sulfoxide (DMSO) and N, N-dimethylformamide (DMF). Conversely, the smaller the DN, the more stable the short-chain polysulfides ( S 4 2 -), such as tetrahydrofuran (THF), DME. Taking advantage of the much smaller DN of PVDF than PEO, Li et al. Coated PVDF outside the S/C positive electrode, as shown in Fig. 10a and B[89]. Compared with the traditional PEO coating, the lithium-sulfur battery designed in this way does not produce polysulfides, and sulfur and Li2S2/Li2S are directly converted during the redox reaction. The reversible specific capacity of PVDF-coated S/C cathode is 630 mAh·g-1 at 55 ° C and 0.05 mA·cm-2.
Both in situ SEI and artificial SEI can construct the quasi-solid phase transformation mechanism of sulfur, and the key is the nature of SEI. The SEI film is required to have certain flexibility to adapt to the volume change of the sulfur positive electrode during the charge-discharge cycle; Sufficiently dense to prevent direct contact of the electrolyte with the sulfur positive electrode; Conductivity of lithium ion is good, and the improvement of battery reaction kinetics is promoted. The lithium ion conductivity of SEI film is closely related to the structure and composition of SEI film. In addition, the solvation structure of electrolyte can also affect the conductivity of SEI film.
The quasi-solid phase conversion mechanism of sulfur cathode constructed by SEI film on the surface still has the problem of slow reaction kinetics in charge-discharge cycles. The commonly used improvement methods are as follows: (1) The use of catalysts, including eutectic accelerators Se and Te, can effectively improve the redox reaction rate. Amine et al. explored the influence of Se-S ratio and carbon material type on battery performance, and constructed quasi-solid phase conversion[83]. And (2) adding an additive into the electrolyte to regulate the ion conduction characteristic of the SEI film. Xie et al. Used the reaction between VC and the polychalcogenide formed in the first ring to regulate the composition and lithium ion conduction characteristics of the SEI film[84].

4 Pseudo-solid phase conversion sulfur anode constructed by electrolyte regulation

In the lithium metal battery system, the traditional organic electrolyte faces the disadvantages of poor stability, volatility, narrow electrochemical window and small ion transfer number. High concentration electrolyte, that is, increasing the concentration of lithium salt, can achieve the advantages of low volatility, good flame retardancy, safety and stability, promoting the conduction of lithium ions and passivating aluminum current collectors under high pressure, which provides a new idea for the development of lithium metal battery system[90⇓~92]. The solvation structure of electrolyte is determined by the interaction among lithium ions, anions and solvent molecules. The main forms are: solvent-separated ion pairs (SSIPs) formed by lithium ions and solvent molecules; Lithium ions coordinate with anions to form contact ion pairs (CIPs); cation-anion aggregates (AGGs) are formed by the interaction of lithium ions, anions, and solvent molecules[93]. There are a large number of solvent molecules in traditional organic electrolyte, and lithium ions mainly coordinate with solvent molecules to form SSIPs. In high concentrated electrolyte, the number of free solvent molecules decreases, and the interaction between lithium ions and anions becomes stronger. CIPs and AGGs are the main solvated structures, and there is even no free solvent molecules[94].
In the liquid electrolyte battery system, lithium ions are responsible for the transport between the positive and negative electrodes. Through electrolyte regulation, the use of high-concentration electrolyte reduces the free solvent molecules in the electrolyte, reduces the dissolution of polysulfides, and is conducive to the construction of a quasi-solid-phase reaction mechanism for sulfur anodes[95]. In 2013, Suo et al. Dissolved 7 mol/L LiTFSI in ether electrolyte and used it in lithium-sulfur system, and the lithium ion transference number was 0.73, which was higher than that of conventional electrolyte, and proposed the concept of "solvent in salt"[96]. The electrolyte has high viscosity, reduces the solubility of polysulfide in the electrolyte, can inhibit the formation of lithium dendrite in the negative electrode, improves the cycle stability of the battery, and lays a foundation for the subsequent development of high-concentration electrolyte in a lithium-sulfur system.

4.1 High concentration electrolyte

In high concentration electrolyte, lithium ions are complexed with solvent molecules, which reduces the solubility of polysulfides in the electrolyte and realizes the quasi-solid phase transformation mechanism. As shown in Fig. 11 a, Nazar et al. Dissolved 3.7 mol/L LiTFSI in acetonitrile ACN electrolyte, and the lithium ion was tightly bound to the solvent ( (ACN)2:LiTFSI)[25]. Colorimetric and X-ray absorption near edge structure (XANES) experiments in tetraethylene glycol dimethyl ether (TEGDME) solvent showed that polysulfides were formed, but because there were no free ACN molecules, the dissolution and diffusion in the electrolyte were limited, resulting in the controlled precipitation of Li2S. The galvanostatic intermittent titration (GITT) test results, as shown in Fig. 11 B, confirm that the (ACN)2:LiTFSI is in an electrochemical equilibrium state with a single plateau discharge, and sulfur is directly converted into Li2S2/Li2S, resulting in a quasi-solid phase conversion reaction. In 2018, they found that the chain length of G2 could wrap the LiTFSI ion pair. Starting from the control of solvation structure, they explored the influence of G2: LiTFSI system with different molar ratios on electrochemical reaction[97]. As shown in Figure 11C, at a G2: LiTFSI molar ratio of 0.8: 1, the electrolyte forms a 3D network, the solvent activity is reduced, and the polysulfides are confined to the positive electrode side. As shown in Fig. 11d, as the G2: LiTFSI ratio decreases, the average voltage for the formation of high-order polysulfides in the first stage decreases, while the plateau for the formation of low-order polysulfides increases. The change of voltage plateau shows that the discharge product lithium sulfide appears earlier during the discharge of the battery, and the discharge process directly converts sulfur into lithium sulfide. During charging, the product sulfur begins to form earlier, and the charging process directly changes from lithium sulfide to sulfur, so the sulfur cathode shows a quasi-solid phase transformation mechanism in high concentration electrolyte. The dissolution of polysulfides in electrolyte is closely related to the proportion of free solvent molecules. According to Amine et al., the interaction between cations/anions (such as Li+, TFSI-, S2-) and solvent in high concentration electrolyte is different, and there is a small amount of solvent-ion exchange process, which will replace a part of polysulfide (solvation-ion-exchange, SIE). As shown in Figure 11E, a new concentrated siloxane-based solvent is reported, which can effectively regulate the interaction between solvent molecules and polysulfides, eliminate the SIE process, avoid polysulfides and lithium dendrite problems, and realize the reaction change of S8 directly to Li2S2/Li2S[93]. As shown in Fig. 11 (f), the first circle of the electrolyte is a single plateau discharge, which avoids the dissolution of polysulfides in the electrolyte and realizes the quasi-solid phase conversion mechanism of the carbon-sulfur cathode.

4.2 Local high concentration electrolyte

Compared with the traditional electrolyte, although the high concentration electrolyte has a series of advantages mentioned above, it still has the disadvantages of high cost, high viscosity, poor wettability of thick electrode and low ionic conductivity, which limit its commercial development[98,99]. In recent years, Watanabe et al. And Zhang et al. Proposed the concept of "local high concentration electrolyte", that is, adding an appropriate amount of diluents, such as HFE, bis (2,2,2-trifluoroethyl) ether (BTFE), 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE), 1H, 1H, 5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether (OFE), etc., to the high concentration electrolyte[92][100]. The diluent does not dissolve the lithium salt and polysulfide, but is miscible with the solvent, so it does not change the coordination structure of the lithium salt and the solvent in the electrolyte. In addition, the local high concentration electrolyte also has the advantages of low viscosity, good wettability, low dielectric constant and low complexing ability. Local high concentration electrolyte with appropriate conductivity is an ideal choice for the quasi-solid state reaction mechanism of structural sulfur, which has become one of the current research hotspots.
Ma and Xu et al added HFME into high concentration electrolyte (4.5 mol/L LiFSI dissolved in DME) by taking advantage of the characteristics of HFME that can not dissolve lithium salts and has low viscosity[101]. As shown in fig. 12A, the electrolyte retains the lithium ion solvation structure in the original high concentration electrolyte, and separates the solution structure of the enhanced three-dimensional network into smaller sizes. As shown in Figure 12b, the effects of lithium salts LiFSI and LiTFSI on battery performance are explored, and the results show that LiTFSI has higher conductivity and lower viscosity, which can significantly improve the electrochemical stability and inhibit the dissolution of polysulfides. As shown in Fig. 12c, Wang et al. Designed a 12 mol/L LiFSI/DME electrolyte, in which polysulfides were confined to the positive electrode region, and the charge-discharge was a quasi-solid state reaction mechanism[102]. In order to save the cost and improve the practicability, the polysulfide-insoluble HFE was added to the low concentration electrolyte, and it was found that the local high concentration electrolyte could achieve the same effect as 12 mol/L LiFSI/DME. As shown in Figure 12D, in the local high concentration electrolyte with HFE added, the high-order polysulfides are insoluble and directly reduced, no shuttle effect is detected, and the specific capacity remains 774 mAh·g-1 after 50 cycles. OFE has a similar structure to HFE, with a higher degree of fluorination and low polysulfide solubility. On the basis of local high concentration electrolyte, they discussed in detail the effect of different volume ratios of OFE and DME solvents in 1 mol/L LiFSI on the electrochemical performance of lithium-sulfur batteries[103]. As shown in Figure 12e and f, at OFE/DME = 95/5, the battery charge and discharge is a single plateau, with high coulombic efficiency and less self-discharge loss, effectively suppressing the "shuttle effect".
It is generally believed that polysulfides will react with carbonate solvents and lead to battery failure. However, Liang et al. explored the electrochemical behavior of sulfur cathode in EC/DEC ester electrolyte with different concentrations of LiTFSI, and found that with the increase of lithium salt concentration, EC/DEC gradually complexed with lithium salt to inhibit the side reaction between polysulfide and carbonate[104]. Therefore, at higher LiTFSI concentration, probably due to the solvated structure, the nucleophilic reaction between the polysulfide analog and carbonate is inhibited, and the transition from unable to charge and discharge to stable long cycle is achieved. The specific capacity of the battery reaches the highest in 6 mol/L LiTFSI EC/DEC electrolyte, indicating that the solvation structure of the electrolyte can affect the reaction mechanism of the sulfur cathode. On this basis, the S/KB cathode can achieve a coulombic efficiency of 99. 5% in the local high concentration electrolyte with HFME diluent at E/S ratios of 1. 5 and 0. 2 C.
The addition of diluents to both high and low concentration electrolytes can reduce the viscosity and improve the ionic conductivity without changing the solvation structure of the electrolyte. Compared with the high-concentration electrolyte, the local high-concentration electrolyte has lower cost, better wettability of the pole piece and wider application prospect. High concentration electrolyte or local high concentration electrolyte is used, in which solvent molecules are tightly complexed with lithium salt, and there are no free solvent molecules. This kind of electrolyte will not dissolve the polysulfide in the reaction process, and confine it to the positive electrode region, so as to achieve the purpose of constructing the quasi-solid phase reaction mechanism of sulfur positive electrode. However, in this electrolyte system, the demonstration of the influence of solvation structure, the stability of the interface between the positive and negative electrodes, and the matching of appropriate electrolyte solvents or diluents need to be further explored.

5 Conclusion and prospect

The sulfur positive electrode prepared by the quasi-solid phase conversion mechanism effectively avoids the generation or dissolution of polysulfides, reduces the loss of active substances, and improves the long cycle stability of the battery; And the dependence of the sulfur positive electrode on the electrolyte is reduced, which is beneficial to reducing the E/S ratio and realizing the sulfur positive electrode with high energy density. The charge and discharge curves of the quasi-solid sulfur cathode show a single plateau, and the CV curve shows a single redox peak, which prevents the dissolution of polysulfides from the cathode or the direct conversion reaction between sulfur and Li2S2/Li2S. In addition to the lithium-sulfur battery system, the quasi-solid phase conversion mechanism can also be applied to the sodium-sulfur battery[105,106].
As shown in Fig. 13, the quasi-solid state reaction mechanism is constructed from the configuration of active material sulfur, the interfacial properties of cathode/electrolyte and the solvation structure of electrolyte by means of microporous carbon, cathode surface SEI film and electrolyte regulation. Sulfur in the microporous carbon-sulfur positive electrode is loaded into carbon pores in the form of S 2 - 4, and the conversion between S 2 - 4 and Li2S is realized in the charge-discharge process. The method is simple, but the sulfur content is limited, generally less than 40%. In addition to the preparation methods of derived materials of carbonized MOFs, high temperature pyrolysis, template method and vapor deposition, other methods can be developed to prepare pore sizes less than 2 nm.
The in-situ or artificial SEI film can conduct lithium ions without conducting electrons, limit the dissolution and diffusion of polysulfides, and is beneficial to increasing the sulfur content in the positive electrode. However, the SEI film is required to be dense enough to isolate the positive electrode from direct contact with the electrolyte. It has good mechanical properties and can accommodate the volume change of sulfur cathode. In the long cycle process, the SEI film will be repeatedly damaged and repaired, which will inevitably affect the stability of the cathode interface, so it is necessary to further improve the structure of the SEI film to enhance the performance of the battery.
Electrolyte regulation is to construct a quasi-solid phase conversion sulfur cathode through the full combination of solvent molecules and lithium ions, almost no free solvent molecules, and no dissolution of polysulfides. The traditional high concentration electrolyte has high viscosity and high cost, and the local high concentration electrolyte is helpful to solve these problems, but the structure-activity relationship between the solvation structure and the reaction mechanism needs further study. How to reduce the cost, or find new substitutes for solvents and diluents, improve the conductivity, broaden the electrochemical window, and realize the commercial development of local high-concentration electrolytes still needs to be explored by relevant researchers.
At present, the two main challenges in the commercialization of sulfur cathode based on dissolution-deposition mechanism are limited energy density and limited cycle life. Among them, the sulfur cathode with limited energy density, mainly due to the dissolution-deposition mechanism, requires more electrolyte, which will greatly reduce the energy density of the battery. The limited cycle life of batteries is due to the dissolution and loss of polysulfides under the dissolution and deposition mechanism. In the sulfur cathode of quasi-solid phase conversion, there is no generation or dissolution of polysulfides, and the requirement for the amount of electrolyte is relatively low, so it is very conducive to obtaining good long-term cycle performance under lean solution conditions[107]. Therefore, the quasi-solid phase conversion sulfur cathode can simultaneously ensure high energy density and long cycle life, and has a wide commercial prospect.
Generally speaking, the quasi-solid phase conversion mechanism of sulfur cathode fundamentally solves the "shuttle effect", but there are intrinsic scientific problems such as slow reaction kinetics and limited lithium ion conduction. To further improve the electrochemical performance of the quasi-solid phase conversion mechanism sulfur cathode, the organic combination of microporous carbon, cathode surface SEI film and electrolyte control can be used, for example, based on microporous carbon sulfur, plus the design of SEI film; The use of eutectic accelerators or catalysts to improve sulfur reaction kinetics; Further improve the composition and structure of the SEI film and enhance the lithium ion conductivity; To design a lithium-sulfur battery system with better performance.

References

Publishing order | Descend order by publishing year | Descend order by cited within
[1]

Fang R P, Zhao S Y, Sun Z H, Wang D W, Cheng H M, Li F. Adv. Mater., 2017, 29(48): 1606823.
[2]

Dirlam P T, Glass R S, Char K, Pyun J. J. Polym. Sci. A: Polym. Chem., 2017, 55(10): 1635.
[3]

Peng H J, Zhang Z W, Huang J Q, Zhang G, Xie J, Xu W T, Shi J L, Chen X, Cheng X B, Zhang Q. Adv. Mater., 2016, 28(43): 9550.
[4]

Grey C P, Tarascon J M. Nat. Mater., 2017, 16(1): 45.
[5]

Peng H J, Huang J Q, Cheng X B, Zhang Q. Adv. Energy Mater., 2017, 7(24): 1700260.
[6]

Pang Q, Liang X, Kwok C Y, Nazar L F. Nat. Energy, 2016, 1(9): 16132.
[7]

Li Z, Wu H B, (David) Lou X W. Energy Environ. Sci., 2016, 9(10): 3061.
[8]

Li G X, Sun J H, Hou W P, Jiang S D, Huang Y, Geng J X. Nat. Commun., 2016, 7(1): 10601.
[9]

Meng T, Gao J C, Zhu J H, Li N, Xu M W, Li C M, Jiang J. J. Mater. Chem. A, 2020, 8(24): 11976.
[10]

Rosenman A, Markevich E, Salitra G, Aurbach D, Garsuch A, Chesneau F F. Adv. Energy Mater., 2015, 5(16): 1500212.
[11]

Yao N P, Heredy L A, Saunders R C. J. Electrochem. Soc., 1970, 117: 148.
[12]

Rosenman A, Elazari R, Salitra G, Markevich E, Aurbach D, Garsuch A. J. Electrochem. Soc., 2015, 162(3): A470.
[13]

Ji X L, Lee K T, Nazar L F. Nat. Mater., 2009, 8(6): 500.
[14]

Ding N, Lum Y, Chen S F, Chien S W, Hor T S A, Liu Z L, Zong Y. J. Mater. Chem. A, 2015, 3(5): 1853.
[15]

Wei Seh Z, Li W Y, Cha J J, Zheng G Y, Yang Y, McDowell M T, Hsu P C, Cui Y. Nat. Commun., 2013, 4(1): 1331.
[16]

Yao Y, Feng W L, Chen M L, Zhong X W, Wu X J, Zhang H B, Yu Y. Small, 2018, 14(42): 1802516.
[17]

Ai W, Zhou W W, Du Z Z, Chen Y, Sun Z P, Wu C, Zou C J, Li C M, Huang W, Yu T. Energy Storage Mater., 2017, 6: 112.
[18]

Pu J, Shen Z H, Zheng J X, Wu W L, Zhu C, Zhou Q W, Zhang H G, Pan F. Nano Energy, 2017, 37: 7.
[19]

Li Z, Zhang J T, Guan B Y, Wang D, Liu L M, Lou X W. Nat. Commun., 2016, 7(1): 13065.
[20]

Liang X, Garsuch A, Nazar L F. Angew. Chem. Int. Ed., 2015, 54(13): 3907.
[21]

Pang Q, Kundu D P, Cuisinier M, Nazar L F. Nat. Commun., 2014, 5(1): 4759.
[22]

Lin H B, Yang L Q, Jiang X, Li G C, Zhang T R, Yao Q F, Zheng G W, Lee J Y. Energy Environ. Sci., 2017, 10(6): 1476.
[23]

Li Y J, Fan J M, Zheng M S, Dong Q F. Energy Environ. Sci., 2016, 9(6): 1998.
[24]

Xin S, Gu L, Zhao N H, Yin Y X, Zhou L J, Guo Y G, Wan L J. J. Am. Chem. Soc., 2012, 134(45): 18510.
[25]

Cuisinier M, Cabelguen P E, Adams B D, Garsuch A, Balasubramanian M, Nazar L F. Energy Environ. Sci., 2014, 7(8): 2697.
[26]

He F, Wu X J, Qian J F, Cao Y L, Yang H X, Ai X P, Xia D G. J. Mater. Chem. A, 2018, 6(46): 23396.
[27]

Deng N P, Ma X M, Ruan Y L, Wang X Q, Kang W M, Cheng B W. Progress in Chemistry, 2016, 28(9): 1435.
[28]

(邓南平, 马晓敏, 阮艳莉, 王晓清, 康卫民, 程博闻. 化学进展, 2016, 28(9): 1435.).
[29]

Manthiram A, Fu Y Z, Chung S H, Zu C X, Su Y S. Chem. Rev., 2014, 114(23): 11751.
[30]

Chen X, Peng L F, Wang L H, Yang J Q, Hao Z X, Xiang J W, Yuan K, Huang Y H, Shan B, Yuan L X, Xie J. Nat. Commun., 2019, 10(1): 1021.
[31]

Dai C L, Lim J M, Wang M Q, Hu L Y, Chen Y M, Chen Z Y, Chen H, Bao S J, Shen B L, Li Y, Henkelman G, Xu M W. Adv. Funct. Mater., 2018, 28(14): 1704443.
[32]

Lei J, Liu T, Chen J J, Zheng M S, Zhang Q, Mao B W, Dong Q F. Chem, 2020, 6(10): 2533.
[33]

Liu Y T, Liu S, Li G R, Gao X P. Adv. Mater., 2021, 33(8): 2003955.
[34]

Zhao M, Li B Q, Zhang X Q, Huang J Q, Zhang Q. ACS Cent. Sci., 2020, 6(7): 1095.
[35]

Wang D W, Zhou G M, Li F, Wu K H, Lu G Q M, Cheng H M, Gentle I R. Phys. Chem. Chem. Phys., 2012, 14(24): 8703.
[36]

Wang D W, Zeng Q C, Zhou G M, Yin L C, Li F, Cheng H M, Gentle I R, Lu G Q M. J. Mater. Chem. A, 2013, 1(33): 9382.
[37]

Lin Y X, Zheng J, Wang C S, Qi Y. Nano Energy, 2020, 75: 104915.
[38]

Ma L, Hendrickson K E, Wei S Y, Archer L A. Nano Today, 2015, 10(3): 315.
[39]

Wang L L, Ye Y S, Chen N, Huang Y X, Li L, Wu F, Chen R J. Adv. Funct. Mater., 2018, 28(38): 1800919.
[40]

Lin Y L, Huang S, Zhong L, Wang S J, Han D M, Ren S, Xiao M, Meng Y Z. Energy Storage Mater., 2021, 34: 128.
[41]

Zhang B, Qin X, Li G R, Gao X P. Energy Environ. Sci., 2010, 3(10): 1531.
[42]

Maria Joseph H, Fichtner M, Munnangi A R. J. Energy Chem., 2021, 59: 242.
[43]

Demir-Cakan R, Morcrette M, Nouar F, Davoisne C, Devic T, Gonbeau D, Dominko R, Serre C, FÉrey G, Tarascon J M. J. Am. Chem. Soc., 2011, 133(40): 16154.
[44]

Hao G P, Tang C, Zhang E, Zhai P Y, Yin J, Zhu W C, Zhang Q, Kaskel S. Adv. Mater., 2017, 29(37): 1702829.
[45]

Sun Z J, Wang S J, Yan L L, Xiao M, Han D M, Meng Y Z. J. Power Sources, 2016, 324: 547.
[46]

Zheng G Y, Yang Y, Cha J J, Hong S S, Cui Y. Nano Lett., 2011, 11(10): 4462.
[47]

Hua Y, Li X L, Zhang X C, Zhang L Y, Shu Y Z, Sheng H J, Fang H G, Wei H B, Ding Y S. ChemElectroChem, 2019, 6(9): 2570.
[48]

Sun J K, Xu Q. Energy Environ. Sci., 2014, 7(7): 2071.
[49]

Morozan A, Jaouen F. Energy Environ. Sci., 2012, 5(11): 9269.
[50]

Zhu Q L, Xu Q. Chem. Soc. Rev., 2014, 43(16): 5468.
[51]

Wang D Y, Liu R L, Guo W, Li G, Fu Y Z. Coord. Chem. Rev., 2021, 429: 213650.
[52]

Li Z Q, Yin L W. ACS Appl. Mater. Interfaces, 2015, 7(7): 4029.
[53]

Hong X J, Tang X Y, Wei Q, Song C L, Wang S Y, Dong R F, Cai Y P, Si L P. ACS Appl. Mater. Interfaces, 2018, 10(11): 9435.
[54]

Yan D, Teng B. Chem. Res. Chin. Univ., 2019, 35(4): 654.
[55]

Li G C, Jiang X L, Liu C, Song M C, Yang S L, Lian J B, Lee J Y. Int. J. Energy Res., 2020, 44(3): 2126.
[56]

Tong Z M, Huang L, Lei W, Zhang H J, Zhang S W. J. Energy Chem., 2021, 54: 254.
[57]

Hu L, Lu Y, Zhang T W, Huang T, Zhu Y C, Qian Y T. ACS Appl. Mater. Interfaces, 2017, 9(16): 13813.
[58]

Zhu Q Z, Zhao Q, An Y B, Anasori B, Wang H R, Xu B. Nano Energy, 2017, 33: 402.
[59]

Zhao Q, Zhu Q Z, Miao J W, Guan Z, Liu H, Chen R J, An Y B, Wu F, Xu B. ACS Appl. Mater. Interfaces, 2018, 10(13): 10882.
[60]

Han J K, Li Y, Li S W, Long P, Cao C, Cao Y, Wang W Z, Feng Y Y, Feng W. Sustain. Energy Fuels, 2018, 2(10): 2187.
[61]

Hu L, Lu Y, Li X N, Liang J W, Huang T, Zhu Y C, Qian Y T. Small, 2017, 13(11): 1603533.
[62]

Sun D, Razaq R, Xin Y, Zhang J H, Li Q, Huang T Z, Zhang Z L. Mater. Res. Express, 2019, 6(8): 085509.
[63]

Li Z, Yuan L X, Yi Z Q, Sun Y M, Liu Y, Jiang Y, Shen Y, Xin Y, Zhang Z L, Huang Y H. Adv. Energy Mater., 2014, 4(7): 1301473.
[64]

Liu X D, Rahmatinejad J, Ye Z B. Chem. Eng. J., 2021, 422: 130129.
[65]

Allahbakhsh A, Bahramian A R. Nanoscale, 2015, 7(34): 14139.
[66]

Nojabaee M, Sievert B, Schwan M, Schettler J, Warth F, Wagner N, Milow B, Friedrich K A. J. Mater. Chem. A, 2021, 9(10): 6508.
[67]

Li Z H, Li X G, Liao Y H, Li X P, Li W S. J. Power Sources, 2016, 334: 23.
[68]

Fan C J, Yan Y L, Chen L P, Chen S Y, Lin J M, Yang R. Progress in Chemistry, 2019, 31(8): 1166.
[69]

(樊潮江, 燕映霖, 陈利萍, 陈世煜, 蔺佳明, 杨蓉. 化学进展, 2019, 31(8): 1166.).
[70]

Aurbach D, Markovsky B, Levi M D, Levi E, Schechter A, Moshkovich M, Cohen Y. J. Power Sources, 1999, 81-82: 95.
[71]

Aurbach D, Zinigrad E, Cohen Y, Teller H. Solid State Ion., 2002, 148(3/4): 405.
[72]

Verma P, Maire P, Novák P. Electrochim. Acta, 2010, 55(22): 6332.
[73]

Sun S, Liu B, Zhang H S, Guo Q B, Xia Q Y, Zhai T, Xia H. Adv. Energy Mater., 2021, 11(8): 2003599.
[74]

Wang W P, Zhang J, Chou J, Yin Y X, You Y, Xin S, Guo Y G. Adv. Energy Mater., 2021, 11(2): 2000791.
[75]

Kozen A C, Lin C F, Zhao O, Lee S B, Rubloff G W, Noked M. Chem. Mater., 2017, 29(15): 6298.
[76]

Guo D, Li X, Wahyudi W, Li C Y, Emwas A H, Hedhili M N, Li Y X, Lai Z P. ACS Nano, 2020, 14(12): 17163.
[77]

Markevich E, Salitra G, Talyosef Y, Chesneau F, Aurbach D. J. Electrochem. Soc., 2016, 164(1): A6244.
[78]

Markevich E, Salitra G, Rosenman A, Talyosef Y, Chesneau F, Aurbach D. J. Mater. Chem. A, 2015, 3(39): 19873.
[79]

Markevich E, Salitra G, Rosenman A, Talyosef Y, Chesneau F, Aurbach D. Electrochem. Commun., 2015, 60: 42.
[80]

Rosenman A, Markevich E, Salitra G, Talyosef Y, Chesneau F, Aurbach D. J. Electrochem. Soc., 2016, 163(9): A1829.
[81]

Lee J T, Eom K, Wu F X, Kim H, Lee D C, Zdyrko B, Yushin G. ACS Energy Lett., 2016, 1(2): 373.
[82]

Chen X, Yuan L X, Li Z, Chen S J, Ji H J, Qin Y F, Wu L S, Shen Y, Wang L B, Hu J P, Huang Y H. ACS Appl. Mater. Interfaces, 2019, 11(33): 29830.
[83]

Wang K, Guan Y P, Jin Z Q, Wang W K, Wang A B. J. Energy Chem., 2019, 39: 249.
[84]

Li S P, Zhang W, Zeng Z Q, Cheng S J, Xie J. Electrochem. Energy Rev., 2020, 3(3): 613.
[85]

Xu G L, Sun H, Luo C, Estevez L, Zhuang M H, Gao H, Amine R, Wang H, Zhang X Y, Sun C J, Liu Y Z, Ren Y, Heald S M, Wang C S, Chen Z H, Amine K. Adv. Energy Mater., 2019, 9(2): 1802235.
[86]

Li S P, Ma J Q, Zeng Z Q, Hu W, Zhang W, Cheng S J, Xie J. J. Mater. Chem. A, 2020, 8(6): 3405.
[87]

He B, Rao Z X, Cheng Z X, Liu D D, He D Q, Chen J, Miao Z Y, Yuan L X, Li Z, Huang Y H. Adv. Energy Mater., 2021, 11(14): 2003690.
[88]

Li X, Lushington A, Sun Q, Xiao W, Liu J, Wang B Q, Ye Y F, Nie K Q, Hu Y F, Xiao Q F, Li R Y, Guo J H, Sham T K, Sun X L. Nano Lett., 2016, 16(6): 3545.
[89]

Li X, Banis M, Lushington A, Yang X F, Sun Q, Zhao Y, Liu C Q, Li Q Z, Wang B Q, Xiao W, Wang C H, Li M S, Liang J W, Li R Y, Hu Y F, Goncharova L, Zhang H M, Sham T K, Sun X L. Nat. Commun., 2018, 9(1): 4509.
[90]

Azaceta E, García S, Leonet O, Beltrán M, GÓmez I, Chuvilin A, Mainar A R, Blazquez J A, Knez M. Mater. Today Energy, 2020, 18: 100567.
[91]

Fang R Y, Xu H H, Xu B Y, Li X Y, Li Y T, Goodenough J B. Adv. Funct. Mater., 2021, 31(2): 2001812.
[92]

Yamada Y, Wang J H, Ko S, Watanabe E, Yamada A. Nat. Energy, 2019, 4(4): 269.
[93]

Liu K X, Wang Z Y, Shi L Y, Jungsuttiwong S, Yuan S. J. Energy Chem., 2021, 59: 320.
[94]

Dokko K, Tachikawa N, Yamauchi K, Tsuchiya M, Yamazaki A, Takashima E, Park J W, Ueno K, Seki S, Serizawa N, Watanabe M. J. Electrochem. Soc., 2013, 160(8): A1304.
[95]

Amine R, Liu J Z, Acznik I, Sheng T, Lota K, Sun H, Sun C J, Fic K, Zuo X B, Ren Y, Ei-Hady D A, Alshitari W, Al-Bogami A S, Chen Z H, Amine K, Xu G L. Adv. Energy Mater., 2020, 10(25): 2000901.
[96]

Kong L, Yin L H, Xu F, Bian J C, Yuan H M, Lu Z G, Zhao Y S. J. Energy Chem., 2021, 55: 80.
[97]

Su C C, He M N, Amine R, Chen Z H, Amine K. Angew. Chem. Int. Ed., 2018, 57(37): 12033.
[98]

Suo L M, Hu Y S, Li H, Armand M, Chen L Q. Nat. Commun., 2013, 4(1): 1481.
[99]

Pang Q, Shyamsunder A, Narayanan B, Kwok C Y, Curtiss L A, Nazar L F. Nat. Energy, 2018, 3(9): 783.
[100]

Zhang Y Z, Liu S, Li G C, Li G R, Gao X P. J. Mater. Chem. A, 2014, 2(13): 4652.
[101]

Fan L L, Deng N P, Yan J, Li Z H, Kang W M, Cheng B W. Chem. Eng. J., 2019, 369: 874.
[102]

Chen S R, Zheng J M, Mei D H, Han K S, Engelhard M H, Zhao W G, Xu W, Liu J, Zhang J G. Adv. Mater., 2018, 30(21): 1870144.
[103]

Huang F F, Ma G Q, Wen Z Y, Jin J, Xu S Q, Zhang J J. J. Mater. Chem. A, 2018, 6(4): 1612.
[104]

Zheng J, Fan X L, Ji G B, Wang H Y, Hou S, DeMella K C, Raghavan S R, Wang J, Xu K, Wang C S. Nano Energy, 2018, 50: 431.
[105]

Zheng J, Ji G B, Fan X L, Chen J, Li Q, Wang H Y, Yang Y, DeMella K C, Raghavan S R, Wang C S. Adv. Energy Mater., 2019, 9(16): 1803774.
[106]

Huang F F, Gao L J, Zou Y P, Ma G Q, Zhang J J, Xu S Q, Li Z X, Liang X. J. Mater. Chem. A, 2019, 7(20): 12498.
[107]

Xin S, Yin Y X, Guo Y G, Wan L J. Adv. Mater., 2014, 26(8): 1261.
[108]

Wei S Y, Xu S M, Agrawral A, Choudhury S, Lu Y Y, Tu Z Y, Ma L, Archer L A. Nat. Commun., 2016, 7(1): 11722.
[109]

Zhao M, Li B Q, Peng H J, Yuan H, Wei J Y, Huang J Q. Angew. Chem. Int. Ed., 2020, 59(31): 12636.

Funding

National Natural Science Foundation of China(21975087)

China Postdoctoral General Foundation(2020M672337)

PDF (25078KB)

2245

Accesses

0

Citation

Detail
Sections
Recommended

/

〈 〉

Address of Editorial Office: No. 33 Beisihuan Xilu, Zhongguancun , Beijing 100190, China
Tel: +86 10 8262 7757
Fax: +86 10 8262 7757
E-mail: progchem@mail.las.ac.cn
http://www.progchem.ac.cn
    • 　
    Copyright © Editorial Office of Progress in Chemistry