In this paper, we review the preparation methods of carbon nanotube (CNT)/graphene composite materials for the electrode of supercapacitors, and introduce the developments of CNT/graphene/pseudo-capacitive material ternary composite materials with highly electrochemical performance. The rational designed CNT/graphene composite nanostructures could largely utilize the characteristics of carbon nanomaterials for electrochemical double-large supercapacitors, such as large specific area, high conductivity and befitting porous structure, and also achieve large mass loading of pseudo-capacitive materials with high dispersion for pseudo-capacitors. As a result, these composite materials are promising candidates for the electrode materials of high-performance supercapacitors with high capacitance, excellent rate performance and long lifetime.

Contents
1 Introduction
2 The preparation strategies of carbon nanotube/graphene composites
2.1 The assembling based on π-π interaction
2.2 The assembling based on electrostatic attraction
2.3 In-situ growth
2.4 Other methods
3 Ternary composite electrodes based on graphene, carbon nanotube and pseudo-capacitive materials
3.1 Carbon nanotube/graphene/conductive polymer
3.2 Carbon nanotube/graphene/metallic oxides (hydroxides)
4 Conclusion