Room-temperature rechargeable Na ions batteries have attracted enormous interest due to its low cost and the environmental abundance of the sodium, which are considered as the best candidate for replacing the Li ion batteries in the large-scale electric energy storage. In recent years, the studies of Na ion batteries have made significant progress and the related components have been enriched. The current researches of anode materials for sodium ion batteries are reviewed in details, with emphasis on the electrochemical properties and charge-discharge mechanisms of carbon-based materials, alloys, non-metal substances, metal oxides and organic compounds. The main problems of these kinds of anode materials are discussed and the probable strategies are proposed. Then, the application prospective and the research directions of Na ions batteries in the future are also forecasted.

Contents
1 Introduction
2 Carbon-based materials
2.1 Graphite
2.2 Ungraphitised carbon
3 Metal or alloy materials 4 Metal oxides
5 Non-metal substance
6 Titanate
7 Organic materials
8 Conclusions and outlook