Abstract:

Sodium-ion batteries could be prepared from wide sources of raw materials and with low price, and thus have been recognized as a new generation of energy storage battery systems with excellent comprehensive performance. However, low energy density and limited cycle life are still major challenges hindering their wide applications. Based on the development experience of lithium-ion batteries, reasonable modification of sodium-ion batteries has been proven to be able to improve their electrochemical performance, especially in the established cathode system. In this review, the structure-performance characteristics of sodium-ion battery cathode materials, such as transition metal oxide, polyanionic compounds, Prussian Blue compounds and organic compounds, were analyzed. The latest research progress in the modification methods of nano-crystallization, surface coating, element doping,etc. was also systematically discussed in detail. Based on the existing researches, the effects of cathode materials modification were summarized, and the research directions of modification of cathode materials for sodium-ion batteries were prospected. In the future research and design, improving the synthesis process to control the particle size, expanding the types of coating materials, gradient doping synergistic elements and looking for different structural characteristics of cathode materials are the research focus.

Key words: sodium-ion batteries, cathode materials, transition metal oxide, polyanionic compounds, Prussian Blue compounds, organic compounds

摘要：

近年来，原料广泛、成本低廉的钠离子电池被公认为新一代综合效能优异的储能电池系统，但较低的能量密度和有限的循环寿命仍然是阻碍其商业化应用的主要挑战。借鉴锂离子电池的开发经验，合理的改性工艺已被证实可以明显提高钠离子电池的电化学性能，尤其是在已建立的正极体系中。本文分析了过渡金属氧化物、聚阴离子化合物、普鲁士蓝类化合物以及有机化合物等钠离子电池正极材料的结构、性能特点，并系统综述了粒径纳米化、表面包覆、元素掺杂等多类改性方法的最新研究成果。未来的研发和设计中，改进合成工艺控制粒径、拓宽包覆物质种类、梯度掺杂协同元素以及寻找不同结构特征的钠离子电池正极材料是研究重点。

关键词: 钠离子电池, 正极材料, 过渡金属氧化物, 聚阴离子化合物, 普鲁士蓝类化合物, 有机化合物