钠离子电池钒基聚阴离子型正极材料的发展现状与应用挑战

Recent progress and application challenges in V-based polyanionic compounds for cathodes of sodium-ion batteries

钠离子电池以其资源丰富、性价比高等优势有望在电动自行车、低速电动车、固定式储能领域获得广泛应用。在众多正极材料中,钒基聚阴离子型化合物因具有能量密度高、功率密度高、稳定性好等优点成为研究热点之一。但是其本征电子电导率较低,同时由于制备方法不当等带来的体相电子和离子传递阻力较大等缺陷,限制了材料的实际比容量、倍率性能及稳定性等。本文从几种典型的钒基聚阴离子型化合物的晶胞结构和储钠特性分析入手,从微观材料本体和介观电极结构的角度讨论钒基聚阴离子型化合物中电荷传递过程、动力学提升策略并总结近期进展;结合钒基聚阴离子型化合物的实用化需求,凝练出推进钒基聚阴离子型化合物进一步发展的重要研究方向。

Sodium-ion batteries have potential applications in the field of electric bicycles,low-speed electric vehicles,and stationary energy storage due to the abundance and low cost of sodium resources.Of the various cathode materials proposed for sodium-ion batteries,vanadium(V)-based polyanionic compounds have become a research hotpot due to their high energy density,high power density,and stable structure.However,the low intrinsic conductivity and improper preparation method of such compounds impede their bulk electron and ion transfer,which limit the specific capacity,rate capability,and structure stability of these materials.In this review,starting from an analysis of the cell structure and sodium storage characteristics of several typical V-based polyanionic compounds,we review the charge transfer process,strategy for improving the kinetics,and progress in V-based polyanionic compounds from the perspective of the microstructure and mesoscopic electrode structure.Meanwhile,combined with a discussion of the practical applications of V-based polyanionic compounds,the important research directions to promote the further development of V-based polyanionic compounds are summarized.