钠电池主流正极材料有哪些？

What are the mainstream cathode materials for Sodium-ion Battery?    

目前产业化成熟、市场主流的钠电池正极材料分为三大技术体系，三类材料各有独特优势和适配场景，构成了钠电池的完整产业矩阵。第一类是层状氧化物正极，技术工艺最成熟、能量密度最高，贴合动力电池性能需求，主要用于入门级新能源汽车、高速两轮电动车等动力场景，缺点是循环寿命中等、原材料成本略高；第二类是普鲁士蓝类正极，生产成本极低、倍率性能优异、低温性能极强，适配大规模电网储能、工商业储能，短板是材料自带结晶水，长期稳定性需要工艺优化；第三类是聚阴离子正极，结构稳定性最强、循环寿命最长、安全系数最高，主打长时储能、基站备电等长效场景，缺点是能量密度相对偏低。

At present, the mainstream cathode materials for industrialized and mature sodium batteries in the market are divided into three major technology systems, each with unique advantages and adaptation scenarios, forming a complete industrial matrix of sodium batteries. The first type is layered oxide cathode, which has the most mature technology and process, the highest energy density, and meets the performance requirements of power batteries. It is mainly used in power scenarios such as entry-level new energy vehicles and high-speed two-wheeled electric vehicles, with the disadvantages of medium cycle life and slightly higher raw material cost; the second type is Prussian blue cathode, which has extremely low production cost, excellent rate performance and strong low temperature performance, and is suitable for large-scale grid energy storage and commercial and industrial energy storage. The shortcoming is that the material has its own crystal water, and the long-term stability needs process optimization; the third type is polyanion cathode, which has the strongest structural stability, the longest cycle life and the highest safety factor, focusing on long-term energy storage, base station backup power and other long-term scenarios, with the disadvantage of relatively low energy density.