介绍了过渡金属氧化物、普鲁士蓝及类似物、聚阴离子型化合物作为钠离子正极材料的特点及存在的问题。层状含钠的过渡金属氧化物由于合成工艺相对简单,理论比容量较大,但在充放电过程中存在不可逆相变等缺点;普鲁士蓝及类似物具有易于合成及高理论容量等优点,但其晶体结构中存在较多的空位缺陷和结晶水,导致在充放电过程中材料出现不稳定现象;聚阴离子型材料种类繁多,且具有较好的结构稳定性和安全性,但存在比容量较低和导电性偏低的缺点。上述种材料均需要采用材料表面包覆、金属元素掺杂、合成工艺改进等方法提高电化学性能。

The characteristics and existing problems of transition metal oxides,Prussian blue and its analogues,and polyanionic compounds as sodium ion cathode materials are expounded.Layered sodium-containing transition metal oxides exhibit the characteristics such as simple synthesis process and large theoretical specific capacity,however,they have the disadvantages of irreversible phase transition in the process of charge and discharge.Prussian blue and its analogues have the advantages of easy synthesis and high theoretical capacity,but they contain many vacancy defects and crystalline water in its crystal structure,lead to its instability during charge and discharge.There are many kinds of polypolanionic materials,and most of them have good structural stability and safety.However,polyananionic materials often have the shortages of lower specific capacity and lower conductivity.All three types of materials need to be coated by some materials on their surface,and doped with metal materials,in addition their synthesis processes need to be modified,so that their electrochemical properties can be improved.