Abstract:Sodium-ion batteries (SIBs) have been considered the most promising alternative to lithium-ion batteries (LIBs) due to their abundant resources and lower cost, and have attracted a lot of attention in the past few years. As an integral part of sodium ion battery, the performance of cathode material plays a very important role in the stability and lifetime of the battery. At present, the common cathode materials for sodium ion batteries mainly include layered transition metal oxides, Prussian blue analogues, polyanionic compounds, etc. These electrode materials have higher capacity, lower cost and are environmentally friendly, but they also generally have disadvantages such as poor electrical conductivity, poor cycling stability and short battery life. Cu is widely used because of its good electrical conductivity and stable structure. This review discussed the effect of Cu doping on the performance of the above three sodium ion battery cathode materials, and summarized the design, preparation and research progress of Cu doped cathode materials in recent years.