Nanoconstruction and nanoeffect of phosphate-based cathode materials for advanced sodium-ion batteries

With the increasing global consumption of secondary batteries, the cost of lithium-ion batteries (LIBs) will gradually become a problem. Compared with LIBs, sodium-ion batteries (SIBs) have natural advantages, such as the higher abundance of sodium in the earth's crust and lower cost. SIBs have a similar working principle to LIBs, based on sodium/lithium ions moving between the cathode and anode. The cathode plays an important role in the performance of SIBs. Among the cathode materials of SIBs, phosphate-based cathodes have been widely studied for their good electrochemical performance and stability. However, there are still some problems that limit their wide practical application, such as unsatisfactory rate performance, low energy density and poor cycle stability. Nanosizing is one of the common modification strategies used to solve the above problems. It not only improves the chemical kinetics of cathode materials but also regulates their thermodynamic properties. This review discusses the influence of nanosizing on the phosphate cathode material and what shapes can be designed to improve performance, and provides a reference for the development of SIBs in the future.