Recent Progress in $\text{Li}_{2}\text{FeSiO}_{4}$ Cathode Materials

Lithium-ion batteries (LIBs) possess high energy density, excellent safety performance, long service life, and no memory effect. These properties make them widely used in electric vehicles and consumer electronics. Cathode materials are critical factors in improving the performance of LIBs, in which $\text{Li}_{2}\text{FeSiO}_{4}$ is the most potential cathode material due to its high theoretical ratio and good structural stability. However, $\text{Li}_{2}\text{FeSiO}_{4}$ is a polyanionic orthosilicate consisting of tetrahedral polyanion structural units $(\text{XO}_{4})^{\mathrm{n}-}$ covalently bonded to $\text{MO}_{\mathrm{x}}$ polyhedral. This structure induces low electronic conductivity and poor $\text{Li}^{+}$ diffusion coefficient, thereby greatly increasing the polarization during electrochemical reactions. In this mini-review, the structures and electrochemical mechanisms of $\text{Li}_{2}\text{FeSiO}_{4}$ were analyzed and the latest developments in the fields of doping, surface coating, and morphology design and tuning were reviewed. Novel perspectives and insights were extracted to further improve the electrochemical characteristics of $\text{Li}_{2}\text{FeSiO}_{4}$ .