Lithium cobalt phosphate (LiCoPO₄) is a lithium ion battery cathode material with olivine structure, which has a high voltage platform of 4.8V and a high theoretical capacity. Using a mild solvothermal method assisted by ascorbic acid, the morphology and particle size of LiCoPO₄ material were optimized by regulating the solvothermal reaction time and calcination temperature, thereby improving its electrochemical performance. The results showed that the plate-like LiCoPO₄ particles were obtained when the solvent-thermal reaction time was 9 h. When the calcination temperature is 700℃, the plate particles have the shortest [010] direction length. Finally, LiCoPO₄ (163.21 mA h/g) material with the best specific discharge capacity was obtained. The electrochemical performance of LiCoPO₄ was significantly improved by doping with Fe₂₊^. Further investigation into Fe₂₊ ^{doping of} LiCoPO₄ revealed that when the Fe^₂₊ doping level reached 9%, the synthesized LiCo_1-xFe_xPO₄ sample exhibited the best cycling performance and rate capability. At a charge-discharge rate of 0.1C, the sample achieved a capacity retention of 77.65% after 30 cycles.