Controlled Hydrothermal/Solvothermal Synthesis of High-Performance LiFePO₄ for Li-Ion Batteries

The sluggish Li-ion diffusivity in LiFePO₄ , a famous cathode material, relies heavily on the employment of a broad spectrum of modifications to accelerate the slow kinetics, including size and orientation control, coating with electron-conducting layer, aliovalent ion doping, and defect control. These strategies are generally implemented by employing the hydrothermal/solvothermal synthesis, as reflected by the hundreds of publications on hydrothermal/solvothermal synthesis in recent years. However, LiFePO₄ is far from the level of controllable preparation, due to the lack of the understanding of the relations between the synthesis condition and the nucleation-and-growth of LiFePO₄ . In this paper, the recent progress in controlled hydrothermal/solvothermal synthesis of LiFePO₄ is first summarized, before an insight into the relations between the synthesis condition and the nucleation-and-growth of LiFePO₄ is obtained. Thereafter, a review over surface decoration, lattice substitution, and defect control is provided. Moreover, new research directions and future trends are also discussed.