Recent Report on the Hydrothermal Growth of LiFePO4 as a Cathode Material

Abstract

Various growth processes have been utilized for the development of lithium iron phosphate including microwave treatment, spray thermal decomposition, sol-gel and the hydrothermal route. However, microwave treatment, spray process and sol-gel suffer from high costs and difficulties in controlling growth parameters. In this review paper, recent synthetic strategies, including the raw materials utilized for the hydrothermal growth of lithium iron phosphate, their effect on the basic characteristics and, as a consequence, the electrochemical performance of cathodes, are reported. The advantages of the hydrothermal process, including high material stability, eco-friendliness, low production costs and material abundance, are explained along with the respective processing parameters, which can be easily tuned to modify lithium iron phosphate characteristics such as structure, morphology and particle size. Specifically, we focus on strategies that were applied in the last three years to improve the performance and electrochemical stability of the cathode utilizing carbon-based materials, N-doped graphene oxide and multi-wall carbon nanotubes (MWCNTs), along with the addition of metallic nanoparticles such as silver. Finally, future perspectives on the hydrothermal process are discussed including the simultaneous growth of powders and solid-state electrodes (i.e., growth of lithium iron phosphate on a rigid substrate) and the improvement in morphology and orientation for its establishment and standardization for the growth of energy storage materials.