Citric acid (CA) was used as a reducing agent for the synthesis of LiFePO 4 (LFP) under hydrothermal conditions, looking for a more environmentally friendly method for production. The CA concentration was tuned for synthesis, ranging from 2 to 10 wt%. The best electrochemical performance of LFP in Li-ion batteries was achieved with the material obtained with a CA concentration of 2 wt%. This is correlated to the superior crystal structure characteristics of the sample, the lack of secondary phases, and most importantly, its heterogeneous-type morphology. At this concentration, the samples exhibited a distinctive bimodal particle size distribution, with predominant spherical nanoparticles of approximately 400 nm in size. Comminution effects transfer into enhanced electrical and ionic conductivities, demonstrating their potential for energy storage applications.
Mondragón et al. (Mon,) studied this question.