Wang Xiaohui, a researcher at the Institute of Metal Research, Chinese Academy of Sciences, and Zhu Kongjun, a professor at Nanjing University of Aeronautics and Astronautics, used microwave hydrothermal synthesis to efficiently prepare nanometer lithium iron phosphate (LiFePO4) in a synthetic environment of pure water. Related results were recently published in Green Chemistry.
Based on a deep understanding of the nucleation growth mechanism of LiFePO4, researchers have reduced the nucleation window time to increase the nucleation rate, and produced LiFePO4 with the highest yield (1.3 mol / L) so far. After 1000 charge / discharge cycles at 3C rate, it can still maintain 88% of the initial capacity, which can meet the needs of large-scale energy storage. At the same time, the researchers used the precipitating agent to recover and reuse the most valuable LiOH in the filtrate. The effective utilization rate of the lithium source exceeded 90%, which greatly reduced the production cost.
Lithium-ion batteries are the first choice for battery technology development, and cathode materials are one of the key components that determine battery performance. LiFePO4 has significant competitive advantages as a positive electrode material. In 2017, LiFePO4 batteries achieved an installed capacity of 16.33 GW / hr, accounting for 48.68%, ranking first in all types of lithium batteries. The previously reported preparation of nano-LiFePO4 mostly uses a solvothermal method, and the product has good electrochemical performance, but the method has low yield and high cost, and cannot achieve large-scale production. Compared with the solvothermal method, the hydrothermal method of preparing LiFePO4 has lower cost, but the product has poor electrochemical performance. Moreover, the effective utilization of lithium sources in both preparation methods is less than one third.
Wang Xiaohui said that this time the Institute of Metals took the lead in achieving green and efficient synthesis of high-performance nano-LiFePO4 in a synthetic environment of pure water, which will strongly promote its large-scale production.