Optimization of leaching conditions and macroscopic kinetics of spent LiFePO4/C powder
Employing efficient recycling techniques to recover the important components from used LiFePO4/C powder is crucial for resource conservation and environmental preservation.Now,for a large number of retired lithium iron phosphate batteries,the majority of studies were concentrated on the selective leaching of lithium without taking into account the leaching behavior of other priceless components like iron,phosphorus,aluminum and copper.This work studied the spent LiFePO4/C powder leaching process condition optimization and macroscopic kinetic studies.Systematically examined were the effects of temperature,acid concentration and duration on the leaching process of iron,phosphorus,lithium,aluminum and copper.The macroscopic kinetics of lithium,iron,phosphorus,aluminum and copper leaching from the powder were thoroughly investigated.The results of the experiments under optimized conditions indicated that the leaching rates of iron,phosphorus,lithium,aluminum and copper were 97.2％,96.9％,89.7％,76.1％and 43.4％,respectively.The internal diffusion model predicted that iron,phosphorus,lithium and copper leached over time,and the diffusion reaction governed this process.The diffusion reaction and chemical reaction-controlled mixed control model,which governed aluminum leaching,was accurate.According to the kinetic model,the apparent activating energies of Fe,Al and Cu leaching were 8.20kJ/mol,34.11kJ/mol and 11.49kJ/mol,respectively.This article elucidated the leaching kinetics of diverse elements in spent lithium iron phosphate offered theoretical guidance for the selective leaching of these elements.
spent lithium iron phosphatesulphuric acidleachingkineticsrecoverykinetic modeling
万方数据
维普
