Effect of freeze-drying gel on properties of lithium manganese iron phosphate prepared by sol-gel method

Abstract Lithium manganese iron phosphate was manufactured via the sol-gel method, and the impact of the gel drying method on the electrochemical properties of lithium manganese iron phosphate and the underlying mechanism of action were investigated. The results demonstrate that lithium manganese iron phosphate produced by freeze-drying and sintering the gel exhibits excellent cycling performance, providing a significant discharge capability of 147.0 mAh g −1 under conditions of 0.1C and a capacity retention rate of 100% after 250 complete cycles under conditions of 1C. This can be attributed to the fact that freeze-drying addresses the agglomeration issue that arises from the conventional drying process. The resulting lithium manganese iron phosphate exhibits a smaller particle size and a more uniform pore structure, which is a consequence of the action of ice crystal separation. This offers a potential avenue for future process optimization in the sol-gel synthesis of lithium manganese iron phosphate.