Synthesis, characterization and electrochemical evaluation of lithium-manganese phosphates for cathode material in lithium ion batteries.

摘要

Lithium ion batteries deliver the highest specific energy and energy density of commercially available secondary batteries. The objective of this study was to evaluate lithium-manganese phosphate (LiMnPO4) for potential application as a cathode material in lithium ion batteries due to its high theoretical capacity and stable phospho-olivine structure. LiMnPO 4 was successfully synthesized via a novel aqueous sol-gel process under an inert nitrogen and air atmosphere. Microstructural design strategies including annealing treatment and the addition of 1 wt% copper dopant were evaluated in order to improve the electrochemical performance of the LiMnPO4 cathode. The cathode particle microstructure and morphology were characterized using X-ray diffraction and scanning electron microscopy. Open circuit voltage was 4.1 V for all samples. The electrochemical performance of LiMnPO 4 is significantly improved by the addition of a dopant in an inert nitrogen atmosphere with a specific capacity of 28 mAh/g achieved during the first discharge cycle.