Revelation of the transition‐metal doping mechanism in lithium manganese phosphate for high performance of lithium‐ion batteries

Abstract

AbstractLithium iron phosphate (LiFePO4) has been widely used due to its high theoretical capacity and good cycle stability, but lithium manganese phosphate (LiMnPO4) with a higher operating voltage (4.1 V) has not been used, so it is necessary to conduct theoretical research on its inherent performance improvement strategy. The large‐scale application of LiMnPO4 is limited by its relatively low electronic and ionic conductivity. Improving the electronic and ionic conductivity of electrode materials by selective doping is an effective strategy. To determine the effect of doping of transition metals on the electrochemical properties of LiMnPO4 and to screen out doping models of cathode materials with excellent battery performance, we established all 3d, 4d, and 5d transition‐metal doping models of LiMnPO4. Through screening by first principles, the structural properties, band gap, doping formation energy, elastic properties, isotropy, and lithium/delithium voltage of the above models were compared and analyzed. According to the screening results, LiMnPO4 doped with Sc, Ti, V, Fe, Co, Mo, Rh, Re, and Ir has excellent electrochemical properties and can be used as a good cathode material for lithium‐ion batteries; the inherent mechanism of the above materials is revealed.