Synthesis and electrochemical mechanism of high voltage lithium nickel manganate cathode materials
Spinel-type lithium nickel manganese oxide(LiNi0.5Mn1.5O4)cathode material has an operating voltage plateau of 4.7V(vs.Li/Li+),which is environmental-friendly cathode material alternatives for lithium-ion batteries with the highest output voltage and lower cost.In this paper,aluminum-doped lithium nickel manganese oxide(LiNi0.45Al0.05Mn1.5O4,Al@LNMO)samples were prepared by a hydrothermal method,and the effect of aluminum doping on the electrochemical properties of lithium nickel manganese oxide(LNMO)was investigated by density functional theory(DFT)calculations.According to the results of DFT calculations,aluminum doping could reduce the band gap of LNMO and increase its conductivity.Structural characterization by XRD and FTIR showed that the crystal structure of the synthesized Al@LNMO was F(3ˉ) dm.In addition,electrochemical cycling tests indicated that the initial specific discharge capacities of Al@LNMO were 137.1mAh/g and 138.0mAh/g at 25℃and 50℃and a multiplicity of 1C,respectively;and the capacity retention rates were 82.9％and 79.1％after 100 cycles,respectively.Moreover,the capacity retention rate of Al@LNMO at 50℃was similar to that at 25℃.This indicated that Al@LNMO had good high-temperature stability.The results showed that Al@LNMO was a promising high voltage cathode material for lithium-ion batteries.
aluminum-doped lithium nickel manganese oxideelectrochemistrycompositesmolecular simulationhigh voltage
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