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The electronic structures,delithiation process and Li-ion diffusion for the Li-rich cathodes materials Li2MnSiO4 and Li4FeSbO6 are investigated by using the spin-polarized DFT+U and the climbing image nudged elastic band(CI-NEB).The cycling performance and electrochemical property of Li2MnSiO4 cathode material can be improved by doping metal cation(Na,Al,Fe and Mg) which enhance the electron conductivity and reduce Li-ion diffusion activation barriers.For the Li-rich layered oxides Li4FeSbO6,the Bader charge distribution and Gibbs free energy for O2 release during the delithiation process indicate that the oxygen release occurs spontaneously at a high voltage.Considering the batteries safety,the metal cation dopants which supply extra electrons for charge compensation can avoid the O vacancy generation and oxygen release.Therefore selecting dopants can effectively improve the cycling stability of the Li-rich cathodes materials.