Electrochemical performance of Li-rich Li[Li0.2Mn0.56Ni0.17Co0.07]O2 cathode stabilized by metastable Li2SiO3 surface modification for advanced Li-ion batteries

With the desirable energy densities, Li-rich layered cathodes have attracted great attention as potential candidates for next generation Li-ion batteries (LIBs). In this context, the Li-rich layered cathode Li[Li0.2Mn0.56Ni0.17Co0.07]O2 (LMNCO) is prepared and surface modified homogeneously with Li-conductive Li2SiO3 layer via a facile co-precipitation process. It is found that the 3 wt% Li2SiO3 modified Li-rich cathode delivers a specific capacity as high as 207 mAh g−1 after 50 cycles, which results from the interplay among the electrode, Li2SiO3 coating layer and the electrolyte. Further analysis indicates that the Li2SiO3 layer could effectively balance the exfoliation of surface alkaline speciation and the dissolution of surface transition metal to generate the Li Mn Ni Co Si O protection layer, which will beneficial to the Li surface diffusion kinetics and the electrochemical stability of Li-rich layered materials as well.