Electrochemical performance of Li-rich Li[Li 0.2 Mn 0.56 Ni 0.17 Co 0.07 ]O 2 cathode stabilized by metastable Li 2 SiO 3 surface modification for advanced Li-ion batteries

Abstract 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[Li 0.2 Mn 0.56 Ni 0.17 Co 0.07 ]O 2 (LMNCO) is prepared and surface modified homogeneously with Li-conductive Li 2 SiO 3 layer via a facile co-precipitation process. It is found that the 3 wt% Li 2 SiO 3 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, Li 2 SiO 3 coating layer and the electrolyte. Further analysis indicates that the Li 2 SiO 3 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.