Dual Elements Coupling Effect Induced Modification from Surface into Bulk Lattice for Ni-rich Cathode with Suppressed Capacity and Voltage Decay

Injection of phase transition from layered to rock salt phase into bulk lattice and side reactions on the interfacial usually cause structure degradation, quick capacity/voltage decay and even thermal instability. Here, self-formed interfacial protective layer coupled with lattice tuning was constructed for Ni-rich cathode by simultaneous incorporation of Zr and Al in one calcination step. The migration energy between Zr and Al from surface into bulk lattice induces dual modifications from surface into bulk lattice, which effectively decrease the formation of cation mixing, the degree of anisotropic lattice change and the generation of microcracks. With the stabilization role provided by the doped Zr-Al ions and protective function endowed by the surface layer, the modified cathode material exhibits significantly enhanced capacity and voltage retention. Specifically, the capacity retention for modified cathode material reaches 99 % after 100 cycles at 1 C at 25 ℃ in the voltage of 3.0~4.3 V, which is outp...