One-pot K+ and PO43− co-doping enhances electrochemical performance of Li-rich Li1.2Ni0.13Co0.13Mn0.54O2 cathode for Li-ion battery

Abstract

The high specific capacity and voltage of Li-rich Mn-based oxides make them promising cathode materials for high-energy-density lithium-ion batteries (LIBs). However, the problems such as low initial coulombic efficiency, fast capacity and voltage fading, poor kinetics, large voltage hysteresis, and poor safety performance hamper their fast commercialization. Herein, we report one-pot K+ and PO43− co-doping Li-rich Mn-based oxides Li1.2Ni0.13Co0.13Mn0.54O2 cathode material to improve the electrochemical performance of the lithium-ion battery. On the one hand, K+ doping can stabilize the bulk structure and enlarge the Li slabs to facilitate the diffusion of Li+, resulting in enhanced cycling and rate performance. On the other hand, PO43− doping changes the electronic structure of the material and weakens the covalency of TM-O, decreasing the irreversible loss of lattice oxygen and stabilizing the structure. As a result, the K+ and PO43− co-doping can effectively alleviate the capacity and voltage decay and the modified sample shows better cycling stability (88.6%@0.5 C@250 cycles) and rate performance (155.5 mAh g −1@5 C) compared to the pristine material. Our strategy here provides a facile one-pot method to modify Li-rich Mn-based oxides cathode material for high-performance LIBs.