Triple modifications of Li-rich manganese-based cathode materials using LiMnPO₄ one-step method

Li-rich manganese-based layered oxide (LMR) is one of the most promising cathode materials for lithium batteries owing to its high specific capacity and low cost. Unfortunately, its commercial application is hindered by voltage decay, capacity diminishing, and poor rate performance during cycling. Thus, a facile surface triple modification method for Li_1.2Ni_0.2Mn_0.6O₂ has been proposed. This method constructs a protective LiMnPO₄ coating layered, a spinel interface, and introduces some oxygen vacancies. The construction of the coating layer and oxygen vacancies alleviates interface side reactions and irreversible loss of O, ultimately suppressing voltage decay and improving cycling performance. The spinel phase constructs a 3D Li⁺ diffusion pathway, which improves the rate performance. As expected, electrochemical tests indicate that the materials coated by 3 wt% LiMnPO₄ exhibit a mitigated voltage attenuation from 2.204 mV to 1.626 mV, an enhanced capacity retention of 85.60 % at 1C after 100 cycles, and a discharge capacity of 171.6 mAh·g⁻¹ at 5C, which is better than that of bare materials (163.9 mAh·g⁻¹ at 5C). This one-step processing method provides a simple and efficient method for modifying LMR materials.