A universal strategy towards high-rate and ultralong-life of Li-rich Mn-based cathode materials

Lithium-rich manganese-based cathode materials (LRMs) have shown promise for the next-generation lithium battery cathodes due to their high discharge specific capacity (similar to 250 mAh g(-1)) and wide operating voltage range (2.0-4.8 V). However, these materials face limitations such as low initial Coulombic efficiency (ICE), poor cycle stability, and inadequate rate capability. To address these challenges, we employed a simple citric acid treatment (CA-treatment) method to fabricate the Li-rich spinel coating layer on LRMs. This in situ formed spinel Li4Mn5O12 layer successfully suppresses the oxygen release, provides three-dimensional (3D) lithium-ion diffusion channels and enriches Li embedding sites, resulting in a substantial improvement in the rate capability and high-rate cycling performance. The modified LRM delivers a high specific capacity of 193.7 mAh g(-1) at 2.0 C and 154.8 mAh g(-1) at 5.0 C, after 1000 cycles at 10.0 C, 77.4 % capacity retention with 102.5 mAh g(-1) is realized. This facile CA-treatment benefits the electrochemical properties of LRMs comparable to those of altering the microscopic morphology. This work offers a new avenue for exploring outstanding LRMs with high-rate and ultralong cycling life.