Zn2⁺ doping regulates the surface morphology and Mn dissolution of spinel LiMn2O4 significantly enhancing its electrochemical performance

The spinel-structured LiMn 2 O 4 cathode material exhibits low specific capacity and rapid capacity decay under high current densities , significantly limiting its commercial application prospects. This study uses a coprecipitation and calcination method to dope Zn into LiMn 2 O 4 , discovering that doping Zn elements causes LiMn 2 O 4 to preferentially grow along the (110) and (100) crystal planes. The (110) and (100) crystal planes provide more Li ion channels, contributing to the improvement of rate performance. In the custom-designed LiZn 0.04 Mn 1.96 O₄ (LZMO-0.04) cathode, the strategic addition of Zn occupying Mn sites makes electrons more delocalized, increasing the free electron gas and enhancing the material’s conductivity. The LZMO-0.04 sample exhibits a rich variety of polymorphic morphologies, a lower Mn³⁺ content, and a higher Li⁺ diffusion coefficient . These optimization effects, resulting from the synergistic action of multiple factors, enabled the LZMO-0.04 sample to achieve an initial discharge capacity of 127.73 mAh/g with a capacity retention rate of 83.06 % after 300 cycles at a rate of 0.5C. Even with an increase to a high rate of 5 C over 1200 cycles, the capacity retention rate remained stable at 81.89 %, exhibiting excellent high-rate cycle stability.