Mitigated Mn Dissolution and Improved Cycling Stability of LiNi_0.5Mn_1.5O₄ Spinel Cathodes by Zinc Doping

The spinel compound LiNi_0.5Mn_1.5O₄ (LNMO) has attracted increasing attention as a potential cathode material for high-energy lithium-ion batteries (LIBs) of the next generation. Despite its attractive properties, LNMO suffers from transition-metal ion dissolution and pronounced capacity fading, which significantly limit its practical implementation. To address these limitations, Zn is introduced into the LNMO structure to prepare Zn-doped LNMO, designed to stabilize the 16c and 8a sites and thus improve its electrochemical performance. This doping approach improves the structural robustness of LNMO and significantly suppresses Mn dissolution during electrochemical cycling. Even after 1000 cycles at a current rate of 1 C (1 C = 147 mA g^-1), the Zn-LNMO sample maintains 81.2% of its original capacity, demonstrating substantially improved capacity retention. Moreover, the Zn-LNMO electrode maintains 98.8% of its initial voltage after 1000 cycles, and the corresponding average decline in voltage is as low as 0.06 mV for each cycle. This study establishes an atomically engineered doping concept that can be generalized to various cathode systems and serves as an effective guideline for designing high-performance LIBs.