Enhanced high-rate capability and cycling stability of Al-doped LiZn0.05Mn1.95O4 spinel cathode materials for lithium-ion batteries

To enhance the structural stability, Zn-doped spinel LiMn 2 O 4 has attracted considerable attention due to its improved cycling performance. However, poor Li + diffusion kinetics and rapid capacity decay at high rates remain critical drawbacks. Therefore, Al doping is introduced to further improve electronic conductivity, and the combined effect of Zn and Al on the electrochemical properties is evaluated in this work. Compared with the LiZn 0.05 Mn 1.95 O 4 (LZMO) sample, the LiZn 0.05 Al 0.03 Mn 1.92 O 4 (LZMO-Al0.03) material via a low-temperature solid-state combustion synthesis route exhibited a well-defined truncated octahedral morphology with a narrowed particle size distribution. This specific structure effectively suppressed the Jahn-Teller distortion and enhanced structural stability during high-rate cycling. Consequently, the LZMO-Al0.03 sample delivered a high initial discharge capacity of 112.4 mAh·g -1 and achieved an outstanding capacity retention of 66.0% after 2000 cycles at 20 C, confirming that appropriate Al 3+ doping plays a crucial role in optimizing the electrochemical performance of the spinel cathode.