Vanadium Doping for Enhanced Electrochemical Performance of the High-Voltage LiCu0.5Mn1.5O4 Cathode

Lithium-ion batteries are widely used in electric vehicles and energy storage systems. Among various cathode materials, spinel-type LiCu_0.5Mn_1.5O₄ stands out for its high voltage (5 V), low cost, and excellent safety. However, its practical application is constrained by limited discharge capacity (<70 mAh/g) and poor cycling stability. In this study, vanadium doping reduced the oxidation state of manganese, significantly enhancing the specific capacity while stabilizing the crystal structure. As a result, the initial discharge capacity increased to 95.2 mAh/g, a 38.2% increase over the undoped material, and exhibited excellent cycling stability─retaining 91.1% of its capacity after 900 cycles at 2 C and 83.4% after 1500 cycles at 5 C. Even under high-temperature conditions (55 °C), it maintained 82.8% of its capacity after 150 cycles. This work provides valuable theoretical insights for advancing LiCu_0.5Mn_1.5O₄ as a high-performance cathode material.