<p>Manganese oxides have emerged as promising cathode materials for aqueous zinc-ion batteries (ZIBs) owing to their low cost, high safety, and environmental benignity. However, the practical application is hindered by poor cycling stability and low electronic conductivity. This study proposes a Cu-Li co-doping strategy to enhance Mn₃O₄’s electrochemical performance, producing the co-doped material (CLMO) using a facile one-step solution combustion method. Experimental results revealed Cu²⁺ substitution at Mn²⁺ sites triggered lattice contraction, shortening Zn²⁺ diffusion pathways, while Li⁺ enhanced cycling stability by suppressing Mn dissolution and stabilizing the lattice. Synergistic co-doping significantly increased oxygen vacancy concentration, improving electronic conductivity. The CLMO cathode exhibited a remarkable capacity of 270 mAh g⁻¹ at 0.1 A g⁻¹ and retained 98% capacity after 800 cycles at 0.5 A g⁻¹, outperforming single-doped and undoped counterparts. EIS analysis further validated the reduced charge transfer resistance (13.17 Ω vs. 75.59 Ω) and accelerated Zn²⁺ diffusion kinetics. These findings elucidate the synergistic mechanisms of bimetallic co-doping and offer a theoretical and technical foundation for developing high-stability ZIBs cathodes.</p>