Ti4+-induced dual-functional α-MnO2 nanowires: boosting transport kinetics and interfacial optimization for aqueous zinc-ion batteries

Aqueous zinc-ion batteries (ZIBs) are attracting widespread attention for large-scale   energy storage due to their high safety, environmental friendliness, high theoretical capacity and favorable cost-effectiveness. Substantial research has focused on addressing side reactions such as corrosion, hydrogen evolution, and dendrite formation at the zinc anode interface. However, the absence of high-performance cathode materials hinders the commercialization of this battery system. Manganese dioxide as a promising cathode candidate for ZIBs suffers from severe capacity decay during cycling, which remains a critical challenge. Herein, an effective strategy for enhancing cyclic stability and specific capacity of α-MnO 2 nanowires via Ti 4+ -induced dual-functionality is provided. As expected, the Ti-doped sample exhibits superior cyclic stability and rate capability compared to the pristine material, delivering an initial specific capacity of 175 mAh·g -1 and maintaining 116 mAh·g -1 after 200 cycles. Notably, the Ti-doped electrode retains excellent long-term stability and comparable specific capacity upon reverting to the initial low current density after stepwise cycling at progressively increased rates, demonstrating enhanced structural and electrochemical reversibility. Comprehensive experimental and theoretical analyses reveal that the incorporation of Ti 4+ offers dual-functionality by reducing energy barriers for electron transitions and ion migration, while optimizing the electrode surface to suppress insulating by-products accumulation, thereby boosting overall electrochemical performance.