Enhanced Kinetics and Stability of Zn-MnO Batteries with a Multifunctional TiO Coating.

Zinc-ion batteries are a promising energy storage alternative, offering safety, cost-effectiveness, and environment-friendliness. MnO is appealing for its high capacity and output voltage, but it suffers from slow kinetics and poor stability due to severe Mn dissolution during cycling. Here, the performance of MnO is enhanced by coating it with a uniform TiO nanolayer that incorporates oxygen vacancies. The TiO-MnO heterogeneous interface results in the formation of Ti─O─Mn bonds and a reduction in the interfacial valence state, thereby leading to the creation of an interface electron-enriched region that facilitates faster electron and ion transport. This multifunctional TiO coating not only promotes proton-dominated electrochemical reactions and ion diffusion but also acts as a protective barrier, preventing Mn dissolution and buffering volume changes during cycling. Consequently, the MnO@TiO cathode demonstrates excellent specific capacity (299 mAh g at 0.1 A g) and cycling stability, achieving 91.4% capacity retention after 2500 cycles at 1 A g and 92.7% capacity retention after 600 cycles at a low current density of 0.2 A g. These results outperform many previously reported manganese-based cathodes, demonstrating MnO@TiO's potential as a high-performance and durable cathode material for zinc-ion batteries and advancing the development of efficient energy storage solutions.