Enhanced Kinetics and Stability of Zn‐MnO ₂ Batteries with a Multifunctional TiO ₂ Coating

Abstract

Abstract Zinc‐ion batteries are a promising energy storage alternative, offering safety, cost‐effectiveness, and environment‐friendliness. MnO 2 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 2 is enhanced by coating it with a uniform TiO 2 nanolayer that incorporates oxygen vacancies. The TiO 2 ‐MnO 2 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 2 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 2 @TiO 2 cathode demonstrates excellent specific capacity (299 mAh g −1 at 0.1 A g −1 ) and cycling stability, achieving 91.4% capacity retention after 2500 cycles at 1 A g −1 and 92.7% capacity retention after 600 cycles at a low current density of 0.2 A g −1 . These results outperform many previously reported manganese‐based cathodes, demonstrating MnO 2 @TiO 2 ’s potential as a high‐performance and durable cathode material for zinc‐ion batteries and advancing the development of efficient energy storage solutions.