Authors: Yanchen Fan, Meng Xu, Qi Li, Mengyao Liu, Xiaoru Zhang, Pan Chu, Biao Zhang, Hongyu Zhou, Yi Zhao, Chenguang Liu
Published: 2025-03-13
Source: Full article
AbstractProton insertion mechanism with fast reaction kinetics is attracting more and more attention for high‐rate and durable aqueous Zn─MnO2 batteries. However, hydrated Zn2+ insertion reaction accompanied with Jahn–Teller effect and Mn3+ disproportionation generally leads to sluggish rate capability and irreversible structure transformation. Here, carboxyl‐carbon nanotubes supported α‐MnO2 nanoarrays (C─MnO2) cathode is successfully fabricated by a convent grinding process for high‐performance Zn batteries. Specifically, the carboxyl‐carbon nanotubes (CNTs) skeleton endows α‐MnO2 with a shorter ion diffusion route and more active sites for proton adsorption, benefiting to the fast electron transport and reversible structure evolution of MnO2. More importantly, electronegative carboxyl groups and Mn─O─C interfacial bonds can effectively restrain Mn2+ dissolution and shuttle for improved structural integrity and redox reactivity. Consequently, the C─MnO2 cathode exhibits high capacity, superior rate capability, and outstanding cycling stability over 10 000 cycles. Even at ultra‐high mass loading (20 mg cm−2), the Zn//C─MnO2 punch cell displays excellent capacity (202 mAh) and 94.5% capacity retention after 114 cycles, providing new insights for the practical application of advanced Zn‐Mn batteries.