摘要：SummaryRechargeable Zn-ion batteries working with manganese oxide cathodes and mild aqueous electrolytes suffer from notorious cathode dissolution during galvanostatic cycling. Herein, for the first time we demonstrate the dynamic self-recovery chemistry of manganese compound during charge/discharge processes, which strongly determines the battery performance. A cobalt-modified δ-MnO2with a redox-active surface shows superior self-recovery capability as a cathode. The cobalt-containing species in the cathode enable efficient self-recovery by continuously catalyzing the electrochemical deposition of active Mn compound, which is confirmed by characterizations of both practical coin-type batteries and a new-design electrolyzer system. Under optimized condition, a high specific capacity over 500 mAh g−1is achieved, together with a decent cycling performance with a retention rate of 63% over 5,000 cycles. With this cobalt-facilitated deposition effect, the battery with low concentration (0.02 M) of additive Mn2+in the electrolyte (only 12 atom % to the overall Mn) maintains decent capacity retention.Graphical AbstractDisplay OmittedHighlights•Key factor of capacity retention: active Mn compound deposition rate•A novel cobalt-catalyzed deposition strategy and the dynamic cobalt movement•Excellent performance (>500 mAh g−1) and retention (63%) over 5,000 cycles•Improvement of cycling stability with minimized Mn2+additiveCatalysis; Electrochemical Energy Storage; Electrochemical Materials Science
