Ammonium ion pre‐intercalated manganese dioxide with hydrogen bond for high‐rate and stable zinc‐ion batteries

Abstract The low‐cost and high‐safety zinc‐ion batteries (ZIBs) are expected to be promising alternatives of lithium‐ion batteries (LIBs). Nevertheless, sluggish kinetics and unstable structure of cathode lead to the low‐rate capability and poor cycling stability of ZIBs, which severely hinder their commercial application. Herein, a (NH 4 ) x MnO 2 cathode with ammonium ions (NH 4 + ) pre‐intercalation is reported. The NH 4 + ions with small molar mass expand the layer spacing, accelerating ion diffusion and act as “structural pillars”, preventing structural collapse. Moreover, hydrogen bond between NH 4 + and MnO 2 promotes the charge transfer and further stabilize the layered structure. Therefore, the (NH 4 ) x MnO 2 cathode delivers a high specific capacity (228.7 mAh g −1 at 0.3 A g −1 ), a superior high‐rate performance (122.5 mAh g −1 at 3.0 A g −1 ), and an outstanding long‐term cycling stability without obvious capacity fading after 1500 cycles at 2.0 A g −1 . This work provides a new perspective for future development of high‐performance ZIBs. image