Tunable Organic‐Inorganic p‐π‐d Electron Conjugation Triggers d‐π Hybridization in Quinonized MnO<sub>2</sub> Superlattice toward Ultrastable and High‐Rate Zn−MnO<sub>2</sub> Batteries
Anqi Zhang, Tiande Chen, Ran Zhao, Yahui Wang, Jingjing Yang, Xiaomin Han, Xinran Wang, Chuan Wu, Ying Bai, Chuan Wu, Ying Bai
Abstract
Abstract Zn‐MnO 2 batteries with two‐electron transfer harvest high energy density, high working voltage, inherent safety, and cost‐effectiveness. Zn 2+ as the dominant charge carriers suffer from sluggish kinetics due to the strong Zn 2+ −MnO 2 coulombic interaction, which is also the origin of pestilent MnO 2 lattice deformation and performance degradation. Current studies particularly involve H + insertion‐dominating chemistry, where the long‐term cycle stability remains challenging due to the accumulative Zn 2+ insertion and structural collapse. Herein, a simultaneously enhanced and stabilized Zn 2+ /H + co‐insertion chemistry is proposed by the quinone‐hybridized MnO 2 superlattice, a first‐of‐this‐kind structure with a distinctive organic–inorganic‐extended p‐π‐d conjugation, which enables a tunable interlayer d‐π hybridization. Theoretical and experimental results substantiate that the interlayer d‐π hybridization triggers the enhancement of polarons occupancy near Fermi level, the downward shift of O p‐band center, the elevated Mn t 2g occupation and thus improved [MnO 6 ] stability upon unprecedentedly high Zn 2+ contribution. The notable d‐π hybridization endows MnO 2 superlattice an ultrahigh specific capacity (435.9 mAh g −1 at 0.25 A g −1 ), state‐of‐the‐art cycle stability (~100 % capacity retention after 30,000 cycles at 10 A g −1 ) with substantially enhanced rate performance. Our findings enlighten a new paradigm in the adjustment of Zn 2+ /H + co‐insertion chemistry towards high‐performance rechargeable aqueous batteries.