Tunable Organic‐Inorganic p‐π‐d Electron Conjugation Triggers d‐π Hybridization in Quinonized MnO2 Superlattice toward Ultrastable and High‐Rate Zn‐MnO2 Batteries

Zn‐MnO2 batteries with two‐electron transfer harvest high energy density, high working voltage, inherent safety, and cost‐effectiveness. Zn2+ as the dominant charge carriers suffer from sluggish kinetics due to the strong Zn2+‐MnO2 coulombic interaction, which is also the origin of pestilent MnO2 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 Zn2+ insertion and structural collapse. Herein, a simultaneously enhanced and stabilized Zn2+/H+ co‐insertion chemistry is proposed by the quinone‐hybridized MnO2 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 t2g occupation and thus improved [MnO6] stability upon unprecedentedly high Zn2+ contribution. The notable d‐π hybridization endows MnO2 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 Zn2+/H+ co‐insertion chemistry towards high‐performance rechargeable aqueous batteries.