W. Gu †, Y.X. Cao †, L.W. Ye †, F. Su, X. Wang *, P. Das, T. Wang, C.Y. Li, S.W. Li, P. Chu *, Z.T. Li * and Z.-S. Wu *

Energy Storage Materials, 2025, accepted.

Battery-supercapacitor hybrid devices (BSHDs) possess great potential for applications owing to their high energy and power density, but the single charge carrier migration mechanism and limited electrode selection constrain their performance improvement. Herein, we report a novel Daniell-configuration dual-ion BSHD (V2O5/G|ZnSO4+Li2SO4|LiMn2O4) employing a pseudocapacitive zinc storage material of amorphous V2O5/graphene (V2O5/G) as anode and a battery-type lithium storage material of LiMn2O4 as cathode, with a mixed aqueous electrolyte of ZnSO4 and Li2SO4. The resulting device achieves a splendid specific capacity of 86 mAh g-1, high energy density of 82 Wh kg-1 and a power density of 3.9 kW kg-1, significantly outperforming most aqueous BSHDs based on single-ion electrolytes. Furthermore, it is revealed experimentally and theoretically that the self-orientating ion selection occurs in Daniell-type principle of Li+ insertion/extraction in LiMn2O4 cathode and Zn2+ insertion/extraction in V2O5/G, respectively. This work demonstrates an innovative device configuration with Zn2+ and Li+ as dual-cation charge carriers with self-orientation in different electrodes, deepening current understanding on the development of high performance electrochemical energy storage devices.