Molecularly crowding electrolytes and tailored electrodes for high-performance aqueous Mn-ion hybrid micro-supercapacitors

Aqueous Mn-ion hybrid micro-supercapacitors (AMIHMSCs) are promising systems, which can greatly improve the energy density and power density of traditional aqueous micro supercapacitors. Unfortunately, the development of AMIHMSCs has been challenging due to the low redox potential and high chemical activity of Mn metal, as well as the low capacity and poor cycle life of electrode material resulting from Mn2 + with high charge density and large solvated ion radius. Herein, we report the first generation AMIHMSCs assembled with molecular crowding electrolytes, hydroxylated Ti3C2Tx MXene (H-Ti3C2 MXene) anode and AlxV2O5 with dimethyl formamide molecules intercalation (AlVO-DMF) cathode. Benefiting from the wide electrochemical stability window and unique Mn2+ solvation structure in molecular crowding electrolytes, excellent capacitance of H-Ti3C2 MXene and enhanced structural stability of AlVO-DMF, the AMIHMSCs exhibit high energy density, power density and long cycle life. This work provides a pathway for designing high-performance AMIHMSCs.