F. Su, J.Q. Qin, P. Das, F. Zhou, and Z.-S. Wu*

Energy & Environmental Science, 2021, 14, 2269 - 2277.

DOI: 10.1039/d1ee00317h [PDF]

Battery-supercapacitor hybrid devices (BSHDs) are promising for certain applications requiring both high energy and power densities, but restricted by the electrolyte-consuming mechanism and imbalance of charge-storage capacity and electrode kinetics between battery-type and capacitor-type electrodes. Herein, a new prototype of rocking-chair lithium-ion BSHD with high energy and power densities is developed by employing pseudocapacitive T-Nb₂O₅with porous nanoflower structure as anode and battery-type LiNi_0.815Co_0.15Al_0.035O₂complexed in a three-dimensional interconnected conductive network as cathode. Benefiting from the rational selection and optimization of active material and electrode architecture, the anode and cathode exhibit exceptionally matched faradaic capacity and kinetics. Consequently, the BSHD delivers superior performance (165 Wh kg^-1at 105 W kg^-1and9.1 kW kg^-1at83 Wh kg^-1) to previously reported rocking-chair BSHDs, and could surpass the state-of-the-art electrolyte-consuming BSHDs at device level. Therefore, this work would open a new avenue towards high-performance BSHDs.