Scandium doping enables superior cycling performance of NiCo-LDHs-based supercapacitors via NH4Br-assisted electrodeposition

Layered double hydroxides (LDHs) have garnered significant attention as electrode materials for their ultra-high theoretical capacitance. However, LDHs are prone to phase transition and volume changes during charge/discharge process, which adversely affect their cyclic stability and applications. In this paper, a small amount of non-electrochemically active element, scandium (Sc), was firstly introduced into NiCo-LDHs by a facile and fast one-step potentiostatic electrodeposition with NH 4 Br as a modulator, effectively mitigating the influence of the Jahn-Teller effect. By doping slight Sc into NiCo-LDHs, the resulting electrode exhibited excellent electrochemical performance , with a specific capacitance of 1994 F g −1 (at 1 A g −1 ), and ultralong lifespan, retaining 82.7 % of its initial capacitance after 30,000 charge-discharge cycles. This work presents a promising strategy for the rapid preparation of LDHs-based supercapacitor electrodes that deliver both high specific capacitance and outstanding cycling performance.