One-step electrodeposited nickel-cobalt-layered double hydroxide nanosheets with anion intercalation for supercapacitor

NiCo-layered double hydroxide (LDH) is a frequently used materials for electrodes in supercapacitors to achieve high conductivity, large capacity, tunable layered structure and cheap. But its poor rate capability and the lack of active sites requires improvement to release maximum performance. Herein, an electrodeposition method is employed to grow NiCo-LDHs with a series of intercalated anions on carbon paper. It is investigated that the insertion of anions between the layers of LDH augments the quantity of available active sites. These locations enable the diffusion phenomenon and enhance specific capacity. As the current density is set at 1 A·g⁻¹, NiCo-LDH intercalated with PO₄³⁻ reaches a maximum specific capacity of 287.5 mAh·g⁻¹ (2070 F·g⁻¹). Moreover, the asymmetrical supercapacitor was put together with this material as cathode has a substantial energy density of 49.2 Wh·kg⁻¹ at 375 W·kg⁻¹, exceptional cycle stability with a 92.0 % capacity retention and 99.5 % coulombic efficiency retention after 10,000 cycles. This study offers fresh perspectives on the compositional and structural design of LDH materials for effective and good cyclic stable supercapacitors. In present research, a novel perspective on the composition and structural design of LDH-based electrode materials was provided for outstanding supercapacitors.