Hydrangea-like NiCo-layered double hydroxide core-shell structure growing on licorice porous carbon for high-performance supercapacitors

Carbonaceous constituents have been considered as a promising target for supercapacitor application. However, it is still highly challenging to realize the controllable synthesis of carbon-derived electrode material with high specific capacity and energy density. Herein, we develop a strategy to produce a 3D core-shell structure composite via in situ grown NiCo-layered double hydroxide employing licorice-derived porous carbon as substrate (ALPC-3/NiCo LDH). In a three-electrode system, the ALPC-3/NiCo LDH electrode demonstrated a good specific capacity of 251.1 mAh g−1 (equivalent to 1807.8 F g−1) at 1 A g−1 current density, as well as high rate performance and cycle stability (82 % preservation after 5000 tests). The resulting asymmetric supercapacitor prepared from the electrodes produces a high energy density (51.5 Wh kg−1 at 374.9 W kg−1) and promising repeatability of electrochemical measurements (111 % retention after 7500 tests). The obtained results point towards improvement over most of the recent literature reported on carbonaceous resources. Considering the simple nature of the synthesis process, the abundance of raw material, and promising performance, this work paves the way for the development of more advanced carbon-based materials that can be used in practical applications relating to energy. [Display omitted] •Hydrangea-like core-shell ALPC-3/NiCo LDH composites were created by regulating the urea content in hydrothermal reaction.•The ALPC-3/NiCo LDH electrode exhibits excellent specific capacity of 251.1 mAh g−1 at 1A g−1•The asymmetric supercapacitor delivers a high energy density of 51.5 Wh kg−1 and power density of 7498 W kg−1.