Synthesis of CoAl-LDH@Ni(OH)2 high-performance supercapacitor electrode composites by hydrothermal-assisted electrodeposition

In order to solve the problem of poor performance of pure CoAl-based layered double hydroxide (CAL), a novel hydrothermal-assisted electrodeposition method is used to combine CAL and Ni(OH)(2) into a novel integrated 3D structure to enhance its electrochemical performance. The discharge specific capacitance of CAL@Ni(OH)(2) composite (CAL-C) prepared by constant current deposition is 2924 F g(-1) at the current density of 1 A g(-1), which is much higher than the 2072 F g(-1) specific capacitance of pure CAL, and is also larger than the 2750 F g(-1) specific capacitance of composite (CAL-P) obtained by pulse electrodeposition. In particular, under the high current density of 10 A g(-1), the specific capacitance of CAL-C and CAL-P composites is up to 2520 F g(-1) and 1760 F g(-1), which is 231% and 161% higher than that of pure CAL, respectively. The analysis shows that the CAL-C composite modified by Ni(OH)(2) can improve the performance of the supercapacitor mainly by regulating the electronic structure of the material, improving the number of active sites and improving the electrical conductivity.