High mass-loading NiCo-LDH nanosheet arrays grown on carbon cloth by electrodeposition for excellent electrochemical energy storage

NiCo layered double hydroxides (LDHs) have attracted extensive attention in supercapacitors nowadays due to their ion insertable layer structure, however, improvement of their electrochemical energy storage performance is still a great challenge work. Herein, three-dimensional NiCo(NA)-LDH nanosheet networks with high mass-loading on an activated carbon cloth are prepared by electrodeposition using a mixed Ni/Co nitrate and acetate as reactants, which is denoted as NiCo(NA)-LDH. When the mass-loading is 16 mg cm−2 and the current density is 10 mA cm−2, the areal capacitance of NiCo(NA)[email protected] electrode reaches 27.3 F cm−2 and the specific capacitance is 1709 F g−1 at 0.62 A g−1, and the mass-loading is positively correlated with the capacitance performance. An asymmetric supercapacitor assembled by NiCo(NA)[email protected] as the positive electrode and acid-etched carbon cloth as the negative electrode achieves a working potential window of 1.7 V and energy density of 2.24 mW h cm−2 at a power density of 3.71 mW cm−2, which are much higher than the previous reports of NiCo-LDH based supercapacitors. In addition, the prepared device shows an excellent cycle stability with 104% capacity retention after 10,000 cycles at 250 mA cm−2.