Facile synthesis and incomplete sulfidation of nickel-cobalt-aluminum ternary layered hydroxide binder-free electrode with enhanced supercapacitor properties. (25th November 2022) - Li, Kailin
Abstract: Layered transition metal hydroxide, a clay-like material, possessing characteristics of large specific surface area, adjustable fraction, and plentiful active components make it a potential energy storage material, especially in the background of energy and environment crisis. Herein, comprehensive applications of cobalt-aluminum-based LDHs for supercapacitors are proposed. Binder-free electrodes were successfully synthesized such as Co3 Al1 -LDH/Ni, Ni2 Co1 Al1 -LDH/Ni and Ni1 Co2 Al1 -LDH/Ni using a rapid green hydrothermal approach. Subsequently, further sulfuration was carried out to obtain a heterostructure of sulfide/layered hydroxide. The electrochemical energy storage properties of binder-free electrodes were investigated, which show that the performance of ternary LDH electrode is better than that of binary one, and the incompletely sulfuration Ni1 Co2 S/Ni has the optimal electrochemical performance among all electrodes, with a specific capacitance of 2186 F g −1 at 1 A g −1 . The Ni1 Co2 S//AG hybrid supercapacitor (HSC) device assembled with Ni1 Co2 S as positive electrode and active graphene as negative electrode delivers an energy density of 13 Wh kg −1 at a power density of 749 W kg −1, good rate capability and cycling stability. Graphical abstract: Unlabelled Image Highlights: Binary and ternary NiCoAl-LDHs were successfully synthesized in situ on nickel foam with vertical structures. Incomplete sulfuration of NiCoAl-LDH was successfully achieved to form a heterostructure. Construction of hybrid supercapacitors Ni1 Co2 S//AG HSC has better rate performance.