Ni₃S₄/Co₃S₄ Heterojunction Tailored by Liquid-Assisted Sintering Strategy for High-Performance Supercapacitors

Nanostructures composed of transition metal sulfides (TMS) exhibit excellent electrochemical properties, rendering them well suited for use in supercapacitor applications. Nevertheless, the conventional synthesis method restricts the synthesis of nanostructures in TMS and the investigation of the synthesis mechanism. In view of the above considerations, a novel synthesis method: liquid-assisted sintering is proposed. This approach retains the advantages of solvothermal synthesis of nanomaterials while providing insight into the reaction mechanism and avoiding densification from sintering. The synthesis mechanism of this method is also revealed by the synthesis of Ni₃S₄/Co₃S₄. The synthesis process is influenced by Le Chatelier's principle, forming a three-step cyclic reaction. This in turn leads to cathode materials with heterojunction structures. The cathode material possesses excellent electrochemical properties. The best devices can achieve an energy density of 57.7 W h kg^-1 at a power density of 102.4 W kg^-1 and maintain an energy density of 21.7 W h kg^-1 at a power density of 3547.8 W kg^-1. This work provides a new way to make nanomaterials and develop electrode materials for supercapacitors.