Multi-dimensional materials with layered structures for supercapacitors: Advanced synthesis, supercapacitor performance and functional mechanism

Supercapacitors (SCs) have been demonstrated to be one of the most promising devices for electrical energy storage and conversion applications and in order to overcome the associated challenge of insufficient energy density, tremendous efforts have been carried out to develop advanced electrode materials to obtain high capacitances. Among the various materials explored, multi-dimensional transition metal chalcogenides (TMCs) with layered structures have shown great promise in SC applications due to their unique sandwich structures, abundant marginal active sites and diverse electrochemical reaction mechanisms. Based on this, this review will comprehensively discuss the crystal structures, properties, advanced synthesis methods, characterizations and functional mechanisms of TMCs. In addition, corresponding challenges are analyzed and possible future research directions are proposed to facilitate further research and development towards practical application. Furthermore, advanced SCs including micro-SCs, wearable and self-charging SCs and implantable SCs are also briefly discussed with an emphasis on their feasibility and future development.