Micron-sized NiMn-glycerate solid spheres as cathode materials for all-solid-state asymmetric supercapacitor with superior energy density and cycling life

Nowadays, it is a great challenge to develop electrode materials with microstructure exhibiting good electro-chemical performances. There is poor adhesion between nano-electrode materials and conducting substrate, because large specific surface area causes serious aggregation and uneven coating, limiting the practical appli-cation of high performance nano-electrode materials. In this work, micron-sized NiMn-glycerate (NiMn-Gly) solid spheres were synthesized via a facile solvothermal method as cathode material of supercapacitor. By optimizing Ni/Mn ratio and designing amorphous structure, NiMn-Gly microspheres electrode delivers a specific capacitance of 719C g(-1) at the current density of 1.0 A g(-1). Furthermore, an all-solid-state asymmetric super-capacitor assembled by NiMn-Gly microspheres and activated carbon exhibits a maximum energy density of 54.4 Wh kg(-1) at 800 W kg(-1) and achieves outstanding cycling stability (100%, 20,000 cycles, 10 A g(-1)). Two devices connected in series can light up a blue LED bulb and keep it bright for more than 15 min. Hence, we successfully prepared micron-sized electrode material with excellent electrochemical performances which may be a break-through for the practical application of supercapacitors.

Automated summary

Developing electrode materials with good electro-chemical performances is a great challenge. Poor adhesion between nano-electrode materials and conducting substrate restricts the practical application of high performance nano-electrode materials. In this study, micron-sized NiMn-glycerate (NiMn-Gly) solid spheres were synthesized as cathode material of supercapacitor, delivering excellent electrochemical performances and providing a breakthrough for the practical application of supercapacitors.