Highly Uniform MnCo2O4 Hollow Spheres-Based All-Solid-State Asymmetric Micro-Supercapacitor via a Simple Metal-Glycerate Precursor Approach

Developing a high-energy-density all-solid-state asymmetric micro-supercapacitor (AMSC) still remains a big challenge. Herein, a simple metal-glycerate precursor strategy is used for the synthesis of highly uniform MnCo2O4 hollow spheres, and the all-solid-state AMSC is fabricated by MnCo2O4 hollow spheres. It is found that the MnCo2O4 hollow sphere electrode processes a high specific capacitance (0.80 F cm(-2)) at 2 mA cm(-2) and an excellent cycling stability (99% capacitance retention after 2000 cycles). The as-fabricated all-solid-state AMSC displays a high energy density of 0.052 mWh cm(-3), a high power density of 320 mW cm(-3), and a long cycling life (95.7% capacitance retention after 10 000 charge/discharge cycles). In addition, the all-solid-state AMSC can be easily assembled in series to achieve a desirable output voltage, which can drive a light-emitting diode. This work demonstrates that the MnCo2O4 hollow spheres can be a promising electrode material for a stable, high-energy-density micro-supercapacitor (MSC).