Three dimensional high-performance micro-supercapacitors with switchable high power density and high energy density

Abstract

In the field of microscale energy storage, the fabrication of micro-supercapacitors (MSCs) with high power density and high energy density has always been a focus of research. In this work, laser-induced porous graphene and chemically deposited manganese dioxide nanoparticles are used as electrode materials, and a switchable MSC with two energy storage principles is obtained by designing symmetric interdigitated and square electrode structures. The aim is to overcome the preparation challenge of supercapacitors with high energy density and high power density by switching between two modes. In this MSC, the energy density of the high energy density mode (5.89 μW h cm⁻²) is 3.36 times that of the high power density mode (1.75 μW h cm⁻²), while the power density of the high power density mode (43.06 μW cm⁻²) is 1.44 times that of the high energy density mode (29.96 μW cm⁻²). In addition, under the drive of five serially connected MSCs, 27 LED lights can be continuously lit for 5 minutes. Therefore, this work provides a facile and novel method for the development of MSCs with high power density and high energy density, suggesting a great practical application value in the development of MSCs.