High-energy all-in-one micro-supercapacitors based on ZnO mesoporous nanosheet-decorated laser-induced porous graphene foams

Micro-supercapacitors with high power density and stability promise emerging energy storage devices. However, their relatively low energy density and poor mechanical stability largely restricts their application. Here, we report an all-in-one planar micro-supercapacitor (MSC) using ZnO nanosheets anchored on the porous and 3D laser-induced porous graphene foams (ZnO@LIG) as the electrode materials. Due to the 3D networks, the hybrid electrode exhibits fast charge transfer and diffusion channels. More importantly, the hybrid approach can simultaneously take advantage of double-layer capacitance and faradaic energy storage mechanisms. The ZnO@LIG electrode displays a high specific capacitance of 14.7 F cm⁻², remarkable rate capability and cycling stability. Furthermore, the MSC showcases high energy density (10.0 Wh kg⁻¹), high power density (0.5 Wh kg⁻¹), long-term stability, and excellent mechanical stability upon bending. The excellent performance parameters of the MSC make it one of the promising micropower sources for flexible microelectronics. Graphic abstract: [Figure not available: see fulltext.].