Development of Supercapacitors with 3D Porous Structures

Abstract The pursuit of supercapacitors with simultaneous high power and energy densities has led to extensive research and successful outcomes through the integration of three‐dimensional (3D) electrodes, encompassing both 3D active materials and 3D porous current collectors. This mini review provides a summary of recent developments in supercapacitors featuring 3D structures. The incorporation of both 3D active materials and 3D current collectors proves effective in enhancing the mass loading of active materials without compromising their specific capacitance. The presence of pores in 3D porous current collectors contributes to additional double‐layer capacitance by offering a large surface area. Moreover, 3D porous transition metal current collectors can provide both double‐layer and faradic capacitances through the in‐situ surface oxidation mechanism. Beyond materials and geometries, this review also discusses synthesis strategies for electrodes, offering insights into the process‐structure‐property relationship crucial for supercapacitors. By combining 3D active materials with 3D current collectors, the energy density of supercapacitors could be substantially improved.