Key issues for supercapacitor electrode materials are their low energy density and slow ion/electron diffusion/transfer kinetics. The formations of nanostructured materials and composite materials with blending/coating conductive additives have been developed to solve above problems. For more efficiently using electroactive metal cations in pseudocapacitance electrode materials, one kind of colloidal supercapacitor electrode materials was introduced to get both high energy and power densities. Colloidal supercapacitor electrode materials have overwhelming advantages, i.e. quasi-ionic state cations, short ion diffusion length and high specific surface area, which is a tradeoff between confined active cations and facile cation diffusion. Multiple-electron transferred Faradaic reactions can occur within the whole colloid, leading to high specific capacitance. The development of colloidal supercapacitor electrode materials can promote the advance of supercapacitors and make their energy densities larger than 100 Wh/kg or more, resulting in replacing batteries. (C) 2016 Elsevier Ltd. All rights reserved.