Supercapacitors: problems and prospects of development

The review describes the design of supercapacitors and demonstrates their advantages over batteries and their main drawback: fast self-discharge. Various types of highly dispersed carbon materials for electrodes, functional groups on their surface, porous structure and hydrophilic–hydrophobic properties are considered. Data on the self-discharge of supercapacitors are discussed. Self-discharge investigation methods, mechanisms and mathematical modelling are analyzed and the effect of surface functional groups on this process is demonstrated. The methods for minimizing the self-discharge are described, in particular, using additives to the electrolyte, design of solid-state supercapacitors and supercapacitors with ion exchange membranes, the use of electrolytes free from impurities and chemical modification of electrodes. The developed new-generation supercapacitors with enhanced characteristics are mentioned. Electrodes based on conductive polymers are considered, and the key characteristics of supercapacitors manufactured by various companies are given.
The bibliography includes 160 references.