Capacitive and non-capacitive faradaic charge storage

Guan, Li; Yu, Linpo; Chen, George Z.

Abstract

This article aims to offer a critical overview of selected literature on capacitive and non-capacitive faradaic charge storage. It is particularly relevant to the concept of pseudocapacitance that is generally described as a result of fast surface faradaic processes. In general, faradaic processes represent electron transfer reactions at the interface between an electrode and its contacting solid or liquid electrolyte phase that is able to accept or donate electrons. Obviously, not all faradaic processes can be associated with pseudocapacitance. The question is how to differentiate pseudocapacitance related faradaic charge storage from the others. Therefore, attempts have been made to apply the band model for semiconductors to account qualitatively for the origin of pseudocapacitance. Capacitive and non-capacitive faradaic processes are then proposed to define and differentiate different charge storage mechanisms in supercapacitor and battery. On the other hand, the unequal electrode capacitance approach and the use of Ca2+ in aqueous electrolytes are discussed in relation with enhanced energy capacity of supercapacitors. In addition, the principle of supercapattery as a hybrid device is explained with recent literature examples.

Citation

Guan, L., Yu, L., & Chen, G. Z. (2016). Capacitive and non-capacitive faradaic charge storage. Electrochimica Acta, 206, 464-478. https://doi.org/10.1016/j.electacta.2016.01.213

• Journal Article Type: Article
• Acceptance Date: Jan 29, 2016
• Online Publication Date: Feb 1, 2016
• Publication Date: Jul 10, 2016
• Deposit Date: Jun 6, 2016
• Publicly Available Date: Jun 6, 2016
• Journal: Electrochimica Acta
• Print ISSN: 0013-4686
• Electronic ISSN: 1873-3859
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 206
• Pages: 464-478
• DOI: https://doi.org/10.1016/j.electacta.2016.01.213
• Keywords: Capacitive charge storage; Faradaic process; Supercapacitor; Supercapattery; Unequal electrode capacitance
• Public URL: https://nottingham-repository.worktribe.com/output/801668
• Publisher URL: http://dx.doi.org/10.1016/j.electacta.2016.01.213
• Contract Date: Jun 6, 2016