Dissipative effects in nonideal supercapacitors and batteries

Autor(es)

Silva, Leonardo Morais Da ; dos Santos, Joao Pedro Aguiar ; Vicentini, Rafael ; de Oliveira, Joao Pedro Jenson ; Doubek, Gustavo ; Zanin, Hudson

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF ENERGY STORAGE; v. 69, p. 11-pg., 2023-06-14.

Resumo

The literature is full of reports containing very high specific energy (E/W h g  1) and power (P/W g  1) values for different classes of electrochemical energy storage devices (EESD) based on distinct types of microstructured and nanosized advanced electrode materials (AEM), such as supercapacitors and batteries. In most cases, the eval-uation of energy and power characteristics for EESD is carried out based on classic theory for electrical systems (Esc = CU2/2 or Ebat = CU), where the charge carriers are assumed as massless point entities, i.e., electrons and holes. However, EESDs operate simultaneously with the transport of electronic and ionic charges involving massive/finite-sized charge carriers (e.g., anions and cations) with pronounced steric effects that control the overall charge transport in migration and/or diffusion phenomena in viscous media. To overcome the inherent theoretical difficulty in studying porous and redox-active electrode materials used in AEMs, and considering the typical case where a robust theoretical model is absent to represent the different classes of EEDs, we propose a phenomenological analysis where the use of an empirical correction parameter denoted as the deviation coefficient (& gamma;) representing the discrepancies from the classic electric predictions results in more reliable specific energy and power values. From the analysis of different experimental data obtained for laboratory-made devices, we verified that using Esc = CU2/2 and Ebat = CU equations can result in important discrepancies characterized by & gamma; =/ 1. Finally, we discussed the distinction between well-behaved supercapacitors and ill-defined EESD systems in light of & gamma;-values. (AU)

• Processo FAPESP: 17/11958-1 - CINE - Divisão para Armazenamento de Energia Avançado
• Beneficiário: Rubens Maciel Filho
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia
• Processo FAPESP: 16/08645-9 - Pesquisas interdisciplinares em redes inteligentes de energia elétrica
• Beneficiário: João Bosco Ribeiro do Val
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 14/02163-7 - Desenvolvimento de dispositivos supercapacitores a partir de grafenos, nanotubos de carbono e diamantes
• Beneficiário: Hudson Giovani Zanin
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores