2023, Gittins, Jamie W., Chen, Yuan, Arnold, Stefanie, Augustyn, Veronica, Balducci, Andrea, Brousse, Thierry, Frackowiak, Elzbieta, Gómez-Romero, Pedro, Kanwade, Archana, Köps, Lukas, Jha, Plawan Kumar, Lyu, Dongxun, Meo, Michele, Pandey, Deepak, Pang, Le, Presser, Volker, Rapisarda, Mario, Rueda-García, Daniel, Saeed, Saeed, Shirage, Parasharam M., Ślesiński, Adam, Soavi, Francesca, Thomas, Jayan, Titirici, Maria-Magdalena, Wang, Hongxia, Xu, Zhen, Yu, Aiping, Zhang, Maiwen, Forse, Alexander C.

Supercapacitors are fast-charging energy storage devices of great importance for developing robust and climate-friendly energy infrastructures for the future. Research in this field has seen rapid growth in recent years, therefore consistent reporting practices must be implemented to enable reliable comparison of device performance. Although several studies have highlighted the best practices for analysing and reporting data from such energy storage devices, there is yet to be an empirical study investigating whether researchers in the field are correctly implementing these recommendations, and which assesses the variation in reporting between different laboratories. Here we address this deficit by carrying out the first interlaboratory study of the analysis of supercapacitor electrochemistry data. We find that the use of incorrect formulae and researchers having different interpretations of key terminologies are major causes of variability in data reporting. Furthermore we highlight the more significant variation in reported results for electrochemical profiles showing non-ideal capacitive behaviour. From the insights gained through this study, we make additional recommendations to the community to help ensure consistent reporting of performance metrics moving forward.

2016, Lee, Juhan, Krüner, Benjamin, Tolosa, Aura, Sathyamoorthi, Sethuraman, Kim, Daekyu, Choudhury, Soumyadip, Seo, Kum-Hee, Presser, Volker

We introduce a high performance hybrid electrochemical energy storage system based on an aqueous electrolyte containing tin sulfate (SnSO4) and vanadyl sulfate (VOSO4) with nanoporous activated carbon. The energy storage mechanism of this system benefits from the unique synergy of concurrent electric double-layer formation, reversible tin redox reactions, and three-step redox reactions of vanadium. The hybrid system showed excellent electrochemical properties such as a promising energy capacity (ca. 75 W h kg−1, 30 W h L−1) and a maximum power of up to 1.5 kW kg−1 (600 W L−1, 250 W m−2), exhibiting capacitor-like galvanostatic cycling stability and a low level of self-discharging rate.

2019, Lee, J., Srimuk, P., Fleischmann, S., Su, X., Hatton, T.A., Presser, V.

Over recent decades, a new type of electric energy storage system has emerged with the principle that the electric charge can be stored not only at the interface between the electrode and the electrolyte but also in the bulk electrolyte by redox activities of the electrolyte itself. Those redox electrolytes are promising for non-flow hybrid energy storage systems, or redox electrolyte-aided hybrid energy storage (REHES) systems; particularly, when they are combined with highly porous carbon electrodes. In this review paper, critical design considerations for the REHES systems are discussed as well as the effective electrochemical characterization techniques. Appropriate evaluation of the electrochemical performance is discussed thoroughly, including advanced analytical techniques for the determination of the electrochemical stability of the redox electrolytes and self-discharge rate. Additionally, critical summary tables for the recent progress on REHES systems are provided. Furthermore, the unique synergistic combination of porous carbon materials and redox electrolytes is introduced in terms of the diffusion, adsorption, and electrochemical kinetics modulating energy storage in REHES systems. © 2018 The Author(s)