Aqueous Electrolytes, MXene‐Based Supercapacitors and Their Self‐Discharge. Issue 2 (8th October 2021)

• Record Type: Journal Article
• Authors: Zheng, Wei; Halim, Joseph; Rosen, Johanna; Barsoum, Michel W.
• Is Part Of: Advanced energy & sustainability research. Volume 3:Issue 2(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-10-08
• Subjects: concentrated electrolytes -- MXene -- self-discharge -- supercapacitors; Renewable energy sources -- Periodicals; Environmental sciences -- Periodicals; Sustainable development -- Periodicals; 621.042
• DOI: 10.1002/aesr.202100147
• Languages: English
• ISSNs: 2699-9412

Abstract

Abstract : Significant efforts have been dedicated to developing Ti3 C2 T z ‐based MXene aqueous supercapacitors (SCs) with improved energy and power densities. Notably less research has been devoted to an equally important characteristic of aqueous SCs, viz. self‐discharge (SD). The SD rates are rarely reported despite their crucial importance from a practical point of view. Herein, the SD rates in four different aqueous electrolytes: H2 SO4, KOH, LiCl, and LiBr in Ti3 C2 T z ‐based aqueous SCs are compared. For the latter two, the SD rates vary as a function of salt concentration in the electrolytes with higher LiCl or LiBr concentrations having the lowest SD rates, viz. 78.3% and 81.5% in 14 m LiCl and LiBr, respectively, after 10 h. Further, the influence of dissolved oxygen and the purities of the starting powders are examined, and it is concluded that parasitic reactions, including oxygen, are responsible for the SD. Abstract : This work aims to raise the awareness of the MXene‐community on the importance of self‐discharge (SD) issue for realistic applications. The SD rates are compared in MXene symmetric supercapacitors in different electrolytes, and it is concluded the high purity salts in high concentrations and the exclusion of oxygen improve the SD performance.