Aqueous Electrolytes, MXene-Based Supercapacitors and Their Self-Discharge

• Significant efforts have been dedicated to developing Ti3C2Tz-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: H2SO4, KOH, LiCl, and LiBr in Ti3C2Tz-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 14m LiCl and LiBr, respectively, after 10h. 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.

Subject headings

NATURVETENSKAP  -- Kemi -- Annan kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Other Chemistry Topics (hsv//eng)

Keyword

concentrated electrolytes; MXene; self-discharge; supercapacitors

Publication and Content Type

ref (subject category)

art (subject category)