Energizing hybrid supercapacitors by using Mn2+-based active electrolyte. Issue 30 (21st July 2020)

• Record Type: Journal Article
• Authors: Yan, Lei; Huang, Jianhang; Dong, Xiaoli; Guo, Zhaowei; Wang, Zhuo; Wang, Yonggang
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 30(2020)
• Page Start: 15051
• Page End: 15057
• Publication Date: 2020-07-21
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0ta04864j
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Supercapacitors have high power density and a long lifespan but poor energy density in contrast with rechargeable batteries, restricting their widespread applications. Abstract : Supercapacitors have high power density and a long lifespan but poor energy density in contrast with rechargeable batteries, restricting their widespread applications. Adding soluble redox-active ingredients into electrolyte is an effective strategy to increase specific energy. However, an ion-selective membrane is generally needed in such supercapacitors to avoid the mixing of anolyte and catholyte, which significantly increases the cost. Here we report a supercapacitor that consists of a modified solid Ti3 C2 T x anode and an active catholyte containing Mn 2+, where the conversion between soluble Mn 2+ and solid MnO2 occurs at the cathode, and the redox of Ti–O with the bonding/de-bonding of H3 O + occurs at the anode. Impressively, this hybrid supercapacitor displays a gratifying specific energy of 43.4 W h kg −1, without using any ion-selective membrane, and excellent cycling stability over 20 000 cycles. Moreover, we also demonstrate its superior low-temperature performance even though the electrolyte has been frozen at −70 °C.