Aqueous proton battery stably operates in mild electrolyte and low-temperature conditions. Issue 33 (12th August 2022)

• Record Type: Journal Article
• Authors: Sun, Tianjiang; Nian, Qingshun; Du, Haihui; Zheng, Shibing; Han, Dong; Tao, Zhanliang
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 33(2022)
• Page Start: 17288
• Page End: 17296
• Publication Date: 2022-08-12
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2ta04272j
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : The double effects of ClO4 − anion in term of the improvement of deposition/dissolution efficiency of Mn 2+ /MnO2 and low-temperature performance for aqueous proton battery. Abstract : The electrode based on the conversion reaction of Mn 2+ /MnO2 is regarded as a promising cathode for aqueous proton batteries (APBs) due to its high redox potential and cost-effectiveness, but it needs a strongly acidic medium to trigger this redox reaction. Herein, a mild perchlorate-based electrolyte without strong acid addition (3.5 M Mn(ClO4 )2 ) is proposed to improve the deposition/dissolution efficiency of Mn 2+ /MnO2 . Comprehensive analyses confirm that the ClO4 − anion not only ensures the fast and stable deposition of Mn 2+ by regulating the solvation energy of Mn 2+ but also accelerates the dissolution of MnO2 by improving the degree of freedom of water molecules. Hence, the novel aqueous proton battery with a carbon felt (CF) cathode, polyaniline anode and 3.5 M Mn(ClO4 )2 electrolyte exhibits a lifetime of 500 cycles with an 81.6% capacity retention rate and excellent rate capability of up to 100C (18 A g −1 ). Surprisingly, this system operates well even at low-temperature conditions because of the anti-freezing electrolyte with a −122 °C freezing point. High discharge capacities of 112 mA h g −1 and 52.9 mA h g −1 are obtained at −50 °C and −70 °C, respectively.