Alkaline all iron redox flow battery with a polyethylene/poly(styrene--divinylbenzene) interpolymer cation-exchange membrane

• Published in: RSC advances 2020-12, Vol.1 (73), p.44824-44833
• Main Authors: Sreenath, Sooraj, Sharma, Nitish Kumar, Nagarale, Rajaram K
• Format: Article
• Language: English
• Subjects: Cation exchanging; Chemistry; Divinylbenzene; Efficiency; Iron; Membranes; Polyethylene; Polyethylenes; Polystyrene resins; Rechargeable batteries; Stability analysis; Styrenes; Volumetric efficiency
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d0ra08316j

This work describes the suitability of a polyethylene styrene-DVB based interpolymer cation exchange membrane for use in a highly alkaline redox flow battery (RFB) with a [Fe(TEA)OH] 2− /[Fe(TEA)OH] − and Fe(CN) 6 3− /Fe(CN) 6 4− redox couple. The alkaline stability of the membrane for 1440 h was evaluated in 5 N NaOH containing a 200 mM Fe(CN) 6 3− /Fe(CN) 6 4− redox couple. It was assessed according to the changes in the electrochemical and physicochemical properties. The performance of the membrane was evaluated over 40 charge-discharge cycles at a current density of 5 mA cm −2 current in a designed RFB cell. The obtained average coulombic efficiency (CE) was 92%, energy efficiency (EE) was 75%, voltage efficiency (VE) was 82% and volumetric efficiency was 34%. Under identical experimental conditions, the values of CE, EE, and VE for Nafion®-112 were 99%, 75%, and 76%, respectively. These results indicate the suitability of the polyethylene styrene-DVB based interpolymer cation exchange membrane for use in an alkaline RFB. A polyethylene styrene-DVB interpolymer cation exchange membrane is reported for use in a highly alkaline all iron redox flow battery.