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

Sooraj Sreenath; Nitish Kumar Sharma; Rajaram K Nagarale

doi:10.1039/d0ra08316j

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

RSC Adv. 2020 Dec 18;10(73):44824-44833. doi: 10.1039/d0ra08316j. eCollection 2020 Dec 17.

Authors

Sooraj Sreenath^{1

2}, Nitish Kumar Sharma¹, Rajaram K Nagarale^{1

2}

Affiliations

¹ Electro Membrane Processes Laboratory, Membrane Science and Separation Technology Division, CSIR-Central Salt and Marine Chemicals Research Institute Bhavnagar 364002 India rknagarale@csmcri.res.in.
² Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India.

Abstract

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.