Zinc cerium redox flow battery
Encyclopedia
Zinc–cerium batteries are a type of redox flow battery first developed by Plurion Inc.(UK) during the 2000s. Negative zinc electrolyte and positive cerium electrolyte are stored in two separated reservoirs and are circulated during the operation. Negative and positive electrolyte compartments are separated by a Nafion
(DuPont
) cation-exchange membrane.
Due to the high standard electrode potentials of both zinc and cerium redox reactions in aqueous media, the open-circuit cell voltage is as high as 2.43 V. Among the other proposed flow battery
systems, this system has the largest cell voltage and power density per electrode area. Methanesulfonic acid
was used as the supporting electrolyte, as it allows both zinc (2.16 M) and cerium electroactive species to dissolve at concentration larger than 1 M.
Since zinc is electroplated during charge at the negative electrode and redox reactions of Ce(III)/ Ce(IV) take places at the positive electrode, this system is often classified as a hybrid flow battery. Unlike the chemistry used in zinc–bromine and zinc–chlorine redox flow batteries, no condensation device is needed to dissolve the halogen gases.
Zn2+ + 2e− ↔ Zn
(−0.76 V vs. NHE)
At the positive electrode (cathode) (titanium based materials or carbon felt electrode), Ce(III) oxidation and Ce(IV) reduction take place during charge and discharge, respectively.
2Ce3+ − 2e− ↔ 2Ce4+
(between +1.28 and +1.72 V vs. NHE)
Because of the large cell voltage, hydrogen (0 V vs. NHE) and oxygen (+1.23 V vs. NHE) could evolve theoretically as side reactions during battery operation (especially on charging).
and Strathclyde
Universities. During charge/discharge cycles at 50 mA cm−2, the coulombic and voltage efficiencies of the zinc–cerium redox flow battery were reported to be 92 and 68 %, respectively. In 2011, a membraneless (undivided) zinc–cerium system based on low acid concentration electrolyte using compressed pieces of carbon felt positive electrode was proposed. Discharge cell voltage and energy efficiency were reported to be approximately 2.1 V and 75 %, respectively. With such undivided configuration (single electrolyte compartment), self-discharge was relatively slow at low concentrations of cerium and acid. Major installation of the zinc–cerium redox flow battery was the > 2 kW testing facility in Glenrothes
, Scotland
, installed by Plurion Inc.
Nafion
Nafion is a sulfonated tetrafluoroethylene based fluoropolymer-copolymer discovered in the late 1960s by Walther Grot of DuPont. It is the first of a class of synthetic polymers with ionic properties which are called ionomers...
(DuPont
DuPont
E. I. du Pont de Nemours and Company , commonly referred to as DuPont, is an American chemical company that was founded in July 1802 as a gunpowder mill by Eleuthère Irénée du Pont. DuPont was the world's third largest chemical company based on market capitalization and ninth based on revenue in 2009...
) cation-exchange membrane.
Due to the high standard electrode potentials of both zinc and cerium redox reactions in aqueous media, the open-circuit cell voltage is as high as 2.43 V. Among the other proposed flow battery
Flow battery
A flow battery is a form of rechargeable battery in which electrolyte containing one or more dissolved electroactive species flows through an electrochemical cell that converts chemical energy directly to electricity...
systems, this system has the largest cell voltage and power density per electrode area. Methanesulfonic acid
Methanesulfonic acid
Methanesulfonic acid is a colorless liquid with the chemical formula CH3SO3H. It is the simplest of the alkylsulfonic acids. Salts and esters of methanesulfonic acid are known as mesylates. Methanesulfonic acid is used as an acid catalyst in organic reactions because it is non-volatile, strong acid...
was used as the supporting electrolyte, as it allows both zinc (2.16 M) and cerium electroactive species to dissolve at concentration larger than 1 M.
Since zinc is electroplated during charge at the negative electrode and redox reactions of Ce(III)/ Ce(IV) take places at the positive electrode, this system is often classified as a hybrid flow battery. Unlike the chemistry used in zinc–bromine and zinc–chlorine redox flow batteries, no condensation device is needed to dissolve the halogen gases.
Cell chemistry
At the negative electrode (anode), zinc is electroplated and stripped on the carbon polymer electrodes during charge and discharge, respectively.Zn2+ + 2e− ↔ Zn
(−0.76 V vs. NHE)
At the positive electrode (cathode) (titanium based materials or carbon felt electrode), Ce(III) oxidation and Ce(IV) reduction take place during charge and discharge, respectively.
2Ce3+ − 2e− ↔ 2Ce4+
(between +1.28 and +1.72 V vs. NHE)
Because of the large cell voltage, hydrogen (0 V vs. NHE) and oxygen (+1.23 V vs. NHE) could evolve theoretically as side reactions during battery operation (especially on charging).
History and development
The zinc–cerium redox flow battery was first proposed by Clarke and co-workers in 2004, which has been the core technology of Plurion Inc. (UK). In 2008, Plurion Inc. suffered a liquidity crisis and was under liquidation in 2010. However, the information of the experimental conditions and charge-discharge performance described in the early patents of Plurion Inc. are limited. Since the 2010s, the electrochemical properties and the characterisation of a zinc–cerium redox flow battery have been identified by the researchers of SouthamptonUniversity of Southampton
The University of Southampton is a British public university located in the city of Southampton, England, a member of the Russell Group. The origins of the university can be dated back to the founding of the Hartley Institution in 1862 by Henry Robertson Hartley. In 1902, the Institution developed...
and Strathclyde
University of Strathclyde
The University of Strathclyde , Glasgow, Scotland, is Glasgow's second university by age, founded in 1796, and receiving its Royal Charter in 1964 as the UK's first technological university...
Universities. During charge/discharge cycles at 50 mA cm−2, the coulombic and voltage efficiencies of the zinc–cerium redox flow battery were reported to be 92 and 68 %, respectively. In 2011, a membraneless (undivided) zinc–cerium system based on low acid concentration electrolyte using compressed pieces of carbon felt positive electrode was proposed. Discharge cell voltage and energy efficiency were reported to be approximately 2.1 V and 75 %, respectively. With such undivided configuration (single electrolyte compartment), self-discharge was relatively slow at low concentrations of cerium and acid. Major installation of the zinc–cerium redox flow battery was the > 2 kW testing facility in Glenrothes
Glenrothes
Glenrothes is a large town situated in the heart of Fife, in east-central Scotland. It is located approximately from both Edinburgh, which lies to the south and Dundee to the north. The town had an estimated population of 38,750 in 2008, making Glenrothes the third largest settlement in Fife...
, Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
, installed by Plurion Inc.
External links
- http://plurionsystems.com/ Plurion Inc.(UK)
- https://www.southampton.ac.uk/ses/research/projects/zinc_cerium_redox_flow_battery.page?Zinc-cerium flow battery project, University of Southampton
- http://www.flowbatteryforum.com/IFBF-2011_conference-programme.html International Flow Battery Forum