ISCF Wave 1: Earth-Abundant Metal-Air Batteries

Lead Research Organisation: University of Liverpool
Department Name: Chemistry


Industrial Strategy Challenge Fund (ISCF) brings together the UK's world leading research with business to meet the major industrial and societal challenges of our time. Clean and flexible energy or the 'Faraday Challenge' is one of the key themes in which will allow UK businesses to seize the opportunities presented by the transition to a low carbon economy, to ensure the UK leads the world in the design, development and manufacture of batteries for the electrification of vehicles.

To meet the goals of the ISCF will we investigate metal-air batteries using earth abundant metals such as calcium and sodium as the anode and charge carrier that offer a low cost and easily raw material resourced high energy storage battery system. Earth-abundant metal-air batteries potentially offer a much greater energy storage and power capability than current batteries such as lithium ion, in addition to their abundance worldwide. In order to achieve progress in the field of such calcium and sodium batteries and their subsequent development, mechanistic understanding of the cell chemistry and the required materials, and cell structure, needs to be understood. The project will construct Lab-scale test cells that will be tested in oxygen (air) and oxygen(air)/carbon dioxide mixtures. Via utilisation of redox mediators it is envisioned that a metal-air system could be demonstrated that reversibly stores energy via electrochemical conversion of oxygen and carbon dioxide to metal oxides and carbonates.

Planned Impact

Research into earth-Abundant Metal-Air batteries has the potential to make a significant impact academically initially & ultimately economically. The programme has huge longer-term applied benefits in the areas of energy storage generating processes of relevance to the chemical & engineering industries. This is confirmed via the letters of support from Faradion, Ionotec, Johnson Matthey, Siemens & Technical Fibre Products. From the start the above industrial partners will receive regular 6 monthly project updates for discussion with the project team, leading to personnel exchange and material evaluation as appropriate. All industrial project partners will be invited to sit on an Industrial Advisory Board that will meet every 6 months to discuss progress towards milestones (see project work plan). Beyond this group, we will work with the Knowledge Centre for Materials Chemistry (KCMC) to ensure the widest possible dissemination of relevant developments to UK chemicals-using and broader industry sectors. KCMC has supported 71 companies in over 100 projects, generating over £6M of industrial funding since 2009. KCMC thus has strong collaborative relationships with many UK-based chemical companies, providing a mechanism for advances in science emerging from the project to be evaluated and where appropriate taken forward for exploitation through engagement of the KCMC Knowledge Transfer (KT) team via individual discussion with companies and themed industry days, using case-study type summaries of both materials and methodologies emerging from the programme prepared by the KT team to maximise impact on potential users. IP will be protected by Business Gateway at ULIV and Science, Agriculture an Engineering Enterprise Team at NEW. LJH has 1 patent and KS 3 patents filed via these mechanisms in the last 5 years. Project advances of societal interest will be disseminated via the ULIV & NEW press office, working with EPSRC as appropriate. The skills & contact network of the project PDRAs will be strongly enhanced by close experiment/theory co-working in this science area, and engagement with the supporting companies and the industry network of KCMC.
The industrial beneficiaries will be chemical and engineering companies. In particular all project partners will benefit from hearing recent data on metal-air battery development, in particular Faradion will benefit from knowledge of novel sodium anodes, Ionotec will benefit from understanding possible new markets for sodium beta alumina solid electrolytes, Johnson Matthey will benefit from knowledge of materials required for the air-cathode, Siemens will benefit from monitoring of potential disruptive energy storage technologies, Technical Fibre Products will benefit from the evaluation of their carbon fibre materials in metal-air battery systems. Society will benefit from the trained personnel emerging from the programme equipped to contribute to UK industry in a high-tech sector. Longer term benefits will arise from the scientific advances enabling enhanced energy storage solutions through the generic impact of enhanced understanding and control of exciting new materials. This programme has long term benefits in reducing the UKs long term carbon dioxide emissions via transportation and as energy storage from renewables such as wind and solar. A very important area for new batteries technologies is in helping to meet the energy challenges of the 21st century, with batteries in particular contributing to energy storage requirements and also "electro-mobility". EPSRC has a strong energy theme, with relevant details laid out in the section "Underpinning Energy Research in Energy Storage Materials". A quarter of all manmade carbon dioxide emissions arise from transportation, any breakthroughs in battery technology regarding significant increases in energy storage (and therefore driving range) with lower cost would allow future electric vehicles (EVs) to become a more attractive to consumers.
Description 1. Discovery of new charge storage mechanism: trapped interfacial redox
Within the project the Liverpool team reported on a distinctive form of charge storage at the electrode interface - trapped interfacial redox [CS]. We started investigating Ca2+ based electrolyte systems as part of understanding how to develop a metal-air battery based upon calcium metal. The research explored the formation of an electrochemically generated interlayer coating (CaxOy) on electrode surfaces that confines the reduced form of oxygen gas known as superoxide, allowing it to then be readily oxidised. The research was carried out in an electrolyte designed for a calcium-air battery, which had so far been shown to be irreversible. We observed that when the electrode was cycled many tens of times, the electrochemical process became steadily more reversible. Through systematic electrochemical and spectroscopy investigations, we identified the mechanistic aspects and found that tetra butyl ammonium superoxide [TBA+--O2-] is confined within the interlayer once it has been fully formed. The mechanism of trapped interfacial redox facilitates a previously unseen degree of reversibility for systems based on the calcium-air battery.

2. Sodium-oxygen battery cathodes utilise the reversible redox species of oxygen in the presence of sodium ions. However, the oxygen reduction and evolution reaction mechanism is yet to be conclusively determined. In order to examine the part played by surface structure in sodium-oxygen electrochemistry for the development of catalytic materials and structures, a method of preparing clean, well-defined Pt electrode surfaces for adsorption studies in aprotic solvents is described. Using cyclic voltammetry (CV) and in situ electrochemical shell-isolated nanoparticle enhanced Raman spectroscopy (SHINERS), the various stages of oxygen reduction as a function of potential have been determined. It is found that on Pt{111} and Pt{110}-(1 × 1) terraces, a long lived surface sodium peroxide species is formed reversibly, whereas on Pt{100} and polycrystalline electrodes, this species is not detected.

3. Effective utilization of metal electrodes is vital for maximizing the specific energy of metal-oxygen (M-O2) batteries. Many conventional electrolytes that support M-O2 cathode processes (e.g., dimethyl sulfoxide, DMSO) are incompatible against all alkali metals such as Li, Na and K. Here, the Liverpool team explored a wide range of ternary solutions based on solvent, salt, and ionic liquid (IL) to understand how formulations may be tailored to enhance stability and performance of DMSO at metal electrodes.

Due to the high reactivity of sodium metal, we first optimised a model lithium system in order to precisely formulate the electrolyte using readily-available, low volatility components enabled us to specially tailor an electrolyte for the needs of metal-air battery technology that delivered greatly improved cycle stability and functionality. We demonstrated that the reactivity of certain electrolyte components can be switched off by precise control of component ratios.
The outcomes from our study really show that by understanding the precise coordination environment of the lithium ion within our electrolytes, we can link this directly to achieving significant gains in electrolyte stability at the Li metal electrode interface and, consequently, enhancements in actual cell performance. Through the use of both calculations (with collaborators in Loughborough) and experimental data we were able to identify the key physical parameters that enabled the formulations to become stable against the lithium metal electrode interface.
The designed electrolytes provide new benchmark formulations that will support ongoing investigations within our research groups to understand and develop new, and practically viable, cathode architectures to reduce round-trip inefficiencies and further extend cycle lifetimes.
We then applied our understanding to Na stripping and platting and demonstrated that the electrolyte optimisation for Li can also be applied with major improvements in plating/stripping cycling, where low overpotentials were realised over for 60 cycles.
Exploitation Route We have shown how the pathways of reaction in the Na-O2 can be changed from the nature of the surface.

We have demnstrated an experimental methodology of single crystal electrochemistry in non-aquoeus electroltytes.
Sectors Chemicals,Energy,Transport

Description Newcastle demonstration Na-carbonate (carb) cell opens up a new application for sodium batteries, thereby potential leading to a new markets and job creation. Technology provides a new application for sodium-ion conducting solid electrolyte produced by UK company, Ionotec. Newcastle demonstration Na-carb cell has the potential to lead to new markets and job creation. Newcastle University team is finalising patent application with patent attorney for submission to protect the innovations that resulted in improved Na-air and Na-Carb battery performance. Newcastle will seek further funding to scale up and commercialise the technology.
First Year Of Impact 2021
Sector Chemicals,Energy
Impact Types Societal

Description Centre for Advanced Materials for Renewable Energy Generation
Amount £2,037,439 (GBP)
Funding ID EP/P007805/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 12/2016 
End 11/2020
Title Single crystal electorchemistry in non-aqueous solvents 
Description Single crystal electorchemistry in non-aqueous solvents 
Type Of Material Improvements to research infrastructure 
Year Produced 2019 
Provided To Others? Yes  
Impact Allows study of surface strucutre with respect to electrchemical activity in non-aquoues solvents 
Description CASE PhD Studentship sponsored by Johnson Matthey 
Organisation Johnson Matthey
Department Johnson Matthey Technology Centre
Country United Kingdom 
Sector Private 
PI Contribution PhD project in partnership with the global science and chemicals company Johnson Matthey (JM) will involve the growth of SHell Isolated Nanoparticles for Enhanced Raman Spectroscopy (SHINERS) and their use in-operando to study electrochemical and catalytic processes.
Collaborator Contribution Indsutrial challenges for technique SHell Isolated Nanoparticles for Enhanced Raman Spectroscopy (SHINERS) to solve
Impact Chemistry Electrochemistry Catalysis
Start Year 2020
Description Ionotec Ltd, 
Organisation Ionotec
Country United Kingdom 
Sector Private 
PI Contribution The company has supplied sodium ion conducting materials have been incorporated into new electrode structures and to form ion conducting membranes in high temperature sodium air batteries. These cells have been tested at temperatures up to 200 Centigrade and produced good capacities in battery cycling.
Collaborator Contribution Ionotec are a manufacturer of a sodium ion conducting electrolyte sodium Beta Alumina , which has application in batteries such as sodium sulphur; a current technology under development by the company. The partner has supplied the research group with is products in the form of powders, tubes and sodium incorporated tubes, for use in low and high temperature testing of sodium air and sodium carbon dioxide batteries. These materials have been incorporated into new electrode structures and to form ion conducting membranes in high temperature sodium air batteries
Impact Preliminary performance data and cell designs have been created, which will be examined for its potential IP and use in patent filing
Start Year 2017
Description Technical Fibre Products 
Organisation Technical Fibre Products
Country United Kingdom 
Sector Private 
PI Contribution Testing of carbon fibre products in sodium air batteries
Collaborator Contribution Technical Fibre Products has supplied of carbon fibres and electrode supports for research
Impact none as yet
Start Year 2019
Description Inivted talk ISE meeting Bologna, Italy 2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Inivted talk Internation Society of Electrochemistry Meeting (ISE) meeting Bologna, Italy 2018 - reported on SHINERS on single crystals and IR spectroelectrochemistry
Year(s) Of Engagement Activity 2018