The Calcium-Air Battery

Lead Research Organisation: University of Liverpool
Department Name: Chemistry


Energy storage in the form of rechargeable batteries is becoming increasingly important for a range of applications and devices including transportation and grid reserves. Alkaline earth metal-oxygen batteries using the earth abundant metals, such as calcium as the anode and calcium cations as the charge carrier present a low cost and easily raw material resourced high energy storage battery system. They offer much greater energy storage a than present day batteries, such as lithium ion, in addition to their abundance worldwide. In order to achieve progress in the field of calcium based batteries and their subsequent development, mechanistic understanding of the cell chemistry and the required materials, and cell structure, needs to be understood. To evaluated the feasibility of a battery system based upon calcium within the project we will construct Lab-scale test cells that will be tested under an oxygen atmosphere.

Planned Impact

Research into calcium based 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 Johnson Matthey & Technical Fibre Products. From the start the above industrial partners will receive regular 3 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 at the beginning (month 1) at the middle (month 9) and at the end of the project (month 18) 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. LJH has 1 patent filed via these mechanisms in the last 2 years. Project advances of societal interest will be disseminated via the ULIV 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 Johnson Matthey will benefit from knowledge of materials required for the air-cathode and 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.


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Description We have calculated the Raman spectra of a host of metal superoxide and peroxides.
We have characterised the electrochemical behaviour of Ca2+ in presence of O2 in non-aqueous solvents
Exploitation Route Help to deveop calcium based batteries
Sectors Energy

Description 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 . 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
First Year Of Impact 2021
Sector Chemicals,Energy
Impact Types Economic

Description Talk: CIMTEC 2022, Perugia, Title: Operando Optical Diagnostics of Battery Chemistries 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A talk
Year(s) Of Engagement Activity 2022