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Recent advances in electrochemical technology have proven lithium-carbon batteries as a feasible method of carbon dioxide capture. The University of Surrey has now announced its ambitious project to develop a commercially viable carbon-capturing battery.
What are Lithium-Carbon Dioxide Batteries?
Lithium-carbon dioxide (Li-CO2) batteries are composed of two electrodes: a positively charged lithium anode and a negatively charged porous carbon cathode.
During charge and discharge, electrons pass between these electrodes via an organic electrolyte infused separator. The incorporation of an active electrolyte catalyst in the cathode increases efficiency. This general process of charge and discharge cycles is concurrent with the operation of other lithium batteries such as lithium-ion batteries.
The differentiating factor that has sparked the interest of researchers worldwide is the promise of a specific energy density seven times greater than that of the most commonly used lithium-ion batteries.
As the need for sustainable energy generation becomes ever more apparent, a means of efficient energy storage for intermittent power generation, such as wind power, is crucial.
These high energy density batteries could, therefore, be a key to the widescale implementation of such energy sources. During the discharge of a lithium-carbon dioxide battery, carbon dioxide is converted to lithium carbonate and carbon, offering a novel means of CO2 capture.
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How can Lithium-Ion Batteries Capture CO2?
The need for carbon capture is evident, however, achieving this in a sustainable and efficient manner has not proved so clear.
Due to the chemical stability of carbon dioxide molecules, significant energy input is required to transform this to other chemicals. Therefore, it is likely that the emissions produced by this process outweigh the CO2 captured.
The most promising avenue to overcome this challenge is to generate the required energy via renewable sources, which is then stored in a lithium-carbon battery. The chemical processes occurring within the battery then fix the carbon dioxide into a solid form.
This crucial chemical transformation occurs as the battery discharges and the electrons are transferred from the lithium anode to the carbon cathode. In doing so, carbon dioxide is converted to lithium carbonate and carbon which is then deposited on the cathode.
As the electron flow reverses during charge, the lithium carbon is recycled, however, the carbon remains on the cathode. This accumulation of carbon with every discharge cycle blocks the active sites of the catalyst, preventing carbon dioxide diffusion, and triggers electrolyte decomposition. The result is a rapid failure of the battery. This has presented a further challenge to the scientific community, as the pursuit for a rechargeable lithium-carbon battery began.
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Current Research in Fully Reversible Lithium-Carbon Batteries
In 2019, researchers at the University of Illinois at Chicago made a monumental breakthrough, as they become the first to demonstrate a fully reversible lithium-carbon battery.
This success is attributed to the unique combination of a Molybdenum disulfide (MoS2) nanoflake catalyst and liquid/dimethyl sulfoxide electrolyte. The discharge product is a multicomponent Li2CO3/C composite which can be reverted upon charge. The prototype battery demonstrated a remarkable 500 consecutive charge/discharge cycles.
In 2020, the University of Surrey announced the launch of its project to develop portable energy storage batteries through lithium-carbon capture chemistry. Led by Dr Yunlong Zhao, the project focuses on the electrochemical mechanisms via a multimodal in situ characterization platform, which has been developed in partnership with the National Physics Laboratory (NPL).
With an award granted by the Engineering and Physical Sciences Research Council (EPSRC), the vision is to propel the UK to a leader in sustainable portable energy storage.
As explained by Professor Fernando Castro, Head of Science, Electromagnetic and Electrochemical Technologies at NPL, “The UK Government has committed to reducing the UK’s greenhouse gas emissions to net-zero by 2050. This project is well-aligned to the national strategy in clean energy and sustainability.”
The launch of the project comes at the optimal time to achieve this ambition, as the technologies involved in the lithium-carbon batteries and the corresponding measurement platforms have the commercial potential to be adopted readily by UK SMEs and industries. The impact of this advancement in novel carbon dioxide capture is indisputable in terms of future environmental and economic sustainability.
References and Further Reading
Gordon, P. (2020) University to develop battery capable of capturing carbon emissions. [online] Power Engineering International. Available at: https://www.powerengineeringint.com/emissions-environment/university-to-develop-battery-capable-of-capturing-carbon-emissions/ (Accessed on 5 August 2020).
IRENA (2017) Electricity Storage and Renewables: Costs and Markets To 2030. Abu Dhabi. https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2017/Oct/IRENA_Electricity_Storage_Costs_2017.pdf
Liu, B. Sun, Y. Chen, J. Yang, B. Xu, S. Yan, X. (2019) Recent advances in understanding Li–CO2 electrochemistry. Energy and Environmental Science. (3) https://pubs.rsc.org/en/content/articlelanding/2019/ee/c8ee03417f#!divAbstract
Patel, P. (2019) Researchers have made a rechargeable carbon dioxide-consuming battery. [online] daily Science. Available at: https://www.anthropocenemagazine.org/2019/10/carbon-dioxide-gobbling-battery-gets-a-long-life/ (Accessed on 6 August 2020).
Penman, H. (2020) Surrey University to develop battery technology capable of capturing CO2 emissions. [online] Energy Voice. Available at: https://www.energyvoice.com/otherenergy/256852/surrey-university-battery-capture-carbon-emissions/ (Accessed on 5 August 2020).
Qiao, Y. Yi, J. Wu, S. Liu, L. Yang, S. He, P. Zhou, H. (2017) Li-CO2 Electrochemistry: A New Strategy for CO2 Fixation and Energy Storage. Joule (1), pp.359–370. https://www.sciencedirect.com/science/article/pii/S2542435117300089
University of Illinois at Chicago (2020) First fully rechargeable carbon dioxide battery with carbon neutrality. [online] Science Daily. Available at: www.sciencedaily.com/releases/2019/09/190926101331.htm (Accessed on 5 August 2020).