Strain induced electrochemical behaviours of ionic liquid electrolytes in an Electrochemical Double Layer Capacitor: Insights from molecular dynamics simulations
Roy, T., Goel, S., Costa, L.T., Titirici, M-M., Offer, G.J., Marinescu, M. and Wang, H. (2023). Strain induced electrochemical behaviours of ionic liquid electrolytes in an Electrochemical Double Layer Capacitor: Insights from molecular dynamics simulations. The Journal of Chemical Physics.
|Roy, T., Goel, S., Costa, L.T., Titirici, M-M., Offer, G.J., Marinescu, M. and Wang, H.
Electrochemical Double Layer Capacitors (EDLCs) with ionic liquid electrolytes outperform conventional ones using aqueous and organic electrolytes in energy density and safety. However, understanding the electrochemical behaviours of ionic liquid electrolytes under compressive/tensile strain is essential for the design of flexible EDLCs as well as normal EDLCs, which are subject to external forces during assembly. Despite many experimental studies, the compression/stretching effects on the performance of ionic liquid EDLCs remain inconclusive and controversial. Also, there is hardly any evidence of prior theoretical work done in this area, which makes the literature on this topic scarce. Herein, for the first time, we developed an atomistic model to study the processes underlying the electrochemical behaviours of ionic liquids in an EDLC under strain. Constant potential non-equilibrium molecular dynamics (MD) simulations are conducted for EMIM BF4 placed between two graphene walls as electrodes. Compared to zero strain, low compression of the EDLC resulted in compromised performance as the electrode charge density dropped by 29%, and the performance reduction deteriorated significantly with a further increase of compression. In contrast, stretching is found to enhance the performance by increasing the charge storage in the electrodes by 7%. The performance changes with compression and stretching are due to changes in the double-layer
|Tension-compression asymmetry; Electrochemical Double Layer Capacitors; charge density; molecular dynamics; ionic liquids
|The Journal of Chemical Physics
|Web address (URL)
|Publication process dates
|24 Nov 2023
|28 Nov 2023
|Accepted author manuscript
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