Weakly solvating ester electrolyte for high voltage sodium-ion batteries

Jayakumar, Rishivandhiga; Pollard, Travis P.; Borodin, Oleg; Shipitsyn, Vadim; Chak, Chanmonirath (Michael); Pastel, Glenn; Zheng, Allen; Johnson, Michel; Hasan, Fuead; Bejger, Christopher M.; Schroeder, Marshall A.; Greenbaum, Steve G.; Zuo, Wenhua; Ma, Lin

doi:10.1016/j.nanoen.2024.109969

DOE OSTI · 2502081

Weakly solvating ester electrolyte for high voltage sodium-ion batteries

Jayakumar, Rishivandhiga·Pollard, Travis P.·Borodin, Oleg·Shipitsyn, Vadim·Chak, Chanmonirath (Michael)·Pastel, Glenn·Zheng, Allen·Johnson, Michel·Hasan, Fuead·Bejger, Christopher M.·Schroeder, Marshall A.·Greenbaum, Steve G.·Zuo, Wenhua·Ma, Lin

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Abstract

Ethyl acetate (EA) was identified as a promising electrolyte solvent for sodium-ion batteries (SIBs), exhibiting low viscosity, cost-effectiveness, and low toxicity. Despite a significant portion of aggregation being linked to the weak solvation of Na + /EA as revealed by molecular dynamics (MD) simulations, pulsed-field gradient nuclear magnetic resonance (pfg-NMR) analysis identified a noteworthy Na+ diffusion coefficient of 3.95×10 -10 m 2 s -1 at 25°C in the presence of 1 m NaPF 6 salt. Employing fluoroethylene carbonate (FEC) as a film-forming additive to create electrode-electrolyte interphase, this electrolyte surprisingly made ~210 mAh Na 0.97 Ca 0.03 [Mn 0.39 Fe 0.31 Ni 0.22 Zn 0.08 ]O 2 (NCMFNZO)/hard carbon (HC) pouch cells achieve a lengthy cycling lifetime of 250 cycles with ~80 % capacity retention, cycled up to 4.0 V at 40°C. X-ray photoelectron spectroscopy (XPS) revealed increasing interphasial organic species over cycling, augmenting charge transfer resistance on both cathode and anode, particularly during fast charging or low temperatures (<10°C), promoting Na plating. Finally, gas chromatography-mass spectrometry combined with density functional theory identified CO 2 as the major gas generated from charged cathode/electrolyte interactions, exhibiting temperature/voltage dependence.

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25 ENERGY STORAGE Electrolyte solvent Ethyl acetate Failure mechanism Non-aqueous sodium-ion batteries

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Jayakumar, Rishivandhiga, Pollard, Travis P., Borodin, Oleg, Shipitsyn, Vadim, Chak, Chanmonirath (Michael), Pastel, Glenn, Zheng, Allen, Johnson, Michel, Hasan, Fuead, Bejger, Christopher M., Schroeder, Marshall A., Greenbaum, Steve G., Zuo, Wenhua, Ma, Lin. 2024-07-05. Weakly solvating ester electrolyte for high voltage sodium-ion batteries. https://doi.org/10.1016/j.nanoen.2024.109969

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