Zarei-Jelyani M, Salehi A, Babaiee M, Loghavi M M. Evaluating Electrolyte Solvent Effects on Low-Temperature Performance of Lithium-ion Batteries Using Electrochemical Impedance Spectroscopy. ASE 2024; 14 (2) :4360-4368
URL:
http://www.iust.ac.ir/ijae/article-1-672-en.html
Department of Energy Storage, Institute of Mechanics, Shiraz, Iran
Abstract: (2521 Views)
The global transition towards renewable energy necessitates efficient energy storage solutions to address the intermittency of renewable sources. Lithium-ion batteries (LIBs), widely utilized in electric vehicles (EVs) for their high energy density and efficiency, yet their performance at low temperatures remains a challenge. This study investigates the influence of electrolyte solvent composition on LIB performance under low-temperature conditions. Three electrolytes were studied: a standard electrolyte (STDE) comprising 1 M LiPF6 in ethylene carbonate (EC) and diethyl carbonate (DEC), a low-temperature electrolyte (LTE) consisting of 1 M LiPF6 in EC, ethyl methyl carbonate (EMC), and ethyl acetate (EA), and a long-cycle-life electrolyte (LCLE) containing 1 M LiPF6 in EC/EMC. The EIS results revealed significant differences in resistance values among the electrolytes at varying temperatures. Specifically, at 0 °C, the STDE exhibited a charge transfer resistance (Rct) of 1055.3 Ω and a solid electrolyte interface resistance (RSEI) of 803.4 Ω, whereas the LTE showed a substantially lower Rct of 507.4 Ω and RSEI of 64.2 Ω, indicating superior low-temperature performance. Similarly, at -20 °C, the Rct values for STDE, LTE, and LCLE were 8878.6 Ω, 854.2 Ω, and 15622 Ω, respectively, with corresponding RSEI values of 172.1 Ω, 92.4 Ω, and 2364 Ω. Notably, the addition of EA in the LTE formulation contributed to enhanced low-temperature performance, likely by lowering the overall viscosity of the electrolyte mixture and improving ionic mobility. This study demonstrates the critical role of solvent composition, particularly EA, in optimizing LIB performance for cold climate applications.