Electrolyte for Optimal Low-Temperature Performance in Lithium-Ion Batteries Using Li₃V₂(PO₄)₃/C as a Cathode Active Material

Currently, it is essential to develop batteries that exhibit stable performance at low temperatures because of their widespread use in various fields, such as polar and space exploration, where reliable operation under frigid conditions is critical. Unfortunately, commercial lithium-ion batteries have poor stability, even at -10 °C. The electrolyte is a crucial factor affecting the low-temperature performance of batteries. In this study, we compared the low-temperature performances of 1 M LiPF₆ in DEC: DMC: EMC (1:1:1 in volume) (1 M-COM) and 1 M LiPF₆ in EC: DEC: DMC: EMC (3:5:4:1 in volume) (1 M-EDDE) using carbon-coated Li₃V₂(PO₄)₃/C (LVP/C) as the cathode active material. The 1 M-EDDE LVP/C half-cell has 43.4% capacity retention, which is approximately three times higher than that of the 1 M-COM LVP/C half-cell at 243 K. Additionally, the diffusion coefficients of the 1 M-EDDE and 1 M-COM LVP/C half-cells are on the order of approximately 10^-10and 10^-11 orders, respectively. However, as the temperature decreased, the polarization of the 1 M-COM LVP/C half-cell became wider than that of the 1 M-EDDE LVP/C half-cell. This study highlights the superior performance of LVP/C half-cells with 1 M-EDDE electrolyte at low temperatures, emphasizing the critical role of the electrolyte in low-temperature applications.<br/><br/><br/>This work was supported by the National Research Foundation of Korea (NRF-2021R1A2C1008272). This study was supported by Ministry of Trade, Industry and Energy, KEIT, under the project title "International standard development of evaluation methods for nano-carbon-based high-performance supercapacitors for electric vehicles" (project # 20016144). This work was supported by Korean Ministry of Industry, KEIT, "Setting and Developing Key Technology Standards Strategy and Development for Global Competitiveness on Materials, Parts, and Equipments" (project # 20015943)