Low-temperature and high-voltage lithium-ion battery enabled by localized high-concentration carboxylate electrolytes

We designed a carboxylate-based localized high-concentration electrolyte that could enable the low-temperature and high-voltage operation of LiNi1.5Mn0.5O4 (LNMO)||Li batteries. Over 80% of the room-temperature discharge capacity at −50°C and reversibly cycling at −40°C were realized. [Display omitted] •Stable LHCE enable low-temperature and high-voltage operation of LNMO||Li battery.•Realize discharging at −50 °C and reversible cycling at −40 °C.•Explain the influences of solvents and diluents on the solvation energy.•Propose a LHCE design principle with low-temperature and high-voltage properties. Using localized high-concentration electrolytes (LHCEs), which have high oxidation resistance and low viscosity, in high-voltage lithium-ion batteries can facilitate the low-temperature operation of the batteries. In this study, a new short-chain fluorinated diluent 1,1,2,2-tetrafluoroethyl methyl ether is used to prepare a methyl acetate-based LHCE that shows good stability against a LiNi0.5Mn1.5O4 (LNMO) cathode. Furthermore, an LNMO||Li battery (3–4.9 V vs. Li/Li+) with the LHCE shows good cycling stability at room temperature at 1C. Owing to the excellent low-temperature performance of the LHCE, the battery can discharge 80.85% of its room temperature capacity at 0.2C at the temperature of −50 °C and show reversible charge/discharge behavior at 0.1C at the temperature of −40 °C. In this study, LHCEs are successfully used to realize a high-voltage battery that could operate with a relatively high current density (≥0.1C) at a low temperature (-50 °C).