Researchers at the Institute of Electrical Engineering, Chinese Academy of
Sciences proposed a solvation de‑shielding electrolyte design for
low‑temperature lithium‑ion capacitors (LICs). The formulation uses
gamma‑valerolactone (GVL) as primary solvent (medium polarity, low melting
point, moderate Li+ coordination), lithium difluoro(oxalato)borate (LiDFOB) as
functional lithium salt, and ethyl acetate (EA) as a weakly coordinating
cosolvent to weaken solvent encapsulation of Li+ and encourage anion
participation in local solvation structure, creating a weakly bound,
anion‑participating solvation environment. Full‑carbon LICs with this
electrolyte maintained strong energy output at −40°C, delivering
electrode‑mass‑based energy density of 106.8 Wh/kg—about 8.9 times that of
conventional carbonate‑based electrolytes. The study reports the approach
overcomes slow interfacial reaction kinetics at low temperature caused by strong
solvation shielding.
