Breaking solvation dominance of ethylene carbonate via molecular charge engineering enables lower temperature battery

Abstract Low temperatures severely impair the performance of lithium-ion batteries, which demand powerful electrolytes with wide liquidity ranges, facilitated ion diffusion, and lower desolvation energy. The keys lie in establishing mild interactions between Li + and solvent molecules internally, which are hard to achieve in commercial ethylene-carbonate based electrolytes. Herein, we tailor the solvation structure with low-ε solvent-dominated coordination, and unlock ethylene-carbonate via electronegativity regulation of carbonyl oxygen. The modified electrolyte exhibits high ion conductivity (1.46 mS·cm −1 ) at −90 °C, and remains liquid at −110 °C. Consequently, 4.5 V graphite-based pouch cells achieve ~98%…

• NN
  National Natural Science Foundation of China

  Awards: 22075074, 2020JJ2004, U21A2081
• SA
  Science and Technology Program of Hunan Province

  Award: 2020WK2013
• NK
  National Key Research and Development Program of China

  Award: 2022YFE0206300