Molecular-docking electrolytes enable high-voltage lithium battery chemistries

Abstract

Ideal rechargeable lithium battery electrolytes should promote the Faradaic reaction near the electrode surface while mitigating undesired side reactions. Yet, conventional electrolytes usually show sluggish kinetics and severe degradation due to their high desolvation energy and poor compatibility. Here we propose an electrolyte design strategy that overcomes the limitations associated with Li salt dissociation in non-coordinating solvents to enable fast, stable Li chemistries. The non-coordinating solvents are activated through favourable hydrogen bond interactions, specifically Fδ−–Hδ+ or Hδ+–Oδ−, when blended with fluorinated benzenes or halide alkane compounds. These intermolecular interactions enable a dynamic Li+–solvent coordination process, thereby promoting the fast Li+ reaction kinetics and suppressing electrode side reactions. Utilizing this molecular-docking electrolyte design strategy, we have developed 25 electrolytes that demonstrate high Li plating/stripping Coulombic efficiencies and promising capacity retentions in both full cells and pouch cells. This work supports the use of the molecular-docking solvation mechanism for designing electrolytes with fast Li+ kinetics for high-voltage Li batteries. Conventional Li-ion battery electrolytes often show sluggish kinetics and severe degradation due to high Li+ desolvation energies and poor compatibility. Now, a molecular-docking strategy between solvents and inducers has been shown to enable dynamic Li+ coordination that promotes fast, stable and high-voltage lithium battery chemistries.