A Thermodynamic Cycle-Based Electrochemical Windows Database of 308 Electrolyte Solvents for Rechargeable Batteries

摘要

Rational design of wide electrochemical window (ECW) electrolytes to pairwith high-voltage cathodes is an emerging trend to push the energy densitylimits of current rechargeable batteries. Traditional single-electronic/gas-phase approximation-based methods (e.g., highest occupied molecularorbital/lowest unoccupied molecular orbital) are increasingly recognized tohave large deviations from experiments when predicting ECWs of electrolytesinvolving complex solvent interactions. Specifically, by examining availableexperimental ECWs of 68 electrolyte solvents extracted from ≈140 000literature sources, which are conventionally divided into five functional-groupcategories (covering commonly used carbonate-based ethylene carbonate(EC)/propylene carbonate (PC) and ether-based tetrahydrofuran), it is foundthat mean-absolute-errors (MAE) of traditional methods reach up to 3.25 V.Herein, a thermodynamic cycle-based ECW prediction approach is proposedincluding two long-term overlooked reorganization-energy and solvationenergycorrections, each of which can be quantified by two geometric descriptors(λ and ΔG_(sol)), reducing MAE below 0.68 V. Following this, a databasecontaining ECWs for 308 electrolyte solvents, obtained by traversing singlefunctional-group substitutions, is established. Furthermore, two omitted solventswith ECWs over 6.00 V and excellent structural stabilities (bond-lengthchange < 0.10 A during redox process) are retrieved by stepwise screening ofstructural/electronic parallel properties. This study demonstrates the benefitsof improving ECW prediction accuracy and accumulating descriptors to acceleraterapid screening of superior battery electrolytes.