Whitepaper
Harish Gudla
CTO at Compular
Ionic liquids (ILs) are emerging as promising electrolytes for next-generation lithium-metal batteries, offering high stability, non-flammability, and broad electrochemical stability windows. Yet their high viscosity and strongly correlated ion motion can limit conductivity, especially at high salt concentrations or low temperatures. Traditional experimental approaches struggle to explore this complex design space efficiently.
At Compular Lab, we use advanced molecular dynamics (MD) simulations with polarizable force fields and ensemble sampling to generate predictive property maps across composition and temperature — long before experiments are performed.
In collaboration with Solvionic, we benchmarked our simulations against experimental density, viscosity, and conductivity data for three IL chemistries:
EMI⁺ – 1-ethyl-3-methylimidazolium
PYR13⁺ – N-methyl-N-propylpyrrolidinium
N1113⁺ – Triethylmethylammoniu
Each system was paired with the FSI⁻ anion and varied LiFSI concentrations (0–4 M) across temperatures from –10 °C to 60 °C.
Key Results
Density – Simulations match experimental data at 25 °C and 60 °C, capturing expected trends across cation structures.
Viscosity – Trends are reproduced reliably: viscosity increases with LiFSI concentration and decreases with temperature. Deviations at –10 °C reveal phase transitions and provide mechanistic insights into reduced ion mobility.
Ionic Conductivity – EMIFSI consistently shows the highest conductivity. Simulations capture the decrease in conductivity with higher salt concentrations and reveal low-temperature phase-dependent behavior consistent with experimental observations.
Why This Matters
Simulation-driven design enables:
Faster screening of IL chemistries and compositions
Targeted experiments focused on the most promising formulations
Mechanistic insight into ion coordination, packing, and transport
Lower development cost by reducing failed experiments
Compular Lab’s MD simulation platform provides reliable predictions of IL electrolyte properties and accelerates the development of next-generation battery electrolytes. By combining simulations with experimental validation, we move from trial-and-error approaches to rational, data-driven design.
