Meaning
Thermodynamic potential values quantifying the interaction strength between a central metal cation and coordinating electrolyte solvent molecules dictate desolvation kinetics at electrode interfaces. Evaluating solvation sheath binding energy explains the charge transfer barrier experienced by lithium ions entering the solid electrolyte interphase. The parameter ceases to dictate kinetics at temperatures where bulk ion transport becomes the primary rate-limiting step.
Interfacial Kinetics
Lithium ions travel through the liquid electrolyte enveloped by a coordination shell of cyclic carbonates, linear carbonates, or ether molecules. Entering the active material lattice requires shedding these tightly bound solvent molecules at the electrode surface boundary. High binding energy increases the desolvation activation energy, restricting rapid charging capabilities and subzero performance.
Electrolyte Formulation
Solvent selection, salt concentration, and fluorinated additives alter the electrostatic binding forces inside the solvation complex. Formulating electrolytes with weakly coordinating solvents reduces the energy barrier for ion desolvation, enabling faster interfacial kinetics. High-concentration electrolytes shift the sheath structure toward anion-contact ion pairs, lowering desolvation resistance.
Desolvation Barrier
Computational density functional theory models predict coordination geometries and calculate binding energies for competing solvent blends. Experimental electrochemical impedance spectroscopy confirms charge-transfer resistance correlations across diverse electrolyte formulations. Optimizing these interaction energies enables cell designs that support high-power discharge without triggering premature lithium plating.
