Meaning
Energy barrier rates associated with desolvating solvated metal ions as they shed their surrounding liquid solvent shells to transfer across electrode interface boundaries dictate interfacial charge transfer speeds. Quantifying solvation stripping kinetics establishes the rate-limiting step for low-temperature charging and high-rate battery performance. This kinetic parameter governs electrolyte formulation design, ceasing to apply when ion transport becomes limited by bulk liquid diffusion rather than interfacial transfer.
Desolvation Barrier
Positively charged lithium ions coordinate with polar solvent molecules, forming stable solvation sheaths in bulk liquid electrolyte. Accelerating solvation stripping kinetics lowers activation energy barriers at the solid electrolyte interphase. Lower desolvation energy facilitates rapid ion insertion into host anode lattices without causing surface metallic plating.
Temperature Sensitivity
Low ambient operating temperatures dramatically increase desolvation energy barriers, slowing ion transfer rates at electrode surfaces. When desolvation becomes sluggish, incoming lithium ions accumulate at the anode interface, driving local overpotential negative. Negative overpotentials trigger metallic lithium dendrite nucleation on graphite surfaces during fast charge cycles.
Developing weak-coordination electrolyte formulations lowers desolvation energy, enabling rapid ion transfer under cold ambient conditions. Fast interfacial kinetics prevent localized polarization spikes and improve energy efficiency during low-temperature charging.
Electrolyte Additives
Functional electrolyte additives alter ion solvation sheath structures, weakening binding energies between metal cations and polar solvent molecules. Modified solvation shells lower kinetic barriers for rapid interfacial mass transfer.
