Enhanced Charge-Transfer Kinetics Enabled by ZrO ₂ –Based Dielectric Layers in Lithium-Ion Batteries

High Resolution Image Download MS PowerPoint Slide The development of high-rate capability lithium-ion batteries (LIBs) requires suppression of charge-transfer resistance ( R CT ) at electrode–electrolyte interfaces. Here, zirconia-based dielectric oxides (MZ; M = Y, Gd, Sm, Er, etc.) were introduced onto LiCoO 2 (LCO) surfaces as electronically and ionically insulating modifiers to accelerate interfacial ion transport. Electrochemical impedance spectroscopy showed that Y 2 O 3 modified ZrO 2 (YZ) decoration reduced R CT from 75.8 Ω in reference LCO to 38.3 Ω, accompanied by a 2.3-fold improvement in capacity retention at 20C. Density functional theory molecular dynamics (DFT–MD) simulations showed that solvated Li ions coordinate with surface oxygen atoms in discharging, and that adsorption energies are governed by local charge distributions determined by stabilizing cations. Optimal adsorption activity, and thus the lowest R CT, occurred when the surface charge corrugation was balanced. These findings provide design principles for dielectric interface engineering to enhance rate capability of LIBs.