• • The ET model, based on Butler-Volmer kinetics, describes current-overpotential behavior with exchange current (i_o) and charge-transfer coefficients (α, 1−α) derived from Tafel analysis; however, it fails at high overpotentials, where Marcus-Hush-Chidsey theory better captures the weak temperature dependence of Tafel curvature.
• • The IT model identifies desolvation of Li+ as rate-limiting, with energy barriers (ΔG_desolv) typically tens of kJ/mol—far exceeding electron tunneling activation energies—necessitating strategies like electrolyte design and electric field modulation to lower these barriers.
• • The two models are not mutually exclusive; a coupled ion-electron transfer mechanism is proposed, where both electron tunneling and ion desolvation contribute to interfacial kinetics, depending on electrode material, electrolyte, and operating conditions.
• • Understanding the coupled mechanism is crucial for optimizing electrode-electrolyte interfaces to achieve higher energy density, faster charging, and longer cycling life in LIBs, as interfacial overpotential directly translates to energy loss and power limitation.