Dual‐Interface Electrolyte Engineering for Wide‐Temperature‐Adaptable High‐Voltage LiCoO 2 /Graphite Cells

Abstract

Lithium cobalt oxide (LiCoO 2 , LCO) suffers from severe interfacial degradation at high voltage, while graphite (Gra) anodes lack durable solid electrolyte interphases (SEI), jointly restricting LCO/Gra cell performance. Herein, a dual‐interface electrolyte engineering strategy is developed by introducing a multifunctional additive, 3‐(tert‐butyldimethylsilyloxy)‐5‐trifluoromethoxyphenylboronic acid pinacol ester (TDTB), which integrates B‐O, Si‐O, benzene‐ring, and ‐CF 3 groups within a single molecular framework to simultaneously stabilize cathode and anode interfaces. Through preferential oxidative/reductive decomposition, TDTB generates robust cathode‐electrolyte interphase (CEI)/SEI layers enriched with Si‐F, B‐F, and LiF species, thereby enhancing interfacial stability, Li + transport kinetics, and structural reversibility. Experimental results confirms that TDTB‐derived CEI suppresses irreversible LCO structural evolution and transition‐metal dissolution, whereas the derived SEI promotes formation of a highly lithiated single LiC 6 phase at 0.005 V, enabling rapid and uniform Li + intercalation. Consequently, LCO/Gra cells achieve 90% capacity retention after 800 cycles at 1 C, with superior rate capability and temperature adaptability, compared with 46% without TDTB. Pouch cells further demonstrate practical feasibility, retaining 76% capacity after 75 cycles vs. 16% for controls. This work provides a molecular‐design strategy for dual‐interface‐regulation additives by integrating complementary functional groups into a single molecule, offering an effective route toward high‐energy‐density lithium‐ion batteries with long lifespan and wide‐temperature‐adaptability.