TiO ₂ /FeCoS Heterojunction Anode for Fast‐Charging Lithium‐Ion Batteries

Abstract

ABSTRACT To develop fast‐charging lithium‐ion batteries (LIBs), optimizing insertion‐type anode structure is crucial for achieving fast lithium‐ion diffusion and high electronic conductivity. Here, we combine insertion‐type TiO 2 with high‐capacity FeCoS to construct a TiO 2 /FeCoS heterojunction, which enhances electron/ion transport, lowers the ion diffusion energy barrier, and thereby improves quick‐charging performance. The resulting anode exhibits a high reversible capacity of 627.7 mAh g −1 at 0.1 A g −1 , 2.3 times that of TiO 2 . Notably, it gives a remarkable capacity of 241.7 mAh g −1 at 10 A g −1 and maintains excellent stability over 10,000 cycles with an ultralow capacity decay of just 0.002% per cycle. Experiments and theoretical calculations confirm the superior performance originates from enhanced Li + ions adsorption and reduced diffusion barrier at the heterointerface, which accelerates Li + insertion/extraction kinetics. This work provides an effective pathway to accelerate electrochemical kinetics and enable fast‐charging LIBs.