Heterojunction-Coated Graphite Anode Enables Fast Charging via Built-In Electric Field-Regulated Interfacial Li-Ion Transport

Abstract

The sluggish Li-ion transport kinetics across anode interfaces remain a critical bottleneck limiting the fast-charging capability of lithium-ion batteries (LIBs). Herein, we design a lithiophilic Nb₂O₅/Zr₆Nb₂O₁₇ (N/ZN) heterojunction to regulate the Li-ion transport behavior across the graphite anode interface. The tailored work function difference between Nb₂O₅ and Zr₆Nb₂O₁₇ components establishes an internal built-in electric field that synergistically addresses the challenges: (i) accelerating interfacial Li ion (Li⁺) diffusion; (ii) optimizing Li intercalation/deintercalation kinetics; (iii) lowering the desolvation energy barrier. Therefore, the graphite anode with the N/ZN coating achieves 80.9% capacity retention at 6C-rate charging while effectively suppressing Li plating. This work demonstrates a heterojunction engineering strategy that concurrently enhances ionic transport and interfacial stability, offering a pathway for developing fast-charging anodes.