Atomic Sn clusters engineered electron-deficient carbon nanofibers enable bulk-interface synergy for high-capacity and durable lithium-ion batteries

Abstract

Alloy-type anodes for lithium-ion batteries face irreversible structural degradation from > 300 % volume changes and unstable interfaces due to electron leakage-induced electrolyte decomposition. Herein, we resolve this via atomic-scale engineering of amorphous Sn clusters (<3 nm) in an electron-deficient nitrogen-doped carbon nanofiber matrix (ASC@NCNF), where robust Sn-N coordination bonds and interfacial charge redistribution create a dual-stabilization mechanism. The isotropic lithiation behavior of amorphous Sn cluster enables adaptive stress dissipation during cycling, suppressing pulverization. Concurrently, the electron-deficient carbon substrate reduces parasitic reactions through controlled electron transfer, fostering an inorganic-rich and ion-conductive SEI. This atomic-to-macroscopic design breakthrough translates to unprecedented electrochemical performance. The as-fabricated ASC@NCNF anode delivers exceptional rate capability (398 mAh g⁻¹ at 10 A g⁻¹) and unprecedented cycling stability (10 A g⁻¹ after 10,000 cycles with 60 % capacity retention), as well as operation at −30 °C (0.5 A g⁻¹). Practical ASC@NCNF//NCM811 pouch cell retains 98 % of initial capacity after 100 cycles at 1 C. Combining X-ray absorption spectroscopy and DFT calculations, we demonstrate the atomic-scale principles governing cluster-substrate interactions and their macroscopic electrochemical consequences. This work establishes a paradigm for bridging atomic-scale cluster engineering with macroscopic electrode durability, offering insights into high-energy-density energy storage systems.