Synergistic Effects of Entropy Tuning in Niobium-Based Oxide Anode for Fast-Charging Lithium-Ion Batteries

The development of fast-charging lithium-ion batteries requires electrode materials with both high-rate capability and excellent durability. Here an entropy-tuned niobium-based oxide (ETNO) anode is introduced, strategically engineered through multi-cation doping by incorporating Nb⁵⁺, Ti⁴⁺, W⁶⁺, Fe³⁺, and Ca²⁺ into the Wadsley-Roth shear structure of niobium oxide. ETNO demonstrates high-rate capability, delivering 171 mAh g⁻¹ at 20.0 A g⁻¹, and retains 79% of its initial capacity after 9,000 cycles under extreme fast-charging conditions. X-ray diffraction (XRD) and operando Raman spectroscopy reveal that the entropy tuning enables a gradual structural transformation during (de)lithiation, facilitating stable phase evolution and minimizing strain. Computational analysis confirms that entropy tuning enhances Li-ion diffusion, reduces bandgap energy, and mitigates volume expansion, collectively improving electrochemical performance. Full cell testing with a LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) cathode validates the practical viability of ETNO, demonstrating superior cycling stability and high capacity retention. This study establishes entropy tuning as a powerful design strategy for next-generation high-power lithium-ion battery anodes, offering exceptional fast-charging capability and durability.