Multi-Metal Synergistic Doping Enabling High-Entropy Copper-Based Nanosphere Libraries for Advanced Lithium-Ion Battery Anodes.

Copper-based materials have emerged as promising anode candidates for next-generation lithium-ion batteries owing to their high theoretical capacity. However, their practical implementation remains fundamentally constrained by inherent semiconducting characteristics and sluggish reaction kinetics. To address these limitations, we develop a universal low-temperature multimetal synergistic doping strategy to construct a high-entropy Cu-based material library (HE-CBMs) encompassing 54 distinct compositions. Through precise modulation of coordination environments and stoichiometric ratios across eight transition metals (Cr, Mn, Fe, Co, Ni, Cu, Zn, and Cd), we first synthesized HE-doped Cu2O (HE-Cu2O) nanospheres via a solvothermal approach, followed by low-temperature reduction to achieve HE-doped metallic Cu (HE-Cu) nanospheres. The multimetal synergy induces lattice distortion and electron-deficient states, synergistically reducing Li+ diffusion barriers while optimizing interfacial charge transfer kinetics. The optimized octonary HE-Cu anode (CrMnFeCoNiCuZnCd) demonstrates exceptional electrochemical performances, delivering a high reversible capacity of 2211.2 mAh g-1 after 250 cycles at 1 A g-1 and retaining 1270.4 mAh g-1 over 900 cycles at 5 A g-1, outperforming most current Cu-based anodes. This work establishes a scalable combinatorial platform for HE material synthesis under mild conditions while elucidating fundamental principles of multimetal synergy for next-generation energy storage systems.