High-entropy-doping effect in a rapid-charging Nb₂O₅ lithium-ion battery negative electrode

Doping is an important approach to tailor materials’ properties, yet the success of doping can depend on factors such as ionic radii similarities. For materials like silicon or perovskite, doping is not only facile to implement but can also enhance material properties. However, for host lattice structures like Nb₂O₅, doping without causing phase change is challenging. Here, we introduce a high-entropy-doping effect in Nb₂O₅. Unlike traditional doping approaches, high-entropy-doping minimizes the chemical properties of doping elements and focuses solely on their quantities. By high-entropizing the doping elements (selecting 10–15 from Mg, Ca, Sr, Ba, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Ga, In, Sn, Sb, Y, Mo, La, Ce) and keeping them within a certain range of doping concentrations (1–3 _mol%), a successful high-entropy-doping is achieved for Nb₂O₅ without phase change. The obtained high-entropy-doped (HED) Nb₂O₅ exhibits rapid-charging capabilities. At a rate of 40 A g⁻¹, the HED-Nb₂O₅ delivers a capacity of 80 mAh g⁻¹, whereas the undoped Nb₂O₅ fails to exceed 25 mAh g⁻¹.