Stannic oxide quantum dots constructed evenly alloyable layer stabilizing lithium metal batteries

Dendrite growth is still a problem that high energy density lithium metal batteries must face to commercialize. At present, the introduction of lithiophilic materials on the current collector has proved to be an effective strategy. However, most works are not conducive to the practical application of lithium metal batteries due to the neglect of the preparation cost and the excessive and uncontrollable modifier. Herein, stannic oxide (SnO₂) quantum dots (QDs) were prepared by a simple dehydration reaction to construct a lithiophilic modification layer on the surface of copper foil. In addition, SnO₂ QDs could induce uniform nucleation and growth of lithium ions at the quantum scale. More importantly, when the copper collector was modified by SnO₂ QDs, the symmetric cell could cycle stably for 3200 h at a current density of 1 mA cm⁻², which is better than other reports. LiFePO₄ was employed as cathodic materials to fabricate a full battery, which delivered a capacity of 130.4 mAh g⁻¹ with a capacity retention rate of 87.75% at 0.5 C for 200 cycles. Therefore, this work can be extended to practical applications, and help lithium metal batteries to be industrialized.