ZnO Quantum Dots as PEO-Based Solid Electrolytes Fillers for Lithium Metal Batteries

Graphical The advantages of quantum size effect and lithiophilic characteristics of ZnO QDs ensure the sufficient contact and uniform distribution with PEO chains, enhance the REDOX kinetics at the Li/PEO interface and the stability of Li anode. Li/PEO/Li and Li/PEO/LiFePO 4 cells with 3 wt.% ZnO QDs electrolyte fillers can work steadily and provide considerable reversible capacity. PEO-based solid polymer electrolyte (PEO SPE) is regarded as one of the most promising solid electrolytes due to its exceptional flexibility, cost-effectiveness, and ease of integration. However, its commercialization is hindered by inadequate ionic conductivity and unstable interface. By incorporating proper ZnO quantum-dots (QDs) fillers with enhanced surface activity, the ion transport inner the PEO-based electrolyte can be improved along with enhanced REDOX kinetics at the Li/PEO interface. The ionic conductivity reaches 5.97×10 −4 S cm −1 at 60 °C. Moreover, ZnO QDs exhibit a quantum size effect and possess lithiophilic characteristics that promote uniform nucleation and redeposition of Li + while forming a stable Li−Zn alloy. This inhibits lithium dendrite formation and enhances the stability of Li anode. Li//Li cell with 3 % ZnO QDs works steadily for more than 2100 h at 60 °C with 0.1 mA cm −2 . The assembled Li//LiFePO 4 cell provides a reversible capacity of 134.91 mAh g −1 after200 cycles at 0.1 C.