Suppressing lithium dendrite growth by a synergetic effect of uniform nucleation and inhibition

The lithium dendrites issue presents a major challenge limiting the commercialization of Li metal anodes for high-energy-density batteries. Herein, an AgPF6-LiNO3 hybrid electrolyte additive was introduced into a carbonate electrolyte, which was found to induce the formation of a homogeneous dense layer of Ag-Li alloy seeds with small sizes on the Li metal surface. The formation mechanism of such fine Ag-Li alloy seeds on the Li metal substrate was evaluated, which revealed an interesting synergistic effect between AgPF6 and LiNO3. The occurrence of such a dense layer of Ag-Li alloy seeds was found to play a significant positive role in homogeneous nucleation and growth of Li dendrites, and LiNO3 could inhibit the growth of Li and act as a grain refiner during a repetitive plating/stripping process, thus enabling profoundly improved structural stability and excellent long-term cycle performance for the Li anode during the cycling process. With the co-presence of AgPF6-LiNO3 in the electrolyte, the relevant symmetric cells could work steadily for 3000 h with slight polarization at a density of 0.5 mA cm(-2); and the Li-graphite battery can exhibit good cycle performances and deliver a specific energy density of 374 W h kg(-1) at a power density of 747 W kg(-1).