Dendrite-Free Lithium Deposition for Lithium Metal Anodes with Interconnected Microsphere Protection

A lithium (Li) metal anode is required to achieve a high-energy-density battery, but because of an undesirable growth of Li dendrites, it still has safety and cyclability issues. In this study, we have developed a microsphere-protected (MSP) Li metal anode to suppress the growth of Li dendrites. Microspheres could guide Li ions to selective areas and pressurize dendrites during their growth. Interconnections between microspheres improved the pressurization. By using an MSP Li metal anode in a 200 mAh pouch-type Li/NCA full cell at 4.2 V, dendrite-free Li deposits with a density of 0.4 g/cm3, which is 3 times greater than that in the case of bare Li metal, were obtained after charging at 2.9 mAh/cm2. The MSP Li metal enhanced the cyclability to 190 cycles with a criterion of 90% capacity retention of the initial discharge capacity at a current density of 1.45 mA/cm2.