Improving the cycling stability of lithium metal anodes through separator modification with nano-molybdenum powder

Abstract

The deposition of lithium ions in an uneven manner can lead to the formation of lithium dendrites, which can puncture the battery separator and cause a short circuit. Additionally, intermediate polysulfides can shuttle between the separator, resulting in damage to the capacity of lithium–sulfur batteries and corrosion of the negative electrode. It is crucial to address these issues promptly. Hence, we developed a modified separator using nano-molybdenum powder, which effectively inhibits the growth of lithium dendrites and suppresses the shuttle effect of polysulfides. The modified separator extends the lifetime of the lithium metal anode, and the uniform pore distribution of the molybdenum powder facilitates the uniform diffusion of Li⁺ ions, thereby slowing down the detrimental effects. As a result, Li–S cells equipped with the nano-molybdenum powder modified separator achieve a remarkable capacity of 802 mA h g⁻¹ at a current density of 0.5C and maintain a capacity of up to 614 mA h g⁻¹ after 200 cycles.