Low-cost fumed silicon dioxide uniform Li+ flux for lean-electrolyte and anode-free Li/S battery

Dendritic lithium (Li) growth hinders the applications of Li metal anode . Here, a fumed SiO 2 is proposed as an electrolyte additive to realize uniform Li + deposition. Due to the abundant hydroxyl group on the surface, the SiO 2 particles as a pump provide an additional way for Li + transport, resulting in a homogeneous Li + flux. Moreover, SiO 2 can also smooth the deposited Li and boost the formation of a LiF-rich SEI . As a result, the anode-free Li 2 S/Cu cell demonstrates a significantly improved rechargeability (1055 mAh g −1 , 1 st cycle; 523 mAh g −1 , 200 th cycle). Moreover, even with limited electrolyte (electrolyte/sulfur ratio, 7 µL mg −1 ) and Li (negative to positive capacity ratio, 3), the Li/S pouch cells can still maintain a high capacity of 689 mAh g −1 after 200 cycles. This work shows a simple and efficient way for constructing high-energy-density Li metal batteries .