Improved Rechargeability of Lithium Metal Anode via Controlling Lithium-Ion Flux

摘要

Among all the possible anode materials for next-generation rechargeable batteries, lithium (Li) metal stands out from the crowd for its high specific capacity and low redox potential. Unfortunately, the issues caused by Li dendrites limit the commercialization of the batteries based on Li metal anodes. Research in recent years has proved that the Li dendrites cannot be completely eliminated. Inspired by the Chinese legend, "King Yu Tamed the Flood," the new strategy of combing dredge and block, to control the diversion of Li ions is proposed. Via Au modification on one side of the carbon fibers matrix (CFs@Au), selective deposition of Li ions on the back side of the current collector is successfully achieved. This is distant from the separator, and hence improves the safety effectively. As a result, the Coulombic efficiency of the CFs@Au-Li anode remains 99.2% throughout 400 cycles. What is more, the Li-S full cell paired with the composite anode also exhibits outstanding performance, even with limited Li. This backside-deposition strategy provides new insight into safe Li metal anode design for high energy density battery systems such as Li-S and Li-O-2.