Improving the performance of anode-free Li metal batteries through the modification of current collector work function

Abstract

Among the next-generation batteries capable of achieving high energy density, the anode-free lithium metal battery (AF-LMB) is known to offer the highest energy density. However, since there is no additional source of lithium provided besides the lithium stored in the cathode, the loss of lithium occurring during battery operation cannot be compensated. As a result, the formation of solid electrolyte interface (SEI) layer due to side reaction between the electrolyte and lithium, as well as the generation of dead lithium, directly contribute to the decrease in the cycle life of the AF-LMB. To create a long-lasting AF-LMB, it is important to alleviate the electrolyte's decomposition originating from the anode. One approach to addressing this issue is to coat the current collector with a material possessing a high work function, making it difficult for electrons to detach from the current collector 's surface. This, in turn, suppresses the electrolyte's decomposition and enhances the cycle performance of the AF-LMB. The modification of the current collector in this manner improves the cycle performance of the AF-LMB.