A Dendrite-Free Lithium Metal Battery by Incorporating Poly(dimethylsiloxane) Layer onto the Porous Three-Dimensional Copper Current Collector

Abstract

As an anode, lithium metal electrode is one of the most promising candidates for lithium batteries because of their theoretically high specific capacity and low redox potential. However, lithium dendrites are formed during the cycle of lithium deposition and dissolution on the copper current collector during charging and discharging, threatening the stability and durability of lithium metal batteries (LMBs). In this study, a three-dimensional (3D) porous copper coated with a polymer layer (polydimethylsiloxane, PDMS) is used as a current collector to ensure high stability. A PDMS-coated 3D porous current collector is prepared by Cu electrodeposition using hydrogen bubbles as a template followed by a PDMS coating. PDMS coating is performed by spin coating of PDMS on a slide glass and transferring it to the current collector. The 3D current collector functionalized by PDMS offers prolonged lifespans in both Li deposition/dissolution and intercalation of the lithium iron phosphate cathode, as the functionalized PDMS-coated 3D porous current collector effectively prevents the growth of Li dendrites at the interface.