Metal-Coated Polymer Fiber Mesh as an Ultralightweight Gas-Diffusible Current Collector for High-Energy-Density Rechargeable Lithium–Oxygen Batteries

Lithium–oxygen batteries (LOBs) have received great attention as next-generation energy storage devices owing to their superior theoretical energy densities. Although there has been considerable technological progress in the field of LOBs, the development of gas diffusion layer materials at the positive oxygen electrode is limited despite their importance in providing an oxygen supply needed to achieve practical power densities. In the present study, we demonstrate the concept of a gas-diffusible current collector, which combines the functions of oxygen mass transport and electron transfer with minimal mass loading. To verify this concept, we fabricated a Ni-coated polymer fiber mesh and investigated its applicability in LOBs. LOB cells equipped with an ultralightweight gas-diffusible current collector exhibit a performance equivalent to that of cells equipped with conventional heavy components at 0.4 mA/cm 2 current density and 4.0 mAh/cm 2 areal capacity. We believe that the concept of an ultralightweight gas-diffusible current collector demonstrated in this study opens future directions in the search for metal–air batteries with high energy and power densities.