Thin Flexible Lithium Ion Battery Featuring Graphite Paper Based Current Collectors with Enhanced Conductivity

Abstract: A flexible, light weight and high conductivity current collector is the key element that enables fabrication of high performance flexible lithium ion battery. Here we report a thin, light weight and flexible lithium ion battery that uses graphite paper enhanced with a nano-sized metallic layers as the current collector, LiFePO4 and Li4Ti5O12 as the cathode and anode materials, and PE membrane soaked in LiPF6 as a separator. Using thin and flexible graphite paper as a substrate for the current collector instead of a rigid and heavy metal foil enables us to demonstrate a very thin Lithium-Ion Battery into ultra-thin (total thickness including encapsulation layers of less than 250 {\mu}m) that is also light weight and highly flexible.