Metallic Glass Fiber Fabrics: A New Type of Flexible, Super-Lightweight, and Three-Dimensional Current Collectors for Lithium Batteries.

Current collectors are indispensable parts that provide electron transport and mechanical support of electrode materials in a battery. Nowadays, thin metal foils made of Cu and Al are used as current collectors of lithium batteries, but they do not contribute to the storage capacity. Therefore, decreasing the weight of current collectors can directly enhance the energy density of a battery. However, limited by the requirements of mechanical strength, it is difficult to reduce the weight of metal foils any further. Herein, we report a new type of current collectors made of three-dimensional (3D) metallic glass fiber fabrics (MGFs), which shows advantages of super-lightweight (2.9∼3.2 mg cm -2 ), outstanding electrochemical stability for cathodes and anodes of lithium-ion and lithium metal batteries, fire resistance, high strength and flexibility suitable for roll-to-roll electrode fabrication. The gravimetric energy densities of lithium batteries exhibit improvements of 9∼18% by only replacing the metal foils with the MGFs. In addition, MGFs are suitable for the fabrication of flexible batteries. We demonstrate a high energy density flexible lithium battery with an outstanding figure of merit of flexible battery (fb FOM ) and flexing stability. This article is protected by copyright. All rights reserved.