Metallic Glass-Fiber Fabrics: A New Type of Flexible, Super-Lightweight, and 3D Current Collector 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, a new type of current collectors made of 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 (LMBs), fire resistance, high strength, and flexibility suitable for roll-to-roll electrode fabrication is reported. 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. A high-energy-density flexible lithium battery with an outstanding figure of merit of flexible battery (fb(FOM)) and flexing stability is demonstrated.

Automated summary

Current collectors in batteries provide electron transport and support to electrode materials. Metal foils are commonly used as current collectors but do not contribute to energy storage. A new type of current collector made of 3D metallic glass-fiber fabrics (MGFs) is reported, which has advantages of lightweight, electrochemical stability, fire resistance, strength, and flexibility suitable for roll-to-roll electrode fabrication. By replacing metal foils with MGFs, the energy density of lithium batteries can be improved by 9-18%. Additionally, MGFs are suitable for flexible battery fabrication, as demonstrated by a high-energy-density flexible lithium battery.