Metallic Glass‐Fiber Fabrics: A New Type of Flexible, Super‐Lightweight, and 3D Current Collector for Lithium Batteries

Abstract

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 (fbFOM) and flexing stability is demonstrated.

3D-hosted lithium metal anodes

“…The group of Prof. Zheng reported a new 3D metallic glass fiber fabric (MGFs, Li-AgCuGF, material 17) current collector with a super-lightweight (2.9–3.2 mg cm −2 ) and flexibility suitable for roll-to-roll electrode fabrication. 98 The results indicated that MGFs show outstanding electrochemical stability, fire resistance and high strength. As a result, the replacement of metal foils by MGFs can effectively improve the gravimetric energy densities of lithium batteries by about 9–18%.…”

MXene‐Based Current Collectors for Advanced Rechargeable Batteries

“…application of Li anode faces challenges because of the unstable SEI, uncontrollable dendrites growth, and undesired side reactions caused by high chemical reactivity. Many strategies have been proposed to address these drawbacks including building 3D current collectors, [162,239] constructing an artificial SEI [240,241] and designing hosts for Li anode. [242,243] MXene shows many promising properties that effectively address the shortcomings, mainly reflected in the following merits.…”

Recent Progress on Nanomodification Applied in Anodes of Rechargeable Li Metal Batteries

“…Hu et al reported a highly conductive and lightweight carbon current collector, and the 3D electrode delivers a high capacity of 7.6 mA h cm –2 (95 Ah L –1 based on volume) at a current density of 0.5 mA cm –2 and energy density of 26 mWh cm –2 . Zheng reported a flexible “metalized glass fiber fabric (MGFs)” that combines lightweight and high mechanical strength, whose surface density is 2.9–3.2 mg cm –2 , which is only 40% of the commercial Cu foil surface density, and the thickness is 20 μm. The lightweight feature can reduce the weight of energy storage devices by about 10% and increase the energy density of devices by 9–18%.…”