Carbon fiber reinforced structural Zn-ion battery composites with enhanced mechanical properties and energy storage performance

Abstract

A carbon fiber structural battery composite, which is attractive for reducing the weight of vehicles, such as airplanes and electric cars, can achieve energy storage and mechanical loads, simultaneously. However, the low mechanical stability and energy storage performance of slurry-coated electrode materials limit the application and development of structural batteries. Herein, optimized structural Zn-ion batteries (OS ZIBs) were prepared based on the in situ grown structural cathode (CF@PANI/MXene) and electrodeposited structural anode (CF@Zn). The composite structural electrodes with carbon fiber as the skeleton obtain great improvement in mechanical strength and structural stability. In addition, the optimized structural separator PVDF-HFP/Zn-MMT achieves high tensile strength, superior to that of commercial glass fiber. The OS ZIBs integrate excellent mechanical properties with electrochemical performance to achieve a bending strength of 268.0 MPa and Young's modulus of ∼4.9 GPa. The OS ZIBs deliver a high specific capacity of 265.0 mA h g⁻¹ at 1 A g⁻¹, superior to that of regular structural batteries (RS ZIBs). Besides, the in situ electrochemical-mechanical testing shows the cycling stability of OS ZIBs under a tensile stress of 20 MPa. Overall, this work demonstrates an effective method for fabricating structural batteries with high energy storage and mechanical properties.