Curved surface coupled structural battery composites manufactured by resin transfer molding process: Microstructure and multifunctional performance

To bridge industrial production and lab-scale research, this work demonstrates a technology to manufacture curved surface structural battery composites (CSBCs) that can simultaneously achieve electrochemical energy storage and load-bearing. The curved-surface carbon fiber structural anode and cathode are fabricated by coating the active materials on carbon fiber fabric with a vacuum-bag-assisted technique. The resin transfer molding (RTM) process is conducted to manufacture the coupled CSBCs by infusing bi-continuous phase epoxy resin electrolyte and curing at high temperatures. The microstructure of structural electrodes and CSBCs is characterized by scanning electron microscopy (SEM). Due to good interfacial compatibility between high mechanical strength carbon fiber structural electrode and high ionic conductivity solid polymer electrolyte bulk for load support, the fabricated CSBCs demonstrate a high density of 294 mWh kg⁻¹ based on the whole mass of devices, a tensile strength of 257.4 MPa with Young's modulus of 12.9 GPa and a flexural strength of 194.1 MPa with flexural modulus of 11.1 GPa. In situ electrochemical-mechanical tests further confirm the durability of CSBCs under mechanical loads with a multifunctional efficiency of 1.07, suggesting the effectiveness of the introduced manufacturing techniques for coupled structural battery composites.