IMPACT OF PROCESSING PARAMETERS ON THE MULTIFUNCTIONALITY OF CARBON FIBRES FOR STRUCTURAL BATTERY ELECTRODES

Paper in proceeding, 2024

Carbon fibres are multifunctional materials considered for the realisation of structural battery electrodes. Processing conditions affect the carbonaceous microstructure of carbon fibres. The microstructure dictates the fibre's mechanical properties, i.e. modulus and strength, as well as its electrochemical capacity. Here, carbon fibre processing conditions are investigated to identify the effect of applied tension during the stabilisation step and carbonisation temperature on carbon fibre multifunctionality. First, different pulling forces are employed during the stabilisation step. The most promising carbon fibre resulting from changing the applied force is then subjected to varying temperatures in the carbonisation step. The precursor material and the oxidation temperatures are kept constant. The carbonaceous microstructure of fibres is investigated via wide-angle X-ray scattering (WAXS) and transmission electron microscopy (TEM) analyses to determine the effect of different processing parameters. Mechanical and electrochemical tests are performed to characterise carbon fibre multifunctionality with respect to mechanical and electrochemical performance. A moderate trade-off between mechanical and electrochemical performance is demonstrated, where the elastic modulus and strength decrease and the electrochemical capacity increases with reduced tensions and carbonisation temperature. Thus, fibres customised for targeted multifunctionality within a limited design space can be realised by carefully selecting the processing conditions in conventional carbon fibre manufacture.