Current collection and encapsulation

While significant progress has been made in constituent development and electrochemical performance, current collection [1] and structural encapsulation remain critical bottlenecks for scale-up and application [2]. Structural encapsulation ensures environmental protection against moisture and oxygen ingress, electrical insulation between cells and structural plies, and mechanical continuity for load transfer. The encapsulation should be lightweight but robust, and can contain multiple cells to minimise the parasitic mass.

The objective of the research on current collection for structural power composites is to identify and model materials and processes that effectively minimize resistive losses and reduce the parasitic mass associated with current collection. This challenge involves optimizing the integration of conductive pathways within structural power composites to enhance electrical efficiency without compromising mechanical performance. The encapsulation aspect of the study focuses on selecting materials that not only serve as robust, impervious barriers to environmental factors but also facilitate efficient mechanical load transfer into the structural power composite, thereby preserving the integrity and functionality of the entire composite system.

This research has advanced the integration of current collection and encapsulation technologies within structural power composites through both modelling and experimental studies. A predictive model was developed and validated to optimize electrode resistivity and current collection performance, particularly using carbon aerogel-reinforced carbon fibre fabric materials. Structural electrodes were thoroughly characterized for both in-plane and out-of-plane resistivity under varying architectures and pressures [3]. The team have scaled up to an A5-sized cell, maintaining the specific capacitance and equivalent series resistance measured for smaller 16 cm² cells. For encapsulation, a comprehensive screening study identified thermoplastics compatible with electrolytes and processing constraints. Moisture permeability was evaluated across temperature ranges, and manufacturing strategies were refined to mitigate electrolyte-encapsulation interactions.

References

1. Valkova et al. Current collector design strategies: The route to realising scale-up of structural power composites, CST, 2023. https://doi.org/10.1016/j.compscitech.2023.109978
2. Nguyen et al. Manufacture and Characterisation of a Structural Supercapacitor Demonstrator, CST, 2024. https://doi.org/10.1016/j.compscitech.2023.110339
3. Qian et al. The electrical response of carbon fibre reinforced electrodes in structural power composites under cyclic compaction,  CST, 2025. https://doi.org/10.1016/j.compscitech.2024.111020