Realisation of structural battery composites

Research Project, 2021 – 2024

The proposed research by Chalmers, KTH and Imperial College London (ICL) aims at the development and demonstration of a multifunctional material that can simultaneously store electrical energy and carry mechanical loads. We have coined this material as structural battery composite. Structural batteries will allow radical weight savings for any electrically powered structural system, from mobile phones to aircraft. Over the last decade, the three universities have performed research to realise structural battery composites. Current structural battery composites have demonstrated an energy density of 24 Wh kg-1 at a Young's modulus of 25 GPa. In the proposed project we seek to develop and demonstrate a second-generation laminated structural battery composite with an energy density of 100 Wh kg-1 and an in-plane modulus (isotropic) of 40 GPa. This is slightly lower than traditional Li-ion batteries and composites but combined into a multifunctional material provides significant mass savings. The structural battery composite is made from carbon fibre reinforced electrodes in a structural electrolyte matrix material. Neat carbon fibres are used as the structural negative electrode, exploiting their high mechanical properties, excellent lithium  insertion capacity and high electrical conductivity. Lithium iron phosphate coated carbon fibres will be used as the structural positive electrode. The electrodes are to be separated by an ultra-thin fibrous separator.

The proposed research is partitioned into four Tasks. The first entails design, manufacture, and characterisation of the full cell. The second Task concerns  development and assessment of highly multifunctional fibre-reinforced structural electrodes. In the third Task, multifunctional interfaces for high-power structural battery solutions are studied. Finally, in the fourth Task, efficient current collection configurations, and multifunctional design methods and structural encapsulation solutions will be developed.