Safety And Fire Reaction Of Structural Power Storage Devices

In the world where we thrive to improve quality of life, the quest to develop more efficient devices which also can provide additional value, for example volume (space) or/and weight savings continues. One approach allowing achievement of the volume/weight savings is the creation of smart structures, where monofunctional devices, for example sensors, actuators or batteries are sandwiched together with structural materials. However, the savings achieved this way are very modest. Another approach is to manufacture devices from the materials which can perform two functions simultaneously, i.e. multifunctional materials. It should be noted that there are similarities between power storage devices and fibre reinforced polymer composites, for example, the electrode arrangement in the power storage devices and specifically in supercapacitors is similar to laminated architecture of fibre reinforced composite. Moreover, both devices use carbon based reinforcements/electrodes infused with a polymeric matrix/electrolyte.
This project is directed at establishing a new international collaboration to investigate the important questions related to the safety and fire performance properties of structural supercapacitors between DU, one of the UK's leading Universities, and the University de Poitiers, one of the oldest Universities in Europe with strong links to CNRS. Experimental work, to be carried out in the laboratory of Prof Rogaume (University de Poitiers), will form a basis for this long-term collaboration. The complementary combined contributions and expertise of the academics involved will address and answer important questions regarding the thermal performance and safety of structural electrolytes and multifunctional/structural supercapacitors, using thermal decomposition in an oxidative media as a basis. Structural/multifunctional supercapacitors are devices which may simultaneously store energy and withstand mechanical load, a rapidly developing research topic since multifunctional devices can provide significant weight and volume savings - for example in the automotive and aerospace sectors. The applicant possesses extensive expertise in the synthesis and characterisation of one of the important components of the structural supercapacitor, namely the structural electrolyte. To date, characterisation of the structural electrolytes has focused on their microstructure, electrochemical performance and mechanical properties, since these are the essential for the optimisation of the electrolyte formulation. However, as structural electrolytes mature, their safety and fire reaction, i.e. a flame spread, flammability and release of fumes and smoke) must be thoroughly investigated. While the thermal stability and degradation of the individual components, such as epoxy based fibre reinforced composites and ionic liquids (used as an electrolyte) are already well researched, no work has been carried out on the final structural electrolyte as well as structural supercapacitors. This study is important as the impact caused by fire cannot be overestimate, especially where people are involved. In all potential applications, structural supercapacitors are closely linked to people, whether they are used as a part of a hybrid/electrical car, aircraft or a case for a laptop / tablet. From this perspective it is very important to know, not only whether or not a device will burst into flames but also what will happen if it is subjected to fire; and what gaseous product would form as a result - knowledge of which is crucial to assessing the associated health hazards. The purpose of the project is to provide preliminary and informative answers to these important questions.

The proposed visit will help to establish a new and long lasting international collaboration and facilitate discussion towards a future grant submission enabling expansion of existing research in the field of multifunctional power storage devices, securing the leading research role for the UK.
Given that this is only three months project it is impossible to expect huge direct impact. However, structural power storage fits a Composites Sector, which is undergoing significant growth, and is recognised as a key technology for the future prosperity of the UK. It was reported that the UK has an opportunity to grow £2.3bn composite product market to £12.bn by 2030. This growth is possible due to properties of the composites such as light weighting, low maintenance and reduced through life cost. Moreover, there is not only further growth of composite use in the established industrial sectors, such as Aerospace and Motorsport to their use in relatively new sectors, such as Automotive. All above mentioned industrial sectors will benefit from structures which are not only lightweight but also can provide energy storing opportunity. Another potential benefit is, the environmental benefit, stemmed from the lighter structures leading to a reduction of emission. As a result using structural supercapacitors would help to rich the UK target for reduction in carbon emissions of 60% (1990 levels) by 2030 and 80% by 2050. It has to be noted, that structural power goes well beyond Transportation: we foresee that these materials will be exploited in mobile electronics and portable electrical (power tools, etc). Being able to provide answers related to a safety aspect of the structural supercapacitor will increase bring the use of the structural electrolytes and supercapacitors on their base in real life applications closer to reality.