Carbons derived from all-cellulose based composites for energy storage devices

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Finding suitable materials for energy storage is very important for a growing use of renewable sources. Cellulose as most common biopolymer is suited for a multitude of applications and a promising basic for high performance composites. The concept of Cellstor is to (i) prepare all-cellulose composites that consist of cellulosic materials having different sizes (nano-micro-macro) and shapes (spheres vs fibrils), (ii) to convert these into activated carbons, and (iii) to assemble these materials into electrochemical energy storage devices (supercapacitors and hybrid capacitors). It is known that the thermal degradation behavior of cellulosic materials depends on crystallinity, molar mass, crystal phase (cellulose I vs II) and morphology. Although the approach may lead to carbon materials with exceptional electrochemical performance, it is not a dedicated objective of the project to provide electrochemical devices with superior properties. The main goal of the proposal is to understand how and to which extent the structure of the all-cellulose composites impacts the formed carbon structures and subsequently the electrochemical performance. The focus therefore lies in the correlation between the initial all-cellulose composite structure and the resulting carbons to directly synthesize of materials with different characteristics as morphology and pore structure. For optimisation of the electrochemical performance of supercapacitors, lignins will be modified and used as additives in aqueous electrolytes.