Paper accepted: Chitosan as enabling polymeric binder material for silicon-graphite based anodes in lithium ion batteries

Today, the third paper on using chitosans as a material in ‘green’ batteries in which our doctoral candidate Max Linhorst was involved has been accepted for publication in the journal Energy Technology. As part of her doctoral project in the framework of the NRW Graduate School “grEEn” initiated and coordinated by Prof. Martin Winter from the Münster Electrochemical Energies Technology centre MEET, NiloofarHamzelui has worked in the group of Prof. Egbert Figgemeier at the Institute for Power Electronics and Electrical Drives (ISEA) of RWTH Aachen University. When this Graduate School started, we were surprised and delighted to see how many colleagues had an interest in chitosan as a material to improve the sustainability of batteries. It fell to Max to produce and provide the different chitosans which we considered most likely to perform well in the different applications. Niloofar compared chitosans with different molecular weights and fractions of acetylation and found that unusually highly acetylated ones performed best as a binder in silicon/graphite-containing anode materials for use in lithium-ion batteries. The performance was further improved by crosslinking this chitosan using citric acid. Like in the other studies supported by Max’ chitosans, it turned out, thus, that it does make a difference which chitosan is used for a given application. Different chitosans preform differently, and the potential of chitosans can only be fully appreciated when performing a systematic study on structure-function relationships. We hope that these results will eventually contribute to making batteries more sustainable.