Poster Prize: Optimization of Silicon-Graphite Anode and Chitosan Binder Material for Lithium-Ion Batteries

Niloofar Hamzelui, working as a member of the NRW graduate school on Green Electrochemical Energy Storage - GrEEn, won the Second Poster Prize at the annual international conference “Kaftwerk Batterie - Advanced Battery Power” which this year, naturally, was organized as a virtual meeting. GrEEn is a collaborative research endeavour of the MEET Battery Research Centre and several research groups of our institute at the University of Münster, the Jülich Research Centre’s Helmholtz Institute in Münster, and RWTH University in Aachen, to develop more sustainable batteries. Chitosan as a renewable biopolymer with excellent material properties had immediately caught the attention of the chemists, and so Max Linhorst, one of the GrEEn candidates of our group, enjoyed several collaborations with other teams, trying to identify potential use cases for chitosans in batteries, and then to optimise the performance by choosing the best suited chitosan and, possibly, modifying it accordingly. Niloofar, in the framework of her doctoral project at Institute for Power Electronics and Electrical Drives (ISEA) of RWTH Aachen University, tested different well-defined chitosans as a binder material in silicon-graphite blend anodes which synergistically combine the advantages of both anode materials. Among the remaining disadvantages are massive volume changes during charge/discharge cycles of the battery. The free amino groups of chitosan as a binder material can interact with the surface of the silicon particles, assuring the mechanical stability of the electrode and concomitantly accommodating the huge volume change of silicon. It is certainly still a long way before biomaterials such as chitosans will become a functional component of batteries e.g. for electromobility – but even for long ways, first steps are essential!