Abstract:

Major breakthroughs in batteries would require the development of new composite materials, with a precisely controlled nanoscale architecture. These materials can be synthesized directly on the electrodes using electrochemical methods, allowing sequential deposition, high structural control, and low cost.
In this context, the present seminar will address first a new pathway to create complex structures made of multilayers of graphene and transition metal oxides/sulfides. This selective approach fully exploits the 2-dimensional shape, versatility and electrical conductivity of graphene to achieve an ideal hierarchical structure. By combining chemical vapour deposition (CVD) and electrochemistry we could obtain multilayers of vertically aligned nanosheets of mixed metal sulfides (NiCoMnSX) alternated with horizontal spacers of reduced graphene oxide (rGO), all electrochemically deposited on a 3D conductive graphene foam. The multilayer composite could be used with no further processing as cathode integrated with an anthraquinone-based redox-active conjugated microporous polymer electrode as anode (IEP-11), showing promising results in rechargeable alkaline batteries.
Moreover, we also successfully deposited graphene and metal oxides on complex geometries made of carbon fibers (CF) for structural Li-ion batteries. Devices which can be included in the framework of airplanes and cars to reduce weight and provide energy for distributed electronics at the same time.
Our electrochemical approach can be used to assemble multilayer composite structures on arbitrary shapes for different applications.

Short Bio:

Jaime S. Sánchez is Postdoctoral Researcher of the Industrial and Materials Science Department at Chalmers University of Technology (Sweden). A Chemical Engineering graduate, he holds a PhD degree in the field of Electrochemistry and Materials Science by Autonoma University of Madrid (2019). His Thesis was developed on the Lab facilities of the Electrochemical Processes Unit at Imdea Energy, focused on the synthesis of graphene-based materials and their application in electrochemical energy storage devices. In this period, he also enjoyed a research stay at the Fritz-Haber-Institute-Max Planck-Gesellschaft, Berlin (Germany) studying the charge storage or catalysis mechanism via in-situ experiments (e.g., XAS and XPS) at BESSY II Synchrotron. After his PhD, he joined the 2D-Materials group of Vincenzo Palermo at Chalmers University of Technology as a Postdoctoral Researcher, where he has developed composites for energy storage applications in the frame of the Graphene Flagship project. He has been involved in several national and European research projects and he is author of 11 research articles included in SCI journals and 17 contributions to international scientific conferences. Since last September 2020 he is visitant researcher of the Electrochemical Processes Unit at Imdea Energy.