Prof. Paul BRAUN, Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign

Abstract

: Through mesoscale design of a 3D current collector, high power and energy density rechargeable batteries can be realized.  At the most fundamental level, mesostructuring enables optimization of the trade-off between energy and power density in energy storage systems due to unavoidable ohmic and other losses that occur during charge or discharge.  By design of the ion and electron transport pathways, we and others have shown it is possible to significantly improve the power-energy relationship.  We have found a particularly effective way to provide these pathways is to use a colloidal-based template to form a mesostructured 3D current collector.  The electrochemically active material is then deposited on this current collector via both electrochemical and hydrothermal routes.  Using this approach, Li-ion batteries which could be discharged in as few as 10 seconds with 75% capacity retention were formed.  The combination of a high surface area and short solid-state diffusion lengths offers a number of unique opportunities for both high energy and high power chemistries.  As examples, we have formed conventional form-factor and microbattery high power cells based on a lithiated manganese oxide cathode and carbon or NiSn anodes, and high energy cells based on a silicon anode.  Time permitting, I will also describe how such engineering can also provide benefits to supercapacitor systems.

Dr. Mariano Campoy

mcampoy@icmab.es