Electrode Processing Towards Ultra-High-Energy-Density Electrode and Its Electrochemical Performance Research

Wednesday, 4 October 2017
Prince George's Exhibit Hall D/E (Gaylord National Resort and Convention Center)
Y. Fu, X. Song, G. Liu, and V. Battaglia (Lawrence Berkeley National Laboratory)
Now worldwide effort is underway to develop electric vehicles (EVs) or hybrid electric vehicles (HEVs) to reduce fossil fuel consumption in the transportation area. Lithium ion batteries are considered as the first candidate to be used in EVs and HEVs due to their high energy and power density in the existing commercial battery system. The most essential parameters in batteries are energy density, cost and safety. The cell energy density depends on the cell chemistry and geometry. Even batteries are with the same active materials, but they can be engineered to meet specific power and energy demands. A laminate of a given thickness and porosity can be compressed to different thicknesses and associated porosities. This leads to electrodes of different energy and pulse power densities. In this research, we focused on material properties and the processing necessary for making ultra-thick electrodes with optimum energy and power density for EVs and HEVs. We determined the maximum energy density that can be achieved with a cathode of NCM that still meets the EV pulse power requirement. To achieve this goal variables are the molecular weight of the binder, viscosity of slurry and calendering. We also examined the role of processing conditions of battery slurries on binder distribution and in turn on the electrode’s mechanical and electrochemical performance properties.