Electrode Calendering Optimization

Monday, 27 July 2015
Hall 2 (Scottish Exhibition and Conference Centre)
D. Gonzalez, I. Rubio (WMG), and S. D. Beattie (Warwick University)
Among commercially available batteries Li-ion has one of the highest volumetric energy densities. A critical step that manufacturers use to maximize volumetric energy density is to calender electrodes after coating to reduce thickness and increase density. Although optimal calendering parameters are well known to industry, useful information in the literature is scarce, and systematic studies are difficult to find.  This dissertation will provide a methodical study of electrochemical performance as a function of calendaring properties.

Graphite electrodes were calendered at different temperatures (room temperature to 120 oC) with different nip openings (40 to 100 μm). Electrode density is correlated with electrochemical performance using data from coin cell hardware.  Results show that the highest amount of calendaring does not necessarily result in the largest volumetric energy density. This may be due to excessive porosity reduction, which prevents the electrolyte from wetting all of the electrode particles.