Batteries have become an omnipresent technology a majority of the population is using every day. The vast majority of these cells are equipped with electrodes composed of current collectors coated with an active material. The current collectors are usually coated on both sides. But applying an asymmectrical lamination of the active material can enhance the energy density of the cells. Rumors are out there, that cell manufacturer Tesla might use such approach in future cells.
However, enhancing the energy density can come with additional obstacles due to inhomogenous current distribution. Asymmetrical lamination causes different resistances and diffusion pathways for each side of the electrode coating. But how exactly?
This question can be answered utilizing a physical-chemical battery model (PCM). The PCM available at the ISEA enables a 3-dimensional simulation of the electrodes to a predefined volumetric resolution. This approach enables the localized and time-dependent analysis of the current, the concentration within the simulated particles, the electrolyte concentration, and the overpotentials within the electrodes as a function of electrode thickness. Based on the simulation results an optimum selection of asymmetrical coating thicknesses and operation strategies can be targeted.
Since sodium-ion batteries are getting more attention and the PCM also works for sodium-ion batteries, this work investigates the asymmetrical lamination of a sodium-ion battery utilizing the PCM. The simulative analysis of asymmetrical lamination supports the development of real sodium-ion battery cells having asymmetrical coating thicknesses without facing tremendous sodium plating due to inhomogeneous current distribtution.