Slurry Coating

A technique used for creating porous electrodes for lithium-ion batteries.

An electrochemically active material such as Lithium Cobalt Oxide is usually ground with a carbon black additive in a mortar and pestle until fully homogenous. This is then added to a glass vial with a magnetic stir bar, and a few drops of a PVDF/NMP solution are added to the vial. A few additional drops of NMP may be added to achieve the desired viscosity, and then the suspension is stirred rapidly overnight. The next day, a slot-casting die is used to evenly spread the suspension across a foil. The electrode is then dried in an oven to remove any NMP, and then moved to a vacuum oven to remove any residual water. Electrodes saturated with NMP should not be placed in a vacuum oven.

More information:

80% Active, 10% carbon, 10% PVDF not uncommon. Blade cast using a 100 micron gap

Marks, T., Trussler, S., Smith, A. J., Xiong, D., & Dahn, J. R. (2011). A guide to Li-ion coin-cell electrode making for academic researchers. Journal of The Electrochemical Society, 158(1), A51-A57.