Rapid electrolyte wetting of lithium-ion batteries containing laser structured electrodes: in situ visualization by neutron radiography

Lithium-ion batteries are widely used as energy storage devices due to their high energy density and versatile applicability. Their dissemination in the mobility sector is presently limited by their high manufacturing costs. The electrolyte wetting process is one major cost driver, as process times of hours or even days are necessary to ensure complete electrolyte impregnation. In this contribution, multilayer pouch cells comprising three different types of electrodes were manufactured and filled with the electrolyte liquid while being subject to in situ neutron radiography. Two different electrode porosities were compared, as well as laser structured electrodes with additionally created micro channels, aiming at an acceleration of the wetting process. With the powerful tool of neutron radiography, it is possible to visualize and determine very precisely the wetting time, which was significantly shorter for the batteries with electrodes of higher porosity. Laser structuring of the electrodes accelerated the wetting process even further, reducing the time to complete wetting by at least one order of magnitude. These findings present great potential for the reduction of the processing time and thereby the manufacturing costs of lithium-ion batteries.