Fully Aqueous‐Processed Li‐Ion Electrodes with Ultra‐High Loading and Potential for Roll‐to‐Roll Processing

Abstract In this study, high‐ and ultra‐high‐loading NMC622‐based cathodes (7.0 and 18.0 mAh/cm 2 ) and graphite‐based anodes (9.0 and 22.5 mAh/cm 2 ) were prepared by using a porous carbon structure as current collector. All electrodes in this work were prepared by an NMP‐free, PFAS‐free and scalable process. Full cells with areal capacities of 7 mAh/cm 2 and 18 mAh/cm 2 were assembled and tested. The results show an excellent cycling stability, reaching up to 950 cycles at 10 mA/cm 2 for the cells with ultra‐high‐loading electrodes (capacity 18 mAh/cm 2 ) and 650 cycles at 8 mA/cm 2 for the cells with high‐loading electrodes (capacity of 7 mAh/cm 2 ). The influence of cathode porosity on the electrochemical performance in cells capacity of 7 mAh/cm 2 showed that a lower porosity leads to a poorer rate capability as well as a worse cycling capability (400 cycles at 6 mA/cm 2 ). Post‐mortem analysis reveal that the anode aging is more pronounced during full cell cycling. Further the scalability of the production process was demonstrated by using a padder tool. With that, cathodes with a loading of 5 mAh/cm 2 were produced in a roll‐to‐roll process.