Investigating the Impact of Thickness and Porosity on Energy Density of Screen Printed Graphite/NMC LIBs with 3D Structures under Fast Charging Condition

Several printing techniques have been developed so far to fabricate advanced electrode structures with different 3D patterns for lithium ion batteries (LIB) applications. Making channels along the thickness of the electrode has been proved to be effective on energy density enhancement of LIBs by reducing the overall tortuosity in the electrode and improving the ionic diffusion along the electrode thickness, especially under fast charging conditions. In this paper, a 3D physics-based electrochemical model of Graphite/NMC (nickel, manganese, and cobalt) full-cell is developed in COMSOL software. The designed electrodes have cylindrical channels in both anode and cathode. The impact of channels on volumetric energy density of electrodes with different thickness and porosity under high current rate of 6 is investigated. The simulation results demonstrated that compared to reference cell with no channels, the patterned cell with similar mass loading is capable of increasing volumetric energy density by more than 2 times. The impact of electrode properties such as porosity, thickness, and cathode to anode thickness ratio is investigated and showed that the channels are more effective on improving energy density of thick electrodes with low porosities when compared to thin or highly porous electrodes with similar mass loading.