Slot-Die Coated Active Carbon Films for Hydrogen Storage Applications

Abstract

Slot-die technique for the deposition of ≈ 3 µm, ultra-pure active carbon layers has been discussed in this paper with their potential use in hydrogen storage applications. Activated carbon nanoparticle inks were manufactured for their use in the process for the deposition of layers on flexible PET substrates whereby the roll-to-roll system provided the continuous feed of the flexible substrate. Different parameters affecting the process and the deposited layer thickness and uniformity such as stand-off distance, flow rate, and substrate speed have been examined through CFD simulations to come up with an optimized parameter combination. Layers with fine uniformity are achieved and an operating envelope is constructed between the applicable values of coating speed and flow rate. Flow rate below 0.9 ml/h and more than 1.75 ml/h was deemed unfit for the process. Based on these values the substrate speed of 70-100 mm/s is determined to be the recommended speed. The thickness of the deposited films varied from 3 µm to 8 µm with varying flow rate and varying stand-off distance. The cost-effectiveness, room-temperature operation, environment friendliness, and simplicity of the process with its possible integration with high throughout manufacturing processes like roll-to-roll process makes it an idyllic candidate for deployment in the challenging field of hydrogen storage at a large scale.