Supporting the transition towards renewable energy sources necessitates minimising the carbon footprint of materials utilised in green technologies, such as Fuel Cells and Electrolyzers. Bipolar plates (BPP) and Gas diffusion layer/Microporous layer (GDL/MPL) are key components in those technologies, and graphite is a critical raw material.
A new family of innovative high-purity biomass-derived synthetic graphite produced at an industrial scale and is commercially available as SU-NERGY. This new graphite significantly reduces CO2 emissions compared to both traditional fossil-based synthetic graphite and purified natural graphite, and demonstrates a compelling carbon footprint of < 0.9 kg CO2 eq/kg in accordance with ISO14040 and ISO14044. It not only offers enhanced sustainability but also achieves performance levels equivalent to or superior to traditional graphite. This study specifically examines the utilization of this material in two essential components: BPP and MPL.
We investigate the material's structural and functional properties, including electrical conductivity, thermal properties, permeability, and porosity, using established testing methodology.
● For BPP, through-plane electrical conductivity of sustainable graphite has been evaluated and compared to standard synthetic and natural graphites using the norm DIN 4880. This improvement is crucial for reducing ohmic losses and optimizing the overall efficiency of the fuel cell stack, with potential applications also extending to electrolyzers and redox-flow batteries.
● For GDL/MPL, graphites offer an advantage compared to carbon black by enabling pore size tuning, ranging from 0.5 to 5 μm. This precise control, measured using mercury intrusion porosimetry, is essential for optimizing the permeability of reactant gases (hydrogen and oxygen) to the catalyst layer and ensuring the effective removal of product water.
Biomass-derived graphite is a high-performance, scalable solution for hydrogen technologies. Its low-carbon footprint and the potential for a sustainable European supply chain, confirmed by these data-driven outcomes, underscore its value.