The Time for Industrialization Has Come: A Pre-Coated Solution for the GW Scale
Authors: Bernuy-Lopez Carlos , Bexell Ulf , Stenstrom Mikael , Norrby Niklas , Westlinder Jörgen 
Published: July 2021

Green Hydrogen has become present in all mass media thanks to their ubiquitous role to overcome the issues related to climate change. It is estimated that green hydrogen and their associated technologies (i.e. fuel cells and electrolysers) will represent 25 % of the total energy mix by 2050 if a 100 % renewable system is achieved. Among these technologies are Solid Oxide Cells (SOC). This technology has the capability to be the more efficient technologies among fuel cell and electrolyser’s technologies as well as the technology made from cheaper and more abundant materials. In addition to this, it has also the capability to function much more easily in reversible mode that their fuel cell and electrolyser siblings (AEM, PEM or even AEM) which give them a great versatile capacity.

In order to make Green Hydrogen a reality and to succeed, an immense work in terms of industrialization needs to be done. In the following years, the industry needs to prove that is ready to deliver the systems in the large volumes that it is going to be demanded if we want to give response to our climate goals (i.e. GW per year). For instance, by 2030 it is estimated that 500 000 micro-CHP (combined heat and power) units will be installed only in the European Union which would require the production of at least as many fuel cell systems for such application. This large number, make a very rapid fuel cell industrialization necessary and a suitable value chain must thus be created.

Sandvik Materials Technology (SMT) is a material provider for the more demanding industries and applications. During our more than 160 years of history, the company has delivered large volumes of materials in forms of tubes and strips, for instance. Solid Oxide Cell systems are constituted by many tubes and strips made of special stainless steel alloys in which SMT is specialized of. More recently, SMT has developed a coil-to-coil process to produce pre-coated strip for the fabrication of bipolar plates and interconnects in both PEM fuel cells and electrolysers but as well for SOC. The pre-coated concept allows the industry to have a cost-effective process ready for the rapid ramp-up of both fuel cell and electrolysis technologies.

Regarding SOC, Sanergy HT 441 is designed to be used as interconnect material. The product is made at industrial scale by Physical Vapor Deposition in the above-mentioned roll-to-roll coating method. It is based on an ASTM 441 steel grade double coated with thin layers of Ce and Co (< 1 µm). The material can be double side coated with the same coating or with a different coating in the other side. This material has shown to form a protective (Co,Mn)3O4 spinel layer that improves corrosion resistance and heavily reduces Cr evaporation. Recent studies has shown that Cr evaporation is reduces up to 10 times thanks to the Ce and Co coating. On the other hand, very recently it has been put on the table challenges with use of Co due to both societal and economical conflicts. At Surface Research in SMT, different Co-free coated materials has been developed in order to offer a different solution to this. Therefore, this work will show the solutions that SMT put in the market to industrialize fuel cells and electrolysis, and concretely SOCs.