Posted on: in Blog

Stuttgart Exhibition Centre 28-30th June 2022

Blog by John Tinson

The Battery Show is Europe’s biggest event focussed on all aspects of design and manufacture for cells, modules and packs. Four halls at the Stuttgart Messe are used, built around a strong conference thread with multiple topic tracks. The sun was shining, I was back at in-person events and once I’d put the chaos of flying abroad behind me I was ready to enjoy the week.

I travelled with a number of objectives:

The event was well attended and well organised, as expected for any German show. Attendance at the conference required an extra fee but sessions typically had 100+ delegates and the associated Q&A sessions allowed for deeper insights from the 6 person panels. In this blog I will give my impressions for the two presentations and panels I attended - a session on silicon anodes and the panel I sat on for solid state electrodes.

As a delegate, I attended the Si anode thread. The use of silicon anodes is becoming a hot topic both in traditional LiB design and for quasi and fully solid state cells. Ines Miller of P3 chaired the session and Myeongjin Choi the Product Manager for Umicore gave the keynote. On the panel afterwards were representatives from Vianode, Leyden Jar, Floatech, Sionic and Elkem. With a panel split evenly between powder-based technology and the adherents to vapour deposition techniques, we looked to be in for some interesting debate.

Myeongjin showed us the timeline and evolution pathway from today’s SiOx anodes, through doped SiOx and onto Si/C and porous Si/C, lastly moving to the more futuristic Si-rich and pure Si powders. TRL and MRLs were addressed for each, and an estimate made that 20% of all batteries may have Si-based anodes by 2030. We then looked at affordability, thankfully seemingly well aligned to the industry needs, before a more technical analysis of issues such as swelling, rate capability and cycle life. Clearly, and certainly for the more Si-rich but high desirable options, there is still much R&D to be done and common deployment cannot be expected until the end of the decade. Solid state type cells are likely to be the key technology drivers for the Si-rich variants.

At panel of course all this can be challenged and with Leyden Jar and Floatech developing a very different, purer and far thinner, Si anode technology we had some interesting debates. The technical outcomes from the plasma vapour deposition technologies is that they enable energy densities of up to 1350 Wh/l whilst controlling swelling due to the µ’s only thickness of the porous pure Si anode. The key criticism often levelled at the CVD process is of course cost, but Leyden Jar surprised everyone by announcing a very large scale up program that would bring production costs within reach of the EV sector.

For the second thread on solid state cell technology, we were chaired by Ulderico Ulissi of Rho Motion, with the keynote given by Dr. Xiaoxi He, the Principle Analyst at IDTechEx, Cambridge. My fellow panellists came from Prieto Battery and Factorial, both representing semi solid solutions, whilst I represented fully solid. Xiaoxi’s keynote looked at 10 global companies developing semi or fully solid next generation cells, these were split into polymer, sulphide and oxide type electrolytes. She looked at safety differences with LiB technology and then outlined the various challenges still being faced by developers of solid state, not least of which being cost and scalability. A long session of questions from the floor allowed the audience to dig deeper in these challenges with the conclusion being that the industry is likely to migrate from LiB towards semi solid technologies after 2026, with fully solid being a final phase as we enter the next decade.