International Battery Seminar Shines Light on Silicon Anodes as Next Evolutionary Step for Lithium-ion Batteries
By Michelle Tokarz, VP of Partnerships and Innovation
In my role as VP of Partnerships and Innovation, I am always attempting to understand current technology and market trends related to The Coretec Group’s products, and most recently, trends related to battery development as it relates to electrification. To that end, I recently attended the International Battery Seminar and Conference in Orlando, Florida.
My main takeaways:
- In addition to novel chemistries theoretically capable of reaching astonishing charge capacities, successful commercialization needs to include considerations of ease of implementation into existing manufacturing methods.
- Successful development of new battery chemistries requires an in-depth understanding of all parts of the lithium-ion battery, including the anode, cathode, and electrolyte. Because of this, industry partnerships – that combine the necessary and specific expertises – offer some of the best promise for creating a full battery that achieves the desired improvements.
- The Coretec Group’s approach to developing a silicon anode for lithium-ion batteries shows great promise as part of the next evolutionary step toward driving better, faster, lighter, and cheaper batteries.
Overall, I found the International Battery Seminar and Conference to be more technical in nature than other trade shows focused on electrification solutions. It drew attendees from industry, government, and academia. Presenters represented the full battery ecosystem, from research to materials suppliers, consulting services to testing and validation firms. While The Coretec Group is focused on applying our knowledge in advanced engineered silicon to manufacture batteries with silicon anodes, we recognize the importance of understanding the full battery ecosystem and the players in it as we develop our prototype battery and engage with appropriate development and manufacturing partners.
Issues addressed included battery safety, recycling, supply chain, and technology developments. Within the realm of technology developments, the ever-elusive “lithium-sulfur” battery appears to be the “Holy Grail” as such a combination would have an extraordinarily high charge capacity for both the anode and the cathode, theoretically as much as 2,600-Watt hours per kilogram. While many speakers presented very exciting developments for this kind of battery, most battery experts agree that the development is still quite early and not easily incorporated into existing battery manufacturing methodologies.
Of a more interesting focus for The Coretec Group was that of lithium-ion batteries, specifically silicon or silicon-composite anodes. If known technical issues of swelling and cycle life can be adequately addressed, there is good reason to believe that such anodes could be incorporated into existing manufacturing methods. Understandably, this increases the interest of battery scientists to solve such problems. In fact, in the drive toward better, faster, lighter, and cheaper batteries, silicon anodes in lithium-ion batteries are seen by many as the next evolutionary step.
The theoretical 10x increase in charge capacity of silicon over traditional graphite anodes may in fact have been the impetus for recent technical developments of such an anode, however, what became immediately clear was exactly how complicated the science of such batteries actually is. This conclusion was further confirmed with one-on-one conversations with exhibitors. When optimizing an anode, for example, the choice of all the other battery components (including cathode, electrolyte, etc.) can have a profound effect on the overall performance, sometimes making it difficult to undeniably discern the positive impact of the improved anode. This complexity can also cause difficulties in successfully commercializing new silicon-based technologies. Many of these early-stage technology companies may have expertise in anode materials, but lack the same depth of knowledge in electrolytes or cathodes. In fact, several speakers mentioned exactly this dynamic as being a very real impediment to advancing necessary improvements in lithium-ion battery technologies. These same speakers also suggested that collaboration among the relevant subject-matter experts might be one of the better strategies to overcome this difficulty.
Finally, there were many talks regarding the “SEI (solid electrolyte) issue” and how it contributes to less-than-ideal cycle life, especially for silicon or silicon-composite anodes. In fact, the irreversible loss in charge capacity from the first to second cycle necessitates that additional measures be taken during the manufacture of the battery in order to compensate. One of the more common measures includes a step called “pre-lithiation” during the formation stage. There is hope that if the SEI issue can be addressed successfully, this irreversible loss in charge capacity could be significantly decreased, minimizing or removing entirely the need for the pre-lithiation step.
The Coretec Group’s contribution to silicon-based anodes includes a bottom-up approach whereby functionalized silicon-based nanoparticles can contribute not only to fast charging, but also to the mitigation of SEI effects. We intend to pursue the use of this highly engineered material in several anode formats that could include a slurry suspension for traditional “jelly-roll” processes, as well as in conjunction with carbon-based supports. By working with the right development partners, we hope to combine our expertise in advanced silicon materials with that of appropriate battery experts to showcase improvements in cycling stability with our approach to silicon-based anodes in lithium-ion batteries.