The future of battery improvement
It might appear that batteries are lagging behind the curve when it comes to technological innovation. But is this a fair assessment? And what could be done to improve batteries as we rely on them more and more? With us to discuss this is the University of Warwick’s Louis Piper.
Chris - Louis is it a fair assessment to say that batteries are a bit behind the curve?
Louis - Well, I wouldn't say that. Since about 1991 when the first lithium ion batteries became available in portable camcorders, we've seen a 98% drop in the cost of production of these. There's a fraction of the price that went from $5,000 per kilowatt hour production to a hundred dollars per kilowatt hour production today. And I think it's a case where it's that combination of being able to deliver all those applications that Jay mentioned in terms of portable electronics and electrification. And it's really a case where the abundance of manufacturing scale has really played in. It is one where, for instance, with electrification, we've seen 50% of the electric vehicle in 2015 was essentially half the price of the battery pack. And that was why the electric vehicles were so expensive. Now we're seeing projections in 2023 where we're expecting a huge drop in battery pack prices such that electric vehicles become on par with petrol vehicles in terms of range of performance and cost.
Chris - And are those the main things that technologists, engineers, chemists are going for? What are the main targets When people present a battery these days and they say, this is where we are, where are we aiming to be? What sorts of problems are we looking to solve in the next five years?
Louis - Well, I view batteries as a complex combination of chemistry problems and manufacturing problems. So we are always trying to balance five key components. We want to increase energy density, we want to increase power. So that means how much energy we can store and how fast we're using it. But we also have to balance that with cost. That's a critical component. Lifetime, we touched upon that we want these to operate over decades. And the second component is safety. And so there's this complex equation where we need to make sure that the solutions we come up with to improve energy density and power are ones which are compatible with manufacturing at the scales. We need to provide ubiquitous power and energy for all of our applications, be them portable electronics to grid scale solutions for renewable energy.
Chris - Indeed. And of course recyclability must play a part in that equation too with an eye on being more sustainable in future mustn't it? How are people approaching this then? Are they breaking it down into a sequence of problems that they're trying to solve one at a time or are many people exploring different things in parallel? How are people trying to improve on batteries that we have today?
Louis - Yeah, that's a great question because there's various roadmaps that exist in the industries, especially like in the automobile sector where that's a key area where different large companies are trying to vie for the solution. We talked about earlier that the battery is made up of active and inactive components. Then you have to separate the chemical reactions. One of the key things with this is you can view your battery as having active components and inactive components and to increase energy density you want to increase how much active component you have as a proportion of your cell and your pack, which is the combination of your cells. And so there's things where engineers have been very active at reducing the amount of packaging, the amount of inactive components you have, the cell design and the cell to pack ratios in order to give you those improvements especially on the electric vehicle side. So there's one component with that. And then the chemistry side, there's been the adoption of kind of trying to move back to originally how we used to have in the first adoption of lithium intercalation batteries, they had lithium metal foils, which are very efficient. But the issue with that is safety and lifetime with those. And so a lot of the research activities like solid state batteries that people might have heard of, or new kinds of post lithium ion battery technology like lithium sulfur or lithium air, these are ones where there's a desire to return back to very thin lithium metal foils. And that's a very complex, R&D problem that the industry is facing. How to get back to that and produce it at scale and cost that is competitive.
Chris - It's interesting though because if Volta came forward 220 years and looked at a battery today, he would pretty much recognise what he had originally conceived of though, wouldn't he, in the majority of batteries. Are we now at a point where we're also beginning to think outside the box a bit or outside the battery box a bit where we're coming up with batteries that he wouldn't recognise, whole new designs of how we do energy storage and transmission?
Louis - I think if Volta looked now you're right, he would recognise there are two spatially separated chemical reactions that facilitate the movement of charge and mass. But what I would say is he would recognise that what we're doing in terms of the periodic table is picking elements like lithium. Lithium and also the interest in hydrogen storage. These are our lightest elements that are able to easily release electrons. So it's hard to point to better elements. And what he'd also be surprised about is the massive scale of adoption we're doing in terms of how ubiquitous, how many of these we're making, how robust the manufacturing and the reliability of these cells are, and how we take them largely for granted how well they operate.