For the past three decades one technology has come to dominate – lithium-ion batteries. From consumer goods to static applications and most recently mass mobility, lithium technology has become the solution.
The father of the technology, Professor John Goodenough, perhaps couldn’t imagine how much of an impact his work would have on the world. As we enter the electrified future – driven hugely by the automotive industry as it races to prepare for the ban on sales of new combustion engine vehicles – there are challenges ahead.
The world faces a huge range of pressures, from soaring costs and higher demand to environmental concerns and issues around extracting raw materials. All these are exacerbated by geopolitical challenges. You only have to look at the price of lithium to see the spike in costs.
Automotive is driving both demand and development of storage technology, but what helps the motor industry could impact other sectors too. So will lithium-ion batteries drive our future? Professional Engineering quizzes three experts to find out what they predict will happen.
Dr Billy Wu, senior lecturer in the Dyson School of Design Engineering at Imperial College London
There are lots of different flavours of batteries, but the reality is that lithium-ion is the one that’s going to be the near-term technology. In the future, when we solve some of the other challenges, solid-state batteries or sodium-ion batteries have potential. But history shows that it takes almost two decades to go from fundamental scientific discovery to commercialisation.
Professor John Goodenough developed the lithium-ion battery back in the 1970s, but it wasn’t until 1991 that Sony first commercialised it with its camcorders.
All devices require slightly different things. Automotive is mostly about cost and energy density – people care about how much their cars cost and how far they can drive. If you look at other fields such as stationary grid applications, when there’s abundance of wind and solar energy we don’t care about energy density that much because it’s just sat on the ground. You care about cost and lifetime. That’s why sodium-ion in those cases might be the most relevant technology.
Most of the battery chemistry is dictated by the cathode. Right now, the state of the art is nickel-manganese-cobalt oxide (NMC). The current trend is to increase the nickel content. That creates the first challenge. If you’ve looked at commodity prices, they’ve gone through the roof, through a combination of geopolitical factors and also increasing car industry requirements.
So people are starting to revisit whether we should be using nickel-rich batteries. There’s another chemistry – lithium-iron-phosphate (LFP) – but it’s not got as good energy density.
For automotive I think between now and the banning of petrol and diesel vehicles it’s going to be nearly exclusively lithium-ion. Where I see the chemistries moving is nickel-rich cathodes for high-performance vehicles and for something like a Ford Fiesta the lithium-iron-phosphate chemistries.
The near-term improvements come from changing the anode. Right now the anode is mostly made of graphite, but we’re adding in small amounts of silicon. But the holy grail battery is using lithium on the anode, and that’s why people want to go to solid-state batteries.
Batteries have become so good in terms of their power capability that the reality is that lithium-ion does everything.
Richard LeCain, director of cell and process engineering at Britishvolt
If you’re talking 2022 to 2035, I think lithium-ion will continue to be the dominant chemistry and really the only game in town. There are other emerging chemistries being developed, but they are not as rapidly commercialisable as lithium-ion. There are also big hurdles to be solved with them, such as expansion, life capability or volumetric density. There would be a lot to overcome and, on top of that, they would need to mature.
For instance, supply chains would have to be in place and rival the ramp down in costs that we’ve seen over the last decade or so with lithium-ion. Years ago, they said, ‘we love your products, but we hate your price’. Now we see the things we envisioned when preparing the supply chain coming to fruition. We get the scale rate and, as the adoption of electric vehicles increases, things will align quickly.
There’s a lot of promising science out there in emerging technologies like LFP or NMC, but it will take time to achieve the necessary scale. It took from approximately 2007 to 2020-ish to get where we are today with lithium-ion, which is competitive. And when you think about 2022 to 2035 for LFP and NMC, it’s not a long time. It took a lot longer than people expected for things to line up, which is why so many battery companies bankrupted between 2005 and 2011.
It’s been said over the past 50 years that fuel cells are going to be the next big thing, and the market continues to say it. Yet the reality is that battery technology and adoption continues to increase year over year.
We talk about hydrogen fuel cells, other types of fuel cells, and integrating capacitors and supercapacitors into things. Perhaps there may be room for that from an energy storage point to the car, but you’re still going to need the battery to reliably charge and discharge. The proof? I think you need to look at what’s out there and what things are running on. That tells the story. Batteries are key.
The world has been using oil and refined oil products for a long time. It seems to me that there’s been a lot of volatility with those resources, yet we still push forward full steam ahead. I think that when things become important enough and achieve those economies of scale, they tend to get figured out on global levels. Perhaps it’s just a case of it getting to that level.
In the short term, where adoption is lower, you’re going to have volatility because the market is smaller and more susceptible. EVs are still reasonably new. Most of them are going on the road, not off. When they do start to come off the road, some of that material will find its way back into the supply and value chain. If adoption continues to increase, I think more attention will be paid to this globally like you see with the volatilities in other commodities. Recycling is going to be key.
James Gaade, research programme director at the Faraday Institution
From a ‘beyond lithium-ion’ perspective, we have projects, essentially looking at solid-state electrolytes. That’s really a combination – from an anode perspective, it could be lithium-metal anodes rather than carbon. It’s taking lithium-ion to the next stage as far as the combination of safety and performance and capability, but there’s many challenges in the solid-state world.
There’s then things such as lithium-sulphur that from a power density perspective could really interest the likes of aviation, more so than automotive, and then there is sodium-ion.
But part of the challenge is what are the application targets, what are you trying to achieve, because essentially how you’re tailoring your application targets translates into the chemistry.
Particularly in the aviation world, if you look at some of its requirements, it is a big stretch for what lithium-ion is capable of today, hence the research into things such as lithium-sulphur. But even with lithium-sulphur what’s the system made up of: electrolyte, cathode, separators. So lithium-sulphur could well be in combination with solid-state electrolytes, for instance. There’s quite a number of avenues that we can go down from a next-generation ‘beyond lithium-ion’ perspective.
Even within lithium-ion, there’s still a lot of research activity that we’re doing that’s particularly looking at things such as understanding degradation mechanisms. And as the boundaries of lithium-ion are pushed, there’s a lot of activity around developing modelling capability, so making sure right from an atomistic level, up to modelling thermal management systems. Again, all that research, then from a developing capability in the UK it is flowing through into what it may mean from next-generation ‘beyond lithium-ion’ research streams.
If you look at the way the core systems are today, even with the alternatives there’s still lithium in the system. It’s an abundant element, it’s then just down to how we ensure that, from the sustainability perspective, the whole process from mining through to recycling, that that whole life cycle will work in the supply chains at material levels.
Read more: 3 potential alternatives to lithium-ion
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.