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Solar farms are great when the sun is shining, but when it’s not you’d better hope you’ve saved some energy up (Getty Images)
Solar farms are great when the sun is shining, but when it’s not you’d better hope you’ve saved some energy up (Getty Images)

ScienceOctober 30, 2018

There’s no renewable energy future without lithium

Solar farms are great when the sun is shining, but when it’s not you’d better hope you’ve saved some energy up (Getty Images)
Solar farms are great when the sun is shining, but when it’s not you’d better hope you’ve saved some energy up (Getty Images)

If the future is going to be powered by renewable energy, the world needs to get a lot better at dealing with one very precious element, the Materialise conference on sustainability in Wellington has heard.

The argument goes something like this: To fight climate change, the world needs to convert to technology that runs on clean, renewable energy, rather than fossil fuels. If we have windmills instead of coal fired power plants, and electric cars rather than gas-guzzlers, then we’ll dramatically reduce emissions, be able to maintain our quality of life, and stave off the worst effects of climate change.

The problem with that is that with current technology, the strategy relies incredibly heavily on an element that we don’t have all that much of left – lithium. It’s in pretty much every smartphone and electric car battery, and is a vital component of the batteries that make renewable energy a reliable source, by storing up power when the sun is shining or the wind is blowing, and then releasing it when that’s not happening. There’s no shortage of sunlight and wind in New Zealand, but with four seasons often cramming into one day, it’s not consistent. That makes battery storage either a limiting or enabling factor in creating a reliable renewable energy supply.

Use of lithium as the ingredient that powers batteries has skyrocketed in the space of a few decades, and accordingly, the price of lithium has shot up as well. The reason is it’s tricky to produce – about half of it takes place in Chile, through a slow process of brine containing lithium being evaporated by the sun. And that’s a difficult process to scale up dramatically, which means the demand for lithium will really start to stretch the supply. And if it can’t be met, then that means dreams like a fully electric vehicle fleet, are just that – dreams.

The element needed for an electrified future was a vital part of two of the keynote speakers at the Materialise conference at Te Papa in Wellington. The keynote speakers were invited based on their work in coming up with new technological innovations at the ‘discovery end’ of the scientific method. The questions being asked around batteries were twofold: what if there were better ways to increase the supply of lithium? And what if, once that had been secured, there were better ways to use it?  

Dr Anita Hill, the Executive Director of Future Industries at the Commonwealth Scientific and Industrial Research Organisation in Australia, was the first of the keynote speakers to raise the topic of lithium. With an eye to the industrialised, digitised society we live in, she spoke about the fundamental relationships between water and material use, energy consumption and economic activity, and how that meant a more sustainable circular economy needed to be built.

Dr Hill’s research focused on what she described as a “recycling bin of the future,” which would operate at a molecular level. It would use metal-organic framework membranes to filter out ions like sodium and lithium from water. Such technology could revolutionise processes like desalination of salt water, so that it can become safe for human use. It would also, somewhat ironically, be applicable to the wastewater created by the mining and oil extraction process known as fracking. Dr Hill acknowledged that it’s strange to consider an environmentally destructive process, which produces carbon emissions through fossil fuels, could have beneficial offsets. But she stressed that research should continue into the area to get it to the point where it could be scaled up to industrial levels, so that some environmental good could come out of fracking.

Dr Anita Hill speaking at the Materialise conference 2018 (Image: Mark Faamaoni).

The thing about lithium though, is that even if more of it were to be produced, wasteful practices are currently depleting the supply of what is available. Here’s an example: When Samsung Galaxy Note 7s started exploding, a worldwide product recall ensued. The lithium ion batteries in the tens of millions of Note 7s were dumped along with the phones, rather than having the totally safe lithium extracted from them first. The second Keynote speaker to talk about lithium Dr Amy Prieto, a chemistry professor and founder of Prieto Battery, said that spoke to a greater morality that needed to come into the equation around these decisions. With a finite supply of a resource, surely the world has a duty to invest more in ways of making those resources go further?

“Part of the problem is that the technology for recycling is challenging, as Dr Anita Hill spoke about this morning,” said Dr Prieto. “Some of that technology doesn’t exist quite yet. But you can’t tell me 100 million batteries isn’t worth figuring this out for.” She says a lot of research still has to go into the area, but she’s trying to show “we can take what is known about lithium ion battery chemistry, but by assembling it in new ways, we can get even more advanced function.”

Dr Prieto’s research focuses on sustainable manufacturing, particularly when it comes to batteries. And she says recycling has to become far more prominent in the life cycle of not only the lithium ions themselves, but the batteries that they’re part of. Because of the way batteries are made, they’ve generally still got some juice after they’ve been exhausted for their primary intended purpose. She cites the example of an electric car battery – even after it can’t be used for that function any more, it could still be used to store power built up at a solar energy farm, for example.

And as to the dangers of lithium batteries? What if they explode? Dr Prieto’s response to that acknowledges that lithium can be highly reactive, but any dangers need to be kept in context. “I mean, most of us drive vehicles that have a highly flammable liquid in basically a plastic jug. And we don’t worry about it.”

The conference as a whole stressed the need for these sorts of connections to be made, for joined-up thinking as a response to the challenges of building a sustainable world. The speakers weren’t confined to any one field or discipline – there were scientists, communicators, government advisors, entrepreneurs and corporate spokespeople, united by an interest in applying themselves to problem-solving and solutions.

Obviously, none of these solutions presented are silver bullets for fighting climate change, or even perfect in and of themselves. But sustainability is situational – the wisest decisions always depend heavily on the circumstances being faced, rather than dogmatic ideas about one solution being inherently better than another. And if the technology lithium makes possible is going to play a part in our future, scientific research and expertise will need to influence how those decisions are made.

This content was created in partnership with the MacDiarmid Institute. 

Materialise: a sustainable future is a one day discussion about future science for an environmentally and and economically sustainable New Zealand.

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