The battery waste problem
One of the world's biggest impending environmental problems is battery waste, which is set to explode globally in the next 10-15 years – and it's already in a bad state.
In Australia today, more than 3,300 tonnes of lithium-ion batteries (LIBs) end up as waste, with a shocking 97 per cent of the batteries we buy going to landfill rather than being recycled. But the next problem will be a lot bigger – literally – than the AAs and AAAs we’re dealing with right now.
"The large-scale batteries being sold today will start coming offline in a decade or so," explains Dr Anand Bhatt, Team Leader for Electrochemical Energy Storage and CSIRO Energy in Clayton, Victoria.
"As an example, we're talking about between 150,000-180,000 tonnes of electric-vehicle [EV] batteries, based on the very small scales of EVs sold currently in Australia. That's just Australian waste."
Add to that, explains Dr Bhatt, "the power-utility battery systems in South Australia, Queensland and Victoria, and suddenly we're talking about millions of tonnes of battery cells coming offline in the next 20 years or so.
"This is going to be a massive environmental problem in the future if we don't start working on it now."
A crushing waste
Even the most advanced approach to recycling batteries in Australia is "let's smash them up," says Dr Chris Vernon, Leader of CSIRO Green Minerals Technology initiative.
Even then, 'recycling' is something of a misnomer.
"They get crushed up, and the bulky base metals are recovered, but the high-value, functional, 'magic powders' inside the battery end up being exported to be recycled elsewhere."
These valuable precursor materials are either fed into a furnace or dissolved in vats of acid for recovery of only the nickel and cobalt value "and the other materials just get dumped," he says.
New consumer behavior needed to recycle batteries
"The problem with recycling LIBs is also that we’ve got to change consumer behaviour and get people to stop throwing them away, but rather collect them and every few months take them to a recycling centre," says Dr Vernon.
"We also need to stop sending them overseas."
"Right now, some are smashed up to make them safe for transportation and to standardise them, maybe some basic metals are recovered before they’re shipped off."
"Mostly they are sent as whole battery units, which is a fire risk – in fact one container load of batteries from Sydney caused a fire in the Port of Colombo and that port no longer accepts battery waste."
A 2018 report from CSIRO (Dr Bhatt is one of the authors) estimated that a combination of Australia’s historically poor collection of LIBs combined with the offshoring of the 'recycling' could by 2036 represent an economic loss to the Australian economy of between $813 million and $3 billion, an estimate based on the potential recoverable value of the materials at current-day commodity prices.
These projections are only for EV wastes – when the household batteries and grid utility batteries are factored in the potential recoverable value is a lot higher. The valuable resources in LIB waste include cobalt, lithium, base and other metals and graphite, which could instead be recovered onshore and reused for new products.
Inventing technologies to give batteries another life
Dr Vernon says Dr Bhatt and his team are developing world-leading innovations to recover and re-use battery materials.
"That's an important distinction: the recovery and reuse of materials," says Dr Vernon.
"Recycling is that big loop where the nickel you take out of an old battery becomes nickel in something else."
"With recovery and reuse, it's always going to be a battery."
Dr Vernon says to his knowledge no one is successfully doing this yet and Dr Bhatt's Electrochemical Energy Storage group has already applied for patents on some of the technologies they've developed.
"One of the most expensive components in the battery is the electrolyte," he explains.
"At the moment we're throwing that value away."
Capturing economic opportunity
The current process to capture lithium from batteries (if it is recovered at all), Dr Bhatt explains, is to convert it using a hydrometallurgical or pyrometallurgical process back to lithium hydroxide or lithium carbonate – essentially the same product that was originally mined – which is worth up to around $10,000 a tonne.
In order to use this for battery manufacture, it has to be converted to lithium hexafluorophosphate (LiPF6).
"The price for LiPF6 is sitting at around $50,000 a tonne," says Dr Bhatt.
"We looked at that and thought it seemed silly: It's in the battery already in the form that's needed to make more batteries. Why are we going backwards?"
He also points out that the process to manufacture lithium PF6 "takes a lot of hydrofluoric acid, so it's not the kind of process that you want going on everywhere".
The CSIRO team came up with the idea to develop a process for the first step of the recycling process.
"Once it is crushed down into a powder for processing, our idea is to capture the lithium PF6 right then as it is, recuperate it, clean it up and put it straight back into batteries."
The process of charging and discharging batteries intrinsically causes chemical change and some damage to the electrode materials.
"You can't get away from that," says Dr Bhatt.
But even at the end of a battery's useful life, there is more than 90 per cent of undamaged battery materials left; 'cleaning it up' separates these materials out for reuse.
This recovery of the precious electrolyte – using a chemical process to extract it and then converting it into a powder ready for reuse in batteries – is the kind of technology that will help us close the loop on energy metals.
"It's a powder which can then be dissolved into a liquid electrolyte and then that liquid is injected into the new battery," says Dr Bhatt.
"We don't want to be redesigning recycling plants or battery manufacturing plants, so this is the most cost-effective way of getting it happening," he says.
A bold vision for a new Australian industry
Dr Bhatt has his eyes on a broader mission than dealing with only Australia's battery waste.
He sees a future where Australia could become the Asia-Pacific hub for this circular battery recycling.
"We can take China's battery waste, India's battery waste, all the Asian waste and turn it into a large-scale industry generating thousands of jobs for Australians," he says.
"Obviously we have to do a lot of economic calculations to show it's viable, but from our perspective as scientists that's where we would like to see this go."
He and his team hope to have the PF6 recovery technology ready for pilot-scale in the next five years, and to have it commercialised for industry five years after that.
"That puts us into the timeframe of 10-15 years when the batteries being sold today will be coming into the waste stream."
"The key for us now is to make sure the technology's ready."