Pilot plant opens in Victoria to test lithium-ion battery recycling

By Ruth Dawkins

CSIRO

A pilot facility trialling safer and more environmentally friendly recycling of lithium-ion batteries has begun operating in Victoria.

Australia produces around 3,300t of lithium-ion battery (LIBs) waste each year.

As of 2021, only about 10% of Australia’s LIBs were being recycled. Globally, that figure is about 5%. There is a long way to go before LIBs reach the 98 per cent recycling rate that has been achieved for lead acid batteries. 

Dr Thomas Ruether, a Senior Research Scientist and Team Leader with the Electrochemical Energy Storage team in the CSIRO Energy Technologies Program,  says there are very few places in Australia that do LIB recycling.

“Due to government subsidies, enabling regulatory frameworks and larger volumes of end-of-life LIBs, about 90% of the world’s recycling capacity is located in Asia and Europe, with a small amount also taking place in the US,” Ruether says.

“Previously, it was common practice in Australia to package our battery waste up and ship it overseas. However, this has become increasingly difficult because of the risks of end of service life LIBs. Much of it is now just warehoused by private industry.”  

Low recycling rates pose several different problems. If LIBs are not properly disposed of, there is risk that harmful materials may leach out of landfill sites resulting in environmental and health issues. Large, concentrated volumes of batteries stored in warehouses or scrap yards need careful management due their flammable electrolyte systems and potential environmental contamination.

The pilot plant, to be operated by CSIRO, Australia’s national science agency, will focus on battery fire risks during collection, transportation, and storage. Additionally, there is recycling lithium-ion batteries into high-value products. This includes second life reuse applications, economic recovery and use of battery electrolyte and graphite, and environmentally friendly recovery of battery metals.

When LIBs reach their end of service life and are collected for recycling, the initial step of the process is to shred them into smaller pieces for further processing. 

Lithium-ion battery recycling demand

Ruether reviewed battery market and recycling trends in a paper he co-authored in 2021, published in the Sustainable Chemistry journal. 

“LIBs are processed to a point where you recover what’s called Black Mass,” he says. 

“Black Mass is essentially graphite and metal oxides – the electrode materials – mixed together in a powder. It can be safely exported offshore for further processing to recover lithium, cobalt and nickel.”

Depending on the processes used, between 50% and 95% of the materials contained in LIBs can be recovered. While the shredding of LIBs is routinely practiced in the recycling industry, there are still significant safety concerns and many unknowns relating to the risk of fire and explosion. There is also the potential release of toxic compounds.

Traditional aqueous wet shredding uses a submerged setting with a brine solution. To mitigate some of these risks, progressive recycling operations are moving away from aqueous wet shredding. Instead, they’re opting for dry shredding under an inert gas blanket to keep air-oxygen out. The dry method also provides the benefit of recovering more recyclable material of value, safely. 

For example, electrolyte salt is a small but valuable component of a battery. It represents about two to three per cent of the electrolyte solution that makes up 15% of a battery cell mass. However, it accounts for more than 60% of the electrolyte solution cost.

In a wet shredding environment, the electrolyte solution reacts with water and decomposes. This results in toxic corrosive gas which needs significant effort to manage. However, in dry shredding it can be safely separated and potentially recovered.

Ruether says improving the safety of LIB recycling is an urgent priority. “Our researchers are focused on two key areas. 

“The first big problem for recyclers is the difficulty of determining what state of charge a battery is in.

“When LIBs come into a recycling facility for processing, they usually contain residual energy. This presents a significant hazard. If you get a short circuit, or they get damaged, they can cause a fire or explosion.”

To address this, Ruether’s team has worked in partnership with an e-waste recycler. They aim to develop an electrical discharge unit that allows for the safe and controlled discharging of batteries.

“During the discharge process you can develop heat, and you need to avoid the batteries going into a thermal runaway reaction.”

The second area of focus involves collecting data on the performance of dry shredding systems at an industrial scale and identifying operational limitations for safe processing.

The pilot facility at the CSIRO site in Clayton, in Victoria, will entail dry shredding of LIBs under an inert nitrogen gas atmosphere (N₂).

The plant, which can handle up to 10kg batches of batteries, is a first of its kind in Australia. It is equipped with several technical features such as optical and thermal (IR) cameras, an additional airtight port for injecting single battery cells, and the ability to measure and clean the exhaust gases emitted from the process.  It also includes a novel process to recover lithium electrolyte salt using the dry shredded material as a pure crystal which can be used for making new batteries.

More value from the lithium-ion battery supply chain.

Originally published in CSIRO News as: “Recycling lithium-ion batteries for a brighter tomorrow.