As the battery boom continues, more researcher and environmentalists are pushing for improvements to recycling. While the majority of lithium batteries are recyclable, only a tiny proportion of them are actually recycled.
As electric vehicles become increasingly common, this problem is likely to compound itself. Combustion engines rely on lead acid batteries, and 98% of these are currently recycled in Australia as there are established schemes in place. Such schemes will be required to avoid huge amounts of lithium battery waste going to landfill, but could also provide an estimated $813m to $3bn worth of resources.
A recent report by the Commonwealth Scientific and Industrial Research Organisation (CSIRO), entitled Lithium Battery Recycling in Australia, identifies the recyclable resources in lithium batteries and the opportunity that it could present for the nation. Research team leader for the report Anand Bhatt explains the scale of the looming problem, and the challenges that will need to be overcome to turn battery recycling into a profitable business.
ML: Could you tell me a little about your recent report Lithium battery recycling in Australia?
AB: Lithium battery waste streams are growing globally and in Australia. Historically, these waste streams have been from portable electronics and rechargeable electronic equipment, and amounted to 3,300 tonnes in 2016.
However, the collection and recycling rate has only been around 2%. Over the past few years, the grid and off-grid renewable energy storage market sector (from residential through to large-scale grid applications) has been rapidly growing. In addition, there is growth in the electric vehicle market sector, which is anticipated to expand rapidly in the next few decades.
ML: How does Australia compare with other countries?
AB: Australia has a number of unique challenges when compared to other countries. We have a relatively small population spread over a very large geographic area – this creates a significant issue for the collection and transportation of wastes from outside highly populated capital cities.
Australia also has limited capability for onshore processing of lithium batteries and, historically, has transported a large majority of batteries for offshore processing. This is a suitable option for low collection volumes, however, when the anticipated 130,000 waste streams arise from EVS and PV applications, and taking into account recent shipping fires reported due to waste lithium batteries, this is no longer an ideal solution. This high volume of waste and difficulties in offshore shipping/transportation is one of the current drivers for increasing our on-shore recycling capability.
ML: What are the challenges with regards to recycling batteries?
AB: Firstly, as with other batteries, the safety risks related to collection, transport and storage can be an issue with waste lithium batteries. Although a battery may be deemed end-of-life, it still contains some energy within the battery casing. Typically, manufacturers will rate a battery to have reached end-of-life when 70-80% of the initial energy storage capacity has been used – with current technology, a device may not function correctly beyond this point and so a new battery is required. If the disposed battery is punctured or short circuited, this remaining energy can be released rapidly and potentially cause a fire. This can be problematic in waste reprocessing centres that contain other waste streams and where the condition of the batteries is unknown. Further, for lithium batteries where a transition metal oxide is used in the cathode, these fires can be difficult to extinguish.
Secondly, there is a need for broader consumer education to promote the recycling of lithium batteries and avoid large numbers going into landfill. A number of states and territories in Australia have implemented landfill bans and begun education and awareness campaigns. Organisations like the Australian Battery Recycling Initiative have published consumer and industry guides to educate the public and industry about how lithium batteries should be recycled. These schemes need to be built upon in the future to drive behavioural changes to ensure a culture of recycling rather than disposal.
Finally, a lack of battery labelling with industry specific requirements can create problems with mixed waste streams during collection, sorting and recycling. Some lithium batteries are similar in shape and form to others, such as lead acid batteries, which comprise different chemistry, and if mixed into lead acid waste streams can create significant safety issues or chemical incompatibility issues during the recycling process.
ML: Have battery technology advancements changed battery recycling to any great extent?
AB: Battery recycling is focussed on the recovery of selected materials such as cobalt, lithium, copper and aluminium because these have high value. The current recycling technology is a chemical extraction process designed specifically for components such as cobalt or lithium. Traditionally, lithium batteries were comprised of a lithium cobalt oxide positive terminal with a graphite negative terminal. More recently, a large variety of chemical species are used in the positive terminals, such as lithium iron phosphate, nickel manganese- cobalt oxide, nickel-cobalt-aluminium oxide and lithium manganese oxide. For the negative terminals, recent composition can be of graphite, lithium titanate, tin-cobalt alloy, silicon etc. This can cause problems when extraction processes are designed specifically for one particular element – additional elements/chemical species can cause issues with fouling or side reactions that can reduce the efficiency of the extraction process or cause other problems.
The second issue is that battery advancements can reduce the economics of recycling. For example, the lithium iron phosphate battery contains no high-value cobalt, which is one of the key economic drivers for recycling.
Finally, emerging lithium battery technology using lithium sulfur, which is being actively researched for electric vehicles due to its higher energy storage capability, is unsuitable for current recycling plants. Sulfur is of very little economic value for recycling, and the lithium metal contained in these batteries can cause problems when exposed to air and moisture. Research in new recycling technologies is required to deal with the challenges that these new battery types create.
ML: How could effective recycling influence the lithium industry?
AB: Effective recycling can help the lithium industry by providing a value-added input to resource production. For example, if the lithium in the batteries is collected and converted to carbonate salt, this can add extra volume to the carbonate sourced from mining. Some mining corporations are already exploring how battery recycling can provide this valuable feedstock. Similarly, other materials in the batteries can be recovered and repurposed. The recycling of lithium batteries should help the lithium industry and avoid the need to compete through the production of similar resources for battery manufacture.
ML: How does the limited recycling affect the green image of battery technologies?
AB: Lead acid battery technologies are already considered to be a ’green’ technology because they are actively collected and recycled at a high percentage rate. This is lacking for lithium batteries.
However, existing partial recycling solutions do exist for lithium ion batteries and there are a number of industry approaches looking at extracting alternative materials. If new solutions and existing technologies are utilised effectively, then the image of lithium batteries can match that of other battery technology types that can be recycled. The key to this is an increase in the recycling rate to divert batteries from landfill – this requires combined regulatory approaches, consumer education, new science solutions and investment. All of these are occurring at present and the continued public interest in the field helps drive these changes.