Following recent articles I wrote on both lithium-ion and lead-acid batteries, I received significant correspondence about the environmental pros and cons of both types of battery. In this article I will use some of the feedback and references I received in an effort to compare and contrast some environmental impacts of these two types of battery.
Because of the long history of lead-acid batteries, there is a significant body of literature discussing their impact on the environment. But lithium-ion batteries are newer to the market, and their environmental impact is still being worked out.
The single-biggest environmental issue with lead-acid batteries involves the lead component of the battery. Lead is a heavy metal with potentially dangerous health impacts. Ingestion of lead is especially dangerous for young children because their brains are still developing.
In the 20th century, leaded gasoline and lead-based paints were extensively disseminated in the environment. Today those sources have largely been eliminated. According to the World Health Organization (WHO), today around 85% of the world’s lead consumption is for the production of lead-acid batteries.
The good news is that lead-acid batteries are 99% recyclable. However, lead exposure can still take place during the mining and processing of the lead, as well as during the recycling steps.
The WHO report referenced above noted that lead recycling is an important source of environmental contamination and human exposure in many countries where it is poorly regulated. Lead recycling in such countries is often carried out without the necessary processes and technologies to control lead emissions.
But this can be a problem even in developed countries with good regulations. The California Department of Toxic Substances Control (DTSC) has written extensively on the case of Exide Technologies, a lead-acid battery manufacturing company.
Exide had to close down a large battery recycling plant in California after it failed to meet emission controls and waste management standards. California regulators believe as many as 10,000 homes could be contaminated with lead from the plant. The cleanup is expected to take many years and cost hundreds of millions of dollars. Exide battery recycling plants in other states have also been cited for contaminating the environment with lead.
The WHO report also highlighted cases in Senegal, Dominican Republic, and Vietnam where contamination from lead-acid battery recycling resulted in negative health effects — including potentially the death of children.
Thus, while the 99% recycling statistic is important, it may understate the potential for lead contamination via this process. However, the situation would definitely be much worse if these batteries were being landfilled, as a single lead acid battery in a landfill has the potential to contaminate a large area.
Many who wrote to me following previous articles maintained that recycling is the Achilles heel of lithium-ion batteries. They stressed that while lead-acid batteries are 99% recyclable, lithium-ion batteries are recycled at a rate below 5%. However, several companies also contacted me to argue that the 5% statistic itself is misleading.
The primary issue with lithium-ion recycling is that beyond smaller batteries used in consumer electronics, relatively few lithium-ion batteries (compared to lead-acid batteries) have reached the end of life stage because they haven’t been in the market all that long and they last a long time.
Further, because lithium isn’t a toxic heavy metal like lead, there has been far less pressure to recycle these batteries. Nevertheless, the issue will have a growing profile as growing numbers of lithium-ion batteries reach the end of their usable life.
The good news is that there are companies that are working on it. Li-ion batteries can be recycled at rates as high as lead-acid batteries, but the issue has simply not yet been viewed as one of critical importance.
Alex Pisarev, the CEO of California-based lithium-ion battery supplier OneCharge responded to a query on the question of lithium-ion battery recycling:
“Our batteries are highly recyclable – based on our Bill of Materials on average we have 83% of steel and copper, by weight. They are close to 100% recyclable. There are technologies being developed to recycle the rest, which is Li-ion cells themselves. Some companies already claim 50%, which takes OneCharge batteries to around 90% recycling rate. It is important to mention that we plan to repurpose the batteries after the end of their useful life in lift trucks. Around 80% of cells usually can still work in less demanding applications, such as home energy storage. There is a lot of potential here, we just have not accumulated enough old batteries, they just keep working!”
And while lithium itself isn’t of great concern from a pollution angle, these batteries do contain metals like cobalt, nickel, and manganese. While these metals aren’t as problematic as lead, they are considered toxic heavy metals.
Further, these metals must be mined, and there can be pollution associated with this activity (as there is with lead mining). In addition to the pollution potential, much of the criticisms surrounding the environmental impact of lithium-ion batteries have been in relation to child labor in cobalt mines in the Democratic Republic of Congo.
I reached out again to OneCharge for comments specifically on the environmental and ethical issues around cobalt use in lithium-ion batteries.
Tim Karimov, President of OneCharge, replied:
“Our batteries are designed for optimal performance and safety required by the Material Handling Industry, and the perfect cell chemistry here is LiFePO4. These cells do not contain cobalt or other metals associated with unethical mining. They are just so much safer for workers and do not cause pollution! This technology is truly sustainable.”
If the broader trend of lithium-ion batteries is to move away from chemistries containing cobalt — something both Tesla and Panasonic are working toward — then it would address one of the primary criticisms focused on growing lithium-ion battery usage.
Electric vehicle sales have exploded in recent years, but those batteries won’t reach the end of life for a few years yet. Projections by industry experts are that China alone will produce half a million metric tons of used lithium-ion batteries through this year. By 2030, 11 million metric tons of Li-ion batteries are expected to reach the end of their service lives. Thus, Li-ion battery recycling is an issue that will take on much greater importance in coming years.
Many of those batteries will be headed to landfills or to China under current trends. But lithium-ion recycling plants are coming online, like this recently-announced recycling plant by Swedish lithium-ion battery maker Northvolt. As Northvolt CEO Peter Carlsson explained: “There’s a pretty significant export flow of used batteries to China, and that’s stupid. It’s important to keep these flows within Europe.”