A new EV battery could last more than 8 times longer, travel farther

A typical lithium-ion battery in an electric vehicle could take its driver the distance between Canada’s two furthest points about 175 times — from Cape Spear in Newfoundland and Labrador to the Yukon and Alaska boundary – travelling about 5,514 km. However, a new battery tested recently by researchers could reach that distance nearly 1,500 times, covering eight million kilometres.

Researchers from Dalhousie University spent six years charging and discharging an emerging lithium-ion battery material to see how many charging cycles it could take: a typical battery lasts 2,400 cycles, while the new battery lasted more than 20,000 cycles. Millions of lithium-ion batteries powering electric vehicles currently on the road will kick the can by the end of the decade, requiring their precious cobalt, lithium and nickel to ideally be recycled. 

While about 95 per cent of precious metals from an EV battery can be recovered, it’s an energy intensive and emissions-producing process, so extending battery life will have positive impacts on the climate, explains Toby Bond, a PhD candidate at Dalhousie and co-author of the study detailing the battery research. Throughout an EV’s lifetime, it does not emit planet-warming greenhouse gases, but mining the precious metals needed for a battery does. 

The battery material Bond and his fellow researchers tested is composed of a single-crystal electrode made from single particles of metals, such as nickel, cobalt and manganese. He compares the particles in typical EV lithium-ion batteries to “little snowballs,” while the single-crystal electrode is more akin to an ice cube. As batteries are charged and discharged, the particles expand and contract — the stress causes the battery to lose charging capacity.

“If you hold a snowball in one hand and an ice cube in the other hand, it's a lot easier to crush the snowball than the ice cube, right? So it's kind of a similar principle,” said Bond, who is also a senior scientist at Canadian Light Source.

“It's basically a really durable material that's much more resistant to mechanical stress.”

To see the impact of the charging cycles, researchers analyzed the batteries at Canadian Light Source at the University of Saskatchewan, a research facility with technology that can scan the batteries and see degradation without taking the batteries apart — like an X-ray. The single-crystal electrode battery showed little sign of stress, while the typical EV battery showed cracks. 

Single-crystal electrode batteries are being produced by a few companies: abroad by LG Chem in South Korea, as well as in Canada by Vancouver-based NanoOne. LG doesn’t list what the batteries are being used for, and NanoOne is manufacturing them at a pilot level. 

The next step is using the battery cells in EV battery packs. When there is a new advancement in EV technology, manufacturers have to “go through a validation process,” which takes a few years and requires testing, explained Bond, but the process to get the batteries in EV packs is “underway.”

The research — with funding from Tesla Canada and the Natural Sciences and Engineering Research Council of Canada — validates the business case for using the batteries in EVs, explained Bond. 

“It's not like this is just only happening in the lab. The testing that we did is the most extensive lab testing that's been published. Nobody else has cycled them for this long,” said Bond.

The researchers used a cut-off point of 80 per cent capacity to test the batteries. Even past that level, the batteries aren’t obsolete — it depends on the EV user and their needs. There are avenues to repurpose the batteries once they are less efficient. However, the United States mandates that EV battery cells hold 80 per cent of their original full charge for eight years of use. 

While Canada doesn’t have a rule around EV battery capacity, “we tend to just follow the U.S. regulations,” and manufacturers use that measurement as a benchmark, Bond explained. 

Grid Storage

The lifespan of EV batteries has gradually improved since Tesla first introduced an EV to the market in 2008, followed by the Nissan Leaf and the Chevrolet Volt in 2010. In newer EVs, the battery at peak efficiency is expected to outlast other parts of the car, Bond said.

That means repurposing EV batteries that outlast vehicles is key. This will be the case with single-crystal electrode batteries once they are put into EV packs, Bond said. A viable option is for grid storage on wind and solar farms, the study notes. 

Even if a battery is at 80 per cent or less capacity, it can be used as energy storage, explained Bond. On a wind farm, for example, batteries can be put together to act as one larger storage unit, compared to an EV, which only has one battery pack. 

The combination of finding more second-life uses for EV batteries and making the material they consist of last longer paints a bright future, Bond said. Even now, EVs have an average of two-thirds lower lifecycle greenhouse gas emissions (which includes the emissions from extracting raw materials for EV batteries, operation, and eventual disposal) than their gas-powered counterparts, which will continue to decline as the grid greens. 

“Even if the electric grid was entirely powered by coal, a [battery-powered EV] would still be better than a gasoline car for the environment,” writes Nate Wallace, program manager for clean transportation at Environmental Defence. 

“Battery electric vehicles are five times more efficient than gasoline-powered vehicles at converting stored energy into motion.”

Just how long EV batteries last in cars can’t be accurately predicted until the cars are on the road. But Bond says the testing process used on the single-crystal electrode batteries is harder than typical driving because they are put through charging cycles more frequently. 

“These single crystal materials are already on the market and I think they'll be in EV battery packs soon. I certainly would love to get one,” Bond said.

“I'm obviously very convinced after doing this research.”