There’s a big push underway to increase the lifespan of lithium-ion batteries powering EVs on the road today. By law, in the US, these cells must be able to hold 80% of their original full charge after eight years of operation.

However, many experts and industry leaders believe we need batteries to last decades. They say after their lifespan with electric vehicles (EVs) batteries need a “second life,” such as bundling them together for wind and solar energy storage for the grid.

New Type of Battery

Researchers from Dalhousie University used the Canadian Light Source (CLS) at the University of Saskatchewan to analyze a new type of lithium-ion battery material – called a single-crystal electrode. According to the researchers, it’s been charging and discharging non-stop in a Halifax lab for over six years.

They say the battery lasted 20,000 cycles (going from full to empty) before hitting 80%. As part of the study, researchers compared their new battery to a regular one, which lasted only 2,400 cycles before hitting 80%.

“The main focus of our research was to understand how damage and fatigue inside a battery progresses over time, and how we can prevent it,” said Toby Bond, a senior scientist at the CLS, who conducted the research for his PhD. He said things got “very interesting” when the scientists used the ultrabright synchrotron light to peer inside the two batteries.

When they examined the inner workings of the regular lithium-ion battery, they saw extensive microscopic cracking in the electrode material caused by repeated charging and discharging. He explains that lithium forces the atoms in the material apart and causes expansion and contraction of the material.

“Eventually, there were so many cracks that the electrode was essentially pulverized.”

Stronger Battery

When the researchers examined the new, single-crystal electrode battery, there was no evidence of mechanical issues. “In our images, it looked very much like a brand-new cell,” Bond said. We could almost not tell the difference.”

Bond attributes the near absence of damage to the new battery’s different shape and behavior of the particles that make up the electrodes. In the regular battery, the electrodes are made up of tiny particles up to 50 times smaller than a hair’s width. If you zoom in on these particles, they are composed of even tinier crystals that are bunched together like snowflakes in a snowball.

As the name implies, the single crystal is one big crystal like an ice cube. “If you have a snowball in one hand and an ice cube in the other, it’s a lot easier to crush the snowball,” says Bond. “The ice cube is much more resistant to mechanical stress and strain.”

Bond suggests that we are nearing a point where batteries are no longer an EV’s limiting component. He said, “We really need these vehicles to last as long as possible, because the longer you drive them, the better its improvement on the carbon footprint is.” Additionally, if battery packs can outlast the vehicle, we can use them for mass energy storage.

The new batteries are already being produced commercially, and Bond believes production will ramp up in the next few years.

“I think work like this just helps underscore how reliable they are,” Bond said. “And it should help companies that are manufacturing and using these batteries to plan for the long term.”