Zinc-Air Batteries Show Promise as Tougher, Safer Alternative to Lithium-Ion

­A research team in Mexico has created a battery that can still function after being punctured and submerged in water – conditions that would likely ignite the lithium-ion batteries currently used in cell phones and electric vehicles. 

The ultra-durable prototype was developed by Noé Arjona and colleagues at the Center for Advanced Materials Research in Chihuahua, Mexico. 

“We are not using lithium-ion batteries because of the many safety concerns regarding the flammability of the electrolytes that are used in that kind of technology,” says Arjona. Instead, the team made a metal-air battery, combining metal and oxygen from the air in place of a flammable liquid. 

“Many metals also create safety concerns when they are used in batteries. Many of the most active materials are in the list of critical materials. So, we wanted to use as little metal as possible,” explains Arjona. Instead of bulk metal inside the battery, they set out to create a carbon sheet dotted with individual atoms of nickel. 

The scientists used the intensely bright light of the Canadian Light Source (CLS) at the University of Saskatchewan to analyze their prototype at the molecular level. They confirmed their design had single atoms of nickel, which – when combined with novel gel polymer electrolytes and Zinc – eliminated the safety risks associated with a battery containing a larger amount of metal and flammable electrolytes. Their findings were published in the journal ACS Applied Materials & Interfaces. 

The team has put their battery to the test by hammering a nail through it, placing it in flames, and submerging it in water. Their prototype continued to work through each of these extreme conditions. 

In addition to being safer, their battery design isn’t impacted by temperature extremes. 

“In Canada, you have a huge problem with recharging batteries in very cold temperatures, such as with electric vehicles,” Arjona points out. “Our kind of technology doesn’t have the same issues with very low or very high temperatures.”  

Since his team is focused on using metals such as nickel -- which are more abundant and affordable than lithium and cobalt -- their work could lead to cheaper batteries. 

Arjona and his team are also exploring ways to make their battery eco-friendlier, including integrating components that are biodegradable. Once the battery reaches the end of its life, these materials could help to enrich soil and grow plants. In subsequent studies, the researchers plan to incorporate bioplastics in their design and to use iron – commonly found in soil – instead of nickel.

While the team is excited about the promise their new design holds, Arjona says more research is needed before this technology is ready to replace current batteries. 

“If we want to have highly safe batteries, we need to design them with single-atom catalysts,” he says. “This is the future of energy storage.”