Suzanne's Mom's Blog

Photo: IAA Mobility.
China’s Changan Nevo A06 features a sodium-ion pack, delivering a range of about 250 miles. Researchers in China continue to hunt even greener solutions and have recently announced a sodium-metal battery that can fully charge in four minutes.

Like most of us, I’m dependent on my phone. But I know that makes me complicit in the damage that the mining of phone-necessary lithium is doing to communities and the environment. So although I don’t always read science articles, I really want to learn about possible substitutes for lithium.

Today I test just how much I can understand about scientific innovations. It helps when science reporters write for a general audience, as Rory Bathgate does in this Live Science article.

Bathgate notes, “Researchers in China have announced a radical sodium metal battery (SMB) design that can fully charge in just four minutes and will retain its capacity for years of use.

“SMBs are a form of ultrafast-charging, stable batteries that scientists say could one day be a cheap alternative to today’s lithium-ion (Li-ion) batteries, which rely on geographically concentrated metals and easily catch fire. SMBs also differ from sodium-ion (Na-ion) batteries in that they use a metallic sodium anode rather than a graphite or hard carbon anode.

“However, SMBs remain largely theoretical because they are prone to a type of degradation known as dendrite formation. This is when the sodium ions passing through the electrode deposit onto the highly reactive, pure-metal sodium anode in spiky, stalagmite-like structures. Over time, this forms a bridge between the cathode and the anode, short-circuiting the battery. …

“Now, researchers say they have solved this issue by using a tough, quasi-solid gel electrolyte … which strengthens the battery against punctures and provides a semisolid internal structure that prevents dendrites from forming. They outlined their findings in a study published May 21 in the journal Nano-Micro Letters.

“To confirm the longevity of this approach, the scientists charged and discharged the battery for over 6,000 hours without dendrites short-circuiting the battery. They also noted that when they charged the battery from zero to 100% capacity in just four minutes, it retained electrical charge. …

“When charged at a slightly slower rate of zero to 100% in 20 minutes, the battery retained 90% of its charge capacity over 2,000 cycles — matching the theoretical limits for Lithium-ion batteries, the scientists said in the study. This slower speed lowered the cost and improved the safety. …

“This is relevant because charging speed remains a sticking point for battery deployment in electric vehicles (EVs). …

“Indeed, most batteries used for modern technologies, such as smartphones and EVs, are Li-ion. However, Li-ion batteries are expensive to produce because they contain the hard-to-obtain metals lithium and cobalt, and they are prone to catching fire.

“Increasingly, battery manufacturers are looking to bring sodium-ion batteries to commercial scale because they are cheaper and safer. However, they are heavier and larger than Li-on batteries.

“SMBs are the focus of intense research because they theoretically combine the best of both types of batteries. “

More at Live Science, here.