Hemp Used in Development of New, More Efficient Battery

Over the past decade, hemp has become a major focus for manufacturing and production as industries become more environmentally-conscious and begin to put more effort into green initiatives. We've seen hemp used like never before for building construction, vehicle manufacturing, and even as a sustainable biofuel!

Now, hemp could be a "key component" in the development of new batteries that are more energy dense with a significantly lower cost!

Bemp Research, a Texas-based company, says their team has developed a new kind of lithium sulfur battery using what they call "B4C-hemp" - short for "boron carbide made from hemp." The company believes this battery has the potential to overcome a number of challenges that come with lithium-ion batteries such as cost, weight, scalability, performance, and recyclability.

In an interview with Energy Tech, company founder, Son Nguyen, explains that the technology used in this project "is superior to Li-ion [lithium-ion] batteries in terms of gravimetric energy density, safety, and, most importantly, costs and environmental friendliness," explaining that the chemistry "uses lightweight and abundant materials such as sulfur, boron, and carbonized hemp – instead of heavy metals such as nickel and cobalt."

Nguyen goes on to explain that hemp was chosen as the project's core material because of the plant's durability, porosity, and low costs.

"LiS [lithium sulfur] batteries have problems such as the cathode contracting/expanding during charging/discharging, and the cathode’s polysulfides shuttling to the anode and hurting the batteries’ performance. Researchers could solve these problems using expensive materials such as graphene, but graphene is impossible to mass-produce. Hemp is a better, lower-cost solution. Hemp’s durability can help the cathode withstand hundreds of cycles of contraction and expansion. Hemp’s porous structure can help “trap” the polysulfides from shuttling to the anode," Nguyen says.

In addition to being less costly and more efficient, the Bemp Research team also believes these new hemp-based batteries will be much safer than traditional lithium-ion.

For example, Li-ion batteries will combust if damaged, punctured, or crushed. If the LiS/B4C-hemp battery is damaged, the sulfur in the battery will react with the lithium to form a "passive layer," preventing combustion.

There is also no metallic oxide used in the battery's chemistry, so the risk of "thermal runaway" seen in Li-ion chemistries is eliminated. "Since there is no cobalt or nickel, and lithium is the only valuable metal in our chemistry, recycling can be done much more easily compared to Li-ion. We just need to recover the lithium, and that is it," states Nguyen.

The Bemp team has already conducted a number of "stress tests" on the battery to assess performance at different charge/discharge rates. According to the test results, the batteries "performed well in a very wide temperature range," but they need to run the cycle for longer periods of time in "extremely cold and extremely hot temperatures" to verify their findings.

What they were able to determine was that the LiS/B4C battery can be fully charged within 20 minutes, and at slower charging rates, "the gravimetric energy density can be even higher," meaning that it could theoretically double or even triple the ranger per charge for electric vehicles. The team estimates that the batteries will last for 100,000 miles after a fast-charge, and even longer with slower charging, before being recycled.

Bemp Research expects that they will be able to begin mass production of these batteries by by 2026 for use in drones and "heavy-duty electric vehicles such as buses and trucks."

Sources:

1. https://cleantechnica.com/2022/10/24/hemp-for-victory-researchers-make-better-cheaper-batteries-from-plant-waste/?utm_source=newsletter&utm_medium=email&utm_campaign=weekly_spotlight&utm_term=2022-11-18