Using Yazami’s new technique could charge an EV battery in just ten minutes. (Image Credit: Waldemar Brandt/Unsplash)
Dr. Rachid Yazami believes his invention, a graphite anode that allows lithium-ion batteries to achieve high performance, could quickly charge an EV battery with a newfound technique. It all started in the mid-1970s when scientists realized that graphene could allow molten or powered lithium to serve as an energy storage material. However, they couldn’t make it into a product. Then, in 1983, he and co-author Ph. Touzain used a solid polymer electrolyte to overcome such an obstacle. This technique has been proven useful, making Li-ion batteries affordable, reliable, long-lasting, and capable of power cycling stability.
Yazami’s company developed a new technique that allows an EV to draw in current for a quick charge. Batteries are usually charged with constant current, similar to how a car owner fills up their gas tank. The approach utilizes nonlinear voltammetry, which controls the voltage rather than the current.
To understand it better, think of voltage as steps on a ladder. The voltage needs to remain constant on one rung of the ladder until parameters are met. Then, it goes to the next step until it arrives at the top once it’s fully charged. This technique provides batteries with rest going through this process, which influences their response.
Although fast charging is convenient for the owner, the battery’s life must also be considered. Ideally, Yazami wants to make improvements on this for the future of lithium-ion batteries. He envisions charging a battery in just 10 minutes for an 800km range.
Two other problems concerning batteries deal with energy density and safety. Before peaking in 2015 or 2016, lithium-ion batteries’ energy density has increased since its introduction in 1991. It increased by 8% per year before it peaked. Sony’s Li-ion battery was around 90 Wh per kilogram. Now, Yazami has already tested commercial Li-ion batteries that are 290Wh per kilogram. Ultimately, his target is to achieve 300Wh. However, reaching this goal can be problematic due to the battery’s life and safety.
Safety is also concerning because Li-ion batteries can malfunction from being punctured or stressed. Last month, a 2019 Tesla Model S crashed as a result of a fire in the battery, which was damaged. Incidents like these could be avoided by integrating a sensor in the battery. It works by measuring the size while the material expands with heat. A display system then notifies the driver of the changes.
Yazami expects EV technology to have further applications other than scooters and cars and that electric planes could become more common in the next 20 to 30 years. He also expects Europe to see an increase in battery manufacturing, from 3% to 20%, since the EU continues to build billion-dollar gigafactories.
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