A team of researchers has developed a new battery material that could help electric vehicles travel farther on a single charge while also extending battery life.
The new technology could be especially attractive to manufacturers because it works with today’s battery production methods, meaning factories may not need expensive new equipment to use it.
The research was led by Professor Ki-Jae Kim from Sungkyunkwan University in South Korea, together with Professor Jang Wook Choi’s team at Seoul National University.
Their findings were published in the journal Nature Communications.
Lithium-ion batteries power electric vehicles, smartphones and many other electronic devices. One way to increase the amount of energy a battery can store is to make its electrodes thicker.
Electrodes are the parts of the battery that store and release energy during charging and discharging.
However, thicker electrodes come with an important problem. During manufacturing, a material called a binder is used to hold the electrode together.
The most commonly used binder, known as polyvinylidene fluoride (PVDF), tends to move toward the surface while the electrode dries.
This uneven distribution weakens the electrode, making it more likely to crack or crumble over time. It also slows the movement of lithium ions inside the battery, reducing both battery performance and lifespan.
To solve this problem, the researchers designed a completely new binder by combining two very different materials. One ingredient is spandex, the stretchy material commonly used in sportswear and other clothing. The other is poly(acrylic acid), a polymer that bonds well with the materials inside a battery.
The combination creates what the researchers call a Dual-Acting Hybrid Polymer binder. The spandex provides flexibility, helping the thicker electrode resist cracking, while the poly(acrylic acid) strengthens the bond between the battery materials and improves the movement of lithium ions.
Laboratory tests showed impressive results. The new binder nearly doubled the adhesive strength compared with the traditional PVDF binder. During the first few charging cycles, it also naturally formed a special interface inside the battery that allowed lithium ions to move more quickly and evenly throughout the electrode. This improved the battery’s overall performance.
The researchers then tested the binder in large commercial-style pouch batteries similar to those used in electric vehicles. Batteries made with the conventional binder began losing capacity quickly and failed after about 95 charge and discharge cycles. In contrast, batteries using the new hybrid binder still retained 86.8% of their original capacity after more than 200 cycles, effectively more than doubling their usable lifespan.
One of the biggest advantages of the new technology is that manufacturers would not need to redesign their production lines. The binder can be used with the existing wet manufacturing process already employed by much of the battery industry, avoiding the cost of installing entirely new equipment.
The researchers believe this practical approach could speed up the development of higher-capacity batteries for electric vehicles and other electronics. If successfully commercialized, the new binder could help future electric cars travel longer distances between charges while keeping batteries reliable for many more years of use.
