For electric vehicles to become mainstream, they need cost-effective, safer, longer-lasting batteries that won’t explode during use or harm the environment. Researchers at the Georgia Institute of Technology may have found a promising alternative to conventional lithium-ion batteries made from a common material: rubber.
Elastomers, or synthetic rubbers, are widely used in consumer products and advanced technologies such as wearable electronics and soft robotics because of their superior mechanical properties. The researchers found that the material, when formulated into a 3D structure, acted as a superhighway for fast lithium-ion transport with superior mechanical toughness, resulting in longer charging batteries that can go farther. The research, conducted in collaboration with the Korea Advanced Institute of Science and Technology, was published Wednesday in the journal Nature.
In conventional lithium-ion batteries, ions are moved by a liquid electrolyte. However, the battery is inherently unstable: even the slightest damage can leak into the electrolyte, leading to explosion or fire. The safety issues have forced the industry to look at solid-state batteries, which can be made using inorganic ceramic material or organic polymers.
“Most of the industry is focusing on building inorganic solid-state electrolytes. But they are hard to make, expensive and are not environmentally friendly,” said Seung Woo Lee, associate professor in the George W. Woodruff School of Mechanical Engineering, who is part of a team of researchers who have uncovered a rubber-based organic polymer superior to other materials. Solid polymer electrolytes continue to attract great interest because of their low manufacturing cost, non-toxicity and soft nature. However, conventional polymer electrolytes do not have sufficient ionic conductivity and mechanical stability for reliable operation of solid-state batteries.