Source: cnBeta
Rubber doesn't seem to be the best choice for battery electrolyte materials as insulators, but researchers at the Georgia Institute of Technology have developed a new rubber material with high electrical conductivity, according to New Atlas. This elastomer electrolyte can make electric vehicle batteries safer and last longer.
Lithium-ion batteries have revolutionized many technologies, from smartphones to electric vehicles. But when a battery is damaged or overheated, there is always a risk of fire or explosion, mainly due to the liquid electrolyte that delivers lithium ions between the electrodes.
Solid electrolytes can help reduce this risk, but they also pose problems of their own. They are usually made of ceramic material, which can be somewhat fragile, and the interface between them and the electrodes may be incomplete, reducing the conductivity of ions in the battery.
Researchers at the Georgia Institute of Technology say their new elastic electrolytes are taking steps to address both of these problems. This rubber material can bounce back from the battery's bumps and maintain a smooth connection with the electrodes. This maintains its high conductivity, but also prevents the growth of lithium dendrites, which are often the first step to battery failure.
However, the rubber itself is not the part that conducts electricity. It embeds a conductive plastic crystal of a material called amber nitrile, while the elastomer provides a three-dimensional scaffold that gives the electrolyte shape and stability.
In tests, lithium-metal batteries made with the new electrolyte were able to operate at 4.5V at room temperature with virtually no capacity attenuation in 1,000 cycles. There is also no sign of dendrite formation after 100 cycles. Of course, there is still room for improvement, and the team is investigating how to improve cycle times and ion conductivity. The team says this could ultimately lead to safer and longer-lasting EV batteries.
"Higher ion conductivity means you can move more ions at the same time," said Michael Lee, lead author of the study. "By increasing the specific energy and energy density of these batteries, you can increase the range of an electric vehicle."
The study was published in the journal Nature.