Scientists develop rubber electrolytes to make electric vehicle batteries safer and more durable

2024-01-12

According to New Atlas, as an insulator, rubber does not seem to be the best choice for battery electrolyte materials, but researchers at the Georgia Institute of Technology have developed a new type of rubber material with high conductivity. This type of elastomer electrolyte can make electric vehicle batteries safer and have longer battery life.

Lithium ion batteries have revolutionized many technologies, from smartphones to electric vehicles. However, when the battery is damaged or overheated, there is always a risk of fire or explosion, mainly due to the liquid electrolyte that transports lithium ions between the electrodes.

Solid electrolytes can help reduce this risk, but they also bring their own problems. They are usually made of ceramic materials, which may be somewhat fragile, and their interface with the electrode may be incomplete, thereby reducing the conductivity of ions in the battery.

Researchers from Georgia Institute of Technology say their new elastic electrolyte has taken a step towards solving these two problems. This rubber material can bounce back from the bumps of the battery 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 in battery failure.

However, rubber itself is not a conductive part. It is embedded in a conductive plastic crystal of a material called succinonitrile, while the elastomer provides a three-dimensional support, giving the electrolyte shape and stability.

In the test, lithium metal batteries manufactured with new electrolytes were able to operate at room temperature with a voltage of 4.5V and almost no capacity degradation over 1000 cycles. There is no sign of dendritic formation after 100 cycles. Of course, there is still room for improvement, and the team is studying how to improve cycle time and ion conductivity. The team stated that this may ultimately lead to safer and more durable electric vehicle batteries.

"Higher ion conductivity means you can move more ions at the same time," said Michael Lee, the lead author of the study. "By increasing the specific energy and energy density of these batteries, you can increase the mileage of the electric vehicle."

This study was published in the journal Nature.

New type of electrolyte for lithium batteries: 1000 charge and discharge cycles without attenuation