Longer life for lithium-ion batteries may soon be possible

A group of scientists at the Gwangju Institute of Science and Technology (GIST) in Gwangju, South Korea, say they have developed a “universal method” to extend the life of lithium-ion batteries.

In a release outlining this breakthrough, it states, “The advent of electric vehicles has increased the demand for energy-dense lithium-ion batteries. This has led to the development of anodes with large charge storage capacities. Unfortunately, this storage Capacity tends to degrade over multiple charge/discharge cycles, shortening battery life.”

The shortened battery life is due to “an irreversible volume change of the anode during cycling, causing degradation of the electrical contacts and structural collapse,” he said.

The sequence of events for a charge/discharge cycle is:

• During charging, lithium ions migrate from the cathode and combine with nanoparticles on the anode.
• During discharge, the lithium ions return to the cathode and, over time, the nanoparticles within the anode crack and cluster at the electrode-electrolyte interface.
• This causes electrical disconnection and reduces the amount of charge that the anode can store or transport.

GIST researchers used their findings to Journal of Materials Chemistry A Earlier this year.

Co-author Professor Hyung Jin Kim said the goal is to develop an electrode process that can increase energy density to meet the rapid growth of the battery industry.

“The method developed by the researchers encapsulates the nanoparticles in a resilient, net-like structure, which strengthens the anode and makes it more resilient to volume changes.”

They then coated the anode surface with a material called reduced graphene oxide (rGO) using a technique called ‘spin coating’. Metal oxide (MGZO) added to it. This his MGZO layer provided structural stability to the anode,” the release states.

“Tests showed that the modified anode was able to retain most of its charge even after several charge/discharge cycles.”

Kim said the structure maintained high storage capacity after 500 cycles and exhibited a 91% coulombic efficiency related to battery life. “This could pave the way for electric vehicles that can travel long distances on a single charge,” he said.

Notably, the researchers said, “The ability to change the anode regardless of manufacturing method makes it a universally applicable method for improving battery life.”