Korea introduces fire-proof EV battery that holds 87% power after 1000 cycles
Researchers at the Daegu Gyeongbuk Institute of Science and Technology (DGIST) in South Korea have developed a triple-layer solid polymer electrolyte containing a lithium-ion battery that can extinguish itself if it catches fire, a statement from the institution said.
The press release also said that the innovative battery is resistant to explosion and shows better lifespan than conventional lithium-ion batteries.
Lithium-ion (Li-ion) batteries are a critical component of the clean energy transition that we have undertaken, replacing fossil fuels with renewable and carbon-free energy.
Made from abundantly available lithium, these batteries offer the most energy-dense storage option available to us to date and can power everything from a smartphone to electric vehicles and beyond.
However, Li-ion batteries use liquid electrolytes with organic materials that are at risk of catching fire.
The separators used to separate the electrodes are also prone to damage and can lead to short circuits, causing explosions. This has raised concerns about using Li-ion battery packs in large-scale energy storage solutions.
Researchers have been working on solid-polymer-based electrolyte systems that are resistant to fire and explosion, but commercializing this technology has proven tough.
Solid-state batteries perform relatively poorly than their liquid polymer counterparts since achieving complete contact between the electrodes and electrolytes is difficult. As a battery undergoes charging and discharging during its usage, lithium-ions form sharp metallic dendrites or tree-like structures.
Not only do these dendrites cause a loss of battery performance, but they also increase the risk of fire and explosion. A research team led by Kim Jae-hyun, a researcher at the Division of Energy & Environmental Technology at DGIST, overcame this hurdle by switching to a three-layer system that makes up the solid polymer electrolyte.
Solid-state batteries are designed to be safer than their liquid electrolyte counterparts. But dendrite formation increases risk of fire in solid-state batteries too
Each layer of the electrolyte performs a specific function. A robust middle layer made from zeolite provides strength to the structure. In contrast, the softer outer layers deliver electrode contact and improve battery performance and efficiency.
On one side is decabromodiphenyl ethane (DBDPE), which prevents fires and can also extinguish one if it occurs, while high concentration salt of lithium bis (trifluoromethane sulfonyl) imide) (LiTFSI) allows faster movement of lithium ions. This helps improve energy transfer rates and prevent dendrites’ formation in the electrolyte.
In laboratory tests, the battery retained 87.9 percent of its performance even after 1,000 charge-discharge cycles. A typical Li-ion battery using a liquid electrolyte can only retain 70-80 percent performance at this stage.
“This research is anticipated to make a significant contribution to the commercialization of lithium metal batteries using [solid polymer] electrolytes, while providing enhanced stability and efficiency [to] energy storage devices,” said Kim in the press release.
Like the conventional Li-ion battery, this triple-layer solid polymer battery could also be used across multiple sectors ranging from smartphones to large-scale energy storage solutions.
The research findings were published in the journal Small.
