LG Energy, KAIST develop Li-Metal battery tech for improved EV range

South Korea’s LG Energy Solution Ltd. and the Korea Advanced Institute of Science & Technology (KAIST) have developed a lithium-metal battery technology that promises a 50% increase in electric vehicle driving range compared to conventional lithium-ion battery cells.

LG Energy, a leading global battery maker, said on Thursday a joint team of researchers with the KAIST has secured the technology that drastically improves energy density for such batteries, also known as Li-Metal Battery (LMB) cells, after two years of research.

The research results were published in a recent edition of Nature Energy, a monthly peer-reviewed scientific journal, LG said.

LMBs hold great promise for EVs and other applications due to their high theoretical energy density and potential for improved safety. However, such batteries have proven difficult to manufacture at scale, hindering their commercial introduction.

BATTERY GAME-CHANGER

Lithium-metal batteries replace the graphite-based anode material with lithium metal, reducing the weight and volume of the anode. As a result, LMBs drastically improve the charging and discharging efficiency and elongate the lifespan of battery cells – a “battery game-changer” as industry watchers put it.

However, the addition of lithium metal into the anode materials damages battery separators, generating a byproduct called dendrite, and causes corrosion through a liquid electrolyte, leading to a shorter battery lifespan and low efficiency.

LG said the LG-KAIST team, for the first time in the world, used borate-pyran-based liquid electrolyte to solve this problem.

The new technology made it possible to increase the charging and discharging efficiency of lithium-metal batteries while achieving an energy density sufficient for an EV driving range of up to 900 km on a single charge, according to LG.

That compares with high-performance lithium-ion battery cells that allow an EV to run for up to 600 km on a single charge.

LG said the new technology ensures a longer battery lifespan with more than 400 recharge cycles, and unlike solid-state batteries, it does not require high temperature and pressure to put battery cells into action.

BREAKTHROUGH IN LIQUID-ELECTROLYTE BATTERIES

For the development of the new technology, LG Energy and KAIST set up a joint research center, Frontier Research Laboratory (FRL), in 2021. LG runs multiple FRLs with other universities and research institutions in Korea to develop innovative technologies.

"This technology is significant in that it has overcome a major hurdle to the commercialization of lithium-metal batteries using liquid electrolytes," said Jung Geun-chang, vice president and head of LG Energy's Future Technology Center.

Kim Hee-tak, a biological science professor at KAIST, said: “The research results proved the feasibility of liquid electrolyte-based lithium-metal batteries, previously considered impossible."

HYUNDAI MOTOR-INVESTED SES TO UNVEIL SAMPLES

Battery makers worldwide are racing to develop next-generation batteries, including an all-solid-state battery (ASSB), as lithium-ion batteries, which most EVs are currently using, have some issues such as the risk of catching fire.

SES Holdings Pte. (SES), one of the industry’s leading ASSB makers, said in November 2021 that it developed a high-performance Li-Metal battery and supplied samples to its key investors, including General Motors Co. and Hyundai Motor Co.

Ford Motor-backed solid-state battery developer Solid Power Inc. of the US is another industry leader.

In Korea, three battery majors – LG Energy, SK On Co. and Samsung SDI Co. – are all working on ASSBs.

Hyundai Motor-invested SES is expected to unveil samples of a Li-Metal battery for urban air mobility (UAM) vehicles next month.

Write to Sungsu Bae at baebae@hankyung.com

In-Soo Nam edited this article.