LG Energy Solutions and the nation's top-ranked Korea Advanced Institute of Science and Technology have made a significant discovery in lithium metal battery technology, as revealed in a research paper in the prestigious journal Nature Energy, potentially increasing electric vehicle range by 50 percent and drastically enhancing battery efficiency and lifespan.
The discovery stems from a collaboration that began over two years ago at the Frontier Research Laboratory, a joint venture between LG and KAIST. The team has developed an innovative electrolyte technology, crucial in connecting the battery's positive and negative terminals. This new approach effectively tackles the primary shortcomings of lithium metal batteries, which, despite their high energy density, have suffered from rapid degradation and reduced lifespan.
The solution presented by LG Energy Solutions and KAIST involves a novel electrolyte made from two chemical compounds called borate and pyran. This electrolyte transforms large LiF crystals, a compound formed during battery operation, into smaller crystals or a glass-like form. This transformation is key, as these smaller or glassy LiF forms create a more effective barrier at the interface where the electrolyte and lithium meet, acting like a shield to reduce lithium damage.
When applied in batteries with high-nickel cathodes and thin lithium layers, this new technology not only enabled the batteries to store over 400 watt-hours per kilogram of energy, but also significantly increased their durability. The batteries demonstrated the ability to undergo up to 400 charge-discharge cycles while retaining 70 to 85 percent of their capacity.
This discovery might increase EV ranges dramatically. For instance, LG Energy Solution estimates that the improved lithium metal battery could achieve up to 900 kilometers on a single charge, a 50 percent increase over the current 600 km range offered by existing high-performance lithium-ion batteries.
"Our research overturns previous assumptions, proving that liquid electrolyte lithium metal batteries are not only viable but also highly efficient," said professor Kim Hee-tak of KAIST's Department of Chemical and Biomolecular Engineering who supervised the research.
"The breakthrough in controlling the lithium metal cathode interface at the nanoscale was the key to unlocking the full potential of lithium metal batteries," said doctoral researcher Kwon Hyeok-jin, the first author of the academic paper.
Unlike all-solid-state batteries, another next-generation battery technology, the newly developed liquid electrolyte lithium metal battery operates without the need for high temperatures and pressures, simplifying the battery system design and expanding its potential applications in EVs.
Moreover, the materials used in this new electrolyte -- borate and pyran -- are relatively inexpensive and abundant compared to those in traditional lithium-ion electrolytes.
An LG Energy Solution official remained cautious about the price benefits at least for now, citing the tricky production and economies of scale in the earlier stage.
The 2023 S&P Global Mobility Survey indicated that nearly half of its 7,500 global respondents view EV prices as prohibitively high, despite a general willingness to accept EV ranges below 480 km.