Chinese lithium producer Ganfeng will provide 47,600 tonnes of lithium hydroxide to the South Korean battery maker over three years to the end of 2022, it said.
The material will be supplied at an adjustable market price, Ganfeng said on Wednesday August 15.
LG Chem, which is 30.1% owned by LG Corp, has been moving to secure long-term lithium supply - it last month signed a deal with Canadian producer Nemaska Lithium for five years of supply of lithium hydroxide.
Demand for lithium is on a long-term uptrend due to its role in electric vehicle batteries
although prices have dipped slightly in August due to slower consumer demand.
[This article was corrected on Monday August 20 to clarify that LG Chem is 30.1% owned by LG Corp, not that LG holds a stake in Ganfeng as previously stated.]