The battery metals price reporting and research agency said lithium hydroxide EXW China was up 11.1% in the past two weeks to US$13,250 per tonne.
Average EXW China battery grade lithium carbonate remained stable at RMB89,000/t but recorded a 0.7% rise in US dollar terms due to the strengthening RMB exchange rate, to $13,800/t.
Likewise, technical grade lithium carbonate was also up 0.2% to $12,775/t, although Benchmark said the average price had fallen marginally to RMB82,500/t as growing seasonal domestic supply from Qinghai brine projects helped meet short-term demand.
On the London Metal Exchange, the Fastmarkets MB lithium hydroxide monohydrate battery-grade price, CIF China, Japan and Korea, has risen from $13/kg on May 6 to $13.25 on May 13.
Benchmark reiterated the impact of growing demand for electric vehicles and battery cells.
"EV and cell production statistics continue to rise within China, up 257.5% and 251.8% on 2020 year-to-date, following record Q1, cementing step change in demand in 2021," Benchmark said.
Product director Andrew Miller said it was great the rebound in lithium prices was reigniting expansion efforts but issued a reminder not to discount the lead time for project ramp-ups.
"Though it's slowed in some areas, don't expect the rally to end any time soon," he tweeted.
"Q4 could be pivotal given expected order increases."