The supply will match JM's expanding demand as its cathode production becomes commercial, with the volumes and phasing aligned to its production plans.
The agreement builds on the existing collaboration deal the two companies from 2016, with Nemaska delivering lithium hydroxide to JM from the phase 1 Shawinigan demonstration plant at its Whabouchi lithium project in Québec, Canada.
JM also made other headway on the road to commercialising eLNO by securing a site in Konin, Poland to build a 10,000 tonnes per annum commercial plant, with space for future expansion capacity in line with anticipated customer demand to up to 100,000tpa.
Construction of the plant will start later this year, with JM on track to start commercial production of eLNO in 2021-22.
JM said the site was "at the heart of Europe, close to major customers in the battery electric vehicle supply chain".
CEO Robert MacLeod said the two developments demonstrated that JM was on track with the commercialisation of eLNO.
"We are firmly delivering in line with our strategy for break out growth in battery materials and JM remains well placed for success as the global market for electric vehicles develops," he said.
