Production of lithium hydroxide is expected to overtake lithium carbonate in the next five years in response to changes in electric vehicle (EV) battery materials, delegates heard at the Advanced Automotive Batteries Conference (AABC) in Strasbourg, France.
Lithium carbonate accounted for around 60pc of lithium demand in 2018, but battery technology development is increasing demand for lithium hydroxide, which is expected to account for a larger share of the market by 2024, said Bart Vanden Bossche, sales director at Chilean producer SQM. Demand for lithium carbonate is expected to rise at a compound annual growth rate (CAGR) of 10-14pc in 2018-27, while lithium hydroxide demand is seen rising at a 25-29pc CAGR.
Consumer concerns about the driving range of EVs have prompted the government in China, the world's largest EV market, to use subsidies to incentivise production of lithium-ion batteries with higher energy densities. That has precipitated a switch to cathode material manufacturers using compounds of lithium nickel-cobalt-manganese (NCM) and lithium nickel-cobalt-aluminium (NCA) rather than lithium iron phosphate (LFP).
But the higher nickel content in NCM cathodes can present challenges in terms of chemical stability. If the metals are used in a ratio of six parts nickel to two parts cobalt and two parts manganese (6-2-2), or 8-1-1, rather than 1-1-1 or 5-3-2 as in the past, the chemistry requires lithium hydroxide rather than lithium carbonate. Cathodes using an 8-1-1 ratio are some way from commercial viability, owing to safety problems with the chemistry, delegates heard.
As nickel content approaches 60pc, the higher temperature required to synthesise cathode material with lithium carbonate damages the crystal structure of the cathode and changes the oxidation state of the nickel metal. But lithium hydroxide allows rapid and complete synthesis at lower temperatures, increasing the performance and lifespan of the battery, said Marina Yakovleva, global commercial manager for new product and technology development at lithium producer Livent.
Trade flows reflect the increasing use of lithium NCM cathodes. China imported 20,394t of NCM oxide from South Korea and Japan in 2018, up from 9,142t in 2017 and 2,352t in 2015, data from Global Trade Tracker show.
That change in demand is prompting producers to expand their lithium hydroxide output and shifting mining projects towards developing lithium hydroxide production rather than lithium carbonate.
"The industry has to make the necessary investments," said SQM's Vanden Bossche. "It will be quite a dramatic change for lithium producers." Production of lithium hydroxide has typically been a two-step process, using lithium brines to produce lithium carbonate, then converting the lithium carbonate into lithium hydroxide.
But mining of lithium spodumene from hard rock is increasing, with producers able to use this to process either carbonate or hydroxide for the same cost. "Companies will either look into more direct conversion into hydroxide or be at a disadvantage," Vanden Bossche said.
Brine producers will continue to produce carbonate as a first step, but will look for ways to reduce costs. SQM is expanding its lithium carbonate capacity in stages to 180,000 t/yr from 70,000 t/yr, while it has received permits to expand its lithium hydroxide capacity to 32,000 t/yr from 13,500 t/yr. The company is looking to further diversify its production, having invested in an Australian spodumene project with lithium hydroxide output and begun looking for opportunities to invest in other countries.
Australia-based Infinity Lithium is developing a project in Spain and has shifted its focus to producing lithium hydroxide rather than lithium carbonate. The cost of producing lithium hydroxide from spodumene rock deposits is below the cost of production from brines, and in future hydroxide will account for the majority of lithium produced, said Infinity vice-president of European corporate strategy and business development, Vincent Ledoux Pedailles.
