Critical supplies

Materials World magazine
,
1 May 2018

The pressure on resources, such as lithium and cobalt, used in lithium-ion batteries is rising. Kathryn Allen examines how this will impact ability to source these materials.  

The availability of lithium and cobalt, components of lithium-ion batteries, could become critical as demand increases. While alternative battery technology, such as sodium-ion batteries, may offer partial relief to this demand, development and performance are not yet up to scratch and they are currently seen as a complementary technology to lithium-ion batteries. 

This is according to a study, A cost and resource analysis of sodium-ion batteries, published in Nature Reviews Materials by researchers at Helmholtz Institute Ulm (HIU) of the Karlsruhe Institute of Technology, Germany. 

The study examines the cost implications of using sodium-ion batteries as an alternative to lithium-ion. 

Using a battery performance and cost model, the team assessed the cost of materials for battery cells and complete batteries, as well as the effect of replacing anode and cathode materials. Production costs and supply chain issues are also considered. 

Analysis showed that while replacing lithium with sodium doesn’t have a major impact on cost savings, the potential cost increase associated with lithium shortages means sodium-ion batteries could be a cheaper option. The low-cost salts, obtained from minerals and brine, used in sodium-ion batteries are also relatively abundant and, unlike lithium-ion batteries, sodium-ion batteries do not require cobalt for ion storage, avoiding the potential increased cost and disruption from a rise in cobalt demand, caused by an increased demand for lithium-ion batteries in, for example, electric cars. 

Supply and demand

South America is home to about two-thirds of global lithium reserves, while China and Australia are also large-scale producers. As lithium is often co-produced with other elements, such as potassium, the HIU researchers state that its production and price are not independent of the demand for these other elements. Currently, Chile has the brine deposit with the highest production of lithium

However, the researchers consider the size of global reserves to be sufficient to meet future demand – driven by an expected increase in the use of electric vehicles. In February 2018, lithium prices fell as investment bank Morgan Stanley warned supply would outstrip demand over the next four years. But, the HIU team claim lithium production will need to expand substantially to meet future demand.

Cobalt, on the other hand, is described in the paper as ‘already under pressure’ and ‘highly dependent on reserves located in unstable regions as well as on the co-production of other elements’. Primary production accounts for only 15% of cobalt obtained, as it is usually a co-product of nickel and copper mining. The price and supply is therefore affected by demand and production of these metals.  

However, Dr Daniel Buchholz, Researcher at HIU, told Materials World, ‘The dependency on host minerals like copper ores might be less critical than expected, since the Democratic Republic of Congo’s share of cobalt production is above 50%, whereas its share of the global copper production and identified reserves is less than 5% and 3%, respectively. This means that an increased production of copper in this region would not automatically disrupt the market with an according price collapse. 

‘Moreover, due to the fact that the price of cobalt is found to be more than seven and 13 times higher than nickel and copper respectively, [...] running operations with a deficit in copper or nickel revenues can still be profitable if the cobalt by-production is high enough.’

Despite this, the limited identified reserves – in terms of size and geographical location – of cobalt pose a risk to future supply. These reserves are concentrated in the Central African Copperbelt, between the Democratic Republic of Congo and Zambia – a politically unstable area. 

According to Christoph Vaalma, PhD student at HIU, ‘Cobalt supply from the Democratic Republic of Congo has faced several interruptions over the last few decades, including a cobalt crisis in 1978 with prices temporarily increasing by 550% from US$18,000 to US$99,000 per tonne. Cobalt is additionally facing a risk from the concentration of refinery capacity, which is mostly located in China.’ 

Warning signs

The rising demand for cobalt as a battery material is evident in Glencore Chief Executive Ivan Glasenberg’s warning in early 2018 that Western car manufacturers – currently developing electric vehicles – haven’t realised the severity of the issue of limited cobalt supply.  

Released in March 2018, Glencore’s Annual Report 2017 revealed the company plans to increase cobalt production 133% over the next three years, expecting an additional 314kt will be required to enable 30 million electric vehicle sales by 2030. Glencore recently signed a deal to supply China with the metal for three years, highlighting concerns over future availability and attempts to secure long-term deals with miners.

The Democratic Republic of Congo has also recently altered its mining code, increasing taxes on mining firms. This was despite opposition from mining companies claiming operations would become unprofitable. 

Considering the location of cobalt reserves in politically unstable regions and the presence of artisanal mining, with the potential associated issues of poor working conditions and lax environmental laws, there is also the issue of sourcing ethically produced cobalt. A scheme attempting to trace cobalt from artisanal mines in the Democratic Republic of Congo through to consumers launched in March 2018. The Better Cobalt pilot, run by RCS Global, an advisory company for responsible sourcing of natural resources, and the Better Sourcing Program, a social impact company, involves electronically tagging cobalt from five artisanal and semi-mechanised mines, aiming to improve control over supply chains. 

What next? 

The HIU researchers predict that, in a scenario with large battery sizes, the number of electronic devices produced by 2050 will require nearly twice the amount of cobalt present in today’s identified reserves. 

Vaalma told Materials World, ‘Regarding the period until 2050, the battery market is expected to grow exponentially, predominantly due to the expected success of electric vehicles. In this context, it needs to be kept in mind that different battery materials are available – some require cobalt, some do not. In the automotive sector, however, only cobalt-containing materials are, so far, able to meet the vehicle-specific battery requirements in terms of weight, volume, power, and lifetime. Because of that, the already tensed cobalt market will be increasingly stressed and the share of the demand by the battery industry will continuously increase.’ 

Supply shortages of lithium and cobalt may drive the use of sodium-ion batteries. Battery research is adapting to these shortages, according to Stefano Passerini, Deputy Director at HIU, with most technology currently being developed not relying on cobalt. However, these technologies aren’t expected to enter the market in the next five to 10 years, as they can’t compete with lithium-ion batteries in terms of cost and performance. 

To read the study, visit go.nature.com/2pHxrLA