The role of cobalt in battery supply

By Cameron Perks
Published: Friday, 16 September 2016

The importance of cobalt to many lithium battery chemistries is sometimes forgotten, with industry news tending to focus solely on lithium itself. Delegates at the Battery Metals Conference in Beijing last week took a closer look at the battery supply chain.

While elements such as nickel, lithium and manganese have important roles to play in various popular battery chemistries, cobalt is the critical mineral concerning many industry experts.

The reason for this is the nature of its source, with over 50% of the world’s supply mined in conflict-stricken Democratic Republic of Congo (DRC).

With rechargeable battery electrodes being the primary use for cobalt, recent instability in the DRC has been unnerving.

Last week there were several reports of violent outbreaks and on Friday the border crossing between DRC and Zambia was closed for 24 hours by the Zambians to prevent trouble spilling over into the country.

To add to the already concerning story, Mo Ke, chief analyst at RealLi Research, said at the 2016 Argus Battery Metals Conference last week in Beijing that there would "probably be a shortage next year", thanks to a combination of increasing demand and restricted supply. Some commentators, such as Ian Pringle, managing director of Bayrock Materials and Pacific Basin Bluestone, thinks that this is an understatement.

Reuters reported in mid-2016 that cobalt prices would likely rise around 45% by 2020 as stricter emissions controls push global demand for electric vehicles (EVs), the news agency calling it "a stampede for cobalt".

 World cobalt supply_usgs
 World cobalt supply by country (Source: USGS)

China’s green growth driving demand

China, the world’s biggest polluter, is also trying to establish a market for new energy vehicles with China’s Ministry of Industry and Information Technology (CMIIT) decreeing that by 2020 there shall be 5m accumulated New Energy Vehicles or NEVs in China. However, according to Yuan Gao, CEO of Pulead Technology Industry Co. Ltd, insiders are expecting more than that with the current rate of NEV production.

The term NEV is a something used in China to refer to any vehicle that can plug into an outlet. This means pure EVs and plug-in hybrid electric vehicles (PHEVs) are included in this category, while some hybrids, like Toyota’s Prius, aren’t.

As if this wasn’t already a large enough market, Elon Musk, CEO of Tesla, has been quoted as saying that stationary storage is "something I think will probably be as big as the car business long term".

byd k9 electric bus_Wikimedia  
China is leading the charge with EVs and electric buses (Wikimedia) 

Need for cobalt in battery chemistry

At the conference, Gao detailed the role of each metal element in the popular Nickel-Manganese-Cobalt (NMC) battery system.

Speaking broadly, Gao said that NMC batteries use a larger amount of nickel than any other mineral, and as more of this material is used, the proportion of cobalt and manganese (or aluminium in NCA chemistries) decreases.

In terms of its function, cobalt provides the battery with a good cycle ability, thanks to the tight molecular compound structure it provides in the cathode.

Gao said that while nickel already has a high percentage use, it is gaining in popularity due to its availability and low price. Goa added that another reason that cathode producers are moving towards using more nickel, is that "we are not assured we have enough cobalt".

There is also a common belief that the more nickel used in a cathode, the more energy dense the battery will be. This is not true however, because as nickel is added, overall voltage is decreased and with it power. To counteract this, cobalt must be used. In addition, increasing the proportion of nickel leaves the battery less thermally stable, a property that may be counterbalanced by manganese, a mineral that has no exothermic tendency.

Despite some researchers attempting to find a NMC battery with zero cobalt composition, Gao estimates that at least 10% cobalt must be used in battery cathode chemistry at all times due to safety and battery longevity reasons.

Many batteries today are using what is termed "333" composition, or one third nickel, one third cobalt and one third manganese. Currently the industry is trying to optimise safety, power, performance and price by moving towards more nickel-heavy compositions like 523, 622, and 811, with the first digit representing nickel, second cobalt, and third as manganese.

Sourcing cobalt

According to the CDI, there is now a greater-than-ever possibility of developing mines with cobalt as a primary metal (or even a pure play), which could take dependency away from the DRC. 

With 94% of cobalt mined as a byproduct of nickel and copper, and 80% of China’s copper being sourced from the DRC’s copper operations, companies like Broken Hill Prospecting (BPL) are stepping up to the plate.

The company, through its subsidiary Cobalt Blue Holdings, owns two cobalt deposits within two granted mining leases (ML66 and ML67) in New South Wales, Australia, known as the Thackaringa Cobalt project.

In its latest annual report, the company said that "the Thackaringa Cobalt project remains at the forefront of investor interest" and "is considered to host one of the world’s largest undeveloped cobalt resources".

The company is planning to undertake metallurgical and resource expansion drilling in the latter quarter of 2016, with a scoping study forecast to commence shortly after and results expected early 2017.

A major supply source for cobalt mined as a primary mineral would be welcomed by the industry. While commentators like Ke and Gao are focused on the demand side of the equation, others such as John Petersen, US battery technology commentator, are forecasting a decrease in the supply side as well.

Petersen says that nickel mining will be reduced due to falling nickel prices, leading to a reduction of 15% in the global cobalt supply, while pressure is mounting on companies like Apple to find sustainable and ethical sources of cobalt for their consumer electronics.

For more information on the raw materials used in the lithium-ion (Li-ion) battery industry see IM's new Battery Price Report.

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