Battery minerals: A question of purity?

By Josie Shillito
Published: Wednesday, 22 July 2015

Competition to supply raw materials to the burgeoning Li-ion battery market is hotting up. Josie Shillito, Reporter, spoke to experts in the industry to discover the importance of producing the appropriate purity minerals to manufacturers and whether sustainable provenance will hamper efforts to keep costs down.

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The performance of Li-ion batteries and ESS is partly determined by the purity of the raw materials that make them (source: Leslie Wong) 

The growth in applications of lithium-ion (Li-ion) batteries is expected to put pressure on supplies of the minerals that make up their constituent parts. Aside from their namesake ingredient – lithium – Li-ion batteries also require the minerals graphite, cobalt and sometimes nickel and aluminium as raw materials. 

Question marks hang over how to secure future supply of these minerals and, just as importantly, how to avoid bottlenecks in processing them to the required specifications.

Because applications for Li-ion batteries are constantly evolving, emphasis has moved to the purity of battery minerals. This topic is particularly pertinent for the electric vehicle (EV) battery market, which requires lighter-weight and higher-density batteries in order to maximise the efficiency of these cars and make them competitive on performance with their hydrocarbon-guzzling peers.

Purity, and how to achieve it, is the new debate in the battery minerals sphere and suppliers are confident that they will be able to command premium prices for highly refined products. However, for consumers deciding whether or not to switch to a technology based on price, and for manufacturers eager to preserve margins while building volume sales, there is also a query over the cost-benefit of paying more for materials that make their products perform just that little bit better.

Demand – More than just batteries

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Source: Roskill (2014)

Energy consumption: Natural vs synthetic graphite production

Battery3  

High purity graphite made from natural graphite ore has a distinct
cost advantage over synthetic material in terms of the energy used
in the manufacturing process (source: AMG Graphite).

Purity

Li-on battery-powered applications now span much more than the widely touted examples of smart phones, tablet computers and EVs. Across the world, the technology is now used in satellites, submarines, ships, aircraft and military equipment, among other high-performing technologies and products. 

Outside the world of EVs, the main
growth area is energy storage systems (ESS) – static battery packs designed to store and release energy to power homes, top up fluctuations in traditional grid systems and provide off-grid electricity to industry and communities.

EVs and ESS require different things from a Li-ion battery. Desirable characteristics for EVs are small size and light weight, since the battery needs to be carried by the car it powers. ESS batteries can afford to be bulky and heavy, however, since they remain stationary.

Would-be suppliers of battery minerals have been quick to take up authoritative positions on this topic in order to explain and promote the essential role their products will play in the green technology revolution.

"For an EV, the purity of the raw material that makes up the battery is upmost," Julien Davy, chief operating officer (COO) at TSX-V-listed exploration company, Stria Lithium Inc., told IM. "If, for example, your anode is bad quality, then you will have issues with your charging systems," he explained.

Stria has developed a technology which allows for low cost lithium production using a chlorination process from spodumene. The process can create 99.99% pure lithium metal which, Stria says, is almost double the value of 99.9% lithium metal. This can be transported in mineral oil, or converted via simple reactions to lithium carbonate or hydroxide.

The source material for this process comes from the Pontax and Wilcox lithium projects, which Stria is developing in Quebec, Canada, and Arizona, US, respectively.

Stria is just one arm of a connected network of young businesses looking to capitalise on the new technology wave. It shares its management with Canadian graphite junior, Focus Graphite Inc. and graphene developer, Grafoid Inc. – all of which are targeting clean energy applications with their products.

According to Focus, its graphite, which it sources from the Lac Knife deposit in Quebec, can also be produced in a purer form. The company’s COO, Jeff Hussey, told IM that, through floatation processes, Focus’ Lac Knife pilot plant can achieve 98% C purity graphite. Once it hits this level, it only takes one further minor process to bring it up to 99.999% purity spherical graphite – the material used in Li-ion battery anodes – via thermal purification.

Hussey says that the type of spherical graphite produced by Focus fetches around $8,000/tonne, while the material’s main competitor, synthetic graphite, made from processed petroleum coke, costs $20,000/tonne. 

Other companies, including established mining and specialised processing groups like Germany-based AMG Graphite (formerly known as Graphite Kropfmuehl), which produces and sells anode grade graphite material, have also stated that natural spherical graphite has a distinct economic advantage over synthetic material.

According to a recent investor presentation by AMG, it takes 200% more energy (7,500 kWh) to produce one tonne of synthetic graphite than it does to produce a tonne of natural material (2,500 kWh) with similar carbon content and particle size.

Hussey also pointed out that natural graphite tends to be more resilient to loss after recharging. In February this year, the company published test results showing that its own carbon-coated spherical graphite yielded a 99.35% efficient Li-ion battery, compared to commercial synthetic spherical coated graphite, showing 93.5% and 96.5% efficiency, respectively.

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Get pedalling: E-bikes are among the wave of new products powered by Li-ion batteries expected to drive demand growth (source: Ciclismo Italia) 

A crowded space

A large number of companies are engaged in extracting high-purity Li-ion battery minerals, according to Lilia Xie, research associate at consultancy, Lux Research. 

California-based sustainable materials technology company, Simbol Materials Inc., in 2013 produced what it claimed was the world’s first battery grade lithium carbonate (Li2CO3) at 99.99% purity from a geothermal brine using an electrolysis method.

Northern Graphite Corp. claims to have developed a proprietary method for the purification of concentrates and spheroidised graphite to 99.95% using ore from its Bissett Creek graphite property in Ontario and says that the cost of this purification process is less than $1,000/tonne. 

Vancouver-headquartered miner Eagle Graphite Inc. also says it has produced 99.995% pure spheronised graphite from a sample of flake graphite taken from its Black Crystal project in British Columbia.

Earlier this year, ASX-listed Syrah Resources Ltd announced that it had successfully produced uncoated battery grade spherical graphite using natural flake material from its Balama graphite project in Mozambique and that samples have been distributed for testing to Japanese anode and battery producers.

The company is also looking into the possibility of building 25,000 tpa spherical graphite plants in both Mozambique and the US to supply the battery market.

Reagent and labour costs dominate opex for both brine and hard
rock lithium operations

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Source: Lin Yuan, Hatch

Purity isn’t everything

As the market for rechargeable batteries matures, getting the minerals out of the ground will only be half of the supply story. More and more technology-related investments are likely to occur to enhance purity, and with this increased competition, costs should come down.

Jon Hykawy, president of consultancy Stormcrow Capital, says that this diversification of purification methods is inevitable for a good reason. "Purity is not overstated, or at least not markedly so, in my opinion," Hykawy told IM

"The biggest factor in causing serious failure in a Li-ion battery cell is dendritic growth – the growth of little metal 'whiskers’ that can cross the electrolyte and separator and cause an electrical short circuit between cathode and anode."  

"This is primarily an effect of some metals in the lithium-based cathode compound or the graphite on the anode leaching out over time and then growing into these little whiskers due to electric field." 

However, the purity of the lithium and of the graphite going into the battery is not enough to prevent this problem. The anode in a Li-ion battery is composed of natural graphite, usually coated in pure synthetic graphite designed to optimise the surface of the spheres and protect the rest of the battery from the 'dirtier’ natural graphite.

"Depending on how thick and uniform that coating of synthetic graphite is, the natural graphite inside does not have to be that clean," Hykawy told IM.

The expensive solution to dentritic growth is to use all-synthetic graphite in a battery, but for cost reasons this is unattractive to Li-ion battery manufacturers.

The purity of the lithium going into the lithium-based cathode material might end up being only loosely coupled to the purity of the final chemical compound. This is because the purity of the nickel, aluminum and cobalt in the cathode material is just as important as the purity of the lithium.

Since there are so many mining and exploration companies looking to place their material into the high value battery market, most will invest at least some money – and a few may invest a lot – in finding ways of making sure their minerals can be used for the job.

But according to Hykawy, there may not be a right answer. "I guess the answer is that it really isn’t clear just how pure the raw lithium or raw natural graphite going into a lithium battery need to be," he said.

Lux Research’s Xie points out that battery producers such as Tesla Motors, Foxconn, Samsung, LG and BYD have not made public the effect of the purity of raw materials on battery performance. Without this analysis, it is tricky to know whether purity of the mineral, beyond a certain minimum threshold, will be a factor to consider in their purchasing decisions.

High performance may even be a self-defeating goal for battery manufacturers. Since the time Henry Ford’s motor cars first rolled off the production line in Detroit, built-in obsolescence has been an important factor in the consumer market. 

The eponymous Ford famously said that he wanted his customers to only buy his cars once – a measure of the quality of the vehicle. Sales of Ford went on to be surpassed in 1931 by competitor General Motors, which implemented annual model-year design changes to convince consumers to buy a replacement each year.

EV manufacturers and ESS providers may find themselves treading the same tightrope between performance and sales. Given that cars are also depreciating assets, and that EVs are a relatively new addition to the car market, it remains to be seen what resale values will be like for cars whose expensive batteries only have a limited lifecycle.

"For battery producers it will probably always be a balancing act of purity versus cost," said Xie.

Lithium carbonate HEVs

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Improvements in technology are bringing down the amount of lithium
carbonate required by HEVs. Purer, higher performing mineral products
could see volumes come down further (source: Ev-sales.blogspot.com, Hybridcars.com, Insideevs.com, Argonne Laboratories - via Juan Carlos Zuleta)

Clean conscience

Sustainability concerns may be equally important to the consumer as a Li-ion performance, points out Stria Lithium’s Davy. In the case of Tesla, it tapped into the conscientious consumer’s supply chain, and possibly patriotic, concerns by announcing that it would source all of its materials close to home in North America, rather than racking up carbon footprint by transporting them from Asia, or elsewhere in the world. 

This presented Tesla with a challenge, in that the cheapest, supply-ready sources of the materials it needed were likely to be outside North America (located in China for graphite, Chile for lithium and the Democratic Republic of Congo [DRC] for cobalt). The company has been working hard to bring down the price of its battery packs and, ultimately, the cars they power, so minimising input costs is important.

In the arenas of EVs and ESS, green conscientiousness is likely to exert a strong influence, because its customer base originates from those concerned about the sustainability of their choices. But, for environmental (and possibly even commercial) reasons, Tesla doesn’t want to just preach to the converted. 

Until green technology products come to compete on price with conventional models in the mass market, which, for EVs, is expected to happen around 2020, it is sustainability-conscious consumers that will drive sales.

Greener processing

"If you buy a battery and it is produced in a 'greener’ way, then that is a great marketing tool for all of us," said Davy. Stria Lithium uses a recyclable process to extract its lithium, by mixing together recycled chlorine and hydrochloric acid to purify the lithium. 

In Nevada, Pure Energy Minerals has been working with Italy-based Tenova Bateman Technologies to conduct lithium recovery process testing of brine samples while doing away with capex/opex intensive evaporation ponds, and their large environmental footprints, at Pure Energy’s Clayton Valley project.

Tenova’s LiSX process was developed at the company’s research facility in Israel and is an advanced solvent extraction technology that efficiently extracts lithium from brine or other feedstocks in less than 12 hours – a method which feeds into what Pure Energy’s CEO, Robert Mintak, refers to as the company’s "invisible mining" operation.

However, in order to supply the quantity of lithium that could be needed in the market by 2020, the industry may also have to look at hard rock and clay lithium extraction, which is more capital intensive and implies a greater environmental impact than brine-based production methods.

Upfront investment and energy is needed in drilling for hard rock lithium, with little guarantee of success until the pre-feasibility study (PFS) confirms the potential viability of developing the resource. 

But the concentration of lithium supplies in Chile, which accounts for around 55% of world production, means that other lithium reserves need to be identified for supply security reasons, and some of these will be hard rock.

Investment in extracting and processing purer lithium from hard rock mining will be key, said Davy. "If it is to be successful, it must be able to produce better quality lithium at a cheaper rate than the brine industry."

Lithium Australia, known until recently as Cobre Montana NL, an ASX-listed mineral explorer, is working on a process of extracting lithium carbonate from lithium-bearing micas with a "zero energy footprint".

"The process we’ve developed removes the high-energy step used in conventional processing that gives you all the financial grief," the company’s managing director, Adrian Griffin told IM.

He explained how the method, developed in collaboration with Perth-based Strategic Metallurgy Pty Ltd and tested on sites in Australia and the Czech Republic, skips the roasting stage usually required to prepare lithium ores for leaching.

While energy intensive roasting is economical for high grade ores such as spodumene, which typically consists of around 6% lithium oxide (Li2O), the industry has so far not been able to make this work economically for micas, which usually grade at between 2% and 4% Li2O.

Lithium Australia’s process uses waste heat generated from the dilution of sulphuric acid with water – creating the reagent needed to dissolve the lithium-bearing mica – to provide the energy needed to leach lithium from its host rock.

Having successfully used the technology earlier this year to produce battery grade lithium carbonate from the Cinovec lithium deposit in the Czech Republic, where Lithium Australia is "in agreement to joint venture on a 50:50 basis" with the site’s licence holder, fellow ASX-listed European Metals Ltd, the company is now proving the process at a Perth-based mini plant with samples from its Western Australian Lepidolite Hill deposit.

However, developing and testing a new, green production method on a demonstration scale is only part of the story.

"Before you can commercialise a technology, you have to get market acceptance for the product it produces, and to do that you need to put product into the market that potential customers can test," Griffin said.

Consumers do not just want small carbon footprints – they are keen to know that the mining industry is ethical. This is where corporate and social responsibility regarding battery minerals could fall down. 

Cobalt, a key battery mineral, is principally sourced from the DRC, which holds one of the world’s worst records for militia-controlled mines and child labour.

Cobalt is a key ingredient in lithium cobalt oxide, typically used in handheld Li-ion devices and in lithium nickel cobalt aluminium oxide in rechargeable batteries. Nearly half of the world’s mined cobalt is produced as a by-product of copper mining in the DRC and Zambia.

According to the International Monetary Fund’s 2013 figures, the DRC is the world’s poorest country. It is also one of the richest in the world in terms of mineral wealth. With few primary deposits of cobalt globally, Li-ion batteries are likely to continue to be reliant on this source for the foreseeable future.

The presence of cobalt in rechargeable batteries undermines any investment in environmentally friendly production methods for lithium and graphite, according to Lux Research’s Xie. 

If investment takes place in improving extraction methods, it should be done as a means in itself, rather than to 'ethicalise’ the end product the minerals go into, since achieving this would require an overhaul of international governance in the medium term, rather than just clever science.

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Impure sources: DRC, one of the poorest and most war-torn countries in the world, is also the one of the biggest global suppliers of cobalt (source: MONUSCO Photos).

Lithium hydroxide

Producers of battery minerals should be preoccupied with sources of lithium hydroxide, according to Lux Research’s Xie. The availability of lithium hydroxide, refined from lithium carbonate, is more important to rechargeable batteries than the purity of lithium carbonate.

Lithium hydroxide produces better-performing battery cathodes, according to Xie, because the mineral contains more lithium than lithium carbonate does. While lithium carbonate is composed of 18% lithium by weight, lithium hydroxide contains 39% lithium.

Japan’s Panasonic Corp., which will manufacture and supply cylindrical Li-ion cells on behalf of Tesla, has specified that it will use lithium hydroxide in its batteries.

"Lithium hydroxide is a superior starting material. It has better morphology, better crystallinity, makes better cathodes, than lithium carbonate," said Xie.

According to figures from Chilean market intelligence business Signumbox, demand for lithium hydroxide is set to grow by 267.4% between now and 2025 to 183,303 tonnes. This is compared to demand growth of 166.9% to 253,739 tonnes lithium carbonate for the same period.

As a percentage of total lithium demand, by 2025 lithium hydroxide will make up 33.9% of the total 540,119 tonnes of expected demand, compared with 27.2% currently.

Lithium carbonate producers are working towards increasing their supply of lithium hydroxide in order to cater for this anticipated demand. 

US-based chemicals giant Albermarle Corp., which completed its acquisition of lithium producer Rockwood Holdings in January this year, is considering whether to build a new plant to make lithium hydroxide.

US competitor FMC Corp. is also mulling the idea, with a decision expected within a year. Both expect that their projects will be built in Asia or in the US.

"Lithium hydroxide’s importance is going to be bigger in the future for its use as active cathode material in batteries for high power applications," Signumbox said. "That means that the lithium hydroxide market is going to be much more important than lithium carbonate, since its capacity is much more limited."

According to Argentina-based lithium producer Orocobre Ltd’s investor presentation in June 2015, "New applications for lithium batteries have not yet been quantified for their effect on lithium demand, but some research groups are suggesting a potential doubling of market size by 2020."

Yet the overreliance of battery markets on a handful of niche mineral producers around the world could see them caught short in terms of the specific materials they require to make their products. 

For Lux Research’s Xie, the biggest concern is the availability of lithium hydroxide as opposed to carbonate. As for the purity question, "it will correlate with price and be less of an issue."

*Conversion made in June 2015