Features, Opinion

Lithium-ion batteries – back to the future

By Adrian Griffin, managing director of Lithium Australia

The ground-breaking work of the 2019 joint Nobel Prize winners – Goodenough, Whittingham and Yoshino – paved the way for the first commercial lithium-ion battery (LIB).

Commercial development began with the founding of Sony-Eveready in 1975. In February 1990, Sony unveiled the camcorder, which was released to the public in September of that year, along with mobile phones supported by lithium cobalt oxide (LCO) cells.

Since then, the LIB, which in those days was created largely for recreational applications, has morphed, chemically and physically, into an enabler of energy storage on a mighty scale and the global champion for portable power.

The LIB has afforded the planet an opportunity to decarbonise transport and power generation and, long-term, may well supply energy to the 600 million people worldwide who presently lack electricity and cannot connect to a grid.

Let us look at early development options for the LIB, how the technology has altered since its inception and where it is heading in the future.

Prevailing LIB technologies

Three major research teams dominated LIB development in the 1980s, each focused on a different cathode crystal structure.

The common surviving technologies include the spinel structures – such as nickel cobalt manganese (NCM) and nickel cobalt aluminium (NCA) – and the olivine structures, including lithium ferro phosphate (LFP), patented by Goodenough et al in 1996.

As LIB technologies have matured, what was formerly a plethora of chemistries has been reduced to a handful of mass-produced variants, and they too can be separated into the two classes mentioned above: the spinels (the nickel/cobalt – or Ni/Co – variants), and the olivines (LFP and related compounds).

The LFP edge

LFP provides a number of distinct advantages over the Ni/Co variants, among them lower cost, greater longevity, improved safety, a wider operating-temperature range, minimal requirements for heating/cooling and the ability to fully charge and discharge (meaning less requirement for control by battery management systems).

In fact, LFP can be used as a direct replacement for lead-acid batteries with no battery management system at all.

If that makes LFP sound like the ideal battery chemistry, what is the downside? The fact that, in its standard form, LFP does have a lower energy density than competing Ni/Co cells.

That said, LFP has long been a staple in energy-storage applications in which the volume of the battery pack is of little consequence.

LFP has also been widely adopted as the LIB of choice for Chinese electric vehicles (EVs) due to its superior safety credentials, whereas in the western world, with its fixation on range anxiety, batteries with Ni/Co spinel structures have been used in EVs.

LFP – cost advantage

Safety aside, cost considerations are becoming paramount as mass production of LIB cells underlines the financial benefits of LFP production compared to that of Ni/Co batteries.

LFP is likely to be the first LIB chemistry to break the $US100/kWh (kilowatt hour), making the total cost of ownership of an EV cheaper than one powered by an internal combustion engine.

LFP – circumventing supply issues

When choosing the type of LIB to use in EV applications, cost and safety are not the only considerations, given that the availability of some critical materials may be constrained by the ethics of supply.

Cobalt, for example, is often sourced from conflict zones – countries in which child labour and human-rights abuses are endemic – and is thus compromised in that regard.

With LFP, containing only one critical material, lithium, supply constraints are fewer than for competing Ni/Co batteries … and LFP requires 20 per cent less lithium per unit of stored energy than NCM LIBs. LFP is thus a far more sustainable option in terms of critical materials.

Finally, putting ethical considerations to one side, the pressure of demand for both cobalt and nickel is likely to run those markets into deficit within a decade.

LFP – back to the future?

As consumers become aware of the benefits of LFP, demand is rising rapidly. Tesla’s LFP-powered variants are being built in China and sold into the European market, and that company will soon offer its low-range LFP vehicles globally.

Meanwhile, China’s BYD is going head-to-head with Tesla in Europe, tempting buyers with luxury LFP-powered sedans. VW, too, is embracing LFP, having indicated that all its entry-level EVs will be based on that LIB platform.

As these EV manufacturers move forward, others will follow. But it is not just about EVs. Telsa is going all-LFP for its energy-storage products, including its ‘Megapack’, designed for large-scale backup of renewable energy.

In the past, most LIB cells produced by BYD in China were used in the production of its own vehicles, but that is about to change.

Theoretically, BYD’s ‘Blade’ technology for EVs – a configuration of LFP battery cells that provides high pack density – can be incorporated as a structural component of any EV, thereby reducing that vehicle’s weight and improving its range (BYD cites a staggering 1000 kilometres per charge).

Once made available to original equipment manufacturers (OEMs), the technology will reduce battery-pack manufacturing costs by increasing volumes and standardising machining.

No doubt the availability of a generic Blade pack will increase demand for LFP. Chinese-based battery manufacturer CATL is, with its Cell-to-Pack technology, pursuing a strategy similar to that of BYD – that of increasing energy density at pack level by improving battery-cell geometry.

LFP – manufacturing volume

Last year, BYD announced an eightfold increase in its LFP output and plans to discontinue production of any LIB cells containing nickel and cobalt – in future, all BYD batteries will be LFP-based.

This year has already seen new highs in the volume of LFP produced. Chinese output in the March quarter was close to that of LFP production in 2020 in its entirety.

In fact, in March this year, China produced more LFP than NCM – a first! Such is the expansion in demand and capacity for LFP that output for calendar 2021 is estimated to be as high as 350,000 tonnes.

The impact of all of this on the lithium chemical industry is clearly being felt, with demand for lithium carbonate rising disproportionately compared to that for lithium hydroxide. This has eroded the traditional hydroxide premium in the Chinese domestic market.

In some instances, prices for carbonate have exceeded those for hydroxide. Such a fundamental shift in battery chemistry demand could have a profound and long-lasting effect on future refining capacity and the types of lithium chemicals produced.

It may even be that neither lithium hydroxide nor lithium carbonate become the dominant precursor for LFP.

Whatever occurs, it does appear inevitable that LFP will be the LIB chemistry of choice sooner rather than later, and that it is likely to remain so for at least the medium term.

With many jurisdictions now taking a shine to LFP, supply shortages are bound to eventuate, given that less than 2 per cent of current demand is met from LFP production anywhere other than China, which consumes most of what it produces.

Western EV manufacturers must ensure security of supply, so the need for vastly increased LFP production capacity outside of China is obvious.

Shortening the supply chain

The production of LFP, as opposed to that of NCM or NCA, has environmental advantages beyond the applications for which it is used.

Current supply chains for NCM/NCA are complex, with most critical materials passing through China on their circuitous route from mine site to end-user.

As the supply chain for nickel-based LIBs matures and cell production decentralises, some shortening of the supply chain will occur; however, the primary sources of nickel and cobalt – that is, the mines themselves – cannot be relocated, so some complexities simply cannot be removed.

Supply chains for Ni/Co battery production therefore remain unavoidably complex and the geological, geographical and geopolitical risks associated with sourcing such critical materials increase the probability of supply chain disruption and price volatility.

LFP requires no nickel or cobalt, only lithium. Reducing the number of critical materials used in battery manufacture from three to one, simplifies the logistics chain and transport required to generate the final product – the LFP LIB. This in turn reduces the emissions profile of the finished goods, a boon for the environment.

Also, because LFP incorporates iron and phosphorous, commodities that are widely available, it is possible to further simplify logistics in a way not possible with NCM/NCA.

If lithium concentrates can be converted to lithium chemicals in refineries located closer to the actual mine sites that produce the lithium, then supply chain efficiencies will render obsolete the current practice of moving spodumene concentrates halfway around the world before converting them to lithium chemicals.

Historically, supply chains for LFP LIBs have been almost monopolistically China-centric but still far simpler than those for nickel-based LIBs.

Because LFP supply chains experience less price and supply volatility, this battery chemistry has the potential to be far more compliant from an environment, social and governance (ESG) point of view than any other LIB option.

Lithium Australia plans LFP production

Lithium Australia subsidiary VSPC Ltd produces advanced LFP cathode powders at its pilot facility in Brisbane, Queensland.

Recently, VSPC completed a pre-feasibility study that demonstrated the viability of LFP production using its proprietary processing technology.

The base case for the production of 10,000 tonnes per annum of LFP has an estimated capital cost of $US113 million, resulting in a net present value (NPV) of $US253 million, an internal rate of return (IRR) of 33 per cent and an annual free cashflow of $US56 million.

VSPC is currently working to improve the energy density of LFP, to bring it more in line with NCM at a cellular level. It is achieving this by adding manganese to the LFP chemistry to produce lithium manganese ferro phosphate (LMFP).

Because LMFP also crystalises in the olivine configuration, the superior attributes of LFP – low cost, safety, longevity, etc – are preserved; however, energy density is increased by around 25 per cent. VSPC-produced LMFP will be available for commercial testing from mid-2021.

A direct route from spodumene to cathode powder

Proprietary technologies developed by Lithium Australia include its LieNA process, designed to recover lithium from the fine or low-grade spodumene (the principal hard-rock source of lithium) usually consigned to tailings when lithium concentrates are produced as feed for conventional convertors.

A caustic conversion process, LieNA has no roasting phase and, importantly, provides the option of producing lithium carbonate, lithium hydroxide or lithium phosphate.

Lithium phosphate is ideal feed for the production of LFP, since it delivers the lithium and the phosphorous required in a single reagent.

Together, LieNA and VSPC’s advanced cathode-powder production technology can create a direct route from spodumene to LFP, eliminating the need to produce lithium hydroxide or carbonate. With the length of the battery supply chain further reduced, economic and environmental benefits will ensue.

Conclusion

One of the longest established variants of the LIB but largely sidelined until now, LFP has avoided extinction thanks to its popularity in China.

Now this battery type is rising like a phoenix from the ashes to take on the world. Indeed, pundits predict that LFP will be the dominant LIB type globally in the very near future.

LFP provides an opportunity to overhaul the battery supply chain by reducing risks and costs, as well as the industry’s environmental footprint.

That said, improving supply chain security requires extensive expansion of LFP production capacity outside of China. Lithium Australia plans to establish such an alternative supply chain while simultaneously reducing the number of steps from mine gates to the production of energy-efficient passenger vehicles.

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