Lithium – the backbone of the energy and mobility revolution

​Article published on 9th December 2019

As a component of batteries of electric cars and stationary battery systems, lithium is a material that will be probably used quite extensively until the next technological advances are achieved in the area of electricity storage technology. All the more interesting is the question of the current sources of lithium, possibilities of recycling and a look on future developments.

The sale of every electric car and stationary storage system goes hand in hand with increased demand for lithium being a light metal and an important component of modern-day lithium-ion batteries. But this resource is non-renewable, and thus available only to a limited extent, and its exploitation raises social and environmental concerns. Therefore, intensive efforts are being made to look for alternative battery storage systems especially for electromobility. In addition, recycling methods are being developed to mitigate the problem of the limited availability of the resource.

In addition to stationary batteries used for optimising self-consumption, for peak shaving or supply of balancing energy, the shift away from fuel to electric engines (and renewable energy) is regarded as a solution for reducing CO2 in the transport sector.  As can be seen in Illustration 1, the transport sector accounts for 24% of global CO2 emissions. With the shift to electromobility, CO2 emissions caused by transport can be reduced.

Illustration 1: Distribution of energy-related CO2 emissions worldwide by sector in 2016.

The number of electric vehicles (EVs) considerably increased between 2014 and 2018, as shown in Illustration 2. Alone between 2017 and 2018, the number of EVs increased by 64%. In 2040, there will be 320 million electric cars on the streets worldwide.

 Illustration 2: Number of electric cars worldwide

The growth in electromobility is closely connected with the increase in lithium production because lithium is the main component of modern-day lithium-ion batteries (LIB). LIBs have successively replaced lead-acid batteries as the main storage technology for home storage systems. In the second half of 2017, LIBs had a nearly 100% share.¹

  
The advantages of rechargeable batteries are obvious. On the one hand, LIBs have a high energy density, which is why they are lighter than comparable batteries; on the other hand, they have good charging characteristics. The typical estimated life of a lithium-ion battery is 1,000 charge cycles. A 50% charge counts as half of the charge cycle. Thus, even intensively used LIBs have a life expectancy of many years. 
In addition, they are rechargeable without the so-called “memory effect”.  Memory effect is an effect where frequently partially discharged batteries gradually lose their capacity to hold charge. For LIBs, this means that they hold charge despite frequent partial discharge. This makes the process of full recharging followed by full discharging obsolete.  LIBs can hold charge even longer if they are recharged frequently but at smaller charge rates.

Another positive charge characteristic of LIBs is their short charge time. Until they are 80% charged, LIBs charge very quickly. The remaining charge capacity is charged more slowly because there is no voltage increase at 80% of the charge, which reduces current intensity.  In addition, LIBs are relatively very safe to use.

The problem is, however, deep discharge. Charging under the final voltage of a LIB  – e.g. due to incorrect recharging or using a defective charging device – initiates the process of deep discharge. Deep discharge causes irreversible damage to LIBs, leads to loss of capacity and, in the worst case scenario, creates a short circuit which can set the LIB on fire. When LIBs are used in motor vehicles the risk of deep discharge is higher, e.g. because of the higher energy requirement of more power consuming appliances such as radios or vehicle heaters or due to frequent driving of short distances. Timely recharging helps minimize the deep discharge risk.

In order to satisfy the demand for LIB, lithium production is already being intensively expedited.  But lithium production does not come without problems. In particular the intensive use of the raw material and social and environmental impacts are being criticized.

It takes about 50% of the world's lithium reserves to build a LIB with a capacity of 60kWh into every car worldwide (approximately 1 billion). But this calculation does not include vans, buses and lorries which would need LIBs with a capacity 10 times greater than that of typical cars.   This thus significantly increases lithium consumption. The admissible share of lorries, buses and vans in the global number of motor vehicles should not exceed 10%, otherwise all lithium reserves would be used up for the car industry alone. Moreover, the calculation does not include LIBs used in electric bicycles, cell phones, laptops and home storage systems. For lorries, buses and vans, however, the use of hydrogen fuel cells seems to be a natural option, since it is impossible to ensure the required energy capacity of batteries carried on the transport unit in an economically viable manner, at least not on the basis of LIB technology.

Therefore, the biggest challenge is the further development of battery cells. The initial goal is to make batteries less expensive, as they make up about 40% of vehicle costs today. ,  In the first half of 2019, the entire battery package cost USD 209 per kilowatt hour (kWh). Thus, a 60 kWh battery is USD 12,540 (EUR 11,286). Experts expect that the USD100/kWh threshold will be undercut by 2025. Despite these forecasts, automobile manufacturers expect prices to increase as the demand for batteries and their materials is growing. For example, Ford Deutschland expects a price increase of approximately 10%.

The growing demand for LIBs due to rising electromobility and increased use of LIBs in cell phones, laptops and home storage systems therefore lead to the question of how long the lithium reserves will last. In order to answer this question, it can be helpful to take a look both at lithium exploitation, which is not unproblematic, and the research into LIB alternatives. Another question is whether lithium used for batteries can be recycled.

Lithium production

Lithium is found as a trace element in water, salts and minerals all over the world. It makes up 0.006% of Earth’s crust.  However, since lithium is highly reactive with oxygen, it is never found in its pure form but always as part of chemical compounds. The highest concentration of lithium is contained in silicate minerals (25%) and mineral-rich brines (59%). Consequently, 50% of world's lithium is produced from brines and 40% from minerals.

More than half of the global lithium reserves is located in salt flats (Spanish: “Salar”) in an area that overlaps Bolivia, Chile and Argentina and, for this reason, is also called the ‘lithium triangle’.  Salt-containing groundwater (brine) is pumped to the surface by means of water pumps. It is then stored in artificial lakes and evaporates in the hot and arid climate. This procedure, which can last between 18 and 24 months, is called solar evaporation. What remains is a thick concentrate containing 6% lithium. This concentrate is then further processed to lithium carbonate (Li2CO3) by heating and adding Na2CO3.

Figure 3: Solar evaporation during lithium production in South America.

Apart from this, lithium can also be mined. Although lithium is contained in 145 minerals, only mining for spodumene, petalite and lepidolite is economically viable, provided the reserves are large enough.  Those minerals are processed into lithium concentrates by way of crushing, grinding, gravity and magnetic separation, flotation, washing, screening, and drying.

In the future, lithium will be mined also in Germany or more specifically in Saxony, which is home to the largest lithium deposits in Europe.  In the East Ore Mountains near the Czech border explorations have shown that about 125,000 tons of lithium are stored in the old Tiefe-Bünau tunnel next to Zinnwald, which now is a tourist mine.  Deutsche Lithium GmbH, a joint venture of Solar World AG and Canada's Bacanora Minerals  expects about 500,000 tons of Li2CO3 to be produced from the zinnwaldite rock which is named after the small community of Zinnwald. Depending on the specific composition, the rock contains between 3 and 4% of lithium. Assuming that 50kg Li2CO3 per electric car are needed, the Zinnwald resources could serve to propel up to 10 million electric cars, which is nearly twice the number in operation in 2018. Assuming production potential of 500,000 tons of Li2CO3 in Zinnwald combined with the price of USD 11,250 per ton of Li2CO3 from July 2019 – as can be seen in Illustration 4 – this leads to potential revenue of USD 5.625 billion (or EUR 5,063 billion).

But lithium exploitation in Saxony would be significantly more expensive than lithium production from the salt flats in South America. By comparison: In South America, the costs of extracting one ton of Li2CO3 are between USD 2,000 and USD 2,500 (solar evaporation), in Australia (mining) they are USD 4,000. Deutsche Lithium GmbH calculates extraction costs similar to those in Australia. Another element of risk is that the increase in demand for electric cars might be not as strong as expected and, in return, will lead to a significantly increased lithium supply. This trend is already perceptible – as shown in Illustration 4. This would mean a decline in the Li2CO3 price, which again would compromise the profitability of the project.  Nevertheless, lithium mining in Saxony offers the opportunity to minimise the global market risk as regards supply bottlenecks and price fluctuations.  Currently, however, the project is on shaky ground due to the insolvency of Solar World AG.

The price (Prices stated for 2015, 2016 and 2018 are the annual average prices for the relevant year. For February 2017, June and July 2019 the prices are stated as monthly average prices.) of Li2CO3, one of the most important lithium compounds, rapidly increased between 2015 and 2018, as shown in Illustration 4. The reason for this is the strongly rising demand. In 2015, 178,000 tons of lithium carbonate and hydroxide were consumed; in 2017, consumption was already 238.000 tons. Deutsche Bank expects the demand to increase up to 534,000 tons by 2025.  Due to growing supply, the price has significantly declined in recent months.

Illustration 4: Commercial price of lithium carbonate.²

Apart from its economic benefits (new jobs and foreign currency inflow to producing countries), lithium production also entails certain problems. The problem arising from lithium production by way of solar evaporation in South America is high water consumption in an (already) dry region. This endangers the existence of the indigenous population and animal species.  The native inhabitants, some of whom live a self-sufficient life do not have access to water they need for everyday life  , on the one hand, and, on the other hand, to salt from the salt flats which they use for agricultural purposes.  Moreover, vast regions with rivers and lakes that used to be home to flamingos have dried out. The Andean flamingo is on the brink of extinction, by now.  Besides, the salt lakes are a magnet for tourists and industrial production could have a negative impact on tourism.

The figures on the volume of water consumed illustrate how controversial the discussion about lithium production is. According to forensic geologist Fernando Diaz, two million litres of water has to evaporate in order to produce one ton of lithium. Other sources, however, calculate (only) on 0.4 litre of water that has to evaporate. Another point made by the latter is that, on the one hand, the rate of water evaporation in the ‘lithium triangle’ was naturally high and, on the other hand, also other resources were extracted through evaporation.

Another problem is that the evaporation process is subject to variation. Brines differ in their chemical composition and degree of contamination. As a result, production processes are different depending on the specific lithium deposit.  Besides, rainfall and sheet floods slow down the evaporation process.  These factors increase the price of production.

Another critical raw material needed for LIB is cobalt. Cobalt is mainly produced through mining. The largest deposits are located in Sub-Saharan Africa. There, cobalt is mined illegally and in difficult conditions.³

The interim conclusion is that battery manufacturers are facing increasing pressure to look for alternative technologies to lithium. The reasons for this are the limited availability of the resource, increasing prices due to growing demand and the environmental damage caused in the production process.

Alternative technologies

As can be seen in Illustration 5, rechargeable batteries represent about 30% of batteries powering devices. Within this group, LIB has the largest share of about 70%. Now, there are two ways of how to work out alternative solutions. 
The first one is the replacement of only (mainly) the lithium metal. The second one means research into new (rechargeable) battery systems. Both options will be analysed below.

Illustration 5: Share of rechargeable batteries and primary batteries put on the market in 2017.

The first alternative is the replacement of lithium as far as possible with materials that have properties similar to those of lithium. To this end, it will be helpful to take a look at the periodic system of elements. Lithium with the atomic number 3 is the first and lightest metal and belongs to the group of alkali metals.  Matthew McDowell and his team from Georgia University of Technology in Atlanta conduct research into rechargeable batteries in which lithium is replaced by sodium (atomic number 11) or potassium (19). Like lithium, sodium and potassium belong to the group of alkali metals and, thus, have similar properties. But they are found in much vaster quantities and are, therefore, less expensive.  Sodium is the sixth most common element on earth. It is mainly produced by mining sodium chloride (NaCl), which is better known as table salt, and solar evaporation.  Like sodium, potassium is one of the tenth most common elements of the Earth’s crust. Its share in it is 2.59%. It is produced similarly to sodium. 

In the salt flats of South America the alkali metals lithium, sodium and potassium can be extracted from brines by way of solar evaporation. Table 1 illustrates the huge difference between lithium and the other two metals.

Table 1: Alkali metal deposits in ppm (parts per million) . Data: Deutsche Rohstoffagentur [The German Mineral Sources Agency] (2017, p.17)

One of the benefits of sodium and potassium ion batteries is their long battery life. But nevertheless their storage capacities and energy density are inferior to those of LIBs. Therefore, researchers work on possibilities to increase energy density. An additional argument for replacing lithium by sodium would be that in these batteries copper, which is also a rare metal, could be replaced by aluminium.  Thus, the price of these batteries could be significantly below the price of LIBs.

Apart from researching into lithium replacement possibilities research also focusses on alternative battery systems, including those shown in Illustration 5. Lead-acid batteries [LABs] were important as an inexpensive starter battery (for starting  the car engine) because of its good low temperature tolerance and the ability to release much energy in short time. The problem is low energy density (30Wh/kg; LIB: 140Wh/kg) which makes LABs too heavy to use them as a starter battery. Nickel-cadmium batteries are not an alternative because they are toxic and were therefore withdrawn from the market. Nickel metal hydride batteries are not an alternative to LIB because of the “memory effect”.

Another alternative would be nickel-zinc batteries which are as powerful as LIBs but lighter and safer. Nevertheless, nickel-zinc batteries do not equal LIBs in terms of energy density and long battery life.

Further hopes are pinned on lithium oxygen batteries. Not only are they lighter than comparable LIBs but with an estimated life of 2,000 charge cycles they have a significantly longer battery life. The problem is oxygen. Oxygen has to be carried along separately because the batteries can be damaged by humidity in oxygenic air.

Redox flow batteries (RFB) represent a class of electrochemical energy storage devices where energy is stored in liquid storage media. Energy conversion is similar to that in fuel cells. Their energy density is comparable to that of lead-acid batteries (30kW/kg) but they have a significantly longer battery life. Because of the external storage device there is virtually no self-discharge. Therefore, RFB can be used for uninterruptible power supply. As for electromobility, the problem is that the batteries need an extra storage device that has to be carried along separately.  This means additional weight and requires additional space.

Finally, research areas also include the optimisation of lithium-ion batteries, in particular how to avoid dendrite formation, which impair the battery performance.  Research also focuses on safety and industrial production so as to make it more cost-effective.

The second interim conclusion is that technical possibilities do exist and their further development should be observed. Currently, however, LIBs remain the best alternative and this raises the question of whether these batteries or, in particular, lithium can be used as part of a sustainable circular economy.

Recycling possibilities

In Germany, every citizen is obliged to dispose of LIBs in battery collection boxes because lithium, cobalt, manganese, silver, copper, steel, zinc and nickel can be recovered from the batteries.  Moreover, according to the European Directive 2006/66/EC on batteries and accumulators , distributors of batteries are required to take back waste batteries and accumulators at no charge and without condition. This means that the legal framework already exists.

Currently, however, only about 1% of used lithium is being recycled. This is due to big deposits and the relatively inexpensive production of lithium, among others.  Besides, the recycling process of LIBs is, as for now, more expensive than the costs of recycled battery materials.  Another factor is that most of the lithium produced is currently in circulation. Consequently, there is not enough lithium waste to justify the respective recycling industry. The growing demand for lithium, however, will initiate the recycling process because lithium recycling is not a complex procedure. The low melting point (180°C) and easy solubility of fluorides, phosphates and carbonates allow recycling lithium by way of lixiviation or ion exchange, which is easy from the technical point of view. Thus, the establishment of a lithium recycling industry is only a matter of time or economic development.  Another lithium recycling alternative is the second use of the batteries as a home storage system.

Conclusion

Increasing electromobility and use of LIBs in electronic devices and home storage systems will lead to growing demand also for lithium. Undoubtedly, an important issue is to ensure that lithium production takes place in a socially and environmentally sustainable manner. Since this is not the case at the moment and the resource is in strong demand, a recycling process has not yet been launched and the cost of electric vehicle batteries still account for a very large part of the total price, intensive research is conducted to find alternatives to LIBs. Research for this article has shown that, for now, there are no real alternatives to LIBs. Therefore, lithium will continue to be the backbone of electromobility and stationary battery systems in the years to come. The ongoing process of technical optimisation of LIBs as well as the foreseeable breakthrough in the recycling industry will further strengthen the role of lithium.

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¹ Kairies, Kai-Philipp: Auswirkungen dezentraler Solarstromspeicher auf Netzbetreiber und Energieversorger. ["Impact of decentralised solar power storage systems on network operators and energy suppliers."] Öffentlicher Vortrag zur Dissertation an der Fakultät für Elektrotechnik, Informationstechnik und Technische Informatik an der RWTH Aachen. [Public lecture on the dissertation at the Faculty of Electrical Engineering and Information Technology at RWTH Aachen University.] . URL: https://ei.uni-paderborn.de/fileadmin/elektrotechnik/fg/nek/Kairies/2019_Kairies_Heimspeicher_TU_Paderborn.pdf (12.08.2019). Folie 25.

² Illustration 4: In-house presentation, based on: Deutsche Rohstoffagentur [The German Mineral Sources Agency] (2017, p.36), Statista  (2018; https://www.statista.com/statistics/606350/battery-grade-lithium-carbonate-price/) and Metallbulletin (2019; https://www.metalbulletin.com/lithium-prices-update).

³ cf. ZDF, Der wahre Preis der Elektroautos [“The true price of electric cars.”], 2018.