Understanding The Environmental Impact of EV Batteries

There are significant advantages to convert from conventional car towards EV, such as (Manzetti & Mariasiu, 2015; (Ahmadi et al., 2014):

• The high torque of the electric motor in traffic that is transmitted to the wheels and the smoother acceleration (and deceleration) compared to vehicles with internal combustion engines (ICE – Internal Combustion Engine)
• EVs also do not emit noise while operating the electric motor and they don’t produce pollutant emissions. These aspects make electric vehicles the ideal vehicles to be used in cities and/or urban areas
• EVs eliminate tailpipe emissions.
• [They are more efficient because] the average Internal Combustion Engine has a fuel efficiency of only 40% – with 60% lost via heat and friction. As a result, ICEs consume far more energy travelling the same distance as an EV.
• Reduced components use (compared to vehicles equipped with ICE).  EVs have far less moving parts and therefore cost less to maintain, and experience less wear and tear (uk.mer.eco, 2022).

Besides the above advantages, there are some disadvantages to using battery electric vehicles (Manzetti & Mariasiu, 2015; Serohi, 2021):

• High production costs 
• Limited autonomy and top speed 
• Large recharging times or the need for special charging places.  These have emerged as important obstacles to the implementation of e-mobility besides range anxiety and inadequacy of charging infrastructure in most countries of the world including India.
• The lack of electric motor noise can cause traffic accidents (persons with hearing disabilities, pedestrians, cyclists, etc.) 
• EVs do not pollute the air as much as ICE vehicles running on fossil fuels do. Yet, in general, the resources utilized in battery manufacturing and improper disposal of used batteries are harmful to the environment.
• Fossil fuels and non-renewable materials are used in the production of EVs and their batteries which still cause pollution, as well as their ongoing charging requiring fossil-fuel energy in many cases.

We must point out that the same supply chain is operative for decentralized power storage applications as well, the rise of which is a parallel trend running alongside that of automobile electrification. These two uptrends both compete for the same or similar raw materials and helps each other in scaling-up in the battery manufacturing and recycling factories (seekingalpha.com, 2017). 

In three segments, i.e., battery cell manufacturing, EV sales, and battery recycling, some competitive advantage can be attained. 

• The manufacturing of battery cells, as part of the parts supplying group, is where the advance of battery technology occurs. Years of heavy investment in R&D has created intellectual properties, which render protection for the IP owner’s hold of EV manufacturers, which in many cases leads to the formation of long-term supply alliances. However, new battery technology may disrupt the oligopoly enjoyed by the entrenched players in this space.
• The car dealerships already exist for most EV manufacturers with the exception of new entrants such as Tesla and can prove to be highly profitable especially when the models carried attract a swarm of buyers.
• Battery recycling may eventually wind up to become a big business within Waste Management. In the future, the battery cell manufacturers may vertically integrate into this domain and become dominant players.

The production in all stages of the EV battery supply chain is concentrated in few companies. Top-three companies by production (country where headquartered) (iea.org, 2022): 

• Lithium: Sociedad Química y Minera de Chile (Chile); Pilbara Minerals (Australia); Allkem (Australia); 
• Nickel: Jinchuan Group (China); BHP Group (Australia); Vale SA (Brazil); 
• Cathode: Sumitomo (Japan); Tianjin B&M Science and Technology (China); Shenzhen Dynanonic (China); 
• Anode: Ningbo Shanshan (China); BTR New Energy Materials (China); Shanghai Putailai New Energy Technology (China); 
• Battery production: CATL (China); LG Energy Solution (Korea); Panasonic (Japan); 
• EV production: Tesla (United States); VW Group (Germany); and BYD (China)  

The three most critical metals for Li-ion batteries are lithium, cobalt and nickel. All three metals are abundant in the earth’s crust, however, supply depends on mine production capacity. The exceptional rise in demand for batteries is now outstripping supply, with new mines not being built fast enough. Figure 3 shows the geographical distribution of the global EV battery supply chain, as we can see, China dominates the entire downstream EV battery supply chain (iea.org, 2022).

Like many other batteries, the lithium-ion cells that power most electric vehicles rely on raw materials — like cobalt, lithium and rare earth elements — that have been linked to grave environmental and human rights concerns (Plumer, 2021).

Lithium is found in three main types of deposits: saline subsurface waters (continental brines), hydrothermally altered clays (sedimentary deposits), and pegmatites (crystalline hard rock). World lithium reserves are estimated to be 21 million metric tons of lithium and the world lithium resource base is estimated to be 86 million metric tons of lithium. The primary commercial sources of lithium are hard rock deposits in Australia and China, and brine deposits in Argentina, Chile, and China. These countries account for the majority of lithium production worldwide. Brine deposits account for between 50 and 75% of the world’s lithium production. Major brine deposits occur in the US, but commercial production of brine lithium occurs predominantly in South America (Stringfellow & Dobson, 2021). 

The most technologically advanced approach for direct lithium extraction from geothermal brines is the adsorption of lithium using inorganic sorbents. Other separation processes include extraction using solvents, sorption on organic resin and polymer materials, chemical precipitation, and membrane-dependent processes (Stringfellow & Dobson, 2021). Operations that use large amounts of groundwater to pump out the brines, drawing down the water available to Indigenous farmers and herders. The water required for producing batteries has meant that manufacturing electric vehicles is about 50% more water-intensive than traditional internal combustion engines. Deposits of rare earths, concentrated in China, often contain radioactive substances that can emit radioactive water and dust (Plumer, 2021).

Lithium-containing brine deposits occur as groundwater under ancient endorheic lake beds (salt pans or salt-flats or salars) and are commonly referred to as “salar brines”. Wells are drilled to access the underground brine deposits and the salar brine is then pumped to the surface and distributed to evaporation ponds. The brine remains in the evaporation pond for a period of months or years until most of the liquid water content has been removed through solar evaporation. During the evaporation process, the lithium concentration is increased from approximately 2000 mg/L to up to 6% in the final brine.

Figure 4 below (image source: Richter, 2021) shows a simplified overview of lithium extraction from geothermal brine. Under current practices, lithium chloride (LiCl) and lithium carbonate (Li2CO3) are produced from brines by evaporative concentration followed by further refining. Lithium hydroxide (LiOH∙H2O) is typically produced from refined lithium carbonate (Stringfellow & Dobson, 2021).

Next, focusing on cobalt, cobalt has been especially problematic. Mining cobalt produces hazardous tailings and slags that can leach into the environment, and studies have found high exposure in nearby communities, especially among children, to cobalt and other metals. Extracting the metals from their ores also requires a process called smelting, which can emit sulfur oxide and other harmful air pollution. And as much as 70% of the world’s cobalt supply is mined in the Democratic Republic of Congo, a substantial proportion in unregulated “artisanal” mines where workers — including many children — dig the metal from the earth using only hand tools at great risk to their health and safety, human rights groups warn  (Plumer, 2021).

Automakers and other manufacturers have committed to eliminating “artisanal” cobalt from their supply chains, and have also said they will develop batteries that decrease, or do away with, cobalt altogether. But that technology is still in development. Experts point out that spent batteries contain valuable metals and other materials that can be recovered and reused. Depending on the process used, battery recycling can also use large amounts of water or emit air pollutants (Plumer, 2021). 

Figure 5 below (image source Notter et al., 2018) depicts the production steps required for the Li-ion battery ranging from the extraction of lithium and the electrode production to the battery pack, the components of the electric vehicle, and the mobility with the electric vehicle. 

The dashed line refers to the functional unit chosen for this study. For all production steps, the required thermal and electrical energy to produce a 1 kg Li-ion battery is quoted. The mass used for the calculation is based on a Kokam battery and the cathode material is assumed to be LiMn2O4.

Detailed input-output tables for all gray boxes and the assumptions for transport distances, infrastructure, and electricity mixes are provided in the Supporting Information. The production of concentrated lithium brine includes inspissations of lithium-containing brine by solar energy in the desert of Atacama. Diesel fuel is required for pumping the brine between different basins. The concentrated lithium brine is further treated with additives for the removal of boron, followed by a purification step. Finally, the addition of soda for carbonation results in the precipitation of lithium carbonate (Li2CO3). The salt is filtered, washed and dried which results in a purity of 99% or higher (Notter et al., 2018). 

Manganese oxide (Mn2O3) is produced by a two-stage roasting process whereby manganese carbonate is roasted in an atmosphere low in oxygen content, followed by roasting in an atmosphere high in oxygen content. Subsequently, lithium manganese oxide (LiMn2O4) is made from Mn2O3 and Li2CO3 by means of several roasting stages in a rotary kiln. During the different stages, the atmosphere in the rotary kiln changes from an inert (addition of N2) to an oxidizing (addition of O2) condition. The powder is then suspended with water followed by spray drying (evaporation of the water  (Notter et al., 2018). 

Base materials for the electrolyte are an organic solvent, typically ethylene carbonate (C3H4O3), and the electrolytic salt, typically lithium hexafluorophosphate (LiPF6). For the production of the LiPF6, lithium fluoride (LiF) is manufactured with a reaction of Li2CO3 and hydrogen fluoride at room temperature. The filtrate is titrated with ammonia (pH 7.5), washed with water, and dried. Phosphorus pentachloride (PCl5) and LiF are then combined in an autoclave and cooled down to -78 °C. Thereafter, hydrogen fluoride is added in excess for complete chlorine-fluorine exchange in PCl5. The reaction in the autoclave occurs in an inert nitrogen atmosphere (Notter et al., 2018). 

The production of the cathode and anode requires the mixture of a few components (binder and solvent, black carbon, LiMn2O4 and graphite respectively) in a ball mill to a slurry, followed by coating the collector foil (aluminum and copper respectively) with the slurry. The binder (modified styrene-butadiene copolymer) is water soluble and has the advantage that no organic solvent is needed. For the production of the separator, a porous polyethylene film is coated with a slurry consisting of a copolymer, dibutyl phthalate and silica dissolved in acetone. Thermal heat energy for the anode, cathode and separator is used to heat up the slurry to 130 °C, evaporate the solvent and completely dehumidify the components of the electrode in a dry channel (H2O content <20 ppm) (Notter et al., 2018). 

Cathode, separator, and anode are calendared, slit to size, winded, and packed into a single cell in a polyethylene envelope. In an inert atmosphere, the electrolyte (LiPF6 dissolved in C3H4O3) is added to the electrode. Finally, single cells, the battery management system and cables are assembled in a steel box  (Notter et al., 2018). 

The presence of EVs on roads has expanded rapidly in the United States and especially in Europe. Though few can doubt the claims made for them, greenhouse gases are not the world’s only pollution concern. In general, EV batteries will have to be replaced every 7-10 years in case of vehicles that are smaller in size and every 3-4 years if the vehicles are as big as buses and vans. A preponderance of EV batteries have a 160,000 km (100,000 mile) drive limit or an 8-year warranty. For instance, the Tesla Roadster uses a lithium-ion battery pack that is expected to have a 5-year lifespan or last 100,000 miles. On completing this span, the pack must be replaced (Serohi, 2021).

Major potential environmental impacts

Thus, the environmental impact of EV batteries is extreme and accelerated by massive Electric Vehicles usage, especially from their batteries, including:

• Natural resource scarcity due to raw material mining and extraction processes (Plumer, 2021).
• Overuse of water from lithium extraction and production process; manufacturing of electric vehicles consumed 50% more water than traditional internal combustion engines (Plumer, 2021; Stringfellow & Dobson, 2021). As a consequence, water overuse can lead to food insecurity and loss of biodiversity. 
• Hazardous chemicals from improper disposal of the batteries. The batteries generate toxic battery waste having adverse environmental implications  (forbes.com, 2018; Serohi, 2021).
• Environmental pollution from mining and refinery activities. The extraction of the key ingredients, lithium and cobalt, has the potential to cause serious water pollution and depletion in water levels and other environmental concerns; such as toxic tailings and slags that can leach into the environment (Plumer, 2021; Serohi, 2021).

As China, a leader in EVs, is finding out, the disposal of EV batteries presents separate and severe environmental risks. That country’s experience may offer a glimpse of this country’s next environmental scare (forbes.com, 2018).

And now because of China’s EV dominance, that country is discovering a new and severe environmental problem. EV batteries are toxic and carry great power to pollute. Early on, the problem was less evident. These batteries last for 5 to 8 years so it took time before China needed to find ways to dispose of them safely. But in the last year, China had to get rid of some 200,000 tons of these things. The government expects that number to grow to 800,000 tons over the next four years, an annual growth rate of over 40%. Neither Cobalt nor nickel can break down in nature. EV batteries also contain manganese that can pollute soil and water as well as air. Only 500 micrograms of manganese in a cubic meter of air will produce manganese poisoning in most people. As lithium batteries degrade, they produce hydrogen fluoride and other pollutants. China has already had to deal with a bout of manganese poising tied to battery disposal in Guangdong Province (forbes.com, 2018).

Finding EV batteries a second life after use

A different, promising approach to tackling used electric vehicle batteries is finding them a second life in storage and other applications. Various automakers, including Nissan and BMW, have piloted the use of old electric vehicle batteries for grid storage. General Motors has said it designed its battery packs with second-life use in mind. But there are challenges: Reusing lithium-ion batteries requires extensive testing and upgrades to make sure they perform reliably. If done properly, though, used car batteries could continue to be used for a decade or more as backup storage for solar power, researchers at the Massachusetts Institute of Technology found in a study last year  (Plumer, 2021). 

Recycling them

Normally, an EV battery would contain a number of important and reusable substances such as nickel, cobalt, and copper. Recycling these batteries will help to reuse these materials, diminish pollution and may even present the opportunity to benefit from it. Organizations that recycle EV batteries even sell EV them to individuals for their personal use. Management of the battery life cycle provides a good opportunity to overturn what seems to be a constraint to the evolution of a new attribute that has the potential to step up and expand EV sales in the times ahead (Serohi, 2021).

Recycling offers the opportunity for the reduction of battery life cycle costs through recovery and repossession of pricey substances. In so doing it helps to anticipate the expenses that need to be incurred for the disposal of hazardous waste materials. This is why one of the key objectives of EV power source developers is to recycle the maximum possible material at the end of their useful lives (Jungst, 2001).

The process of recycling is able to help reclaim nearly 50% of the expensive metals, that include aluminium, cobalt, copper, lithium, manganese and nickel. Once reclaimed these metals can then be put to secondary use  (Serohi, 2021).

To understand how recycling may be able to decrease the effects and costs of battery [usage], the materials used in batteries and their costs should be defined, and the cost of new materials and recycled materials compared. Mining and refining of virgin materials and recycling used materials for batteries exact environmental costs. As an example, 1 ton of virgin lithium requires 250 tons of ore or 750 tons of brine. While refining brine requires less energy than refining spodumene, it requires 18–24 months, yields lower-grade lithium and recovers less of the lithium present in brine than is recovered from the ore. In addition, water use is a concern; 65% of the water in Chile (one of the major sources of lithium) is consumed by the mining industry. On the other hand, recycling also has environmental costs including transportation, preparation, and high energy use (Baum et al., 2022).

Waste batteries pose serious challenges for producers of EV batteries in connection with end-of-life waste management. Producers, therefore, should try to gain access to strategic elements that are regarded as crucial for manufacturing EVs. Recycled lithium-ion batteries from EVs are supposed to provide an important secondary source for these crucial inputs (Serohi, 2021).

The ongoing EV boom will generate 11MT of consumed lithium-ion batteries that will have to be recycled during 2017-2030 to avoid the accumulation of environmentally hazardous waste, a key environmental impact of EV batteries. Typically, after completing a few thousand charging cycles a normal EV lithium-ion battery’s performance will start to go downhill rapidly. The battery loses its capability to run the vehicle as it should. Replacement by a new one becomes a necessity. However, this in no way means that the battery has reached the end of its life. before being discarded completely as useless waste materials, these spent batteries can still live for 2-3 lives provided they are put to less intensive uses. for this, however, the right kind of markets and techniques need to be primed and made ready to breathe a little more life into these seemingly used and exhausted batteries. Modern-day examples of such businesses practice are the telecom- tower operators and utility companies, who are trying to extract the best out of these recycled batteries in order to build upon their operational cost front  (Serohi, 2021).

Besides low recycling efficiency, the excessive cost of recycling acts as a big deterrent. According to industry sources, the cost associated with the recycling of lithium-ion batteries in India is estimated at Rs 90-100 (US$1.1-1.2)/ kg, approximately. Astronomical sums need to be invested in technology to collect, transport and manage the resources used in a Lithium-ion battery facility. The profile margins, however, are quite low. At least 5 years are needed to break even – before any cost recovery and profit booking can take place (Serohi, 2021).

There is no doubt that the job involving the collection and transportation of waste lithium-ion batteries is quite a difficult task. Presently, no more than 5% of the exhausted lithium-ion batteries, are being collected. In the absence of any scientific guiding principles and regulations defined clearly and distinctly for Li-ion batteries, the return on investments made in setting up recycling units remains poor for this capital-intensive initiative (Serohi, 2021).

Recycling lithium-ion cells not only reduces constraints imposed by materials scarcity and enhances environmental sustainability, but also supports a more secure and resilient domestic supply chain that is circular in nature (Figure 6 Source: energy.gov, 2021). 

In the recycling process, Li-ion batteries must be first classified and most often pretreated through discharge or inactivation, disassembly, and separation after which they can be subjected to direct recycling, pyrometallurgy, hydrometallurgy, or a combination of methods, as shown in Figure 7 (image source: Baum et al., 2022).

Direct methods, where the cathode material is removed for reuse or reconditioning, require disassembly of LIB to yield useful battery materials, while methods to renovate used batteries into new ones are also likely to require battery disassembly since many of the failure mechanisms for LIB require replacement of battery components. Reuse of LIB in stationary applications will require battery classification and the determination of charge state and capacity (Baum et al., 2022).

Pyrometallurgy uses heating to convert metal oxides used in battery materials to metals or metal compounds. In reductive roasting (smelting), the battery materials (after pretreatment) are heated in a vacuum or inert atmosphere to convert the metal oxides to a mixed metal alloy containing (depending on the battery composition) cobalt, nickel, copper, iron, and slag containing lithium and aluminum. Pyrometallurgical methods require simpler pretreatment methods (most often shredding or crushing) to prepare batteries for recycling and require fewer different methods to recycle LIB of differing compositions, shapes, and sizes. Lithium is recyclable by some pyrometallurgical methods, but the methods are most effective for particularly valuable metals such as cobalt (Baum et al., 2022).

Hydrometallurgical methods use primarily aqueous solutions to extract and separate metals from LIBs. The pretreated battery materials (with Al and Cu current collectors previously removed) are most often extracted with H2SO4 and H2O2, although HCl, HNO3, and organic acids including citric and oxalic acids are commonly used. Once metals have been extracted into the solution, they are precipitated selectively as salts using pH variation or extracted using organic solvents containing extractants such as dialkyl phosphates or phosphinates (Baum et al., 2022).

In many cases, combinations of hydrometallurgical and pyrometallurgical methods are used to process lithium-ion batteries today (Table 3 – Source: Baum et al., 2022).

Pyrometallurgical methods are likely used because they allow flexibility in battery feedstock (the Umicore method is used for both lithium-ion and nickel metal hydride batteries) and due to fixed investment in existing facilities. Methods in development, on the other hand, rely on hydrometallurgy to a larger degree, at least in part because the cost of facilities to implement the methods is smaller. Lithorec and Aalto University (Finland) have both devised hydrometallurgical methods, while Accurec, Battery Resources, and OnTo use both hydrometallurgical and pyrometallurgical methods (Baum et al., 2022).

Pyrometallurgical methods are implemented relatively simple, but incur environmental and significant energy costs for combustion and calcination of the batteries. While hydrometallurgical methods require less energy for processing than pyrometallurgical methods, many reagents are required and water must be purified afterwards.

No doubt future technologies will rid EV batteries of their toxicity and find better ways to dispose of and/or recycle them. But even with all the benefits – present and future – the potential pollution problems should remind both the public and government officials.