Electrical vehicles (EVs) are commonly hailed as something of a panacea to combating the issue of climate change. By dispensing with "dirty" and polluting combustion engines, these all-electric modes of transport are, so it is claimed, just the ticket for a greener, more sustainable future.
But, is this really true?
To answer this, let's take a long hard look at the validity of EV's "green credentials."
What is the environmental impact of EVs?
There are some very real environmental benefits to EVs on paper, in reality, there is no such thing as "free lunch"; they may not be that "clean" after all.
A paradox, if you will.
EVs, like anything manufactured, require raw materials in order to be produced, and some of these materials come bundled with very serious potential environmental costs.
One of the most serious being lithium. Forming the cathode of most lithium-ion batteries, some of the ways that lithium is sourced are far from environmentally friendly.
An alkali metal, lithium has seen enormous growth in demand over the last few decades.
This is partly a result of the growth in demand for EVs, but also the fact that lithium is used in the batteries of many electronic devices, such as smartphones and laptops. Lithium is also an important raw resource for the production of glass and ceramics, too.
And its use has been accelerating over time. According to some sources, between 2008 and 2018, annual production of lithium rose from 25,400 to 85,000 tons.
Li-ion battery production aside (we'll dedicate a section to that later), other environmental impacts include the kinds of motors used in EVs. Depending on the model, these will either be permanent magnets or induction motors.
The former tend to be made of rare-earth metals which require energy-intensive extraction and refinement processes. The mining of these materials can also lead to the release of toxic byproducts that, in countries with less than ideal environmental practices, can be devastating for the environment.
Another environmental impact of EVs is the method in which the electricity used to power them is sourced. For many countries, this still includes large amounts of fossil fuel power stations.
Carbon dioxide emissions aside, the combustion of carbon-based fuels releases other noxious fumes, including sulfur and nitrous oxides, as well as particulate matter. This can lead to secondary environmental impacts like acid rain and can cause respiratory problems if the particulate matter reaches a certain threshold.
EV vehicles, like combustion-engined vehicles, also release particulate matter from their braking systems. This so-called "non-exhaust particle emissions (PM)" can also contribute to respiratory diseases in built-up areas like cities.
And the effects of this can be significant. According to some statistics, this form of PM may be responsible for thousands of premature deaths in the UK alone. It is important to note that these kinds of statistics rarely distinguish between the source of the PM, and include various sources including EVs and convention combustion-engined vehicles.
Interestingly enough, asbestos used to be used as brake pads in many vehicles, but has since been banned in many countries around the world. But we digress.
While generally considered a smaller contributing source than internal combustion engine vehicles (ICEs), EVs still require friction braking systems to operate safely. Regenerative braking systems can be used to alleviate the issue of PM generation when braking, but ultimately to stop any vehicle, some form of friction-based braking will likely be necessary.
For this reason, a factor termed the "rebound effect" could come into play. As EVs become more popular over time, they are incentivized by authorities, their costs reduce over time, and more people will be encouraged to use them.
The result, as the argument goes, is that we will see more of them on our roads, although since they release fewer PMs overall, this may be a benefit. The issue with PMs could also be mitigated, for all types of vehicles, with advancements being made in frictionless braking systems (like eddy current brake systems), although these are likely some years away from being commercially viable.
What are the benefits of lithium-ion batteries in EVs?
Lithium-ion batteries, Li-ion for short, are one of the most ubiquitous sources of portable power in the world today. You can find them in cellphones, laptops, power tools, and, of course, electrical vehicles. The reason for this is varied but, in short, the technology is reliable, requires low maintenance, lasts a relatively long time, can be charged quickly, and is usually safe and easy to use.
All great attributes as a portable source of power.
But one of the main standout features of this technology is the ability to recharge the batteries as needed. In fact, most Li-ion batteries can be charged, discharged, and recharged hundreds of times before expiring. Compared to other common types of batteries, Li-ion batteries also tend to have a higher energy density, voltage capacity, and lower self-discharge rate too.
This makes them a great way to store and transport energy efficiently and easily. Let's expand on some of the technology's main benefits:
- Li-ion batteries require less maintenance: With regards to maintenance, Li-ion batteries, unlike lead-acid batteries, do not need to be "watered" meaning they require less monitoring and skilled operatives to conduct maintenance on them.
- They last a long time: Li-ion batteries, as previously stated, last a relatively long time. On average, a Li-ion battery can be expected to remain serviceable for eight or more years (depending on use).
- Li-ion batteries are rechargeable: Whether used for domestic appliances, or industrial machines, the ability to recharge them at will is incredibly useful. Charging is also relatively fast, and getting faster (as we have seen with advances in super-quick charging in EVs).
- They are generally safe: As Li-ion batteries do not need the highly toxic chemicals found in more conventional batteries, such as acidic components in lead-acid batteries, they are relatively safer to use and dispose of.
- Li-ion batteries are relatively environmentally friendly: When compared to lead-acid batteries and to fossil fuel alternatives, Li-ion batteries are much better for the environment. Lithium isn’t a toxic heavy metal like lead, and directly replacing internal combustion-engined vehicles with EVs using li-ion batteries as a power source helps reduce emissions.
However, as you are about to find out, the environmental benefits of Li-ion batteries may in some ways be shortsighted.
What is the environmental impact of battery production and disposal?
Possibly the most important environmental impact of EVs is the way lithium for their batteries are sourced.
These batteries tend to consist of lithium cobalt for the cathode and graphite for the anode. A typical EV lithium-ion battery's electrolyte is also made of lithium salt.
More than half of this lithium comes from the so-called Lithium-Triangle that lies under Argentina, Bolivia, and Chile. To extract it, miners drill holes in the salt flats and pump the salty, mineral-rich brine to the surface, leaving it to evaporate in huge artificial lakes or ponds.
This process uses a lot of water, over 500,000 gallons (close to 2 million liters) for each ton of lithium produced. Such enormous consumption of water impacts not only the surrounding ecosystems but also has a huge impact on local farmers — for obvious reasons.
Not only that, but these large evaporation pools are often far from sealed. This can, and has, led to the leaching of toxic substances into the surrounding water supply. As happened in Tibet a few years ago, the accidental release of substances like hydrochloric acid kills large amounts of aquatic animals such as fish.
But EV batteries are not just all about lithium. There are some other key components that are just as potentially harmful to the environment as lithium, if not more — enter cobalt and nickel.
The former is found in large deposits across the Democratic Republic of Congo and central Africa. And this is one of the main problems — its geographical location.
It is relatively easy to extract cobalt, which has produced a large incentive to dig it out and sell it. However, this is often conducted unsafely and with little concern for the environment in enterprises termed "artisanal mines." These informal mines often involve the use of child labor who extract the raw materials by hand with little to no protective equipment.
Cobalt mining produces a lot of airborne particulate matter, which often contains toxic contaminants like uranium. Inhalation of these substances has been linked to serious health problems, including respiratory disease and birth defects.
Cobalt mining sites also often contain sulfur-containing materials that can generate sulfuric acid when exposed to air and water. When this acid drains from the mines, it can devastate rivers, streams, and other aquatic and terrestrial environments for a very long time.
Where the batteries for EVs are made is also an important factor when considering their environmental impact. According to Forbes, batteries produced in China produce somewhere in the region of 60% more carbon dioxide than internal combustion engines.
If China could be convinced to adopt Western standards for production, this could be significantly reduced. The report also found that these factories could cut their emissions by up to 66% if they adopted manufacturing techniques used in America or Europe manufacturing techniques. If this were to happen, the extraction process and production of batteries would be on a par or slightly higher than the manufacturing process of ICE vehicles.
EV batteries also tend to be pretty heavy. This can result in other, often overlooked, environmental impacts like the need to attempt to reduce the weight in other parts of the car.
Lighter materials like carbon-fiber-based polymers tend to be more energy-intensive to produce and difficult to recycle.
Another issue with EVs is the way in which the electricity used to charge its batteries is generated. While leaps and bounds have been made in adding renewable technologies to many countries' energy mix, many are still heavily reliant on carbon-based power stations.
This is not insignificant either. According to some sources, EVs, on average, emit around 4,450lbs (2018 kg) of CO2 each year indirectly. To put that into perspective, conventional gasoline cars emit at least twice much. However, it is important to note that this varies widely around the world.
Battery production is only half the story, however. The way that batteries are disposed of at the end of their life can also potentially damage the environment.
At present, there are few countries that regularly attempt to recycle lithium-ion batteries. This has led and will continue to lead, to large amounts of spent batteries ending their days in landfills.
This is incredibly wasteful, as many of the main components, like lithium, could be recovered and reused. While recycling can be achieved, most of the current research has focused on improving durability, efficiency, and reduced cost of production.
Current practices involve simply smelting (high-temperature melting and extraction) of old batteries in a process fairly similar to the mining industry. This is a very energy-intensive process (compounding the hidden CO2 cost of EVs during their construction).
Where does lithium come from?
Lithium, one of the main components of lithium-ion batteries, comes from two major sources: brine and hard rock deposits. The former is generally found in salt lakes and is extracted by evaporating off the water to leave lithium-concentrated salts.
Brine evaporation is the simplest, and most common form of lithium extraction, but tends to yield the lowest grade of the material. At present, more than half of the world's lithium resources lie under the salt flats in the Andean regions of Argentina, Bolivia, and Chile.
Extraction is conducted by pumping huge amounts of brine groundwater from drilled wells to be left to evaporate in brine pools or ponds. Also called salterns, or salt pans, or salars, here the lithium-rich brine water is left to evaporate in the sun.
Depending on the makeup of the groundwater, this tends to lead to a concentrated mixture of manganese, potassium, borax, and lithium salts. This is then filtered, and placed in another evaporation pool until a commercially viable amount of lithium carbonate salt can be extracted.
These pools or ponds can become havens for some types of wildlife, including algae, and some endangered birds. As a general rule of thumb, it takes about 2 million liters of water to produce a ton of lithium.
Hard rock deposits, on the other hand, tend to produce the best yields of lithium. So, how is lithium mined?
Hard lithium mining requires significantly higher investment costs as well as extensive geological mapping and exploration to find suitable deposits. Once found, drilling equipment is used to extract the lithium ore, which provides better quality lithium at the cost of increased monetary burden.
There are various lithium ores including, but not limited to, petalite (LiAl(Si2O5)2, lepidolite K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2, spodumene LiAl(SiO3)2. To date, the largest hard rock sources of lithium include Australia and Chile.
Hard rock lithium extraction tends to require about 3-4 years of capital investment before becoming productive, and mines (depending on the ore reserves) tend to have an average productive life of about 16 years.
Brine evaporation extraction methods tend to require 5 or so years of investment prior to production but will tend to last much longer than hard rock mining, with average lifespans of about 30 years.
Can lithium-ion batteries be recycled?
As we have previously touched upon, lithium-ion batteries most certainly can be recycled. However, the current practices of Li-ion battery recycling, and projects currently in the works, are still very much in their infancy.
For example, in Australia, only about 2-3% of spent batteries are currently collected and sent offshore for recycling. European and US rates are not that much better, at around 5%, give or take.
“There are many reasons why Li-ion battery recycling is not yet a universally well-established practice," Linda L. Gaines of Argonne National Laboratory said in an interview with c&en. The reasons include things like technical constraints, economic barriers, logistic issues, and regulatory gaps, to name but a few.
At present, most suppliers and their clients are currently focusing on improving the battery's lifespan, efficiency, and lower their costs rather than seriously focusing on recycling them at the end of their lives.
The most common method of recycling the batteries is to melt spent batteries at high temperatures to recover the precious metals within them. This takes a lot of energy and is actually more expensive than extracting and refining new materials from raw sources.
Research is ongoing, but most efforts are still small-scale projects conducted by independent research groups or startups. However, some government initiatives have also been launched to attempt to stem the growing tide of used batteries.
For example, in January of 2019, the US Department of Energy (DOE) launched the country's first Li-ion battery recycling R&D center, the ReCell Center. The idea is to help make battery recycling profitable, and allow the US to become self-sufficient in battery resources it lacks, like cobalt.
The U.S. DOE has also launched a $5.5 million Battery Recycling Prize to help encourage the free market to find innovative solutions for the collection, storage, and recycling of spent batteries.
Across the pond, in the UK, a group of researchers from various universities has also created a consortium to achieve a similar goal. Called the Reuse and Recycling of Lithium-Ion Batteries project, it brings together 50 scientists and engineers from eight institutions and 14 industry partners.
What can be done to make EVs truly "green"?
So, given the very real environmental impacts that EVs have on the planet, what can be done to make them truly "green"? Here are some examples.
1. Dispense with Li-ion batteries altogether
Since EV batteries are hazardous to the environment, from cradle to grave, the most logical step to take would be to stop using them altogether. However, this is a lot harder than it sounds. There are, after all, good reasons why Li-ion batteries have become so ubiquitous (as we detailed earlier).
That being said, there are some potential avenues to explore.
One example is the salt-based batteries currently under development through a collaboration between the University of Nottingham and six research institutes across China. By combining the performance of oxide fuel with metal-air batteries, these batteries could prove to be a viable replacement for Li-ion batteries. The best part? These batteries would be fully recyclable, affordable, safe, and, in theory, "green."
Other interesting examples include titanium-nitride batteries or using the "wonder material" graphene.
Other exciting initiates include a potential "never-ending" battery, too. Made from recovered and reused nuclear fuel, these batteries could last for more than 28,000 years — or so the developers claim. Currently in development by a California-based startup, these nano-diamond batteries are nye-on indestructible and will be cheaper than existing Li-ion battery packs if they can be fully developed.
Other, more esoteric, examples include eco-friendly, liquid batteries that run on vanillin. Currently, in development by researchers at the Graz University of Technology, this interesting line of research would be truly sustainable.
Another option could be by using Zinc-air batteries. These have been shown to significantly out-perform Li-ion batteries on all levels, and are also a lot better for the environment. However, it should be noted that zinc, if leaked into the environment, can be devastating for local ecosystems.
2. Make Li-ion batteries more long-lasting
Another potential solution is to make the batteries as long-lasting as possible if a viable replacement for Li-ion is not found. This would help alleviate the need to extract new raw materials to replace spent batteries, and would also help reduce the need to either dispose of or recycle them at the end of their lives.
And, thankfully, some options are currently being investigated to achieve just this. One example is to add molybdenum and sulfur to Li-ion batteries to produce cheap, very light, batteries with almost twice the energy density of existing Li-ion batteries.
Currently in development by the University of Texas, molybdenum and sulfur would be used to replace the lithium electrodes while still providing a viable battery unit.
Other solutions include the use of sulfide electrodes to help extend the working life of Li-ion batteries too. Currently being investigated at the University of Florida, sulfide-Li-ion batteries should be able to extend the number of charge-discharge cycles with little to no degradation of the battery.
3. Try to find lithium sources in places that care about the environment
Failing either to replace Li-ion batteries or finding ways to extend their functional lives, another alternative could be to find more sustainable sources of lithium.
Whether this is opening up mining and refining operations in countries with strong environmental regulations, or searching for sources with a high bar to entry for extraction, this would go a long way to reducing the environmental impact of lithium battery production and, by extension, the EV industry in general.
Seawater, for example, is a potential source of lithium, although it will require fairly sophisticated extraction methods. Refining the process to make it as cheap as evaporation pools is going to be a very real challenge.
Other countries, like Portugal, are also pushing forward with finding ways to produce lithium domestically.
But again, these all require the extraction and use of raw materials that have the potential to produce some form of pollution. This is where finding ways to use what we already have, with regards to lithium, might be the best option. After all, the "damage" to the environment from extraction has already been done.
This would mean recycling old batteries. Many landfills around the world are literally packed with spent electronic devices from laptops to old smartphones. Could these be "mined" instead of removing fresh lithium from the environment?
And that is exactly what researchers at the University of Birmingham, UK are proposing. They are hoping to use robotics technology developed for the nuclear industry to safely dismantle potentially explosive Li-ion cells from EVs to extract the precious metals within.
But that is really only half the story. Any battery that relies on electrochemistry, like Li-ion batteries, runs the risk of having its electrodes degrade and decay. You won't necessarily know the condition of these materials without opening up the battery.
This has led some other researchers to look into alternative ways to recycle batteries and recover materials like lithium in a more predictable manner. They propose a biological recycling process that would use bacteria to process the waste metals, coupled with hydrometallurgical techniques which use solutions of chemicals in a similar way to how lithium is extracted in the first place.
If successful, this kind of initiative could be a very real gamechanger for lithium and EV industries.
So, in conclusion, are EVs really that "green" and sustainable for the planet? We will let you make up your own mind.