Published at 2020, March 9th
What’s the lifespan of an electric car battery? Long long does an electric car battery last for? What happens to a lithium-ion battery at the end of its lifecycle? How is its disposal done? Or is it recycled?
Transportation has a very significant impact (14% according to the IPCC) across the total amount of greenhouse gas emissions humans release into the atmosphere. The negative effects of the increasing rate of air pollution, especially in urban areas, are being increasingly studied and discussed. And there’s an urgent need to reach, at a global scale, net-zero emissions by 2050 to keep the global temperature below 2ºC.
Electric vehicles are a very important solution to the challenges above. Since the electric mobility was found to be a greener and more eco-friendly solution compared to thermal vehicles, their demand has been on the rise.
According to the International Energy Agency’s EV30@30 Scenario, the sales of electric vehicles (EVs) might reach 43 million and a stock number greater than 250 million. But let’s remember the often ignored side of the so-called zero-emission vehicles: their batteries.
The Impact Of Electric Car Batteries: Are They Bad For The Environment?
One of the main criticisms made to electric cars and electric vehicles in general has to do with their batteries. These lithium-ion batteries (LIBs) are very much like a scaled-up version of a smartphone’s battery. Only electric vehicles s don’t use a single battery like a phone. Instead, they use a pack comprised of thousands of individual lithium-ion cells working together. Be it on a small or a large scale, these batteries have significant environmental and social impacts across their lifecycle.
First thing first: the extraction of rare earth minerals for electric car batteries. For instance, if we consider the two main modes of primary production, “it takes 250 tons of the mineral ore spodumene when mined, or 750 tons of mineral-rich brine to produce one ton of lithium“. Just like that.
In fact, according to the same source (Harper et. al. 2019), the water demand to process lithium produced in this way is very high: a ton of lithium requires 1,900 tons of water to extract, which is consumed by evaporation. Still on this issue, Chilean farmers often need to import water from other regions – as Chile has intensively mined areas active. Despite its high environmental costs, lithium reserves, from a size perspective, are not a threat. But cobalt reserves can be.
Cobalt reserves, whose demand for battery production might consume about 14% of current cobalt reserves by 2050 are highly concentrated at the Democratic Republic of Congo – an often unstable political region. So if one of the benefits of electric vehicles is that they reduce the dependence on foreign oil imports, cobalt’s price fluctuations can also be a challenge. Moreover, ethical questions related to artisanal mines employing child labor can be raised too.
How Long Do Electric Car Batteries Last For? Are Their Recycled?
The impacts above help explain why the zero-emissions tag is often considered unfair and can be misleading. Because even if electric vehicles don’t release any emissions on the road, the batteries inside them have their share of impact. Also, cars powered by electric grids that run mostly on fossil fuels might not emit on the go, but emissions have still taken place in some distant power-plant.
Nicknames aside, lithium-ion batteries are estimated to have a lifespan of 15-20 years. Tens of hundreds of charging and discharging cycles after, what happens when a battery is too worn out for driving? What will happen to the 250,000 tons of waste that will result from the 1 million electric vehicles sold in 2017 – researchers from the University of Birmingham, and now the reader too, wonder.
Gaines, a researcher at the Argonne National Laboratory, suggests most batteries are either sent to landfills or stockpiled and stored – both very criticizable solutions. While the first can contaminate the surrounding soil and underwaters; the second is criticized as there have been fires at waste-storage sites due to lithium-ion batteries (sent as lead-acid batteries). However, new and interesting exits for electric car batteries are being found.
The Desired Lifecycle Of An Electric Car Battery
The researchers from Birmingham University say the net impact of manufacturing lithium-ion batteries “can be considerably reduced if more materials can be retrieved from end-of-life LIBs, in as close to usable form as possible.” In the same study, they also speak of a waste management hierarchy and a range of recycling options.
According to this model, batteries should first be designed in a way that they use fewer critical-materials as possible. They should then be re-used, which means electric-vehicle batteries should have a second use before being recycled – where materials should be recovered as much as possible and the structural value and quality of a battery should be preserved.
At the “recovery” phase that follows, some battery materials should be used as energy for processes such as fuel for pyrometallurgy. The last step is getting disposed of what has no value and sending it to landfills. This means that when the battery of an electric vehicle is only able to store energy at 70-80% compared to its initial levels, recycling isn’t the step that should follow – re-using comes first. But where can batteries be re-used? And how?
Where Can Electric Car Batteries Be Re-Used Before Being Recycled?
As the used electric-vehicle battery market for energy storage is growing, demand might just surpass supply. However, this is a slow and, up to some point, uncertain growth. And the reasons for it are simultaneously simple and complex.
Repurposing batteries in order to re-use them for a different end such as charging stations or stationary energy storage (be it in factories, residential buildings, hospitals…) is the logic exit for a battery leaving that leaves behind an electric vehicle. Only it is not as simple as taking a battery from one side to another.
Before sending batteries to be re-used, packs, modules, and cells need to be assessed on issues such as how long they can still hold a charge for and how charged they are at the moment. While the first is especially important to determine if it worth sending a battery to be re-used (and for which applications), assessing how much energy is stored matters for safety (or even economic) concerns in recycling processes. In either case (repurposing or recycling), the road that follows is quite challenging.
Dismantling Batteries: A Manual, Dangerous And Expensive Process
Whatever happens next to a battery, after assessing its charge properties it needs to be dismantled by hand – and here is where things get hard. Because of a battery’s heavyweight and high voltages of traction, specialized insulation tools are needed, together with qualified mechanics (of which there seems to be a shortage) to operate them.
Moreover, some studies point to the fact that in countries with high labor costs, the revenues from the extracted materials may not be economically worth it. Because of all this, automated disassembly techniques become part of the discussion as a possible solution.
Automation would eliminate the danger factor of the equation and as its development would overtime decrease its cost. Robots would also help improve the “mechanical separation of materials and components, enhancing the purity of segregated materials and making downstream separation and recycling processes more efficient – according to Harper et. al..
Dismantling Electric Vehicle Batteries Is Too Complex For Robots
Electric vehicle batteries are hard for robots to crack. This happens because automation and robotics are based on repetitive tasks and electric batteries bring along challenging requirements such as design diversity.
There are different lithium-ion electric battery designs that don’t allow a standardized automation process. Computer vision algorithms to recognize and differentiate different batteries, components and materials are being developed for use. However, for their tasks to be (more easily) successfully fulfilled manufacturers need to print machine-readable features such as QR codes or labels or other on key battery elements.
Moreover, dismantling batteries means, for instance, unscrewing or dealing with bonding methods and fixtures that require strong work by robots with sensitive battery components. This leads to complicated dynamics and control problems like simultaneous force and motion control. It’s a complex job, but one probably achievable in the future.
The Last Challenge In Dismantling Electric Vehicles Batteries: Recycling
Recycling, not landfills, should be the ultimate fate of all lithium-ion batteries, even if before they get to be used for different purposes other than storing electric vehicles’ energy. It avoids harmful pollution in landfills and the possibility of explosions in pilled up batteries. It can also bring important economic benefits thanks to the value of the minerals recovered and avoid constant mineral extractions – putting less pressure across supply chains.
Once batteries reach recycling facilities they get to be discharged and the materials making them up sorted out. In this way, materials such as nickel, cobalt, manganese or copper are sorted out via heating and shredding processes followed by others such as ferromagnetism or hydrophobicity.
If the batteries remain with a significantly dangerous charge, batteries are either be shredded in an inert gas such as nitrogen or carbon dioxide or they can be discharged through salt solutions – both are ways of avoiding chemical reactions with different pros and cons.
The Future Of Electric Vehicles And Lithium-Ion Batteries
As we’ve seen, there are many limitations creating a gap between how batteries should ideally be dealt with and what effectively happens to them. Keeping them away from landfills will remain crucial to secure the supply of critical materials such as cobalt or lithium but dismantling them remains a dangerous and expensive job done by hand.
These challenges can nevertheless be overcome as better sorting technologies develop, together with automated disassembly and smart segregation of different batteries to different streams (remanufacture, re-use or recycling). Nonetheless, optimizing battery designs for reusing and/or recycling would also make automated battery disassembly easier.
The Birmingham study also finds it important to address the challenge of designing new stabilization processes that enable end-of-life batteries to be opened and separated, and developing techniques or processes to ensure that components are not contaminated during recycling. Most likely, as the electric mobility grows, so will the research and experiments on how to overcome these and other challenges inherent to keeping electric vehicle batteries in a circular loop and away from landfills.
[Image credits to Nick Starichenko on Shutterstock]