Electric products are all around us. Whether in transportation, household equipment, camping gear or just about anything else. It is said electric equipment is better for the environment than their fuel-dependent counterparts since they can be charged with clean energy. However, what happens when these so-called clean products are worn-out? More specifically, what happens to their batteries?
To gain a better understanding on the matter, it is important to know how a lithium battery is made. Although there are many different types out there on the market, here we single out on the NMC battery. One of the most used in the automotive industry. NMC stand for: lithium nickel manganese cobalt oxide. And, as these words might suggest, these are also many of the ingredients used to create an NMC battery. Figure 1 below lists all major components incorporated in a Lithium battery.
Worn-out Lithium batteries have three possible destinations. they are either re-used, recycled or they end up as waste. At present, re-use is the most preferred option since lithium batteries contain valuable components such as aluminum, cobalt and nickel. In addition, re-use is also preferred because refurbishment costs are currently lower than the cost of recycling.
Before re-use is possible, Lithium batteries must be disassembled and analyzed at first. However, disassembly is a hazardous task which must be performed by skilled personnel equipped with special tooling. Once torn apart, it must be determined which modules or cells are still fit for re-use and which ones are worn-out and hence, could be destined for recycling. Despite re-use or recycling preferences, it estimated that less than half of all lithium batteries is recycled today.
Low re-use or recycling rates are largely caused by the inability to automate the disassembly process. Since lithium batteries come in many different varieties, it is difficult to standardize the disassembly process. For example, some batteries have cylindrical forms while others have prismatic forms. Both of which require totally different dismantling techniques. To illustrate this, think about opening a cylinder versus opening a prismatic surface. The former can be accomplished with Dremel tooling whilst the latter requires can-opening techniques.
Besides different shapes, there are also many different cathode chemistries. As one can recall from the second paragraph, the cathode of an NMC battery contains large quantities of nickel, manganese and cobalt. In contrast, the cathode composition of an NCA battery is largely comprised of nickel, cobalt and aluminum. These different chemistries make it difficult to apply a singular process as to material reclamation which further complicates the automation of battery disassembly.
Moreover, to be able automate disassembly lines, intelligent behaviour is required from robotic dismantling machines. For example, distinction must be made between different objects, shapes and sizes. This can be achieved by artificial intelligence which requires complex programming of software. Furthermore, sophisticated force and motion control is required as, for example, too much force with cutting can cause a host of other problems such as short-circuiting, thermal runaway and the release of toxic gasses.
Since fully automated disassembly is still difficult to achieve, most worn-out lithium batteries today are dismantled by hand. However, as mentioned before, this requires a trained workforce, which in turn adds substantially to the cost of re-use or recycling. Despite the drawbacks, there is hope for the future as new recycling processes are being developed that can be applied to economies of scale. Pyrometallurgy and hydrometallurgy are both mentioned as promising techniques for material reclamation.
It seems little is known about what exactly happens to all worn-out lithium batteries. According to some estimates, only 5% is recycled while others estimate the recycling rate is about 50%. Nevertheless, it would be safe to assume that at least more than half is not recycled; meaning the majority is either stashed somewhere in or above the ground or scattered throughout the globe.
When talking about numbers, a paper published at the World Economic Forum website estimated that more than 200.000 tons of lithium batteries reached their end of life in 2020. Even if 50% of this amount were to be recycled, that still leaves us with 100.000 tons of waste. This is equivalent to 100 million kilos which is probably enough to fill almost two football stadiums. And that is only for 2020. One can only imagine what will happen in the future as the production of electric vehicles have surged over the last few years.
When lithium batteries are worn-out, three things can happen. They are either re-used, recycled or end up as waste. Clearly, re-employment is the most preferred option, however, to date it remains difficult automate re-use or recycling processes. As such, more than half of all worn-out lithium batteries end up as waste leaving the world with a gigantic problem.