For any item at the end of its working life or when it ceases to be usable in its original form the options are generally in accord with an accepted waste treatment hierarchy as below.
This is essentially an order of preference for the reduction and management of waste with the primary objective of extracting the maximum practical benefits from products whilst minimising the generation of waste. The application of this hierarchy seeks to reduce emissions of greenhouse gases, energy and pollution whilst conserving resources via virgin material displacement.
When applied to batteries that are deemed to be unusable or end-of-life the options most commonly considered are remanufacture, re-purposing or recycling which within the context of the generic waste treatment hierarchy are middle ranking options with remanufacture and re-purposing being elements of reuse.
Remanufacturing may be considered the most beneficial option as this is essentially one of repairing failed batteries in the identical configuration for reuse in the same application or generic applications.
Repurposing of end-of-life batteries is the refurbishment in a different configuration for second life usage such as stationary energy storage.
Recycling may be considered as a treatment approach to extract materials from end-of-life batteries for subsequent use. Within the scope of recycling are embraced a number of processes which essentially comprise:
Disassembly, which may be manual, semi-automated or automated, to generate such as aluminium, copper, steel, plastics and cells.
Disassembly and mechanical conditioning to generate aluminium, copper, steel, plastics or a black mass which may in turn yield lithium, cobalt nickel and copper. Pyro-metallurgy post mechanical conditioning may generate iron, cobalt nickel and copper with the hydro-metallurgical methodologies offering generation and separation of lithium, cobalt, nickel and copper.
Of these three end-of-life options, remanufacturing would appear to be more feasible and hence more cost effective than repurposing if only as a reflection of the greater level of technical challenges involved in the latter.
The recovery options may be conveniently summarised:
Recycling – considered that economy of scale is important and that the approaches and methodologies are continually evolving and are moreover sensitive to the evolution of battery technology in respect of the entrained elements.
Repurposing as an approach does not necessitate large volumes to be effective but is sensitive to the future and evolving price of new batteries as to its cost effectiveness. There are considered to be technological challenges to repurposing and additionally safety and regulatory issues will be important.
In contrast, remanufacturing also does not necessitate large volumes for cost effectiveness and whilst there are technological challenges involved there are less organisational and legal constraints in this approach.
As to the future of these approaches – given the status of the technologies and then inexorably increasing scale of market penetration and thus volumes of end-of-life batteries it may be envisaged that recycling and the economies of scale therein will become the most economical choice over repurposing or remanufacturing but that niche applications for the latter two approaches will be of significance.
The development and emergence of new recycling processes which operate at lower temperatures than existing pyro-metallurgical options and recover more valuable materials, is continuing but these have yet to be employed on any significant scale. Although some niche stationary storage applications may find second-life Li-ion batteries more affordable, the Li-ion battery driving the electric revolution is hence considered more likely to be recycled than reused.
A recent report by Gartner Inc. has highlighted the fact that many wearable devices are short lived. Whilst being marketed as the future landscape of electronics and embedded intelligence the popularity of current devices seems to dwindle quickly. The report identified that approximately 30% of smart watches and 30% of fitness trackers are abandoned shortly after purchasing. Reasons given by those who no longer used their devices included ‘not finding them useful’, ‘novelty of the device wears off’ or the objects break.
What is not often considered when these items come to the end of their life is how they are recycled. Smart watches as well as other wearable devices contain complex electronics that must be recycled under the Waste Electrical and Electronic Equipment Directive. The devices also contain batteries, which too must be recycled under the Batteries and Accumulators Directive. However, because these devices are so small, many do not make it into the recycling network, but are disposed of with household waste. In Europe there is currently a large deficit in these items being recycled compared to what has been placed on the market. Some of these losses may be due to illegal waste handling, but is it believed that a significant proportion of small WEEE is being thrown away.
The issue for batteries within these products is that there is a possibility of them being reused (such as what the PESURB project is trying to achieve). Whether the wearable device is physically broken (strap or packaging) or whether the electronics have failed, it is likely that after such a short duration the batteries have not reached their true end of life.
The design of wearable electronics has a long way to go, and therefore more effort should be provided to design these goods for reuse and recycling. Especially, if these complex electronic devices are to become fashion accessories and discarded with trends, a viable recovery route for materials and resources must be developed.
The Li-ion battery dominates the secondary batteries market and will continue to do so, given the furious investment that companies (e.g. Tesla, and BMW) are making in order to stay at the front of the electric vehicle and energy storage markets. Globally, electric vehicles are anticipated to roll out on our streets, dominating the market by 2050. The UK government predicts that by 2020 there will be 1.2 million electric vehicles registered on the road. In other countries, similar explosive growth is anticipated, with India predicting 7 million vehicles, Germany 1 million, China 1.4 million, and the USA predicting 1 million, giving rise to a forecasted 17 million electric vehicles on the roads globally, all by 2020.
Investment in Li-ion batteries is now huge. Tesla is investing $5 billion into its 'Gigafactory 1' near Sparks, Nevada, £40 million has been invested in Nexeon, and the UK government invested £16 million in Dyson’s new adventure into electric vehicles and a further £20 million with Nissan for the development of a new generation of Li-ion batteries.
However, a recent article from the Brookings Institute states that this may not be an entirely good thing. The large on-going investment in Li-ion based technology may stifle the market, leaving innovative technologies in the dark and undeveloped. The article states that Li-ion technology has already reached its 90% threshold for theoretical capacity. To gain the last 10 percent is likely to be increasingly costly for each incremental development. Li-ion technology could therefore be reaching its practical limits in terms of performance and cost.
There are already many other new developments in battery chemistries, which could prove to outperform current Li-ion technology, for both energy density and longevity. These include lithium-sulphur, aluminium-air, silicon anode batteries, sodium ion, aqueous hybrid ion, aluminium-graphite, and others like foam and magnesium batteries. Some of these technologies are capable of outperforming current storage capacities in terms of key performance attributes such as, cycle lifetimes, costs, current densities, and safety of Li-ion. In addition, the movement away from Li-ion could reduce the environmental impacts associated with lithium mining, the rare earth content, and the presence of heavy metals. For example, the aqueous hybrid ion battery has already been awarded an environmental cradle-to-cradle certificate for using materials with higher global abundance and lower toxicity than the materials found in Li-ion batteries.
The other important issue to factor in is the safety of the battery chemistry. Samsung, Panasonic, Denon, HP, Sony, and Toshiba are just a few of the companies this year (2016) that have had to recall products over safety issues with their Li-ion batteries. There are innovative technologies which could provide much safer products, and this may become a critical factor in the race to create energy storage systems for our vehicles and homes.
In addition to the safety issues related to product use, the impact of Li-ion stability on end-of life treatment is also important. With over 1 million secondary batteries being received by the EU each year, the volume of batteries sent for waste treatment is set to rise steeply. These batteries must be moved, stored and handled under specific conditions, because of the health and safety issues with Li-ion batteries spontaneously catching fire.
The Brookings Institute report suggests governments should consider investing in alternative technologies, as well as Li-ion, to prevent crippling the market and potentially following a dead end. The full article can be found here.
The feasibility of recycling is not the critical aspect of achieving a zero waste Europe, but actually the feasibility is determined by the economic driver to recover low concentration strategic metals.