Inside Green Innovation: Progress Report - Fourth Edition highlights:
- Innovation in lithium-ion battery recycling has significantly increased recently, with an exponential rise in patent filings in the last three years.
- Rapid innovation appears driven by new entrants to the field, showcasing opportunities available.
- Innovation in the recycling and extraction of lithium is outpacing that of other precious metals (Co, Ni, Cu, Mn).
- There is no obvious leading geographical region for innovation in lithium-ion battery recycling, with innovation taking place in Europe, the US, Korea, China and others.
Recycling is one of the core concepts for developing, sustainable circular economies to reduce humanity’s impact on the planet, such as climate change, waste and pollution. From a commercial strategy viewpoint, transforming nuisance waste streams into valuable reclaimed materials can create lucrative opportunities for growth. However, the reality is that recycling is incredibly challenging, and the bottleneck is often the development and innovation of new methods and processes that overcome significant material, chemical and physical challenges.
A shining example is the recycling of lead batteries. Over 99% of lead batteries in the United States are recycled, surpassing recycling rates of aluminium, paper and glass. Modern lead battery production is essentially a “closed loop” process: recycled precious materials such as lead and plastic are reused, resulting in reduced requirements on raw materials, a minimisation of industrial waste and conservation of natural resources.
Unfortunately, the success of lead batteries is not shared by lithium-ion batteries which are significantly harder to recycle owing to instability, flammability and the complex composite nature of this battery type. There is an urgent need for new technologies and methodologies to efficiently extract valuable materials from lithium-ion battery waste, especially with the rapidly increasing electric vehicle (EV) market, from which it is estimated that about 1400 EVs per day will be available for recycling by 2040. This is reflected in projections of market size for battery recycling globally, estimated to more than double between 2023 and 2030 to USD 54bn.
Moreover, the relative scarcity of lithium represents a significant challenge to energy security. The main known lithium deposits are currently confined to Australia, Chile, Argentina and China, leading some commentators to express understandable concerns around potential supply chain vulnerabilities and price volatility. To ensure future energy security, finding further sources of lithium, improved recycling and alternative battery technologies may all play a part. For example, in 2023, Britain’s first lithium mine in Cornwall secured over GBP 53m of investment led by the UK Infrastructure Bank. In addition, the US Energy Department recently offered a USD 2.3bn loan to Lithium Americas to boost lithium production.
Building on battery technology articles from the past three editions of our Inside Green Innovation Progress Report, this year we deep-dive into patent activity surrounding lithium-ion battery recycling. From our review, it is clear that this technical field has rapidly gained momentum over the past three years, and we expect it to be a hot topic for the next decade. Innovation in this sector undoubtedly has significant potential for groundbreaking, patentable technology.
Examining priority filings for battery recycling over the past forty years (Figure 1) reveals that, although the field has been growing at a steady pace for the last decade, it has experienced an almost exponential rise in filings over the past three years.
Figure 1: Forty-year trend (1983 - 2022) - global priority filings – battery recycling
(Priority filing = the first time a patent application for a unique invention has been filed (the first filing)
This sharp rise in filings is apparently due to new entrants to the market. While applicants like Toyota, LG, and Duesenfeld have filed patents in this space consistently over the past decade, new applicants such as BASF, Guangdong Brunp Recycling Technology Co., and Volkswagen have filed numerous patents over the last three years (Figure 2).
Figure 2: Ten-year overview (2013-2022) – top global filers – battery recycling
Despite the new entrants to the field, examining the filings by jurisdiction reveals that growth is not led by one geographical area, and that growth over time is comparable for Korea, US and Europe (Figure 3). While the relative filing rate is higher for China, this is driven by a sole filer (Guangdong Brunp Recycling Technology Co.) and it is unclear why there are few competitors across the jurisdiction as a whole.
Figure 3: Ten-year trend (2013-2022) - global priority filings by territory – battery recycling
To investigate the growth of lithium-ion battery recycling innovations, it is important to understand the processes involved. The initial stage of lithium-ion battery recycling is mechanical dismantling of the cells, typically by shredding. This allows the separation of plastics, copper-rich metallic foil and black mass (an active powder containing precious metals).
The recycling of plastic and copper foil is relatively straightforward. Recent innovation has focussed on black mass which contains valuable metal content including nickel, cobalt, manganese, carbon and, of course, lithium. Interestingly, there are barely any patent filings mentioning the term “black mass” before the last decade and use of the term became widespread only around 2018 (Figure 4).
Figure 4: Twenty-year trend (2003-2022) - global priority filings – black mass
The rapid rise of patent filings for black mass in the past three years correlates strongly to that in battery recycling technologies as a whole (i.e. Figure 1). Unsurprisingly, the applicants behind the patent filings for black mass are similar to those mentioned earlier: BASF is leading filings in this space, followed by Guangdong Brunp Recycling, Ascend Elements and AGR Lithium (Figure 5).
Figure 5: Five-year overview (2018-2022) - top global filers – black mass
Using the International Patent Classification (IPC) system – which provides over 70,000 “IPC Codes” for different technical areas – we investigated the IPC codes designated to refining of specific metals: Li, Cu, Ni/Co, and Mn. Consequently, we can further dissect the patent filing data by relevant metal (Figure 6) which confirms that applications for recycling of batteries to extract lithium are outpacing those targeting other metals, underpinning the value of lithium in the current global economy.
Figure 6: Twenty-year trend (2003-2022) - global priority filings – battery recycling by metal
In last year’s article, it surprised us to find that flow battery innovation was strongly weighted toward electrical engineering (see Figure 10 of that article). A similar examination of the filing data of Figure 6 shows almost identical development in both the chemistry and electrical engineering fields (Figure 7). This data shows how innovation in this area is significantly interdisciplinary, with patent filings appearing to have both chemical and electrical engineering aspects.
Figure 7: Twenty-year trend (2003-2022) – global priority filings (battery recycling by metal) – filings by field/sector
Innovation surrounding black mass has been through both pyrometallurgy (heat treatment) and hydrometallurgy (chemical treatment) methods. Pyrometallurgy is a relatively mature technology, in which the black mass is heated to high temperatures to burn away residual carbon and provides, on cooling, a clean and high-yielding alloy of Co, Ni, and Cu and a slag material which contains lithium. Historically, the lithium containing slag is a low-value waste material sold to the construction industry, but newer methods of lithium extraction are a growing area of innovation. For example, in PCT/US2022/050478, Ascend Elements Inc. describe an improved process employing a partial-oxygen environment at selected temperatures to react lithium with the carbon of the black mass to produce lithium carbonate, which can then be extracted. However, pyrometallurgy is energy intensive and has a high carbon footprint. Conversely, hydrometallurgy is less energy consuming. The extraction of Co, Ni, and Cu using hydrometallurgy is a relatively mature technology, but the addition of a lithium extraction stage presents new challenges and opportunities for optimisation and innovation. Existing methods of extracting lithium via hydrometallurgy are known and rely on the extraction of lithium carbonate. However, each tonne of lithium carbonate extracted results in 10 tonnes of sodium sulphate by-product. BASF recently addressed this issue in its patent application PCT/EP2022/070700, which describes methods that extract lithium chloride and lithium hydroxide instead of the carbonate, potentially offering the extraction of lithium in a more economical and commercially-desirable form. Another notable innovation in this field relates to improving the safety of lithium-ion battery recycling: during the mechanical dismantling of the fuel cells, typically by shredding, the cells are compressed. Under compression, the anode and cathode materials can contact each other, causing a short-circuit and thermal runaway, leading to fire and explosions. Moreover, the shredding of batteries creates dust and other hazardous particles. Li-Cycle addresses these issues in its patent application PCT/CA2018/050640, which has gone to grant globally in Europe, the US, Australia and China, and describes an innovative, submerged shredding technology which enables safer processing of lithium-ion cells. By shredding cells in a submerged, anaerobic environment using a non-flammable immersion, liquid fire risk is reduced. The process also eliminates hazardous dust and therefore avoids the requirement for ventilation systems.
Implications for innovation and future patent filings
As the demand for lithium-ion batteries continues to soar, driven by the growth of markets for electric vehicles, renewable energy storage and portable electronics, the need for effective recycling solutions for battery components has never been more pressing. We believe that the next decade will see a surge in innovation aimed at addressing the challenges of battery recycling: from improving the recovery of valuable metals and other key materials to developing eco-friendly and cost-effective recycling processes.
A significant increase in patent filings is likely to accompany this wave of new advancements, as companies and research organisations compete to pioneer new technologies that make lithium-ion battery recycling more efficient. As these innovations take shape, they will not only help reduce environmental impact but also contribute to the creation of a circular economy in the battery industry, securing a more sustainable future for energy storage.
