Critical minerals: patent activity in battery recycling

Minerals of concern are used in electronics (e.g. smartphones), energy generation (e.g. wind turbines, photovoltaics and nuclear reactors), transport (e.g. electric vehicles) and military equipment.

As clean energy technologies tend to be more mineral-intensive than their fossil-fuel equivalents – not only does an electric car require six times the mineral inputs of a conventional car, but a wider variety of minerals too[6] – increased demand for clean energy technologies causes an increased demand for the requisite minerals.

Electric batteries, used to store energy collected from renewables and to power electric cars, are in particularly short supply. As early models of electric batteries reach the end of their lifecycles, an increasing proportion of important minerals is locked up in hardware which is no longer used. Battery recycling therefore makes an interesting case study when investigating the critical minerals bottleneck.

In order to investigate global patent trends for inventions in the field of battery recycling, we carried out a search for published patent applications and granted patents directed to the recycling of batteries[7]. Nearly 5,000 patent families met our search criteria, comprising over 19,000 patent applications of which over 8,000 have been granted. Some of these results are provided in Figure 1.

Figure 1: Worldwide patent applications and grants directed to battery recycling. Source: PatBase Analytics.

Prior to 2008, patent filings remained relatively uniform at around 500 applications filed per year. Since 2008, the number of patent filings in this field has generally increased year-on-year, with an uptick in recent years reaching over 2,300 applications filed globally in 2021.

The annual number of grants shows a generally similar rate of growth over the same period, increasingly relatively steadily from 70 grants in 2001 to over 700 grants globally in 2021. Changes in the annual number of grants are typically offset from changes in the annual application rate by a few years, reflecting the time taken by patent offices to examine applications.

We therefore see an increasingly strong global interest in inventions directed to battery recycling.

Figure 2 compares the actual growth in patent activity related to battery recycling since 2014 with the projected growth based on patent filing trends across all technologies.[8] The trajectories follow one another closely until 2016, after which battery recycling patent activity accelerates. Both trajectories have a small dip in 2019, after which battery recycling patent activity accelerates still further. In the years 2014 to 2021, general global patent activity has an average growth rate of 4%, whereas patent activity in the field of battery recycling has an average annual growth rate of 21%.

Figure 2: Global growth in patent filing activity in the field of battery recycling compared with global growth in all technologies. Source: PatBase Analytics.

Considering now the applications and grants directed to battery recycling by jurisdiction, as shown in Figure 3, we have found that the IP5 offices (the five largest intellectual property offices in the world) receive the most applications, along with WIPO which administers the international or PCT route.

Figure 3: Top 10 filing jurisdictions for battery recycling-related inventions. Source: PatBase Analytics.

The US and Japan are particularly strong filing destinations, perhaps due to the size of their automotive markets and the growing demand for electric vehicles.  It is also notable that a large number of applications are filed directly in Germany (rather than via the EPO), possibly reflecting German laws on employee inventions and/or the size of the automotive industry in Germany.

Based on the numbers of patent families and patent applications, we can determine that each family has a mean of 3.9 patent applications suggesting that it is common for applicants to file around four applications per invention, including a first filing at an IP5 office and around three foreign filings in the jurisdictions of other IP5 offices.

Figure 4 shows the top 10 applicants worldwide over all time according to the number of applications filed in the field of battery recycling.

Sumitomo and Guangdong BRUNP Recycling are the largest filers by a significant margin, having each filed over 600 applications globally. However, Sumitomo has over three times as many granted patents as Guangdong BRNUP Recycling (294 vs 94).

Overall, the top 10 includes five applicants headquartered in Japan (Sumitomo, JX Nippon Mining and Metals Corp., Toyota, Mitsubishi, JFE Holdings Inc.), two applicants headquartered in China (Guangdong BRUNP Recycling, GRST), and one applicant headquartered in each of South Korea (LG), the US (Aqua Metals Inc.) and Germany (BASF SE).

Figure 4: Top 10 applicants worldwide in the field of battery recycling. Source: PatBase Analytics.

The top applicants globally therefore tend to be multi-national companies with international interests, which accords with the data on patent family sizes and jurisdictions.

In order to determine how patent activity in the field of battery recycling is distributed between critical minerals, we performed a keyword analysis of the full text of each patent application. This analysis is shown in Figure 5.

Figure 5: Distribution of patent applications between the critical minerals considered, using a full text analysis of the whole patent specification. Source: PatBase Analytics.

Of the critical minerals considered, patent applications in the field of battery recycling are relatively evenly distributed between lithium, nickel, copper, cobalt and manganese. Rare earth elements (as a group) are mentioned in only 1% of patent applications.

In order to focus on the documents in which the core of the invention likely involves the named critical mineral, we performed a keyword analysis of the title, abstract and claims (the “T/A/C”) of each patent application. This analysis is shown in Figure 7.

Figure 6: Proportion of patent applications having the named critical mineral in the T/A/C as a proportion of patent applications have the named critical mineral in the full text. Source: PatBase Analytics.

From Figure 6, we can see that 71% of patent applications mentioning lithium are likely concerned with lithium as the subject of the invention, compared with around 40% for cobalt, nickel and copper, followed by rare earths at 25%. Manganese is significantly lower than its peers at 4%.

Accordingly, of those patent applications mentioning any of the above critical minerals, it is much more likely that an application that mentions lithium is directed towards lithium as the focus of the invention when compared with the other critical minerals.

Given that, in 2022, 60% of lithium demand, 30% of cobalt demand and 10% of nickel demand was for electric vehicle batteries[9], the prevalence of these three minerals in battery recycling-related patent activity is not surprising.

To drill down into battery recycling inventions directed to lithium, we determined the proportion of European patents having lithium in the granted claims that includes lithium in an independent claim. By considering independent claims in this way, we can more clearly determine whether lithium forms an essential part of the patented invention. The results are shown in Figure 7.

Figure 7: Granted European patents including lithium in the independent claims as a proportion of granted European patents including lithium in the claims. Source: PatBase Analytics.

Although the number of patents meeting the above criteria is relatively low, it does appear that there is a trend towards increasing essentiality of lithium in lithium-related battery recycling inventions. Lithium therefore appears increasingly to be the focus of battery recycling inventions.

This is commensurate with an expected 40-fold increase in lithium demand between 2020 and 2040 which is significantly greater than its critical mineral peers[10].

This is for general information only and does not constitute legal advice. Should you require advice on this or any other topic then please contact hlk@hlk-ip.com or your usual HLK advisor.