Section 5: Short-term energy storage
Lithium-ion & solid-state batteries
The growing proliferation of electric vehicles (EVs), while vital to reduce CO2 emissions from motor transport, raises questions about their most critical component: batteries. According to the International Energy Agency (IEA) report, 'Global EV Outlook 2021 - Trends and developments in electric vehicle markets', there were ten million electric cars on the world’s roads in 2020. This marked a forty-three percent increase on 2019, with battery electric vehicles accounting for two-thirds of new electric car registrations and two-thirds of all EVs in 2020, continuing to exceed hybrid vehicles. The report found that lithium-ion (Li-ion) battery production totalled 160 gigawatt-hours in 2020, an annual increase of thirty-three percent. However, demand for batteries in Europe exceeded domestic production capacity. A recent paper from Oxford University found that between 1995 and 2018 the cost of Li-ion battery production dropped by twelve percent per year, a trend expected to continue as the technology matures. If so, Li-ion batteries should proliferate as they become more affordable. Solid state batteries offer an alternative EV power source. Rather than being powered by a cathode and anode in an electrolyte solution, solid state uses solid lithium material, making progress using similar materials to Li-ion but with potentially higher capacities and longer lifespans. R&D and patent activity has grown in this area in recent years. The higher demand for electric vehicles also poses the challenge of battery recycling and disposal as the global supply of used batteries grows. As less than five percent of Li-ion batteries are currently recycled, better technologies are needed to dispose of or recycle them more effectively and to avoid:
- Significant greenhouse gas emissions during manufacture
- Environmental damage in mining
- Ethical concerns from mining raw materials such as lithium, nickel, and cobalt (usually mined in locations with low supply chain transparency)
- Future limited supplies
- Hazardous materials going to landfill
Companies developing new battery technologies face high upfront manufacturing infrastructure costs as well as possible difficulties competing with large suppliers already integrated within supply chains and able to exert price pressure. Identifying growth areas and future needs of the market will be key for these companies. Global patent activity
Li-ion patent application numbers appear high at a first glance, with assignees based in China filing dramatically more than other jurisdictions.
Figure 5.1 Priority filing trend - top ten filing jurisdictions - Li-ion battery technology Click graph to enlarge
Continued investment and R&D are likely driving this trend in China, as technological advancement is a key part of China’s green technology drive. Consequently, China holds eighty percent of the world's battery manufacturing capacity. Outside China, patent filings for Li-ion battery technology peaked in 2011 and have been waning since. In the E.U., Germany is leading with the highest number of new patent filings. This is probably due to the large number of German car manufacturers taking an interest in the fast-growing market for EVs, and the German government’s involvement; it has planned to spend USD 1.1bn by 2023 commercialising battery technology, with an extra USD 1.7 bn in COVID relief stimulus to support local battery cell production. This type of initiative reflects the importance of rechargeable battery production to many governments’ green energy goals.
Figure 5.2 Priority filing 20-year trend - China v. rest of world - Li-ion battery technology Click graph to enlarge
Note: Due to an 18-month lag between patent application and full publication of patent data, data from 2021 has not been reported, and data from 2020 includes data through May 2020.
For solid state batteries, data shows the highest number of new filings have been made in Japan, followed by China, the U.S. and South Korea. European countries are lagging behind, with Germany again having the highest number of filings, but still underperforming when compared to the top jurisdictions.
Figure 5.3 Priority filing trend - top ten filing jurisdictions - solid state battery technology Click graph to enlarge
There is clearly scope to grow in this market. Solid-state battery patent applications have grown exponentially since 2013, peaking around six hundred new patent applications in 2019. The full dataset for 2020 is not yet available, however, data-to-date suggests this trend will continue. Also based on this partial data, Japan had the highest number of new patent filings in 2020, however, China looks set to overtake Japan in future. It’s important to note that although the number of yearly, new filings for solid-state batteries is still significantly lower than those for Li-ion batteries, the former should soon surpass the latter. Arguably, this may have already happened in jurisdictions outside China. This reflects its potential as a key innovation, particularly for EV markets.
Figure 5.4 Priority filing 20-year trend - top five filing jurisdictions - solid state battery technology Click graph to enlarge
Note: Due to an 18-month lag between patent application and full publication of patent data, data from 2021 has not been reported, and data from 2020 includes data through May 2020.
Notable companies Many of the recent top patent filers for Li-ion batteries within China are major players in the automobile industry, with Hefei Guoxuan, Ningde Amperex Technology Ltd. and BYD subsidiaries manufacturing battery products suitable for vehicles and their electronic management systems. Clearly, motor manufacturing companies will take an interest in this technology, given the future of the industry. Outside China, German engineering and technology firm Robert Bosch GmbH is a key assignee for Li-ion technologies, consistently filing among the largest numbers of priority filings each year in the past ten years. Battery and EV technologies – such as an electric drive application – appear to be a significant part of the firm’s wide portfolio of interests. As in China, car manufacturers including General Motors, Toyota and BMW are notable applicants. Li-ion batteries also have many applications in mining and chemical treatment. JX Nippon Mining and chemical processing company Sanyo Chemical Industries hold many priority filings. That said, even among the largest assignees, filing numbers have remained relatively low in recent years. It’s unclear whether the notable dip from 2020 onwards is due to an incomplete dataset or if R&D has been affected by supply chain and manufacturing issues.
Figure 5.5 Priority filings by assignee - previous ten years - Li-ion batteries Click graph to enlarge
Note: Due to an 18-month lag between patent application and full publication of patent data, data from 2021 has not been reported, and data from 2020 includes data through May 2020.
Assignees of applications for solid state batteries follow similar trends. Car manufacturers such as Toyota, Honda and Hyundai again show a great deal of activity as seen by the number of new patent applications filed over recent years. Companies such as Murata MFG, TDK and FDK are similarly concerned with electronics and battery manufacture. The most rapid growth in recent years has come from Chinese automotive supplier and battery cell manufacturer Svolt Energy Tech, which established its European production site in Germany in 2019. Overall, Svolt has filed over 550 patents worldwide, indicating its ambition to be a key player in the EV market.
Figure 5.6 Priority filings by assignee - previous ten years - solid state batteries Click graph to enlarge
Note: Due to an 18-month lag between patent application and full publication of patent data, data from 2021 has not been reported, and data from 2020 includes data through May 2020.
The number of overall granted patents suggests the automobile industry remain very active in this technology area. Other companies, such as Murata MFG, Polyplus Battery Co, Mallory and Co. Inc. and I-TEN are similarly concerned with electronics and battery manufacture. Dyson subsidiary Sakti3 also appears to be active in this area, showing Dyson’s interest in expanding its product portfolio. Chemical firms LG Chem and Mitsubishi Gas Chemical Co. are also showing an interest in developing the key materials for solid state batteries, positioning themselves as potential suppliers and manufacturers for key battery components.
Implications for innovation and future patent filings Considering the types of patents filed in this area, there has been significant R&D and patent activity in anode/cathode materials, and in making structural changes to the battery to maximise electrochemical performance, e.g., using layered oxides. Most patent applications concerning both Li-ion and solid-state batteries are aimed at improving the available energy density by altering or replacing the active materials used for the cathodes/anodes, primarily the positive anode. Thin films of carbon (in the form of graphene derivatives) have emerged as promising separator components in an increasing number of applications. There is also a focus on replacing components with materials that are easier to recycle, dispose of safely or use in second life applications, e.g., using NCM cathode material that allows for the recovery of lithium/transition metals. We believe this will be an important growth area in the future, given the increasing prevalence of EVs and the need to dispose of and reuse materials from old batteries in safe and environmentally friendly ways. The automotive industry is, understandably, very active in both Li-ion and solid-state innovation, with Toyota, Hyundai, General Motors, and Nissan taking top spots. In the past year alone, Toyota has filed patent applications for everything from the lithium solid electrolyte to use as an anode in a solid-state battery, to the casing necessary to efficiently accommodate the batteries in a vehicle. Though still relatively early in this technology’s life, there is much room for innovation and investment. Improvements in the production and performance of Li-ion batteries are necessary with the ever-wider roll-out of EVs and the technology continues to receive considerable private and government funding. In turn, certain areas of research – such as battery recycling and second life uses – will become more prevalent and reduce the environmental concerns about EVs. These areas might be easier for small or medium-sized entities to tackle than battery manufacturers, where they are more susceptible to price pressure from larger companies already integrated into the necessary supply chains. As it stands, there is much room for market growth with the existing technology. Solid state batteries offer a significant improvement over Li-ion technology, though the number of immediate applications may be lower. With the existing focus on Li-ion manufacturing and supply chains, any technology that achieves even minor improvements in performance could be more beneficial for inventors or investors.
With both Li-ion and solid-state battery technologies firmly in the sights of large companies, especially those operating in the EV market, filing for patent protection to strengthen a commercial position and investment in R&D processes should happen as early as possible. Innovators should also pay close attention to the jurisdictions that are providing generous R&D funding and other stimuli to bring these technologies to market.
Paul Beynon Senior Associate, MEng, CPA, EPA
Rory Brown Trainee Patent Attorney, MPhys, PhD