Batteries
Highlights:
- High filing activity by a small number of innovators generates an innovation boom in lithium-ion battery technology.
- Whilst development of electrode active materials continues to deliver high patent filings each year, a clear trend has emerged over the past decade indicating up to fifty percent growth in interest in cathode active materials over anode active materials.
- In 2023, South Korea overtook Japan as global leader in patent filings directed to electrode active materials.
- Beyond materials development, innovation in control and systems technologies such as battery management systems is rapidly gaining momentum.
Battery innovation has become a foundation of the much needed global transition to cleaner energy, enabling everything from renewable power integration to the expansion of electric mobility.
As our ability to harness renewable energy continues to rise, so does the demand for reliable and efficient energy storage to provide power when the sun isn’t shining or the wind isn’t blowing. Smart storage solutions are essential to balance supply and demand, ensuring clean power remains reliable around the clock. A wide range of technologies can be leveraged to this effect, from batteries to pumped hydropower storage to green hydrogen.
For example, excess renewable energy could be used to drive the production of green hydrogen which offers a versatile chemical energy storage medium. However, large-scale commercialisation of green hydrogen appears to be bottlenecked by losses in its production, concerns about leakage in the existing gas transport system and wider safety issues. Given these challenges, the storage of energy in batteries remains a more commercially viable and immediate solution.
Battery innovation has become a foundation of the much needed global transition to cleaner energy, enabling everything from renewable power integration to the expansion of electric mobility. Advances in this field carry profound implications for both economic progress and environmental sustainability. Building on battery technology articles from the past four editions of our Inside Green Innovation Report, this year we review how patent activity into lithium-ion technology has evolved over the past 5 years. We also dive into progress in electrode active materials – the core material technology of batteries – and consider innovation beyond material developments.
Lithium-Ion: five years on
Battery technology has been a key part of our Inside Green Innovation report since the first edition was published in 2021. Now that we arrive at our fifth edition, we begin this edition by reviewing progress in this field since 2020 (allowing for the 18 month delay between filing and publishing a patent application). A broad review of patent filings directed at rechargeable Li-ion (secondary) battery technology since 2017 has revealed that activity has continued to rise over the succeeding years, reaching a historic high in 2022 (Figure 1).
Figure 1: twenty-year trend (2003-2023) – global priority filings – li-ion technology
The notable peak in filings between 2021-22 can be attributed to a surge in filings by LG and Samsung in particular, together with high filings by Toyota, Panasonic, and Bosch (Figure 2).
Figure 2: nine-year overview (2015-2023) – top global filers – Li-ion technology
To dissect this surge in filings by LG and Samsung, a review of keywords across these patent filings, revealed that applications claiming inventions in particle size (particularly on the nanometre scale), discharge capacity, lithium sulphur cells and electrolyte layers appeared to drive the peak filing activity in 2021 and 2022. Figure 3 shows the prevalence of these keywords across the patent data and across all top applicants shown in Figure 1, demonstrating that particle size and electrolyte layer technology are particular current hot topics.
Figure 3: twenty-year trend (2003-2023) – global priority filings by topic – Li-ion technology
It is clear that over the past five years patent activity related to lithium-ion rechargeable technology has grown at a steady and significant pace, underscoring the sector’s role as a cornerstone in modern energy innovation. However, patent filings dropped in 2023, the first time patent activity has dropped in this field since 2015.
It remains to be seen whether this signals a real change in the field, or if the flurry of innovation from the industry leaders, outlined above, caused a temporary boom in filings over 2021-22. Extrapolation of the limited data available for 2024 suggests the latter. In any case, far from reaching saturation, the momentum in intellectual property activity in general indicates that investment and competition in this space will remain strong for the foreseeable future.
The development of novel electrode active materials is a cornerstone of battery innovation, as such materials largely determine a cell’s energy density, charging speed, cycle life, and overall safety.
Electrode active materials
The development of novel electrode active materials is a cornerstone of battery innovation, as such materials largely determine a cell’s energy density, charging speed, cycle life, and overall safety. Breakthroughs in both cathode and anode active materials have shaped the evolution of modern batteries, from the introduction of lithium cobalt oxide cathodes in early lithium-ion cells to the ongoing exploration of novel chemistries today, such as composite materials.
Recent trends in patent filings provide interesting insight into where research and industry are concentrating their efforts. Specially, patent data reveals a divergence in innovation focus over the past decade. Up until around 2012, patent filings for anode and cathode active materials grew at a similar pace, reflecting balanced investment in both sides of the cell. Since then, however, a clear trend has emerged: anode-related filings have plateaued, whilst cathode-related filings continue to climb steadily upward. (Figure 4)
Figure 4: forty-year trend (1983-2023) – global priority filings – anode and cathode electrode active materials
It is important to recognise that there are still over one thousand new patent filings related to anode materials annually, and so there is clearly strong continuing innovation in anode materials. However, filings relating to cathode materials has overtaken the interest in anode materials by almost fifty percent.
That is, whilst both electrodes continue to be the target of research and provide resulting innovation, the greater number of filings for cathode electrodes may indicate that “low-hanging fruit” in anode development may have been captured. For example, graphite optimisation and silicon-based composites have both rapidly become popular as high performance anode materials.
On the cathode side, however, innovation is still accelerating. Research is increasingly directed toward high nickel chemistries, cobalt reduction strategies, and new material families that can deliver higher energy density while maintaining safety and stability (Figure 5). This sustained patent growth may also reflect the cathode’s central role in determining battery performance and cost, especially for electric vehicles and large-scale storage.
Figure 5: ten-year trend (2013-2023) – global priority filings – cobalt and nickel free technologies
Innovation in electrode active materials has historically been dominated by Japan, which has long been the leading jurisdiction. However, over the past 5 years, there has been a slowdown in filings originating from Japan and notably a crossover point with South Korea, which emerged as the leading global filing jurisdiction for electrode active materials in 2023 (Figure 6).
Figure 6: forty-year trend (1983-2023) – global priority filings by jurisdiction – electrode active materials
In summary, both anode and cathode materials innovation remain strong but while anode innovation may have levelled off, cathode materials reflect an even more dynamic area for battery research and development. It remains to be seen whether anode or cathode technology will drive the next major advancements in commercial electrode active materials and it will be interesting to see whether South Korea maintain its position globally in this particular field over near future.
Battery management systems
Alongside recent advancements in battery materials and engineering, the role of battery management systems (BMS) has become increasingly critical. A BMS essentially acts as the "brain" of a battery pack, improving safety and efficiency, and generally improves the longevity of the battery and component parts. A BMS typically continuously monitors key parameters (voltage, current, temperature, etc.) across individual cells and the overall system, preventing overcharging, deep discharging, or overheating that could compromise performance and/or lead to safety risks.
More recently, battery management systems have begun to integrate sophisticated algorithms to handle more complex tasks, including optimising energy distribution, balancing charge levels between cells, and predicting remaining battery life. Predictive capability is particularly crucial in electric vehicles (EVs) and renewable energy storage, where reliable performance and accurate estimations are essential. Innovative interest in BMS is reflected in patent activity. Over the past decade, global patent filings (Figure 7) related to BMS have grown consistently, highlighting both the commercial importance and the technical complexity of this field.
Figure 7: thirty-year trend (1993-2023) – global priority filings – battery management systems
The consistent growth in patent filings year on year signals that the landscape remains highly competitive, with incremental improvements generating significant intellectual property. Interestingly, a review of patent activity attributed to the originating applicant over the past decade (Figure 8) reveals that each applicant has had a different peak year in patent activity, potentially reflecting a staggered entry to this particular field.
Figure 8: twenty-year trend (2003-2023) – global priority filings by applicant – battery management system
An emerging aspect of BMS innovation is connectivity and the “Internet of Things” (IoT). Smart BMS platforms increasingly use IoT and cloud integration to provide real-time insights, such as remote monitoring or predictive behaviours. Patent filings specifically disclosing battery technology and IoT have only recently started to emerge (Figure 9), however, 2024 appears set to be a historic high for this field, because the limited publications already available for patents filed in 2024 are already essentially equivalent to the peak in 2021, indicating strongly that this particular field is set for rapid development over the next 5 years. This trend may be attributable to the growing interest in AI-related inventions, although the patentability of which fluctuates across global jurisdictions, as discussed in this episode of Appleyard Lees' The Greenshoots Intellectual Property Podcast.
Figure 9: ten-year trend (2013-2023) – global priority filings – internet of things
Ultimately, as batteries scale up in capacity and application, from household devices to industrial grid storage, the sophistication of BMS will determine how effectively we can harness their potential and value.
Conclusion
Alongside recent advancements in battery materials and engineering, the role of battery management systems (BMS) has become increasingly critical. A BMS essentially acts as the "brain" of a battery pack, improving safety and efficiency, and generally improves the longevity of the battery and component parts. A BMS typically continuously monitors key parameters (voltage, current, temperature, etc.) across individual cells and the overall system, preventing overcharging, deep discharging, or overheating that could compromise performance and/or lead to safety risks.
More recently, battery management systems have begun to integrate sophisticated algorithms to handle more complex tasks, including optimising energy distribution, balancing charge levels between cells, and predicting remaining battery life. Predictive capability is particularly crucial in electric vehicles (EVs) and renewable energy storage, where reliable performance and accurate estimations are essential. Innovative interest in BMS is reflected in patent activity. Over the past decade, global patent filings (Figure 7) related to BMS have grown consistently, highlighting both the commercial importance and the technical complexity of this field.
Kealan Fallon European Patent Attorney
Chris Mason Partner and Patent Attorney
David Walsh Partner and Patent Attorney