Insight into battery and energy technologies

Paving the way for a clean energy future

Renewable energy use is increasing fast worldwide, with last year becoming the first in which solar and wind generated more power than fossil fuels in Europe. As Europe accelerates the clean energy transition and promotes electrification, energy storage becomes increasingly important to enabling energy security.

Over the past decade, growth in areas such as e-mobility has led to much more variable demand for electricity, as charging needs evolve. Combined with the variability of factors such as sunlight hours and windspeed linked to renewables, this has increased the need for flexibility in power systems and driven growth in demand for batteries, whether those used in electric vehicles or in stationary applications to support homes, industrial facilities and smart grid solutions.

Here, technological advances offer more and more flexibility to store excess renewable energy during periods of abundance and low demand, then release it when supply is scarce. In addition, batteries provide a clean source of back-up power in areas such as digital infrastructure, including data centres and artificial intelligence.

Since 2016, filings at the EPO in the batteries area have surged 340%. At the beginning of the decade, they comprised just 17.5% of all patent applications in the field of Electrical machinery, appliances and energy, climbing to 45.1% by 2025. Last year, the market for lithium-ion (or Li-ion) batteries, now the preferred solution across a range of sectors, exceeded USD 150 billion, an increase of over 20% from 2024, according to the International Energy Agency (IEA). This confirms that innovation continues to be translated into value at scale, at the same time as fostering greater sustainability, both in terms of clean energy and economic growth. 

Over the past five years, R. Korea has consolidated on its lead in battery innovation, now accounting for over a third of filings in the area, with LG leading the way by a significant margin. Samsung and SK ensure that Korean applicants dominate the top five, which is completed by China’s CATL and Japan’s Panasonic. Volvo Group is the sole European player in the top 15, where there are no US applicants. Meanwhile, in the area of electric vehicle charging (classified under Transport), the filings of German applicants such as Siemens, Mercedes-Benz and BMW make them well-placed to compete internationally.

While battery innovation clearly accounts for overall growth in the field of Electrical machinery, appliances and energy, European applicants nevertheless maintain a leading role by virtue of their filings in more traditional areas of industry and the performance of a diverse range of applicants, including startups, universities, public research organisations and spin-offs. 

Signify, whose origins as the former lighting division of Philips go back to the beginning of electrification and whose filings have also continued to grow rapidly in recent years, remains in the top five applicants. Several other large European applicants fall just outside the top ten, including Siemens, Schneider Electric, ABB, TE Connectivity, Robert Bosch, Siemens Energy and Valeo.

The predominance of German companies among the top applicants reflects the country’s lead in the field among EPO member states, with France, Switzerland, the Netherlands and UK completing the top five countries of origin in Europe. Meanwhile, Sweden and Italy account for a significant share of filings in batteries.

The sophistication of European startups in expanding the boundaries of battery innovation across various industries can be futher explored using the EPO’s Deep Tech Finder, which is designed to connect inventors and investors by showcasing a range of emerging players in a variety of sectors, including university spinoffs.

The power of patent and business intelligence

Stockholm-based Polarium offers a range of smart and scalable energy storage solutions, including modular battery energy storage systems (BESS) for commercial and industrial applications. It also supplies home batteries and energy storage solutions for the telecoms industry. While currently focussed on Li-ion technologies, the company is continually exploring new battery chemistries. 

Meanwhile, Edinburgh-based Dukosi develops technologies that improve the performance, safety and efficiency of battery systems, enabling a more sustainable battery value chain. The company's chip-on-cell monitoring solution and communication platform is designed for electric vehicles, industrial transportation and stationary battery energy storage. These are just two of many more example startups for which patent portfolios and business intelligence can be viewed on the Deep Tech Finder.

The diversity of the European innovation ecosystem is reflected across a range of related areas in which startups are thriving on the basis of their patent portfolios, which enable them to attract funding and take their innovations to the next level, even in the face of unexpected setbacks. This has led to international partnerships, including in the context of cross-field advances. 

Driving the future: at the interface of solar mobility and batteries

The Dutch startup Lightyear has pioneered new forms of solar mobility, leading to reductions in energy consumption, battery size and vehicle weight. The company is currently collaborating with Nissan on developing advanced solar charging systems. There is more about this case study in the EPO Observatory’s 2025 study Mapping investors for European innovators, part of the Observatory’s Financing innovation programme. 

Alternative battery technologies

Two emerging areas have proved particularly promising in recent years, with European patent applications surging most years since around 2017, albeit from a relatively low base. The first concerns the hunt for the next generation of Li-ion batteries, where solid-state electrolytes comprise a growing area of innovation. Commercial applications of solid-state electrolytes in electric vehicles are anticipated and could generate further innovation that would help to make these batteries competitive for other applications too.

As for alternative chemistries, innovation in sodium-ion batteries has seen a similar surge recently. Sodium-ion has also been highlighted by the IEA for its potential to diversify battery chemistries and supply chains. Investments in the area are driven primarily by the prospect of improving battery performance in cold climates and reducing exposure to lithium‑price volatility. However, while sodium‑ion batteries tend to perform better in low temperatures than lithium‑ion batteries, they also display lower energy density.

Further technologies for securing a clean energy future

The work of the EPO Observatory on Patents and Technology has covered a range of technology areas with the potential to contribute to greater global sustainability. Past studies have not only explored batteries and grid technologies, but the role of hydrogen in securing a clean energy future (in each case jointly with the IEA), the commercialisation of clean tech innovation (jointly with the European Investment Bank) and the rapid rise of digital agriculture to address global food security and climate challenges.

Last year’s technology insight report on advances in photovoltaics delivered more unique insights into technology trends that support energy security, lower electricity costs and create jobs in manufacturing, installation and maintenance. As the efficiency of solar panels improves and costs decline, photovoltaics are becoming more accessible in both industrialised and developing regions around the world. Looking ahead, advancements in materials, storage integration and smart grid technologies are expected to further enhance energy systems as we move towards a more sustainable, decentralised and resilient global energy infrastructure.