Tara Olivo, Associate Editor08.08.24
The battery separator market is poised for significant growth in the coming years, driven by widespread use in the automotive, consumer electronics and renewable energy industries. Battery separators are crucial for battery performance because they serve as an isolating layer between the cathodes and anodes in the battery.
According to MarketsAndMarkets, the battery separator market is estimated to grow from approximately $7.29 billion in 2024 to $14.73 billion in 2029 and further to $26.08 billion in 2034.
“Nonwoven materials, often made from fine fibers like polypropylene, play a critical role in battery separators,” explains Shantanu Parashar, associate manager, Chemicals & Materials. “These webs of fibers act as a porous barrier between the positive and negative electrodes, allowing lithium ions to flow freely while preventing a physical short circuit. The well-defined pore structure of the nonwoven material helps the battery separator hold enough electrolytes for efficient ion exchange. Additionally, some nonwovens can be engineered to close their pores at high temperatures, enhancing battery safety.”
Globally, Asia Pacific is expected to have significant growth in the coming years, according to MarketsAndMarkets. The demand for separators in the region is mainly driven by China. Parashar says heavy investments in the automotive and electronics sectors have driven the battery separators demand in China. Outside of Asia Pacific, Europe is estimated to witness exponential growth. “With a strong commitment towards sustainable use of energy, it’s expected that the full European battery production will reach 238 GWh in 2025, 413 GWh in 2027 and 773 GWh in 2030, up from 69 GWh in 2022. Europe’s plans to develop gigafactories for EVs and lithium-ion battery (LIB) production is expected to drive the demand for battery separators in the region,” he adds.
Increasing demand for energy storage devices is expected to be one of the major growth opportunities, according to Parashar, whereas lack of government support in terms of infrastructure for electric batteries in emerging economies can negatively impact the growth of the battery separators market.
As the automotive industry moves towards electric vehicles (EVs), there is an increasing demand for high-quality battery separator materials as EVs require large, high-performance batteries.
Dave Rittenhouse, group leader—Advanced Battery Materials, Glatfelter, says EVs are an obvious growth area for battery separators. “There has been approximately $380 billion allocated for EV/LIB development combined in the Infrastructure and the Inflation Reduction Acts. This has brought a massive amount of capacity online,” he explains.
Regardless of how much of this money gets spent, Rittenhouse says there are also many non-EV applications such as drones, eVTOL (electric vertical take-off and landing), BESS (battery energy storage systems) and the electrification of devices which were previously driven by small internal combustion engines. “In many cases, the battery-driven versions are easier to handle and use than their gas-powered equivalents,” he explains.
Based on this experience, Glatfelter took a fresh look at the manufacturing process for battery separators several years ago, according to Rittenhouse. The team prioritized a list of attributes that they felt an ideal separator should have including: Fast Charging (increased charge rates without loss of capacity or cycle life); Thin (increased energy density, reduced weight/size); Safety (low thermal shrinkage with optional high-temperature variants); Versatile (platform technology can readily be tuned to diverse applications); Secure (U.S. sourced technologies, materials and manufacture); and Economic (margin compression impacting EV industry, savings needed).
“We felt that a fibrous structure would be the best method for making a separator that met these objectives,” Rittenhouse says.
While the company can’t provide specifics on its Generation II separator platform—in many cases Glatfelter’s technology is proprietary—the process that Glatfelter uses enables the independent control of many of the parameters of the separator, including the pore size, temperature resistance, strength, surface chemistry and many other properties. This enables Glatfelter to tailor the separator for a specific application or use case, according to Rittenhouse. Glatfelter is in the process of applying for patents to protect these technologies.
“The versatility of the Gen II platform enables us to make separators that provide value in both high power applications where fast charge/discharge rates are required, and high energy applications, while providing a level of safety not achievable by wet or dry processed films,” he says.
Glatfelter has invested millions of dollars into LIB separator research and production. Its current capacity can support smaller, specialized commercial applications. “Our process is very scalable which means that we could scale to full commercial in a relatively short time,” he explains.
Glatfelter has also invested in building a world-class Advanced Battery Research Center in Old Hickory, TN. “We have hired technicians and PhDs to support our development. This facility and our staff enable us to have robust and exciting new product developments with leading-edge customers,” Rittenhouse says.
While the growth of the EV market is the largest single driver of LIB growth, he believes the capability of LIBs to provide energy to devices will create a pipeline of new products that have not been dreamed of previously. “Growth markets for LIBs have transitioned from cell phones to laptops to EVs and now drones are a major weapon system in the conflict in Ukraine. I don’t know what new device or technology will be ‘the next big thing,’ but this area is very exciting and Glatfelter is perfectly positioned to be part of it.”
“Nonwoven materials are an important functional element of the battery,” says Thomas Petzel, SVP Global Business Division General Industry at Freudenberg Performance Materials. “Besides separating the electrode and cathode, Freudenberg Performance Materials’ separator also serves as an electrolyte reservoir in the battery. They influence the battery’s functionality, self-discharge, and cycle life, and can prevent short circuits due to dendrite growth.”
Freudenberg’s battery separators are being used in a variety of applications, especially with aqueous electrolytes, including nickel metal hydride, nickel cadmium, nickel zinc and other emerging battery technologies, as well as a scrim in lead acid batteries.
Significant investments in R&D capacities enable the company to adapt quickly to changing customer needs or market trends, Petzel says.
Recently, the company enhanced its unique surface finishing processes that provide excellent electrolyte absorption and improve the speed of electrolyte absorption.
In addition to growth in the EV market for lithium-ion batteries, Freudenberg is witnessing significant growth from renewable energies where stationary energy storage solutions are needed, with primary growth opportunities in North America and Asia.
For lead acid batteries, Ahlstrom develops microglass separators based on a wetlaid process. The company makes Absorbent Glass Mat (AGM) media, a key component in lead acid batteries that are used for automotive start-stop applications and industrial applications.
For lithium-ion batteries, Ahlstrom has developed a proprietary technology that is also fiber-based and uses the wetlaid process. For this category, Ahlstrom is also targeting automotive and industrial applications, but energy storage has become a focus for the company. “Automotive batteries are already quite well advanced, and we are coming in with a new technology into a market that is using a film-type separator. Therefore, the market would require a shift of mindset and that’s something that does not happen overnight,” says Marcus Ulrich, head of sales, Energy Storage, Ahlstrom.
As part of its growth plan, Ahlstrom has made several significant investments in recent years. In 2022, a new production line at its plant in Turin, Italy, began producing glass microfiber media. The line is also capable of using other fibers like cellulose and other polymeric fibers. Additionally, last year, Ahlstrom started up another glass fiber line at its plant in Madisonville, KY. While this line does not target separators specifically, it is for glass mat uses that are used in combination with polyethylene separators.
Additionally, in 2023, Ahlstrom expanded its offering with a hybrid pasting material. Pasting materials are one of the key components in the lead-acid battery assembly process. They are laminated onto the electrodes to stabilize the active material. Ahlstrom’s hybrid pasting material is a unique combination of natural and synthetic fibers with superior uniformity and better handling properties compared to other pasting materials. The synthetic content provides better adhesion of the active material on the battery plate surface, after the natural fiber content has dissolved in the battery acid. This specific property stabilizes the active mass on the grid, allowing higher cycling and longer battery life, as well as easing battery recycling.
Ulrich says Ahlstrom is the only company globally that offers a whole range of materials for the energy storage market. “We offer AGM separators, we offer microglass pasting, cellulose pasting and hybrid pasting,” he says. “There’s no producer worldwide who has this whole range of capabilities. We try to market ourselves as the one-stop shop for fiber-based solutions in the industry.”
Asahi Kasei positions its Energy Storage related business as one of the “10 Growth Gears” (GG10) expected to drive future growth in its medium-term management plan for fiscal 2024. The core of its Energy Storage business is its Hipore wet-process LIB separator, which has a business history spanning over 40 years, and is currently expanding its sales in automotive applications in addition to consumer electronics applications.
Christian OKeefe, external marketing and corporate communications specialist, Asahi Kasei America, says the decision to build a lithium-ion battery separator plant in Canada was driven by several key factors. “In addition to the favorable conditions created by the Inflation Reduction Act (IRA), there has been a significant increase in the establishment of facilities by automotive OEMs and battery manufacturers in North America,” she says. “The North American market, currently lacking companies with mass production experience for wet process separators, presents a high-potential opportunity for us. Furthermore, a warm welcome from the Canadian and local communities, the abundance of clean energy/skilled talent and agreement with the company’s philosophy/values made Canada an ideal location for this new plant.”
Asahi Kasei and Honda reached a basic agreement based on the shared understanding that it is essential to establish a supply chain for the stable supply of high-performance batteries for the North American plug-in electric vehicle market, which is expected to grow over the medium to long term. Studies are advancing for the establishment of a joint venture to manufacture Hipore separator for batteries installed in EVs made by Honda and other vehicle manufacturers for the North American market.
In addition to Hipore, Asahi Kasei manufactures Celgard battery separators. According to OKeefe, the company’s battery separators, which are both based on film, achieve high production speeds, approximately double the industry standard for both base film and coating processes. Its range of coated membranes ensures high quality and improved battery yield, with a uniform pore structure that contributes to extended battery service life. The company uses non-fluorinated coatings and maintains a high rate of recycling process materials.
Asahi Kasei expects significant growth in the lithium-ion battery separator market. “By 2030, it is anticipated that over half of the vehicles sold in North America will be BEVs (Battery Electric Vehicles) or PHEVs (Plug-in Hybrid Electric Vehicles),” OKeefe says. “This shift will drive a substantial increase in demand for LIB separators, with the market projected to grow from 1.0 billion square meters in 2023 to 8.7 billion square meters. This expected growth is fueled by the accelerating adoption of electric vehicles and the corresponding need for high-quality battery components.”
Due to their high energy density, high discharge rate and long-life lithium thionyl chloride batteries are typically used in applications where battery replacement can be costly, in military applications and in areas with extreme temperatures. These batteries can withstand a wide temperature range from -60 to 85 degrees Celsius, making them particularly useful in colder climates. Craneglas materials enable the exceptional performance characteristics of these batteries to be realized under extreme conditions.
To further enhance the performance of batteries, Gessner has developed the Craneglas SD material. This variant boasts superior fiber dispersion and very uniform density & thickness. These attributes are critical in the battery market, especially in the winding process where precise thickness is paramount.
The uniformity of the Craneglas SD material ensures that each layer of the battery is consistent, which in turn guarantees optimal performance. A battery with inconsistent layer thickness can lead to uneven power distribution and ultimately, reduced functionality. Therefore, the homogeneity of Craneglas SD makes it an ideal choice for battery manufacturers.
According to MarketsAndMarkets, the battery separator market is estimated to grow from approximately $7.29 billion in 2024 to $14.73 billion in 2029 and further to $26.08 billion in 2034.
“Nonwoven materials, often made from fine fibers like polypropylene, play a critical role in battery separators,” explains Shantanu Parashar, associate manager, Chemicals & Materials. “These webs of fibers act as a porous barrier between the positive and negative electrodes, allowing lithium ions to flow freely while preventing a physical short circuit. The well-defined pore structure of the nonwoven material helps the battery separator hold enough electrolytes for efficient ion exchange. Additionally, some nonwovens can be engineered to close their pores at high temperatures, enhancing battery safety.”
Globally, Asia Pacific is expected to have significant growth in the coming years, according to MarketsAndMarkets. The demand for separators in the region is mainly driven by China. Parashar says heavy investments in the automotive and electronics sectors have driven the battery separators demand in China. Outside of Asia Pacific, Europe is estimated to witness exponential growth. “With a strong commitment towards sustainable use of energy, it’s expected that the full European battery production will reach 238 GWh in 2025, 413 GWh in 2027 and 773 GWh in 2030, up from 69 GWh in 2022. Europe’s plans to develop gigafactories for EVs and lithium-ion battery (LIB) production is expected to drive the demand for battery separators in the region,” he adds.
Increasing demand for energy storage devices is expected to be one of the major growth opportunities, according to Parashar, whereas lack of government support in terms of infrastructure for electric batteries in emerging economies can negatively impact the growth of the battery separators market.
As the automotive industry moves towards electric vehicles (EVs), there is an increasing demand for high-quality battery separator materials as EVs require large, high-performance batteries.
Dave Rittenhouse, group leader—Advanced Battery Materials, Glatfelter, says EVs are an obvious growth area for battery separators. “There has been approximately $380 billion allocated for EV/LIB development combined in the Infrastructure and the Inflation Reduction Acts. This has brought a massive amount of capacity online,” he explains.
Regardless of how much of this money gets spent, Rittenhouse says there are also many non-EV applications such as drones, eVTOL (electric vertical take-off and landing), BESS (battery energy storage systems) and the electrification of devices which were previously driven by small internal combustion engines. “In many cases, the battery-driven versions are easier to handle and use than their gas-powered equivalents,” he explains.
Glatfelter
Glatfelter’s know-how in battery separator technology for LIBs has expanded since it made a significant investment in technology company Dreamweaver International in 2014. This process made separators for LIBs based on papermaking/wetlaid technology. At 20 microns thin, the separator was developed for applications including energy storage for solar cells, electric vehicles, power tools, industrial cells and some portable electronics.
After years of manufacturing this technology, Glatfelter eventually sold the paper mill where it was produced and ceased its production altogether.Based on this experience, Glatfelter took a fresh look at the manufacturing process for battery separators several years ago, according to Rittenhouse. The team prioritized a list of attributes that they felt an ideal separator should have including: Fast Charging (increased charge rates without loss of capacity or cycle life); Thin (increased energy density, reduced weight/size); Safety (low thermal shrinkage with optional high-temperature variants); Versatile (platform technology can readily be tuned to diverse applications); Secure (U.S. sourced technologies, materials and manufacture); and Economic (margin compression impacting EV industry, savings needed).
“We felt that a fibrous structure would be the best method for making a separator that met these objectives,” Rittenhouse says.
While the company can’t provide specifics on its Generation II separator platform—in many cases Glatfelter’s technology is proprietary—the process that Glatfelter uses enables the independent control of many of the parameters of the separator, including the pore size, temperature resistance, strength, surface chemistry and many other properties. This enables Glatfelter to tailor the separator for a specific application or use case, according to Rittenhouse. Glatfelter is in the process of applying for patents to protect these technologies.
“The versatility of the Gen II platform enables us to make separators that provide value in both high power applications where fast charge/discharge rates are required, and high energy applications, while providing a level of safety not achievable by wet or dry processed films,” he says.
Glatfelter has invested millions of dollars into LIB separator research and production. Its current capacity can support smaller, specialized commercial applications. “Our process is very scalable which means that we could scale to full commercial in a relatively short time,” he explains.
Glatfelter has also invested in building a world-class Advanced Battery Research Center in Old Hickory, TN. “We have hired technicians and PhDs to support our development. This facility and our staff enable us to have robust and exciting new product developments with leading-edge customers,” Rittenhouse says.
While the growth of the EV market is the largest single driver of LIB growth, he believes the capability of LIBs to provide energy to devices will create a pipeline of new products that have not been dreamed of previously. “Growth markets for LIBs have transitioned from cell phones to laptops to EVs and now drones are a major weapon system in the conflict in Ukraine. I don’t know what new device or technology will be ‘the next big thing,’ but this area is very exciting and Glatfelter is perfectly positioned to be part of it.”
Freudenberg Performance Materials
Freudenberg Performance Materials has several decades of experience and extensive expertise in the battery industry, developing tailor-made solutions to meet the battery separator requirements of its customers. The company utilizes all available nonwovens technologies such as wetlaid, drylaid, spunbond, etc., using different kinds of fibers or polymers, as well as various finishing techniques to tune its separators’ performance to the application needs.“Nonwoven materials are an important functional element of the battery,” says Thomas Petzel, SVP Global Business Division General Industry at Freudenberg Performance Materials. “Besides separating the electrode and cathode, Freudenberg Performance Materials’ separator also serves as an electrolyte reservoir in the battery. They influence the battery’s functionality, self-discharge, and cycle life, and can prevent short circuits due to dendrite growth.”
Freudenberg’s battery separators are being used in a variety of applications, especially with aqueous electrolytes, including nickel metal hydride, nickel cadmium, nickel zinc and other emerging battery technologies, as well as a scrim in lead acid batteries.
Significant investments in R&D capacities enable the company to adapt quickly to changing customer needs or market trends, Petzel says.
Freudenberg’s wetlaid material for battery separators.
Recently, the company enhanced its unique surface finishing processes that provide excellent electrolyte absorption and improve the speed of electrolyte absorption.
In addition to growth in the EV market for lithium-ion batteries, Freudenberg is witnessing significant growth from renewable energies where stationary energy storage solutions are needed, with primary growth opportunities in North America and Asia.
Ahlstrom
Ahlstrom, one of the world’s largest nonwovens producers, is relatively new in the energy storage market, entering the sector around six years ago.For lead acid batteries, Ahlstrom develops microglass separators based on a wetlaid process. The company makes Absorbent Glass Mat (AGM) media, a key component in lead acid batteries that are used for automotive start-stop applications and industrial applications.
For lithium-ion batteries, Ahlstrom has developed a proprietary technology that is also fiber-based and uses the wetlaid process. For this category, Ahlstrom is also targeting automotive and industrial applications, but energy storage has become a focus for the company. “Automotive batteries are already quite well advanced, and we are coming in with a new technology into a market that is using a film-type separator. Therefore, the market would require a shift of mindset and that’s something that does not happen overnight,” says Marcus Ulrich, head of sales, Energy Storage, Ahlstrom.
As part of its growth plan, Ahlstrom has made several significant investments in recent years. In 2022, a new production line at its plant in Turin, Italy, began producing glass microfiber media. The line is also capable of using other fibers like cellulose and other polymeric fibers. Additionally, last year, Ahlstrom started up another glass fiber line at its plant in Madisonville, KY. While this line does not target separators specifically, it is for glass mat uses that are used in combination with polyethylene separators.
Additionally, in 2023, Ahlstrom expanded its offering with a hybrid pasting material. Pasting materials are one of the key components in the lead-acid battery assembly process. They are laminated onto the electrodes to stabilize the active material. Ahlstrom’s hybrid pasting material is a unique combination of natural and synthetic fibers with superior uniformity and better handling properties compared to other pasting materials. The synthetic content provides better adhesion of the active material on the battery plate surface, after the natural fiber content has dissolved in the battery acid. This specific property stabilizes the active mass on the grid, allowing higher cycling and longer battery life, as well as easing battery recycling.
Ulrich says Ahlstrom is the only company globally that offers a whole range of materials for the energy storage market. “We offer AGM separators, we offer microglass pasting, cellulose pasting and hybrid pasting,” he says. “There’s no producer worldwide who has this whole range of capabilities. We try to market ourselves as the one-stop shop for fiber-based solutions in the industry.”
Asahi Kasei
Asahi Kasei is constructing an integrated plant in Ontario, Canada, for the base film manufacturing and coating of its Hipore wet-process lithium-ion battery (LIB) separators. In relation to this plant, Asahi Kasei concluded a basic agreement with Honda Motor Co., Ltd. and the two parties are currently studying joint investment.Asahi Kasei positions its Energy Storage related business as one of the “10 Growth Gears” (GG10) expected to drive future growth in its medium-term management plan for fiscal 2024. The core of its Energy Storage business is its Hipore wet-process LIB separator, which has a business history spanning over 40 years, and is currently expanding its sales in automotive applications in addition to consumer electronics applications.
Christian OKeefe, external marketing and corporate communications specialist, Asahi Kasei America, says the decision to build a lithium-ion battery separator plant in Canada was driven by several key factors. “In addition to the favorable conditions created by the Inflation Reduction Act (IRA), there has been a significant increase in the establishment of facilities by automotive OEMs and battery manufacturers in North America,” she says. “The North American market, currently lacking companies with mass production experience for wet process separators, presents a high-potential opportunity for us. Furthermore, a warm welcome from the Canadian and local communities, the abundance of clean energy/skilled talent and agreement with the company’s philosophy/values made Canada an ideal location for this new plant.”
Asahi Kasei and Honda reached a basic agreement based on the shared understanding that it is essential to establish a supply chain for the stable supply of high-performance batteries for the North American plug-in electric vehicle market, which is expected to grow over the medium to long term. Studies are advancing for the establishment of a joint venture to manufacture Hipore separator for batteries installed in EVs made by Honda and other vehicle manufacturers for the North American market.
In addition to Hipore, Asahi Kasei manufactures Celgard battery separators. According to OKeefe, the company’s battery separators, which are both based on film, achieve high production speeds, approximately double the industry standard for both base film and coating processes. Its range of coated membranes ensures high quality and improved battery yield, with a uniform pore structure that contributes to extended battery service life. The company uses non-fluorinated coatings and maintains a high rate of recycling process materials.
Asahi Kasei expects significant growth in the lithium-ion battery separator market. “By 2030, it is anticipated that over half of the vehicles sold in North America will be BEVs (Battery Electric Vehicles) or PHEVs (Plug-in Hybrid Electric Vehicles),” OKeefe says. “This shift will drive a substantial increase in demand for LIB separators, with the market projected to grow from 1.0 billion square meters in 2023 to 8.7 billion square meters. This expected growth is fueled by the accelerating adoption of electric vehicles and the corresponding need for high-quality battery components.”
Gessner
Gessner’s Craneglas is a unique wetlaid nonwoven made with coarse glass. Unlike typical micro glass separators which have a smaller pore size, Craneglas has a larger pore size making it suitable for a specific kind of primary, non-rechargeable battery. Lithium thionyl chloride batteries (LiSOCl2) have a liquid cathode, unlike other lithium batteries that have solid materials as their cathode.Due to their high energy density, high discharge rate and long-life lithium thionyl chloride batteries are typically used in applications where battery replacement can be costly, in military applications and in areas with extreme temperatures. These batteries can withstand a wide temperature range from -60 to 85 degrees Celsius, making them particularly useful in colder climates. Craneglas materials enable the exceptional performance characteristics of these batteries to be realized under extreme conditions.
To further enhance the performance of batteries, Gessner has developed the Craneglas SD material. This variant boasts superior fiber dispersion and very uniform density & thickness. These attributes are critical in the battery market, especially in the winding process where precise thickness is paramount.
The uniformity of the Craneglas SD material ensures that each layer of the battery is consistent, which in turn guarantees optimal performance. A battery with inconsistent layer thickness can lead to uneven power distribution and ultimately, reduced functionality. Therefore, the homogeneity of Craneglas SD makes it an ideal choice for battery manufacturers.
