September 20, 2025: I Squared Capital is acquiring a majority equity stake in ENTEK Technology Holdings the lead and lithium battery separator firm, for $800 million.
“The investment will fund construction of a gigafactory in Terre Haute, Indiana — the only facility in the US producing wet-process lithium-ion battery separators,” said the two firms in a joint statement released on September 17.
I Squared’s investment complements a loan from the US Department of Energy’s Advanced Technology Vehicles Manufacturing (ATVM) program of up to $1.3 billion.
With initial funding already provided, these combined investments underscore the importance of strong public-private collaboration in securing US, domestic manufacturing of strategic technologies, said the statement.
I Squared is a global infrastructure investment firm with some $50 billion of funds under management.
Vast swathes of the battery industry are now owned by institutional investment firms.
In no particular order, Clarios is owned by Brookfield Business Partners, Stryten by Atlas Holdings, Ecobat has been owned by private equity firm Endless since this June, Trojan/C&D Technologies is owned by KPS Capital. Microporous has been part of Trent Capital since February last year. Fiamm Energy Technology, as agreed this August, is being acquired by the global private equity investor Aurelius from the Japanese company Resonac Holdings Corporation.
It is known that at least three other battery manufacturers have been put up for sale in the past three years.
“The issue for the battery industry as a whole,” says one commentator, “is to work out what the tactics of these types of investors will be. Are they trying to flip the acquisition in a couple of years or are they positioning themselves as long-term players?
“If they are looking to hold a short-term stake — venture capital firms typically look for profits of a multiple of at least three times when selling in a three to five year window — then one can expect cost slashing and redundancies.
“If it is as a longer player then the change of management style may be more strategic — such as looking for accelerated growth and market positioning rather than focused on cutting costs.”
Gautam Bhandari, managing partner for I Squared Capital, said: “ENTEK exemplifies the type of critical, high-growth infrastructure platform that we seek to scale. ENTEK’s revenues are underpinned by long-term agreements with blue-chip clients, and its products are essential to US re-industrialization and energy security.
“With DOE support and rising demand in EVs, energy storage, and defence, ENTEK is uniquely positioned to deliver sustainable growth for our investors and the US economy.”
Supported by Endeavour Capital and Joshua Green Corporation’s investment in 2019, ENTEK has grown its operations across eight countries and is the only company to have expanded the application of advanced materials to include all battery separator types, including lead acid, lithium, and other emerging energy storage technologies.
The company’s patented wet process method for lithium-ion battery separators will provide strong regulatory and performance advantages, say the firms.
Larry Keith, CEO for ENTEK, said: With I Squared’s capital, strategic expertise, and global network, we will expand the US’s manufacturing footprint, create high-quality jobs, and meet surging demand for batteries across critical applications, from EVs and energy storage to military defence equipment and data centers.
The Terre Haute, Indiana project, which will be executed in partnership with Clayco as the EPC contractor and Brueckner Group, will produce 1.4 billion square meters of wet-process lithium-ion battery separators annually in its first two phases and is designed to expand to 2.1 billion square meters.
“The investment,” said the joint statement: “will position ENTEK as the only scaled, US-based supplier able to meet the sourcing requirements for battery manufacturers to receive 45X production tax credits and comply with the content requirements under the Inflation Reduction Act (IRA), as amended by the One Big Beautiful Bill Act (OBBBA), which reduced the allowance for Chinese materials — including separators.
“ENTEK’s product will provide a significant advantage to battery manufacturing customers seeking credits under the OBBBA.”
In addition to the DOE’s up to $1.3 billion ATVM loan, the project has secured more than $200 million in 48C advanced manufacturing tax credits for Phase One of the project and will be eligible for ongoing 45X production tax credits in Phase Two.
A definitive agreement has been signed and the transaction should close following regulatory approvals.
The facility is expected to create approximately 763 construction jobs and 635 operations jobs in Terre Haute once operational.
