California-based startup Anthro Energy has begun construction of a battery-materials plant in Louisville, Kentucky, which it describes as the first large-scale, locally owned and operated U.S. facility for producing advanced electrolytes. The facility is scheduled to begin operations in late 2027, with production capacity of approximately 12,000 metric tons of polymer electrolyte per year.
The company says this amount would be enough to support the production of up to 25 gigawatt-hours of lithium-ion batteries. If all of the output were allocated to stationary electricity storage—which will not happen because Anthro is targeting multiple markets—it could supply 6.25 gigawatts of storage projects, assuming each project has a four-hour storage duration.
Why Do Electrolytes Matter in Grid Batteries?
The electrolyte is the medium that transports lithium ions between the positive and negative electrodes while a battery charges and discharges. Most current lithium-ion batteries use a flammable liquid electrolyte, making the properties of this material an important factor in large storage systems containing thousands of closely packed cells.
Anthro’s Proteus platform relies on injecting the material into the cell in liquid form using conventional battery-manufacturing equipment. During the standard formation stage, it then becomes a solid or semisolid polymer through a chemical reaction. According to the company, this polymer may be more resistant to fire, short circuits, and swelling, potentially limiting the risk of a failure spreading from one cell to another. This property is especially important when storage systems are installed near homes, businesses, or critical infrastructure.
What Changes in Practice?
Anthro also says its electrolyte could improve the cells’ energy density and operating life, potentially meaning that more electricity could be stored within the same space and that capacity could be maintained for longer with daily charging and discharging cycles. However, these results remain dependent on demonstrating the technology’s performance at large-scale commercial production.
One practical point the company emphasizes is that using Proteus does not require replacing existing battery-manufacturing equipment. This could facilitate adoption compared with solid-state battery designs that may require entirely new factories, although the source provides no independent details on conversion costs or long-term commercial test results.
Federal Funding and a Local Supply Chain
The project is worth more than $42 million. It received a $24.9 million grant from the U.S. Department of Energy through the Infrastructure Investment and Jobs Act, which was enacted during the Biden administration, along with $18.4 million in investment tax credits under the Inflation Reduction Act’s 48C program.
Anthro says the plant will use inputs that are not subject to restrictions concerning “Foreign Entities of Concern” from the outset, providing U.S. battery manufacturers with a domestic source of a material that may otherwise be associated with risks of foreign supply disruptions or federal procurement restrictions. The project is expected to create 110 permanent manufacturing and technical jobs, in addition to approximately 390 temporary construction jobs.
In addition to grid storage, the plant’s electrolytes will be used in transportation, defense, robotics, and consumer-electronics batteries, expanding the target markets beyond the energy sector alone.