Active pharmaceutical ingredients, dyes and specialty chemicals manufacturer Macsen Labs recently announced a breakthrough in sodium-ion battery technology through the successful research and development- (R&D-) scale synthesis of its high-performance Prussian White, a next-generation cathode material for sodium-ion batteries.

The company has filed a provisional patent for its proprietary synthesis process. The material has already undergone optimisation for battery use at the company’s electrochemistry and battery R&D facility and has shown promising results, with the next phase being pilot-scale manufacturing.

“It’s an interesting story, how a pharmaceutical company like ours entered the energy storage space,” says Macsen Labs CEO and project lead researcher Achal Agrawal.

“While working on Prussian Blue as a drug for radioactive poisoning, we discovered its derivative – Prussian White, which was emerging as a leading candidate for sodium-ion battery cathodes. That moment of curiosity led us down this path.”

Roughly a year ago, with zero experience in electrochemistry, Macsen’s team fabricated a basic pouch cell inside a regular chemistry R&D lab, without specialised equipment.

“We had no glovebox, no coater, no calendering machine, just our lab experience and synthesised material,” recalls Agrawal. “When that small cell lit up a light-emitting diode bulb, we knew we had something worth pursuing. That spark led us to establish a full-fledged electrochemistry lab.”

Today, Macsen’s battery R&D facility includes an argon-filled glovebox for inert atmosphere handling, coin and pouch cell fabrication stations, electrode coaters, crimpers, vacuum dryers, and electrochemical testing systems, such as cyclers and potentiostats. With this setup, Macsen can rapidly prototype and test battery cells using its own synthesised materials, significantly reducing development time.

The company already operates a pilot-scale chemical synthesis facility, which is now being used to produce Prussian White at a kilogram scale. Through numerous experiments conducted over the last year, the team has gained proficiency in Prussian White chemistry and has achieved what is likely to be “one of the finest quality variants” produced to date.

Through its proprietary process, Macsen has achieved an energy density exceeding 150 mAh/g with Prussian White, which is comparable to lithium-iron-phosphate (LFP). The material also shows “excellent” stability, fast sodium-ion mobility, owing to its open crystalline structure, and compatibility with existing lithium-ion (Li-ion) cell manufacturing infrastructure.

“Performance-wise, it’s [on] par with LFP, but made from abundant, low-cost materials like sodium and iron,” said Agrawal. “These elements are easily available, affordable and free from geopolitical constraints.”

This project, originally incubated within Macsen Labs, is now being advanced under a dedicated entity currently under formation — ‘Macsen Energy’, which will focus exclusively on energy storage innovation.

“The real potential of sodium-ion batteries lies not just in electric vehicles (EVs),” said Agrawal. “It lies in stationary energy storage systems that store and manage renewable energy from solar and wind. This is where India’s energy transition will happen at scale.”

Macsen’s current sodium-ion battery technology, using its Prussian White as cathode paired with a hard carbon anode, is well suited for applications such as battery energy storage systems for grid and solar, household backup and inverter systems, short-range EVs, auto-rickshaws, two-wheelers, city buses, rural microgrids, and energy access solutions.

The company is now focusing not only on improving cycle life, energy density, charge-discharge rates, and optimising electrolyte-additive systems, but also on reducing the cost of other components of the cell.

Macsen aims to develop economical form factors by innovatively combining low-cost battery materials, components, and manufacturing processes, especially for large-scale stationary energy storage. One inherent cost advantage of sodium-ion technology is its use of aluminium in place of copper as the cathode current collector, which would further reduce raw material costs.

To demonstrate the performance of Prussian White in commercial large-format cells, Macsen is setting up a pilot-scale cell fabrication line. The company is already sourcing equipment for this and aims to have the pilot-scale production facility operational by early 2026.