Indian startup **Macsen Energy** claims that its sodium-ion battery cell, utilizing a cathode material based on **Prussian white**, has surpassed 1,500 charge-discharge cycles in laboratory tests, maintaining 90% of its initial capacity after 1,000 cycles. The company is planning to construct a production facility for this cathode material and a pilot line for cell manufacturing, with construction expected to start in 2027. The company has not confirmed whether these results have been verified by an independent third party. "Exceeding the 1,500 cycle threshold while maintaining stable capacity and high coulombic efficiency, and retaining 90% of the cell's initial capacity after 1,000 cycles, represents a major result for our team," said Achal Agrawal, CEO of Macsen Group, who is also involved in the research. "This result comes from cycling a real sodium-ion cell in our battery research laboratory. It confirms the potential of our cell technology for long-term energy storage and demonstrates the ability of our Prussian white-based cathode material to provide durable performance across repeated cycles." **Prussian white** is a sodium-rich compound based on iron, commonly used as a cathode material in sodium-ion batteries. Its open crystalline structure allows for the reversible insertion and extraction of sodium ions during the charge and discharge phases. This material offers potential advantages, such as low production costs, the availability of raw materials, fast charging, and a long cycle life. Its high sodium content can also contribute to a higher initial capacity and energy density. "The synthesis of Prussian white may seem simple, but producing a material that approaches its theoretical capacity while maintaining excellent electrochemical performance over repeated charge-discharge cycles is a much more complex task," Agrawal noted. "We consider it a high-tech battery material; our work covers chemical synthesis, material characterization, as well as cell fabrication and testing." According to its website, **Macsen Energy**'s main approach to cell development combines a **Prussian white** cathode with a hard carbon anode. The company is also exploring alternative anode materials and anode-free configurations. It states that the cathode material operates within a voltage range of 2.2 V to 4.0 V, with an average discharge voltage between 2.5 V and 3.6 V. The company claims that its production process overcomes major manufacturing challenges, such as sensitivity to humidity and exposure to oxygen, while enabling the creation of a highly crystalline, fully sodiated, low-moisture material with improved air stability. It reports a specific capacity exceeding 150 mAh/g, a coulombic efficiency of approximately 99.9%, and a capacity retention of at least 90% after 1,000 charge-discharge cycles. These performances are attributed to the material's open crystalline structure, which allows for rapid and reversible movement of sodium ions with minimal structural changes. **Macsen Energy** has reserved a 10,000 square meter site for a facility aimed at producing **Prussian blue-type** cathode materials at a capacity of around a ton. Construction is expected to begin in 2027, although the location has not been disclosed. The site will also host a sodium-ion battery pilot line to refine **Prussian white**-based cells, including electrode preparation, cell assembly, validation, and performance testing under conditions similar to commercial production. The company has also initiated research and development activities on hard carbon synthesis to advance its complete cell technology.