Sodium-ion battery technology, developed as an alternative to lithium-ion batteries, has achieved significant success in safety tests. Developed by US-based UNIGRID, sodium chromium oxide cells successfully completed the rigorous safety tests in Hyundai Motor Group’s technical evaluation program. The tests confirmed that the cells do not cause fires or thermal radiation. These results are considered a critical step for power storage systems requiring high safety standards.

Safety and Performance Tests

The collaboration between UNIGRID and Hyundai Motor Group began in 2025 under the ZER01NE Accelerator program. The program’s main focus was on the use of fireproof battery technologies with high safety standards in power storage systems.

Thermal spread in battery systems means that excessive heat starting in one cell can spread to other cells, turning into a large fire. This poses a significant safety risk, especially in power storage facilities where thousands of cells are used together.

UNIGRID’s cells also successfully passed cycle life tests. Capacity loss remained low throughout all charge and discharge cycles performed at 100% discharge depth.

In temperature tests, it was confirmed that the cells operated without problems in a wide range between -20°C and 60°C. The ability of batteries to be used in both freezing and high temperatures is a technical necessity for stationary power storage systems.

Sodium-Ion and Lithium-Ion Comparison

UNIGRID’s sodium chromium oxide chemistry differs fundamentally from lithium-ion cells, which are common in everything from phones to electric cars. In lithium-ion batteries, ions move between the positive and negative electrodes, while in sodium-ion cells, sodium ions perform this function.

Lithium-ion technology has long held a dominant position in consumer electronics and electric vehicles due to its higher power density. The ability to store more power in the same volume or weight provides a significant advantage for portable devices such as phones and cars.

One of the biggest advantages of sodium is its abundance and accessibility as a raw material. Sodium is much more abundant in nature than lithium and can offer a more economical option in the long run in terms of costs.

However, at the current production scale, the total cost of a completed sodium-ion battery is not currently lower than that of lithium-ion batteries. Power density also remains one of the main technical drawbacks of sodium-ion technology.

For this reason, current sodium-ion cells are more suitable for use in grid-scale power storage systems than in phones where weight and volume are critical. In fixed storage, the space occupied by the battery is of less importance compared to portable devices.

The commercialization of sodium-ion technology is not limited to UNIGRID alone. CATL, one of the world’s largest battery manufacturers, is also taking sodium-ion production to an industrial scale and starting deliveries in the power storage sector.

CATL aims to reach a total of 1 GWh of sodium-ion shipments in power storage systems by the end of 2026. In addition, the company, which developed a mass-produced passenger car with sodium-ion batteries with CHANGAN, also signed a major supply agreement with HyperStrong.

Another area in battery research focuses on designs where the anode material is completely eliminated. Power density, cycle life, and safety criteria will determine the future of next-generation battery chemistries.

The increasing electrical demand of artificial intelligence data centers is accelerating research into new battery chemistries. Do you think sodium-ion batteries could completely replace lithium-ion technology in the future?

The sodium-ion battery technology developed by UNIGRID successfully completed Hyundai Motor Group’s safety tests without any fire risk.