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RWTH Aachen is expanding its M5Bat research battery storage system, featuring a sodium-ion storage unit with a capacity of 1.5 megawatt-hours (MWh), operational in real market conditions with Uniper SE. This project aims to evaluate alternatives to lithium-ion technology.

The expansion includes two battery units, including the largest sodium-ion battery storage in operation in Germany, with a performance of 750 kilovolt-amperes (kVA). Additionally, a battery cabinet utilizing semi-solid-state LFP cells, featuring 125 kVA and 250 kWh capacity, will be integrated.

The technology supports safety and compatibility with existing production lines. Both systems were procured from MegaLion Europe GmbH, a subsidiary of ENPERIUM GmbH, with commissioning planned for spring 2026. Uniper employs M5Bat in a multi-market strategy, participating in both wholesale electricity and balancing power markets to analyze the performance of new cell chemistries.