A Sandia-led team has developed a way to make a magnetic material that could lead to lighter and smaller, cheaper and better-performing high-frequency transformers, needed for more flexible energy storage systems and widespread adoption of renewable energy. The work is part of a larger, integrated portfolio of projects funded by Department of Energy's (DOE) Energy Storage Program in the Office of Electricity Delivery and Energy Reliability.

Transportable energy storage and power conversion systems, which can fit inside a single semi-trailer, could make it cost effective to rapidly install solar, wind and geothermal energy systems in even the most remote locations.

"Such modular systems could be deployed quickly to multiple sites with much less assembly and validation time," said Sandia researcher Todd Monson of Nanoscale Sciences Department, who led the team with Stan Atcitty of Sandia's Energy Storage Technology & Systems Department.

Sandia manufactures iron nitride (γ'-Fe4N) powders by ball-milling iron powders in liquid nitrogen and then ammonia. The iron nitride powders are then consolidated through a low-temperature field-assisted sintering technique (FAST) that forms a solid material from loose powders through the application of heat and sometimes pressure.

The FAST manufacturing method enables the creation of transformer cores from raw starting materials in minutes, without decomposing the required iron nitrides, as could happen at the higher temperatures used in conventional sintering. Previously, the γ' phase of iron nitride has only been synthesized in either thin-film form in high-vacuum environments or as inclusions in other materials, and never integrated into an actual device.

Monson said using this method could make transformers up to 10 times smaller than they are currently.