Bending salty ice could be a power source of the future - Energy & Green Tech - Hi Tech & Innovation

Mechanism of streaming flexoelectricity. Credit: (2025). DOI: 10.1038/s41563-025-02332-5. https://www.nature.com/articles/s41563-025-02332-5

For most of us, ice is a hazard. Whether it's making roads dangerously slippery or covering our sidewalks, this frozen form of water is something we often try to avoid. Yet, a discovery suggests that bending ice and adding salt to it could transform this winter nuisance into a new source of sustainable power.

Xin Wen and his team at Xi'an Jiatong University in China found that ice is flexoelectric, a phenomenon where a material generates electricity when it is bent. Although it was previously known that glaciers colliding or stressed ice sheets could create electricity, no one had figured out how to make the effect powerful enough for practical use.

Bending salty ice

In a study published in Nature Materials, the scientists describe how they created different batches of ice by freezing water with various amounts of ordinary salt (NaCl), from no salt to a very high concentration. They made samples in specific shapes, including cones, beams and flat slabs.

To measure their electrical output, the team put the frozen samples through a three-point bending test. This involved placing the ice on two supports and then applying a force from above, which caused the ice to bend. The results were remarkable: bending the salty samples made the ice up to 1,000 times more efficient at generating an electric charge than pure ice.

The research team then used microscopy and Raman spectroscopy to peer inside the frozen samples to see why adding salt was so effective. They discovered that it prevents the ice from freezing completely and creates tiny channels filled with the salty water. When the ice is bent, the pressure forces the liquid to flow through these channels. As water carries an electric charge when it moves, the flow creates a streaming current.

With ice covering around 10% of Earth's surface, the potential for generating electricity from this untapped source is huge.

"The high flexoelectricity of saline ice brings the vision of harnessing ice power one step closer to reality, and may also be relevant to the electrical activity of ice-covered terrestrial regions and icy ocean worlds such as Europa or Enceladus," wrote the researchers.

While promising, the technology is not without its challenges. Saline ice devices suffer from mechanical fatigue, losing up to 80% of their power-generating ability after numerous cycles of being bent back and forth. And even though the flexoelectric effect is many times stronger than in pure ice, the power output is still lower than that of commercial piezoelectrics because a significant portion of the electrical energy is wasted as heat. Nonetheless, if we are able to harness ice power, it could spark a new era of clean, sustainable energy. 

by Paul Arnold, Phys.org

edited by Gaby Clark, reviewed by Robert Egan 

Source: Bending salty ice could be a power source of the future