Stanford works on a new liquid battery to help struggling RE.

Stanford chemists are aiming to stabilize renewable energy on the electrical grid by developing a liquid battery for long-term storage. This liquid organic hydrogen carriers (LOHC) battery is designed to store energy and smooth out the fluctuations of renewable power production without negative side effects. The team's work was published in the Journal of the American Chemical Society.

“We are developing a new strategy for selectively converting and long-term storing of electrical energy in liquid fuels,” said Robert Waymouth, a Stanford chemistry professor, in a university news release. “We also discovered a novel, selective catalytic system for storing electrical energy in a liquid fuel without generating gaseous hydrogen.”

Addressing Renewable Energy Variability

Our current electrical grid consumes energy as it is generated, which works well with consistent energy sources. However, renewable energy sources like solar and wind produce energy unevenly. Therefore, we need efficient ways to store excess energy produced during high-energy-production periods for use during low-energy-production times.

The Potential of LOHCs

The Stanford team believes LOHCs can act as “liquid batteries,” storing energy and releasing it as fuel or electricity when needed. They propose converting the excess energy into stable ingredients such as acetone and isopropanol (rubbing alcohol), which can be stored as high-density liquid forms of hydrogen.

“When you have excess energy and there’s no demand on the grid, you store it as isopropanol,” Waymouth explained. “When you need the energy, you can convert it back into electricity.”

Overcoming Efficiency Challenges

Current methods to produce isopropanol with electricity are inefficient. “We need a way to make isopropanol directly from protons and electrons without producing hydrogen gas,” Waymouth said.

This study introduces a solution using acetone, iridium, and a surprising additive: cobaltocene, a cobalt-based compound. “The researchers found that cobaltocene is unusually efficient when used as a co-catalyst in this reaction,” the news release stated. “It directly delivers protons and electrons to the iridium catalyst rather than liberating hydrogen gas, as previously expected.”

A Non-Toxic Energy Storage Solution

The team’s approach uses accessible, non-toxic ingredients for long-term energy storage. They plan to explore various catalysts, such as iron, to make the liquid battery system more affordable and scalable.

“This is basic fundamental science,” Waymouth said, “but we think we have a new strategy for more selectively storing electrical energy in liquid fuels.”