Researchers at Stanford University have made progress on an emerging technology that uses liquid organic hydrogen carriers (LOHCs) to essentially create a ‘liquid battery’ for storing renewable energy from wind and solar power.

The team, led by chemistry professor Robert Waymouth, has developed a new catalytic system that can efficiently convert electricity into the liquid fuel isopropanol, or rubbing alcohol, without generating gaseous hydrogen as a byproduct.

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

Storing energy from renewable sources like solar and wind has been a major challenge, as production fluctuates based on sunlight and wind conditions. According to the California Energy Commission, the state alone is projected to need over 50,000 MW of battery storage capacity by 2045 to handle renewable energy generation.

While lithium-ion batteries are commonly used for storage, LOHCs like isopropanol could provide another solution acting as a liquid battery. Excess electricity could be stored in liquid isopropanol, which can then be used in a fuel cell to generate electricity when needed.

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

The key advance was using the inexpensive additive cobaltocene to enable an iridium catalyst to directly produce isopropanol from acetone using electrons and protons rather than first making hydrogen gas.

While still in the initial stages of research for now, the Stanford team believes liquid organic hydrogen storage could become an important energy storage technology complementing batteries. The work was funded by the National Science Foundation.

Recently, researchers from the Korea Advanced Institute of Science and Technology (KAIST) and Lawrence Berkeley National Laboratory developed a high-energy, high-power hybrid sodium-ion battery through an innovative hybrid energy storage system that integrates anode and cathode materials.

Earlier, a team of researchers from the University of Adelaide in Australia and the University of Maryland in the U.S. claimed to have developed a new type of aqueous sodium-ion battery that they claim can last for over 13,000 charge cycles.