One Step Closer to Solving the Storage Problems of Renewable EnergyMay 26, 2020 by Luke James
Researchers at Martin Luther University Halle-Wittenberg (MLU) have reportedly found a way to treat cheap electrode materials and improve their properties during electrolysis.
Although hydrogen is thought by many to be the solution to renewable energy storage, the green production of it is hindered by the poor conversion of the supplied electricity. "One reason is that the dynamic load of the fluctuating electricity from the sun and wind quickly pushes the materials to their limits. Cheap catalyst materials rapidly become less active," says Professor Michael Bron from the Institute of Chemistry at MLU.
A New and Cheap Alternative to Expensive Catalysts
According to research published in the journal ACS Catalysis, Bron’s research team has discovered a method that increases the stability and activity of inexpensive nickel hydroxide electrodes—a cheap alternative to expensive catalysts like platinum.
Current scientific literature recommends heating the hydroxide up to 300 degrees Celsius to improve the material’s stability and partially convert it to nickel oxide. "We wanted to see this with our own eyes and gradually heated the material in the laboratory to 1,000 °C," says Bron, a bold move because higher temperatures are said to completely destroy the hydroxide.
A vial containing nickel hydroxide, the compound used by researchers to replace expensive catalysts for the electrolysis process.
Generating More Electricity at High Temperatures
As the researchers increased the temperature, they observed the expected changes to the individual particles under an electron microscope—they were converted to nickel oxide and grew together to form larger structures.
However, subsequent electrochemical testing showed a constantly high activity level of the particles. This is something that should no longer have been seen in the electrolysis. "We therefore attribute the high level of activity of our much larger particles to an effect that, surprisingly, only occurs at high temperatures: the formation of active oxide defects on the particles," said Bron.
Using X-ray crystallography, the team concluded that when heated to 900 degrees Celsius, the particles exhibit the highest activity level and the active oxide defects undergo a transitioning process that completes at 1000 degrees Celsius.
Even after 6,000 cycles, the heated particles still generated 50% more electricity than untreated particles.