A new production method allows much more efficient production of hydrogen. At the same time, a new charging method makes it possible to recharge electric car batteries to a range of 320 to 480 kilometres in just 10 minutes.
Hydrogen production uses electrolysis, a process in which an electric current is used to separate hydrogen and oxygen. If the electricity required for this is generated sustainably from, for example, a wind turbine or solar panel, the process can be carried out without any CO2 emissions.
Almost twice as much hydrogen per millivolt
Researchers from several British, Portuguese, German and Hungarian universities have developed a new production method that allows hydrogen to be produced more efficiently. By passing a pulsating electric current through a layered catalyst, the researchers have managed to almost double the amount of hydrogen produced per millivolt of electricity.
The method is based on research showing that electrodes coated with a molybdenum telluride catalyst produce more hydrogen gas during electrolysis if an electric current with a specific pattern is passed through the catalyst. By optimising this pattern, the amount of energy required to create hydrogen can be reduced by almost 50%.
Storing renewable energy
Among the opportunities the researchers see in their discovery is to store and preserve sustainably generated energy. "Experts predict that we will soon reach the point where we produce more renewable electricity than we need. Right now, however, excess generated energy must be used as soon as it is produced to prevent it from being lost. It is therefore vital that we develop a robust set of methods to store energy for later use," says professor Alexey Ganin from the University of Glasgow's School of Chemistry.
"Batteries are one way of doing this, but hydrogen is a promising alternative. Our research provides important new insights to make hydrogen production using electrolysis more effective and cheaper, and we look forward to exploring this promising development further."
More information can be found in the paper published by the researchers in Nature Communications.
Recharge battery in ten minutes
The new battery charging method has been developed by US Penn State University. If traditional lithium-ion batteries are rapidly charged at temperatures below 10 degrees Celsius, their quality deteriorates. This is because at this temperature, the lithium ion is not delivered to the carbon anodes evenly, but with spikes. This process is also known as lithium plating. Lithium plating not only reduces the capacity of battery cells, but can also lead to peak voltage and unsafe batteries.
If batteries are charged above 10 degrees Celsius, this process does not occur. A previously designed battery was therefore designed by the researchers so that at a temperature of 10 degrees Celsius, it could be fully charged in 15 minutes. The charging speed can be increased by charging at a higher temperature, but this higher temperature can shorten the life of the battery.
Fast charging without damage
To optimise the charging of lithium-ion batteries, Wang and his team therefore conducted further research on the impact of heat on batteries. Their research shows that if specially prepared lithium-ion batteries are heated to a temperature of 60 degrees Celsius for a period of up to 10 minutes and then cooled in a short period of time, lithium plating does not occur and the battery is not damaged. By charging at 60 degrees Celsius, however, the battery can be charged faster.
The battery that Wang and his team have been experimenting with heats itself. The battery has a thin layer of sheet copper, with one side connected to the negative pole and the other placed outside the battery cell to create a third pole. A temperature sensor connected to a switch causes electrons to flow through the sheet copper and close the circuit. Thanks to heat resistance, this foil heats up in a short time, after which the foil heats the inside of the battery.
Reach up to 480 kilometres in ten minutes
"We have demonstrated being able to charge an electric vehicle in ten minutes to a range of 320 to 480 kilometres," explains Penn State University professor Chao-Yang Wang. Wang is William E. Diefenderfer Chair in mechanical engineering, professor of chemical engineering, professor of materials science and director of the Electrochemical Engine Center at Penn State University. "And we do this while maintaining 2,500 charge cycles, which is equivalent to a distance of over 800,000 kilometres.
Wang calls the ability to fully recharge a battery in 10 minutes essential for the embrace of electric vehicles, as it addresses concerns about their range.
Author: Wouter Hoeffnagel
