When it comes to energy storage, hydrogen is becoming more and more promising. From hydrogen fuel cell vehicles to the “artificial leaf” to the transformation of waste heat into hydrogen, researchers are looking to hydrogen for answers to the growing demand for energy storage.
At the Lawrence Livermore National Laboratory (LLNL), researchers are using hydrogen to make lithium ion batteries operate longer and have faster transport rates.
In a response to the need for higher performance batteries, the researchers began by looking for a way to achieve better capacity, voltage, and energy density. Those qualities are primarily determined by the binding between lithium ions and electrode material. Small changes to the structure and chemistry of the electrode can mean big things for the qualities of the lithium ion battery.
The research team from LLNL discovered that by subtly changing the electrode, treating it with hydrogen, lithium ion batteries could have higher capacities and faster transport levels.
“These findings provide qualitative insights in helping the design of graphene-based materials for high-power electrodes,” said Morris Wang, an LLNL materials scientist and co-author of the paper.
The demand for lithium ion batteries ranges from their potential in electric cars to the possibility of integration into large-scale energy storage.
This from LLNL:
[The Livermore team’s] experiments and multiscale calculations reveal that deliberate low-temperature treatment of defect-rich graphene with hydrogen can actually improve rate capacity. Hydrogen interacts with the defects in the graphene and opens small gaps to facilitate easier lithium penetration, which improves the transport. Additional reversible capacity is provided by enhanced lithium binding near edges, where hydrogen is most likely to bind.
“The performance improvement we’ve seen in the electrodes is a breakthrough that has real world applications,” said Jianchao Ye, who is a postdoc staff scientist at the Lab’s Materials Science Division, and the leading author of the paper.
Researchers believe that this hydrogen treatment could optimize lithium transport and reversible storage in other graphene-based anode materials.
