Pollen could be used as anodes in lithium-ion batteries
When life gives you pollen, make pollen-based batteries?
Batteries aren't usually my beat, but plants and their powers are so I'm intrigued by this question: Could that which makes countless humans suffer immeasurable sniffing and itching and sneezing - pollen - be put to good use? A new study from Purdue University suggests that perhaps it could after a team of researchers tested its potential use in lithium-ion batteries.
"Our findings have demonstrated that renewable pollens could produce carbon architectures for anode applications in energy storage devices," said Vilas Pol, an associate professor in the School of Chemical Engineering and the School of Materials Engineering at Purdue University.
And before anyone starts griping about how impractical this might be, the researchers admit that this is just the beginning of their work: "We are just introducing the fascinating concept here," Pol said. "Further work is needed to determine how practical it might be."
But nonetheless, it's indeed fascinating! The team tried carbons derived from both bee pollen (pictured above in a colorized, scanning electron microscope image) and cattail as anodes.
"Both are abundantly available," said Pol, who performed the research with doctoral student Jialiang Tang. "The bottom line here is we want to learn something from nature that could be useful in creating better batteries with renewable feedstock."
It was Tang's mom who inadvertently inspired the project.
"I started looking into pollens when my mom told me she had developed pollen allergy symptoms about two years ago," Tang said. "I was fascinated by the beauty and diversity of pollen microstructures. But the idea of using them as battery anodes did not really kick in until I started working on battery research and learned more about carbonization of biomass."
The team used high temperatures in a chamber containing argon gas to process the pollen, ending up with pure carbon that retained the original shape of the pollen. The carbon was then activated to create a more porous structure to ramp up energy-storage capacity.
They tested the pollen-based anodes at various rates and in a range of temperatures to mimic different climates – they discovered that charging for 10 hours created a full charge; a charge of one hour resulted in more than a half charge. "The theoretical capacity of graphite is 372 milliamp hours per gram, and we achieved 200 milliamp hours after one hour of charging," Pol said. Also noting that the cattail pollens resulted in better performance than bee pollen.
Where this will lead nobody knows, but exploring renewable resources is always a good direction – especially if such a bane could be turned into a boon. The researchers say that next they will study the application in a full-cell battery with a commercial cathode.