To improve lithium-ion batteries, scientists have found inspiration from silly putty, packing peanuts, and algae. Now a team at Purdue University is using a material that is all too common in nature. “I started looking into pollens when my mom told me she had developed pollen allergy symptoms about two years ago,” said researcher Jialiang Tang. “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.”
Tang, a doctoral student at Purdue, worked with a team of engineers to test whether pollen could actually be a viable option for replacing the graphite that is used in most lithium-ion batteries. The researchers processed pollen under high temperatures in a chamber containing argon gas using a procedure called pyrolysis, which yielded pure carbon in the original shape of the pollen particles. Additional processing at lower temperatures in the presence of oxygen formed pores in the carbon structures to increase their energy-storage capacity.
The researchers then tested the pollen-based anode and found it to be promising, although its storage capacity turned out to be lower than graphite and it took ten hours to charge completely. “The bottom line here is we want to learn something from nature that could be useful in creating better batteries with renewable feedstock,” said Vilas Pol, an associate professor at Purdue’s School of Chemical Engineering and the School of Materials Engineering. The research is described in a paper in Nature’s Scientific Reports. The team’s future research will include studying the pollen-based material in a full-cell battery with a commercial cathode. “We are just introducing the fascinating concept here,” Pol said. “Further work is needed to determine how practical it might be.”