Process for converting portabella mushrooms into anodes for lithium-ion batteries. Image: UC Riverside.
Process for converting portabella mushrooms into anodes for lithium-ion batteries. Image: UC Riverside.

Can portabella mushrooms stop cell phone batteries from degrading over time? Researchers at the University of California, Riverside’s Bourns College of Engineering think so.

They have created a new type of anode for lithium-ion batteries from portabella mushrooms, which are inexpensive, environmentally friendly and easy to produce. Synthetic graphite is the current industry standard for rechargeable lithium-ion battery anodes, but it is costly to manufacture because it requires tedious purification and preparation processes that are also harmful to the environment.

With the demand for rechargeable batteries for use in electric vehicles and electronics predicted to increase, a cheaper and sustainable source to replace graphite is needed. Using biomass as a replacement for graphite has garnered attention recently because of its high carbon content, low cost and environmental friendliness.

UC Riverside engineers were drawn to using mushrooms as a form of biomass because past research has established that the mushrooms are highly porous. This porosity is important for batteries because it creates more space for the storage and transfer of energy, a critical component to improving battery performance.

In addition, the high potassium salt concentration in mushrooms generates increased electrolyte-active material over time by activating more pores, gradually increasing the battery’s capacity. In a conventional anode, by contrast, lithium can only fully access the anode material during the first few cycles, with capacity fading from electrode damage from that point on.

"With battery materials like this, future cell phones may see an increase in run time after many uses, rather than a decrease, due to apparent activation of blind pores within the carbon architectures as the cell charges and discharges over time," said Brennan Campbell, a graduate student in the Materials Science and Engineering program at UC Riverside.

The research findings are outlined in a paper in Scientific Reports. It was authored by Cengiz Ozkan and Mihri Ozkan, both professors in the Bourns College of Engineering, and three of their current or former graduate students: Campbell, Robert Ionescu and Zachary Favors.

Nanocarbon architectures derived from biological materials such as mushrooms can be considered a green and sustainable alternative to graphite-based anodes, said Cengiz Ozkan, a professor of mechanical engineering and materials science and engineering. The nano-ribbon-like architectures in the mushroom transform upon heat treatment into an interconnected porous network. Such porous networks possess a very large surface area for the storage of energy, a critical component to improving battery performance.

Nearly 900,000 tons of natural raw graphite would be needed to fabricate the anodes for the nearly six million electric vehicles forecast to be built by 2020. This requires that the graphite be treated with harsh chemicals, including hydrofluoric and sulfuric acids, a process that creates large quantities of hazardous waste. The European Union projects that this process will be unsustainable in the future.

This paper involving mushrooms is published just over a year after the Ozkans’ labs developed a lithium-ion battery anode based on nanosilicon derived from beach sand. The Ozkans’ team is currently working on developing pouch prototype batteries based on these nanosilicon anodes.

This story is adapted from material from the University of California, Riverside, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.