Researchers at the University of California, Riverside’s Bourns College of Engineering have developed a technique to create high performance lithium-ion batteries utilizing sulfur and silicon electrodes. The batteries will extend the range of electric vehicles and plug-in hybrid electric vehicles, while also providing more power with fewer charges to personal electronic devices such as cell phones and laptops.
The findings were published in an article titled, “Advanced Sulfur-Silicon Full Cell Architecture for Lithium Ion Batteries,” in the journal, Nature Scientific Reports. Cengiz Ozkan, professor of mechanical engineering, and Mihri Ozkan, professor of electrical and computer engineering, led the project.
“The demand for renewable energy has pushed the need for higher-performance batteries,” Cengiz Ozkan said.
As a result, researchers have turned toward new lithium-ion battery systems with higher capacities. Silicon is the most promising anode candidate, storing up to 10 times the capacity of graphite anodes. Sulfur is the most promising cathode candidate, with up to six times the capacity of cathodes. Sulfur-silicon lithium-ion full cells, utilizing silicon as the anode and sulfur as the cathode, are one of the highest-capacity potential systems that have been studied. However, the practice of building sulfur-silicon full cells is challenged by the limitations in materials and equipment.
“This has limited the amount and extent of research done on the sulfur-silicon full cells, which is why the team proposed and tested a new approach to incorporate lithium into a sulfur-silicon full cell,” Mihri Ozkan said.
To create the sulfur-silicon full cells (SSFC) with the new architecture, the team added a piece of lithium foil into the traditional full-cell architecture, while enabling contact between the lithium foil and the current collector. This allows the lithium foil to integrate into the system while the battery is being cycled, allowing for control over the amount of lithium inserted.
“In order to bring together sulfur and silicon electrodes, it is necessary to explore alternative methods of introducing lithium to the system,” said Jeffrey Bell, a UC Riverside graduate student who worked on the project. “We believe that we’ve provided one such solution that will further advance research on sulfur-silicon full cells.”
“In half cells, pure lithium is used as the anode, which raises safety concerns such as dendrite formation and lithium corrosion. In a full cell, silicon is used as the anode instead, which mitigates the safety issues created by pure lithium anodes, while maintaining the desired high-battery capacity,” added graduate student Rachel Ye.
This research is the latest in a series of projects led by the Ozkans to create lithium-ion battery materials and architectures from abundant resources and environmentally friendly materials. Previous research has focused on developing and testing anodes from glass bottles, portabella mushrooms, sand, and diatomaceous (fossil-rich) earth.
Source: UC Riverside