A paperlike battery electrode developed by a Kansas State University engineer may improve tools for space exploration or unmanned aerial vehicles.
Gurpreet Singh, associate professor of mechanical and nuclear engineering, and his research team created the battery electrode using silicon oxycarbide-glass and graphene.
The battery electrode has all the right characteristics. It is more than 10 percent lighter than other battery electrodes. It has close to 100 percent cycling efficiency for more than 1000 charge discharge cycles. It is made of low-cost materials that are byproducts of the silicone industry. And it functions at temperatures as low as minus 15 degrees C, which gives it numerous aerial and space applications.
The research appears in Nature Communications article "Silicon oxycarbide glass-graphene composite paper electrode for long-cycle lithium-ion batteries."
Singh's research team has been exploring new material combinations for batteries and electrode design. It has been difficult to incorporate graphene and silicon into practical batteries because of challenges that arise at high mass loadings -- such as low capacity per volume, poor cycling efficiency and chemical-mechanical instability.
Singh's team has addressed these challenges by manufacturing a self-supporting and ready-to-go electrode that consists of a glassy ceramic called silicon oxycarbide sandwiched between large platelets of chemically modified graphene, or CMG. The electrode has a high capacity of approximately 600 miliampere-hours per gram -- 400 miliampere-hours per cubic centimeter -- that is derived from silicon oxycarbide. The paperlike design is made of 20 percent chemically modified graphene platelets.
"The paperlike design is markedly different from the electrodes used in present day batteries because it eliminates the metal foil support and polymeric glue -- both of which do not contribute toward capacity of the battery," Singh said.
The design that Singh's team developed saved approximately 10 percent in total weight of the cell. The result is a lightweight electrode capable of storing lithium-ion and electrons with near 100 percent cycling efficiency for more than 1000 charge discharge cycles. The most important aspect is that the material is able to demonstrate such performance at practical levels, Singh said.
The paper electrode cells also are able to deliver a capacity of 200 miliampere-hour per gram even when kept at minus 15 degrees C for about a month, which is quite remarkable considering that most batteries fail to perform at such low temperatures, Singh said.
"This suggests that rechargeable batteries from silicon-glass and graphene electrodes may also be suitable for unmanned aerial vehicles flying at high altitudes, or maybe even space applications," Singh said.
The silicon oxycarbide material itself is quite special, Singh said. It is prepared by heating a liquid resin to the point where it decomposes and transforms into sharp glasslike particles. The silicon, carbon and oxygen atoms get rearranged into random 3-D structure and any excess carbon precipitates out into cellular regions. Such an open 3-D structure creates large sites for reversible lithium storage and smooth channels for lithium-ion transportation. This structure and mechanism of lithium storage is different than crystalline silicon electrodes. Silicon oxycarbide electrodes are expected to be low cost because the raw material -- liquid resin -- is a byproduct of the silicone industry.
Moving forward, Singh and his team want to address practical challenges. Singh's goal is to produce this electrode material at even larger dimensions. For example, present-day pencil-cell batteries use graphite-coated copper foil electrodes that are more than one foot in length. The team also would like to perform mechanical bending tests to see how they affect performance parameters.
"Ultimately, we would like to work with industry to explore production of lithium-ion battery full-cells," Singh said. "Silicon oxycarbide can also be prepared by 3-D printing, which is another area of interest to us."
The research received funding from the National Science Foundation, including Singh's $500,000 CAREER award.
Other Kansas State University researchers involved include Lamuel David, 2015 doctoral graduate in mechanical engineering, Oak Ridge, Tennessee; Romil Bhandavat, 2013 doctoral graduate in mechanical engineering, Hillsboro, Oregon; and Uriel Barrera, 2015 bachelors graduate in mechanical engineering, Olathe.
Gurpreet Singh | EurekAlert!
Scientists create biodegradable, paper-based biobatteries
08.08.2018 | Binghamton University
Ricocheting radio waves monitor the tiniest movements in a room
07.08.2018 | Duke University
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
15.08.2018 | Physics and Astronomy
15.08.2018 | Earth Sciences
15.08.2018 | Physics and Astronomy