Researchers at Kansas State University have created a paper-like battery with an electrode made from silicon oxycarbide-glass and graphene, that could develop better tools for space exploration or unmanned aerial vehicles. The electrode is said to be over 10% lighter than other battery electrodes and features close to 100% cycling efficiency for more than 1,000 charge discharge cycles. It’s also made from inexpensive materials that are byproducts of the silicone industry, and it functions at temperatures as low as -15 C which can accommodate several aerial and space applications.

The research team addressed the challenges that arise when trying to incorporate graphene and silicon into practical batteries, like low capacity per volume, poor cycling efficiency and chemical-mechanical instability, 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% chemically modified graphene platelets.

The scientists explained that the paperlike design is 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. The result is a lightweight electrode capable of storing lithium-ion and electrons with near 100% 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.

Looking ahead, the team aims to address practical challenges, with a goal is to produce this electrode material at larger dimensions. The team also would like to perform mechanical bending tests to see how they affect performance parameters.



Source: 
Tags: