Several sources report on Samsung’s announcement that they have developed a new technology that enables them to coat silicon battery cathodes with high crystal graphene, virtually doubling the capacity of lithium-ion batteries. Of course, Samsung relates this immediately to their popular smartphones and tablets, but the significance of this is not lost on electric vehicle designers. Doubling the range of EVs “without adding a single pound of weight” would be a true game changer. But don’t get excited too quickly. Silicon electrodes have been a major research effort for people like Dr. Yi Cui, who spoke at this year’s Electric Aircraft Symposium. Issue surrounding their successful use have included silicon’s expansion when being charged and contraction when being discharged. This errant flexibility causes eventual disintegration of the electrodes and shuts down the battery. Attempts to use silicon nanowires still have led to embrittlement. Kompulsa.com reports Cho Jin-young from BusinessKorea explaining, “Currently, the development of high-capacity battery materials has been mostly done …
Making Graphene and Carbon Fibers Even Lighter and Stronger
While scientists at Columbia University have used chemical vapor deposition (CVD) to create large sheets of stronger-than-average graphene, a research team at Massachusetts Institute of Technology (MIT) has found ways to weave stronger carbon nanotubes. James Hone and Jeffrey Kysar, professors of mechanical engineering at Columbia University, learned that the enormous strength of graphene is usually achieved in only small patches. The “grain boundaries” for larger sheets were often far weaker than the theoretical strengths of which the material is capable. That strength is phenomenal. Hone explains, “It would take an elephant, balanced on a pencil, to break through a sheet of graphene the thickness of Saran Wrap.” Results of their study were published in the journal Science. The paper’s lead author, Gwan-Hyoung Lee, a postdoctoral fellow in the Hone lab, says, “Our findings clearly correct the mistaken consensus that grain boundaries of graphene are weak. This is great news because graphene offers such a plethora of opportunities both for …