Remember Silly Putty? That strange, tacky material that can pick up newsprint? Most people play with it when they're kids, rolling it into balls or making wee sculptures, but did you know that the material was discovered by accident? Silly Putty was first synthesized by James Wright, a scientist working for General Electric in 1943. In an effort to create synthetic rubber, Wright mixed boric acid and silicone oil, creating a sort of goo that was not a suitable substitute for rubber, but was a lot of fun to play with. Recently, researchers at the University of California Riverside have been playing with Silly Putty, but not to lift prints from the funny pages. They have been working on figuring out how to use what is essentially Silly Putty to create better lithium-ion batteries that can last up to three times longer than the industry standard.
Reinventing the battery
Lithium-ion batteries are used everywhere. From computers to cell phones, even electric cars are benefiting from improvements to this ubiquitous technology. Most lithium-ion batteries use carbon-based anodes, which are cheap and relatively efficient. However, as the UC-Riverside scientists discovered, there are much better alternatives to carbon.
The magic chemical in this case is silicon dioxide, a component of Silly Putty that can be rolled into nanotube anodes. The researchers chose to focus on silicon dioxide because it is abundant, cheap to produce, environmentally friendly and non-toxic. While some work had previously been done to determine the effectiveness of silicon dioxide, engineers had so far been stymied in their efforts to synthesize the material into highly uniform, exotic nanostructures with high energy density and long cycle life.
But the UC-Riverside team was able to beat the odds and create durable silicon dioxide nanotubes, which are extremely stable when used as anodes. In testing, the researchers discovered that the Silly Putty-based anodes could be cycled 100 times without any loss in energy storage capability. The team believes that the anode could be cycled hundreds more times without any diminishing returns.
Future research will focus on developing methods to scale up production as part of an effort to make silicon dioxide nanotubes a commercially viable product. Ramping up production and developing new means of manufacturing always requires a degree of materials testing, which must be completed before commercialization is possible.