HOUSTON (Nov. 1, 2012) Researchers at Rice University have refined silicon-based lithium-ion technology by literally crushing their previous work to make a high-capacity, long-lived and low-cost anode material with serious commercial potential for rechargeable lithium batteries.
The team led by Rice engineer Sibani Lisa Biswal and research scientist Madhuri Thakur reported in Nature's open access journal Scientific Reports on the creation of a silicon-based anode, the negative electrode of a battery, that easily achieves 600 charge-discharge cycles at 1,000 milliamp hours per gram (mAh/g). This is a significant improvement over the 350 mAh/g capacity of current graphite anodes.
That puts it squarely in the realm of next-generation battery technology competing to lower the cost and extend the range of electric vehicles.
The new work by Rice through the long-running Lockheed Martin Advanced Nanotechnology Center of Excellence at Rice (LANCER) is the next and biggest logical step since the partners began investigating batteries four years ago.
"We previously reported on making porous silicon films," said Biswal, an assistant professor of chemical and biomolecular engineering. "We have been looking to move away from the film geometry to something that can be easily transferred into the current battery manufacturing process. Madhuri crushed the porous silicon film to form porous silicon particulates, a powder that can be easily adopted by battery manufacturers."
Silicon can hold 10 times more lithium ions than the graphite commonly used in anodes today. But there's a problem: Silicon more than triples its volume when completely lithiated. When repeated, this swelling and shrinking causes silicon to quickly break down.
Many researchers have been working on strategies to make silicon more suitable for battery use. Scientists at Rice and elsewhere have created nanostructured silicon with a high
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