derekmead writes "Batteries rule everything around us, which makes breakthroughs a big deal. A research team at Rice says they have produced a nice jump: by using a crushed silicon anode in a lithium-ion battery, they claim to have nearly tripled the energy density of current li-ion designs. Engineer Sibani Lisa Biswal and research scientist Madhuri Thakur reported in Nature's Scientific Reports (it has yet to be published online) that by taking porous silicon and crushing it, they were able to dramatically decrease the volume required for anode material. Silicon has long been looked at as an anode material because it holds up to ten times more lithium ions than graphite, which is most commonly used commercially. But it's previously been difficult to create a silicon anode with enough surface area to cycle reliably. Silicon also expands when it's lithiated, making it harder to produce a dense anode material. After previously testing a porous silicon 'sponge,' the duo decided to try crushing the sponges to make them more compact. The result is a new battery design that holds a charge of 1,000 milliamp hours per gram through 600 tested charge cycles of two hours charging, two hours discharging. According to the team, current graphite anodes can only handle 350 mAh/g."