A Flexible Paper Li-ion Battery Yi Cui/Stanford UBatteries are the bane of all portable electronics. Bigger, heavier batteries make devices less portable, while smaller batteries lead to low performance or short battery life – or both. But while Stanford’s new lithium-ion batteries don’t necessarily cut down on footprint, they certainly cut down on mass; the new ultra-thin, rechargeable battery has been fabricated on a single sheet of paper, making it super-light, flexible, and as portable as a piece of A4.
The batteries were fabricated by materials scientists at Stanford by depositing a thin film of carbon nanotubes followed by another thin film of metal-containing lithium compound on top of the nanotube layer. These thin bilayer films are layered onto both sides of a piece of ordinary paper, which serves as both the structural support of the battery as well as the electrode separator. The lithium serves as electrodes, while the nanotube layers are current collectors.
The result is a working battery just 300 micrometers thick – that’s 300 millionths of a meter – that is flexible, super-thin, and more energy dense than other thin-bodied batteries. It’s also durable; over a 300-cycle recharge test, performance remained satisfactory. It’s also fairly easy to fabricate, making it far more commercially viable than other methods of downsizing battery technology.Related Articles
A Portable Battery That Runs on Saltwater – or Urine Vibration-Powered AA Battery Charges Up When You Shake It Swapping Graphite Anodes For Silicon Improves Li-ion Battery Capacity Five Times Tags
Technology, batteries, battery tech, carbon nanotubes, lithium ion batteries, materials science, stanfordSuch batteries aren’t ideal for every application, but they could be extremely useful in future incarnations of smart packaging, RFID sensing, and electronic paper products.
Power to the Paper: Researchers Turn Paper into Flexible Lithium-Ion Battery
Wednesday, September 22, 2010
New Process Uses Genetically Modified Yeast to Turn Carbon Dioxide Emissions Into Bricks for Construction
CO2 To Bricks Carbon dioxide is bubbled into water and then added to a solution of mineral ions. Genetically engineered yeast help turn the dissolved CO2 into solid carbonates. Patrick Gillooly/MITA method developed at MIT and modeled after seashells could provide a new way to sequester carbon dioxide — by using it to manufacture new carbonate building materials.
To reduce the amount of carbon dioxide in the atmosphere (and therefore lessen global warming), some researchers are studying ways of sequestering it in underground reservoirs. But this is expensive and difficult, and has not yet been achieved on a large scale. MIT engineer Angela Belcher is leading an effort to remove CO2 from the atmosphere and construct buildings out of it.
To make the CO2 bricks, Belcher and her graduate students modified baker's yeast to express genes that are normally found in sea creatures like abalones, which make hard carbonate shells. Carbon dioxide is bubbled into water, and then combined with mineral ions to make solid carbonate materials. Enzymes in the yeast help the mineralization process.Related Articles
Tags
Technology, Rebecca Boyle, biobricks, biomimicry, building, carbon dioxide, carbon sequestration, CO2, yeastThe process can produce two pounds of carbonate for every pound of captured CO2, according to MIT.
Other environmentally friendly bricks use fly ash, a byproduct of coal power plants, or even sand and urine. Bricks made of CO2 could solve two problems by sequestering CO2 and eliminating additional CO2 emissions from traditional brick-making.
Belcher and her graduate students are not the first to propose solidifying captured CO2, but they are the first to prove a biological process works. It involves no chemicals or temperature changes, unlike chemical solidification methods.
The researchers hope to scale up the process so it could be used in a power plant or industrial factory.
[MIT News]
