One problem with today’s lithium-ion batteries used in electric vehicles and plug-in hybrids is that much of the battery’s volume is taken up by inactive materials, such as packaging, conductive foils, and glues, which make the batteries bulky and costly. Only about 25 percent of the battery’s volume is comprised of materials that store energy. A battery startup, 24M, has developed a new kind of battery meant to make electric vehicles go farther and cost less. 24M’s battery aims to greatly reduce the inactive material in the battery, and estimates the result would be a battery able to achieve almost twice the energy density of today’s vehicle battery packs. Higher energy density means the battery would be smaller and cheaper, and electric and hybrid cars would be less expensive. The new battery has sludge-like materials stored in tanks – one for positive electrode material and another for negative electrodes – unlike conventional batteries that have solid film electrodes. The researchers added nanoscale carbon particles into the sludge, allowing the electric charge to be pulled out of the substance. Challenges remain before the battery can be commercialized, but, says 24M CEO Throop Wilder, “We’re making good progress on the technology. The acceptance of the paper [in the journal Advanced Energy Materials] is strong validation of the fundamental principles that drive our development.”
http://www.technologyreview.com/energy/37632/page1/