'Replace cells in pack, rather than the whole pack' 'What Comes After Lithium-Ion Batteries To Power Electric Cars, And When?'
http://ecomento.com/2015/12/03/researchers-claim-new-battery-pack-design-allows-for-individual-cell-replacement/ Researchers claim new battery-pack design allows for individual cell replacement December 3, 2015 [image http://cdn.ecomento.com/wp-content/uploads/2015/12/Fraunhofer-electric-car-battery-with-brains-740x425.jpg ] Electric-car battery packs are made up of many individual cells, and these cells don’t typically degrade uniformly. But when individual cells fail and compromise the integrity of a battery pack, they can’t simply be replaced. Generally, it’s the entire pack that has to go. Researchers at Germany’s Fraunhofer Institute for Manufacturing Engineering and Automation claim to have come up with an alternative battery-pack design that allows more flexibility, though. The modular design’s allowance for the replacement of individual cells could make it more cost effective over the life of a car, relates Phys.org. Fraunhofer researchers equipped battery cells with built-in micro-controllers that monitor different parameters, including temperature and state of charge. The cells can also “talk” to each other, transmitting signals through the wiring that’s already used to connect cells in conventional battery packs. They can also communicate with a car’s onboard control unit, giving an overall clearer picture of the battery’s health and how much energy it is storing, researchers say. This communication system is intended to allow a car to continue operating as long as some cells are storing the necessary amount of energy, rather than triggering a failure warning because of problems with one or a handful of cells. Any cells that have failed are decoupled from the rest of the pack. This practice could help boost range of aging battery packs by four percent, or even 10 percent for the oldest packs, researchers say. Owners could also realize significant cost savings, because individual cells will be able to be replaced, rather than the entire pack. If only a handful of cells are dead, owners could even just continue driving on the remaining cells for a period of time, researchers say. They also claim that this system will reduce costs for manufacturing battery packs, because greater variability among individual cells will be allowed. Researchers already have a prototype of the “talking” battery cell, but say the electronics will have to be miniaturized for use in an electric car. As with all research, it’s also worth noting that ideas that seem good in the laboratory don’t automatically translate into commercially-viable products. [© ecomento.com] http://www.greencarreports.com/news/1101233_what-comes-after-lithium-ion-batteries-to-power-electric-cars-and-when What Comes After Lithium-Ion Batteries To Power Electric Cars, And When? Dec 3, 2015 Stephen Edelstein [images http://images.thecarconnection.com/med/nissan-prototype-60-kwh-battery-pack--nissan-technical-center-october-2015_100532729_m.jpg Nissan prototype 60-kWh battery pack - Nissan Technical Center, October 2015 http://images.thecarconnection.com/med/battery-pack-assembly-for-2015-chevrolet-spark-ev-electric-car-at-gms-brownstown-michigan-plant_100466966_m.jpg Battery pack assembly for 2015 Chevrolet Spark EV electric car at GM's Brownstown, Michigan, plant http://images.thecarconnection.com/med/tesla_100325170_m.jpg Tesla Motors - Model S lithium-ion battery pack ] All mass-market plug-in electric cars on sale today have one thing in common. They are powered by battery packs composed of cells with lithium-ion chemistries. But to surpass current limits on range and charging speed--as well as to lower the cost and weight of battery packs--researchers are diligently looking for ways to augment or replace lithium-ion cells with something even better. But what could possibly replace lithium-ion cells in electric-car battery packs? According to a recent Navigant Research blog post, lithium-ion technology could hit a development ceiling by the end of the decade, necessitating a switch to some alternate chemistry. In the near term, though, the energy density of lithium-ion cells is expected to increase steadily--accompanied by a decrease in costs. Economy of scale offered by higher-volume production at plants like Tesla's Nevada "Gigafactory" is expected to help bring prices down, as will hoped-for decreases in the amounts of precious metals used. Navigant estimates that overall lithium-ion battery pack prices will continue to decline by about 5 to 6 percent annually for the remainder of the decade. And carmakers are hoping to unlock additional efficiency gains as well. Speaking at the October eCarTec conference in Munich, Renault battery-development chief said that improvements in energy density will allow for 200 miles of range in mainstream electric cars by 2020. Before then, Renault alliance partner Nissan is widely expected to be selling a 200-mile Leaf electric car, and the 200-mile Chevrolet Bolt EV and Tesla Model 3 will also debut over the next few years. But beyond that, analysts believe other chemistries could gradually supplant lithium-ion. At the same Munich conference, supplier Bosch predicted that alternatives like lithium-air, lithium-sulfur, and solid-state batteries will soon become commercially significant. Solid-state batteries will be the first of these technologies to be commercialized in the short term, said Dr. Holger Fink, senior vice president of engineering for Robert Bosch Battery Systems. Solid-state batteries replace the typical liquid electrolyte with a solid material. The technology has already received some attention from carmakers including Volkswagen, which owns a stake in solid-state battery firm QuantumScape. Lithium-sulfur batteries may become commercially viable around 2030, Fink said. With lithium-ion well established, though, the transition to alternative battery chemistries will likely be slow and gradual. No other cell chemistry has reached the stage where a mainstream carmaker is ready to commit to using it in production vehicles. And even when these new technologies do become commercially viable, it will likely take time for them to erode lithium-ion's market share. 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