Several start-ups have recently announced that they are using nanotechnology to make better ultracapacitors, leading to a new type of energy-storage technology that could boost the range of electric cars. Ultracapacitors have the advantage of delivering fast bursts of power and can be recharged hundreds of thousands of times without losing much capacity, but conventional ones are expensive and store too little energy to replace the traditional batteries. A startup called Nanotune, based in the United States, has now developed a way to make electrodes that result in ultracapacitors with five to seven times as much storage capacity as conventional ones. Nanotune says its ultracapacitors could soon surpass batteries in terms of energy storage. All of the start-ups are hoping to solve the biggest problem with electric cars today – the high cost of the batteries and the limited storage capacity. Today’s battery systems are expensive and bulky because the batteries degrade as they are used, and when exposed to extreme temperatures. Automakers often pair batteries with cooling and heating systems, and extra battery cells, to offset losses in performance over time. Ultracapacitors can be recharged without degrading and work well in a wide range of temperatures. Nanotune’s technology is currently very expensive, but the company says the costs could come down if the prices of some key materials continue to fall, and as manufacturing is scaled up. Nanotune CEO Kuan-Tsae Huang says the company hopes to double the current storage capacity of its ultracapacitors by the end of the year, which would result in an improvement over the batteries used in some hybrid vehicles.
http://www.technologyreview.com/energy/37519/