Envia has a 40 Ah pouch cell, the new system could lower Li-ion cell costs to $180/kWh, according to Sujeet Kumar, Co-founder, President & CTO, with further reductions to come. The cells feature active materials with high specific capacity: a 300 mAh/g cathode and nano Si-C composite anode with a capacity of 1600 mAh/g. Kumar said that the results have been verified by ARPA-E at an independent cell test facility.
2. China is targeting the development of high efficiency, high-capacity (over 150 mAh/g [half the Envia system]), long life (over 2000 cycles), high safety performance cathode materials, including the Li-ion phosphate system, NMC, and LMO series. By 2015, China will add 45,000 tons per year capacity for cathode materials.
Eventually Aquion plans to sell stacks of batteries in countries that have electrical grids. They could provide power during times of peak demand and make up for fluctuations in power that big wind farms and solar power plants contribute to the grid. Those applications require tens to hundreds of gigawatt-hours’ worth of storage, so to supply them, Aquion needs to increase its manufacturing capacity. Competing with natural-gas power plants—especially in the United States, where natural gas is so cheap—will mean waiting until economies of scale bring costs down.
The company has said that it initially hopes to make batteries for under $300 per kilowatt-hour, far cheaper than conventional lithium-ion batteries. Lead-acid batteries can be cheaper than Aquion’s, but they last only two or three years. Aquion’s batteries, which can be recharged 5,000 times, could last for over a decade in situations in which they’re charged once a day (the company has tested the batteries for a couple of years so far).
Jay Whitacre, a Carnegie Mellon University professor of materials science and engineering who developed Aquion’s technology and founded the company, says the cost will need to drop to less than $200 per kilowatt-hour for grid-connected applications. Reaching this price, and production capacity on the scale of gigawatt-hours, “will take a long time,” he says. “But you have to start somewhere.”