Renewable energy sources are only as reliable as the natural world that fuels them. A cloud passing overhead cuts off solar power; the wind stops blowing and windmills stop working. In order for us to depend on undependable power sources, we need a grid-sized backup to acts of God.
In 2012, president Barack Obama’s energy secretary Stephen Chu issued a “5-5-5” challenge to those in the energy storage field, bring us a 5% reduction of cost, a five times increase in capacity, and do it in five years or less. Yet-Ming Chiang, MIT’s department of material science and engineering and founder of multiple battery-research startups, was the lead author on a study published earlier this week in the journal, Joule, that described a battery conceived and designed with a wary eye on that first five in Chu’s challenge. “We said, ‘If we want energy storage at the terawatt scale, we have to use truly abundant materials,’” Chiang told MIT News.
Chiang’s team knew from jump they wanted to use sulfur as the cathode, or negative terminal, and water as the electrolyte solution that holds the energy. After some false starts, the researchers fell upon oxygen as an anode, or the positive terminal, completely by accident when an incomplete seal in a prototype allowed for air to get in to the system. The final step was finding that adding salt to the water could help carry the charge back and forth between the two terminals more efficiently. All told, the total chemical cost of Chiang’s battery, comes to about $1 per kilowatt hour (kWh).
Recent Comments