From Sweden comes news of a new concrete battery-yes, you heard that right, concrete.
Recalling the original Edison nickel-iron batteries, Swedish researchers use the same metal electrode combination in their unusual battery. The concept involves a cement-based mixture [electrolyte], with small amounts of short carbon fibers added. Embedded within the mixture is a metal-coated carbon fiber mesh -- iron for the anode, and nickel for the cathode. And there are the main components of the battery!
Batteries like this are a way to store renewable energy during peak production times (like the sunniest part of the day for solar cells, or the windiest days for wind turbines) and feed it back into the grid during peak usage times. Imagine a cement building becoming a giant storage battery, turning our most versatile building material into a valuable storage technique. Why not sidewalks as long storage batteries?
Concrete's "energy per unit volume" isn't very big, but we use so much cement that the small energy amount quickly adds up. For comparison, lithium-ion batteries (small, but very powerful) have an energy density of about 250 to 350 watt hours per liter (Wh/L). Swedish scientists found prepared concrete rates at just 0.8 Wh/L. While this would perform way below almost any existing material that touts itself as a battery, our way of life requires so much concrete there will always be a huge, steady supply into which we can tap.
Talk to you again soon...
Harry