CPO26 & HempCrete!
One of the best Green building materials discussed at COP26 during can now store energy like a battery! Hemp has thousands of uses from autos to zero-energy buildings as shown in the videos.
And now this carbon-negative material just became the next building block to energy created by nature and stored in the building itself. From Science Daily, "The ever-growing need for sustainable building materials poses great challenges for researchers. Doctor Emma Zhang, formerly of Chalmers University of Technology, Sweden, joined Professor Luping Tang's research group several years ago to search for the building materials of the future. Together they have now succeeded in developing a world-first concept for a rechargeable cement-based battery.
The concept involves first a cement-based mixture, with small amounts of short carbon fibres added to increase the conductivity and flexural toughness. Then, embedded within the mixture is a metal-coated carbon fibre mesh -- iron for the anode, and nickel for the cathode. After much experimentation, this is the prototype which the researchers now present.
"Results from earlier studies investigating concrete battery technology showed very low performance, so we realised we had to think out of the box, to come up with another way to produce the electrode. This particular idea that we have developed -- which is also rechargeable -- has never been explored before. Now we have proof of concept at lab scale," Emma Zhang explains.
Luping Tang and Emma Zhang's research has produced a rechargeable cement-based battery with an average energy density of 7 Watthours per square metre (or 0.8 Watthours per litre). Energy density is used to express the capacity of the battery, and a modest estimate is that the performance of the new Chalmers battery could be more than ten times that of earlier attempts at concrete batteries. The energy density is still low in comparison to commercial batteries, but this limitation could be overcome thanks to the huge volume at which the battery could be constructed when used in buildings.
A potential key to solving energy storage issues
The fact that the battery is rechargeable is its most important quality, and the possibilities for utilisation if the concept is further developed and commercialised are almost staggering.Energy storage is an obvious possiblity, monitoring is another. The researchers see applications that could range from powering LEDs, providing 4G connections in remote areas, or cathodic protection against corrosion in concrete infrastructure.
"It could also be coupled with solar cell panels for example, to provide electricity and become the energy source for monitoring systems in highways or bridges, where sensors operated by a concrete battery could detect cracking or corrosion," suggests Emma Zhang.
The concept of using structures and buildings in this way could be revolutionary, because it would offer an alternative solution to the energy crisis, by providing a large volume of energy storage.
More Hempcrete videos!
From World Hemp Expert Barbara Filippone at EnviroTextiles, an early version of one of their hemp processing machines now available!