Modern batteries usually rely on lithium-ion or lithium-polymer cells, but these have come under criticism, particularly because of their resource consumption. The mining of lithium is problematic and, on top of that, the material is only available to a limited extent. That’s why various alternative technologies have been researched for years, for example based on the much more common substances sodium or calcium. There is now apparently a breakthrough from China in the latter technology.
At room temperature – and flexible
There, researchers at Fudan University in Shanghai have apparently succeeded in operating calcium-air cells at room temperature. Until now, this required temperatures of over 75 °C, which severely limited the possible applications. However, this problem can be solved with a new structure, which the researchers describe in a paper on Nature (paywall). Apparently the decisive factor here is an electrolyte specially developed for this purpose. This is located between a calcium-coated fiber and a surrounding network of carbon nanotubes.
With this structure, the calcium-air battery can reportedly survive 700 charging cycles. At the same time, there is talk of a storage capacity of 500 mAh per gram – around one and a half times as much as lithium-ion cells. In addition, the cells built in this way should be very flexible and can even be woven into fabrics to power wearables, for example. According to World of Physics, at least 1,500 charging cycles would be necessary for it to be ready for series production. The development of calcium-air batteries is far from finished.
Suitable for: Chinese developers are working on batteries that should last 50 years
In addition, it cannot be ruled out that mass production of the new approach would fail due to other problems – for example costs or a lack of scalability. In this case too, the research work presented could of course help with further development and possibly make it possible in the future for calcium-based batteries to become a sensible alternative to lithium cells, at least in some areas.
Source: via T3N / World of Physics