Scientists from the Queensland University of Technology (Australia) have designed a new energy storage device based on ... a spring. Only in this case is it made of an extremely promising innovative material - diamond nanowires. So far, there are only small experimental samples of this material, but in the near future, when the production of threads becomes cheap and affordable, they will become the basis for many new technologies.
A nanowire is a one-dimensional structure in the form of a chain of carbon atoms, which is flexible enough to twist it in any way, but at the same time strong enough to withstand such deformations. If you take several nanowires and tie them into a bundle, you can twist it and get a tiny spring. When compressed, it will accumulate energy, while unwinding, release it - this is a good old principle on the basis of which many winding mechanisms work.
Simulation has shown that a hypothetical storage device made of such a material has a capacity of 1.76 MJ / kg of energy. This is 4-5 orders of magnitude more than steel springs, and three times higher than lithium-ion batteries. An additional bonus - mechanical systems are many times more stable than chemical analogs, they exclude the risk of fire and detonation. Also, such a drive does not contain toxic substances, and its disposal is not a problem. The field of application of such batteries is extremely wide - from space to microimplants.