Storing energy on space missions can be tricky. Batteries do not like the cold of space and so have to be heated in order to be useful. This requires heaters inside the battery enclosure, which adds a little extra mass (bad) and also incurs a penalty on the spacecraft power budget.
It would be more convenient all around if there was some form of energy storage solution that could function in extreme environments such as in space proper, or on some other frigid wasteland of a planet.
Well there is possibly some good news on that front, as a team of engineers have used additive manufacturing to create a supercapacitor which works when cold. Really cold!
The supercapacitor electrodes are first printed into a matrix structure using a carbon aerogel cellulose nanocrystal-based ink. The matrix is then freeze dried and a surface treatment is applied.
This process results in a porous structure with holes measuring just 500 microns across on the surface as you can see in the picture below. You can see smaller pores in the beams of the matrix itself. These smaller pores measure in the nanometer scale and the resulting porous network allows the ion diffusion and charge transfer through the electrode. And what’s more is that it allows this process to occur at temperatures as low as -70°C, which is perfect for those cold Martian nights, and even for Polar regions right here on Earth.