I think this is not linked with battery storage. Superconductivity allows a material to conduct electrons without any resistance, thus losing less energy and generating less heat. I could be wrong though, I am no expert.
You can use superconductors for energy storage. An inductor stores energy, but can not be used for long-term energy storage due to resistance. A superconducting inductor can be used to store energy, as there is no loss due to resistance.
https://en.wikipedia.org/wiki/Superconducting_magnetic_energ...