Multi-Block Power Storage Device

This is just an idea I had. I was thinking it'd help with large power storage systems if you could make them large multiblock structures, but all working as a single component to reduce lag from swapping power between blocks as you have in many large storage solutions. It'd be slightly cheaper per block than a batbox, not requiring the batteries as components, but requiring new materials that would act as power storage without all the wire needed. It would store about as much as a batbox for each piece, but with a large storage area, it'd help with allowing for cheap but huge storage. I was also thinking it could be modular, providing whatever current is requested by an attached piece that would act as the connection for output, allowing multiple different levels of power to be output by it.