Japanese physicists have found something called the Spin Seebeck Effect that could lead to practical magnetic batteries:
Essentially, this spin-segregated rod now has two electrodes and serves as the basis for a new kind of battery that produces “spin voltage,” or magnetic currents, which have been difficult to produce. With this tool, physicists can work toward developing more kinds of spintronics devices that store information magnetically.
Magnetic information storage is inherently more efficient than storing information electronically because there is no waste heat.
This is an interesting development. There seems to be a lot going on in the world of practical applications for quantum dots, quantum cryptography and spintronics. I suspect it will be one of those areas that heralds a lot of unexpected innovation over the next few years and decades.