Increasing the voltage of a battery.

Iron nails and copper wire can make a transformer, it's basically two coils with a specific number of loops. Actually since you need alternating current for a transformer to work you're probably going to have to connect your battery to a motor, then attach the motor to another motor, then attach that to the transformer. Hmm, that seems like it would create a lot of loss. You probably don't need that much voltage to lift a paperclip anyway.