Implantable battery is charged up by the body’s oxygen supply

Batteries designed to run on oxygen from inside the body could last months or years before needing to be recharged or replaced, and might one day power everything from pacemakers to brain implants.

Xizheng Liu at Tianjin University of Technology in China and his colleagues made their batteries from a sodium-based alloy and a porous form of gold, taking advantage of the fact that sodium reacts with oxygen to create electrical power. That means these batteries can be implanted in the body and exploit…