In Japan Water-Activated Paper Battery Was Discovered 

Researchers from Tohoku University have unveiled an environmentally friendly, disposable magnesium air battery. To activate it, you only need plain water. The battery is based on magnesium, which interacts with water and air (oxygen). This battery is easy to recycle and can be used for diagnostic and wearable devices.

It uses a neutral electrolyte and a safe, highly efficient pigment-based AZUL electrocatalyst.

The paper battery produced in this way provided a DC voltage of 1.8 V. The current density reached 100 mA/cm2, and the maximum output power was 103 mW/cm2. The safety of the materials used in the paper battery was separately tested and confirmed. In addition, scientists showed examples of the use of an experimental battery in wearable sensor devices, such as a pulse oximeter (SpO2 sensor) and a GPS recorder.

Scientists believe that magnesium air batteries are better than lithium batteries for a range of applications.