Swedish scientists have created a battery from environmentally friendly materials: wood, coconut, and lemon. Depending on the external conditions, this battery is able to maintain both heat and coolness.

To create this device, the wood structure is filled with citrus and coconut based molecules. They turn into a polymer that enables to store and release energy.

“The elegance is that the coconut molecules can transition from a solid-to-liquid which absorbs energy; or from liquid-to-solid which releases energy, in much the same way that water freezes and melts,” explained the researchers.

They say this battery can be charged using sunlight or any other heat source.

The device enables to adjust the temperature at around 24°C.