Innovative paper-based Al-air batteries as a low-cost and green energy technology for the miniwatt market

This work demonstrates an innovative Al-air battery made of paper, which can inhibit Al corrosion, simplify battery system and reduce electrolyte storage. One major advantage of it is its minimum cost of fabrication. The corrosion inhibition effect originates from the high porosity and tortuosity of paper, which restricts the diffusive transport of hydroxyl ions to the Al surface. In this manner, low-grade Al can be directly utilized. Targeted for different application fields, three battery subtypes are proposed. The mechanically-rechargeable battery can be used repeatedly by refreshing its Al anode, providing relatively high power for charging portable electronics. The flexible battery employs embedded Al inside paper as anode and oxygen reduction ink as cathode, which is suitable for various single-use and flexible devices. Lastly, a printable battery is proposed by developing a successful Al ink for anode fabrication. Combined with existing printing techniques, this design may lead to a much smarter and more economic battery application in the future.