A respiration-detective graphene oxide/lithium battery

Typical lithium ion batteries can only supply electricity, but not detect human respiration at the same time. Herein, we report a self-powered and respiration-detective battery via the simple assembly of Li foil and a graphene oxide film (GOF) without additional electrolytes. In the Li-GOF battery, the GOF can rapidly capture and transfer the moisture originating from the exhaled gas. Meanwhile, Li foil serves as a micro-reactor to trigger the redox reaction between lithium and adsorbed moisture (2Li + 2H(2)O = 2LiOH + H-2). The produced electrons flowing in an external circuit can reflect the rate and depth of respiration in real time. As an extra-power-free device, the respiration-detective Li-GOF battery can supply a specific capacity of 36.4 mA h cm(-2), which is ca. 36 times higher than that of conventional lithium ion batteries. Interestingly, the battery can reversibly control the on/off of a light emitting diode by adsorbing/desorbing moisture, respectively. Even if submerged in water, the Li-GOF battery can light up a LED in water for over 1 hour, which can be applied for submarine search and rescue. Beyond this, the Li-GOF battery provides a new platform and allows the construction of a similar hybrid structure for various functions.