A Multifunction Lithium–Carbon Battery System Using a Dual Electrolyte

Fuel cells, Li-ion batteries, and supercapacitors are attracting extensive attention, and it is highly desired to integrate the advantages of these devices into one system. Herein, a multifunction Li–carbon system was designed by using an aqueous–nonaqueous dual electrolyte to combine a nitrogen-doped ordered mesoporous carbon cathode with a metallic lithium anode. It is demonstrated that the nitrogen-doped ordered mesoporous carbon exhibits high performance in various applications of O 2 reduction reaction, supercapacitors, and H 2 evolution reaction, which makes the Li–carbon system exhibit multifunctionality. When operated in the ambient with O 2, the system can work as a Li–air fuel cell or/and rechargeable battery with high energy density. When operated in an environment without O 2, the battery can be used as a Li-ion supercapacitor which exhibits long-term cycling stability and improved energy performance. Finally, this cell can also be applied as a Li–water fuel cell for H 2 evolution.