The Effect of Different Carbon Materials on Manganese Oxide-Based Lithium-Air Batteries in Ambient Environment

Rodlike manganese oxide (α-MnO₂) was prepared through a homogeneous hydrothermal reaction. Air electrodes, made with a mixture of graphite/acetylene black (G/AB) with and without the as-made α-MnO₂, were prepared for lithium-air cells. Linear sweep voltammetry (LSV) results show that the as-made α-MnO₂ can greatly increase the rate of the oxygen reduction reaction (ORR), and that the graphite has a very low catalytic activity towards ORR, while acetylene black has a better catalytic activity towards ORR. The batteries were tested in ambient atmosphere. The results show that graphite can improve the charge and discharge performance, and acetylene black can improve the specific capacity. When using 28% α-MnO₂+56% graphite as catalyst, the initial discharge capacity was 200mAhg^-1, and the number of cycles reached up to 5. When using 28% α-MnO₂+56% acetylene black as catalyst, the initial discharge capacity was 1150mAhg^-1, but did not realize the charge and discharge cycles.