Na-CO batteries: devices to trap CO.

Metal-gas batteries that remove CO gases would provide enormous environmental benefits. We report here Na-CO batteries using the combination of a sodium anode and a binder-free multiwall carbon nanotube cathode with a CO reactant. The constructed Na-CO batteries show a high discharge capacity of 8000 mA h g-1 based on the mass of carbon nanotubes (corresponding to ∼865.9 W h kg-1 based on the mass of total active materials) and a stable cycling of 70 cycles with an increased gap of only 3.7 mV. This work offers a promising strategy for efficient utilization of CO to generate electricity through an electrochemical conversion method.