Multiwall Carbon Nanotubes as Microscopic-Cables to Boost Discharge Performance of Li-O2 Batteries

Graphical A simple carbon black (Ketjenblack, KB)-multiwall carbon nanotubes (MWCNTs) composite was fabricated and used as the air cathode in a Li-O 2 battery, achieving significantly improved specific capacity (up to 10611 mAh/g carbon ), rate capability and cyclability than pristine KB, owing to the synergy of KB's abundant surface area for accommodation of discharge products and MWCNTs’ long-range electronic conductivity. A simple carbon black (Ketjenblack, KB)-multiwall carbon nanotubes (MWCNTs) composite was fabricated and used as the air cathode in a Li-O 2 battery where MWCNTs primarily serve as microscopic cables to enhance long-range electronic conductivity. With optimal KB:MWCNTs mass ratios, the composite exhibited significantly improved specific capacity (up to 10611 mAh/g carbon under 100 mAh/g carbon ), rate capability (up to 9598 mAh/g carbon under 500 mAh/g carbon ) and cyclability than pristine KB, owing to the synergy of KB's abundant surface area for accommodation of discharge products and MWCNTs’ long-range electronic conductivity to guide even and compact deposition of discharge products, and mitigate passivation/clogging of the air cathode surface during discharge. This strategy of using MWCNTs as microscopic cables could also be applied for other commercial materials to construct high-performance and low-cost air cathodes.