One step “growth to spinning” of biaxially multilayered CNT web electrode for long cycling Li-O2 batteries
Li-O2 battery has been a great attention because its high theoretical energy density which exceeds the best that can be achieved from Li-ion batteries. Basically, the operation of Li-O2 battery is the formation and decomposition of Li2O2 at the cathode. Lots of cell degradation comes because remaining discharge products accumulated on the pores generates pore clogging. Therefore, the complete removal of discharge products would be key issue in reversible charge/discharge process. In this study, specially designed high crystalline CNT web has been fabricated by one-step growth to spinning process by FCCVD method. High crystallinity of CNT surface reduced the decomposition of CNT surface and bi-axial alignment of CNT enables to open CNT framework for O2 gas and electrolytes without the pore clogging. From the pore size distribution based on Barrett-Joyner-Halenda (BJH), it is verified that Mesopores and Macropores are better developed in A2CNT, which facilitate the networking of O2 gas and electrolytes. With this specially designed CNT as a cathode electrode, the 70％ improved cycleability and dramatic reduced overpotential have been demonstrated.