Lithium-Air Cells Assembled with Nitrogen and Sulfur Co-Doped Graphene Electrode

Rechargeable lithium-ion batteries are widely used as the power source for portable electronic devices, electric vehicles and energy storage systems. However, their energy density cannot fulfill the requirements of applications for electric vehicles.  In this respect, lithium-air batteries have been in focus due to their higher energy density than the currently commercialized Li-ion batteries.  Recently, diverse approaches on air electrode have been reported to enhance the cycling performance of Li-air batteries, such as nanostructured metal oxide, superfine platinum particles, bi-functional catalyst loaded onto carbon and metal free graphene nanosheets [1].  Graphene has been receiving a lot of attention for energy storage applications because of its high electronic conductivity, high surface area, chemical stability and good mechanical strength. Furthermore, chemical doping in graphene materials showed a considerable increase in electrochemical activity relative to pristine carbon materials [2].  In this study, we synthesized nitrogen and sulfur co-doped graphene to improve the electrochemical performance of lithium-air cell. The cycling performance of lithium-air cells assembled with N,S-doped graphene cathode was investigated and compared to that of a cell with carbon-based air electrode. The detailed investigation was carried out using electrochemical impedance spectroscopy, FE-SEM, HR-TEM, RDE and XPS analyses.

References

1. B.Sun, B.Wang, D.Su, L.Xiao, H.Ahn, G.Wang, Carbon, 50,727 (2012).

2. A.L.M.Reddy, A.Srivastava, S.R.Gowda, H.Gullapalli, M.Dubey, ACS Nano, 11, 6337 (2010).