An effective methodology to explore highly efficient oxygen electrocatalysts and electrodes for Li−O2 batteries is developed via intimate layer-by-layer hybridization between mesoporous carbon layer and highly anisotropic 2D metal oxide nanosheets. The obtained multilayer hybrid nanosheets of mesoporous carbon−layered MnO2 display outstanding functionalities as oxygen electrocatalysts with low overpotential and as the electrodes of Li−O2 batteries with huge discharge capacity of ˜7000 mAhg−1 at 200 mAg−1 and improved cyclability. The excellent electrocatalyst/electrode bifunctionality of the present material is attributable to enhanced electron transfer kinetics, maximized active sites, promoted electrocatalysis kinetics, and stabilization of unstable Mn3+ species. This multilayer hybrid nanosheet structure is advantageous for facilitating reversible formation/decomposition of discharged product during cycling in Li−O2 batteries via promoted electrolyte−oxygen diffusion. The present study underscores that exfoliated metal oxide nanosheet can be used as an efficient immobilization matrix for synthesizing novel 2D multilayer hybrid nanosheets with synergistically-improved electrocatalyst/electrode functionalities.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF-2017R1A2A1A17069463, NRF-2017R1A2B3004383) and by the Korea government (MSIT) (NRF-2017R1A5A1015365). The experiments at PAL were supported in part by MOST and POSTECH.
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF- 2017R1A2A1A17069463 , NRF- 2017R1A2B3004383 ) and by the Korea government (MSIT) (NRF- 2017R1A5A1015365 ). The experiments at PAL were supported in part by MOST and POSTECH.
© 2019 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Environmental Science(all)
- Process Chemistry and Technology