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.
All Science Journal Classification (ASJC) codes
- Environmental Science(all)
- Process Chemistry and Technology