Abstract
Designing an efficient and effective air electrode catalyst material is the most intrinsic requisite for rechargeable lithium-oxygen (Li-O2) batteries showing long cycling lives and high rate capacities. Here, we present for the first time, hierarchical multiroom-structured molybdenum carbide/carbon composite microspheres grafted with Ni nanoparticle-embedded N-doped carbon nanotubes (NCNTs) (i.e., mNi-NCNT-MoC-C), which are prepared by pilot-scale spray drying and subsequent surface growth of NCNT bundles. The designed mNi-NCNT-MoC-C microspheres show efficient bifunctional catalytic activities toward both oxygen reduction and evolution. In addition, the hierarchical multiroom structure of mNi-NCNT-MoC-C microspheres increases the discharge capacity by providing sufficient space to accommodate Li2O2, which forms during discharging. A Li-O2 battery prepared using mNi-NCNT-MoC-C microspheres as an air electrode exhibits excellent electrochemical performances including a long cycle life (199 cycles) and low overpotentials of 0.20 and 0.21 V for charging and discharging, respectively. The synergetic effects of efficient morphology (i.e., the multiroom structure), highly electrocatalytically active materials (i.e., NCNT, Ni, and MoC), and high electrical conductivity (imparted by the NCNTs) is responsible for the superior performance of mNi-NCNT-MoC-C microspheres as an air cathode material for Li-O2 batteries.
Original language | English |
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Pages (from-to) | 886-896 |
Number of pages | 11 |
Journal | Chemical Engineering Journal |
Volume | 351 |
DOIs | |
Publication status | Published - 2018 Nov 1 |
Bibliographical note
Funding Information:This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (Nos. 2017R1A2B2008592, 2013M3A6A8073184). This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2017R1A4A1014806).
Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government ( MSIP ) (Nos. 2017R1A2B2008592 , 2013M3A6A8073184 ). This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning ( NRF-2017R1A4A1014806 ).
Publisher Copyright:
© 2018 Elsevier B.V.
Keywords
- Hierarchical structure
- Lithium-O batteries
- Molybdenum carbide
- N-doped carbon nanotubes
- Spray drying
ASJC Scopus subject areas
- General Chemistry
- Environmental Chemistry
- General Chemical Engineering
- Industrial and Manufacturing Engineering