Hierarchical hybrid sandwiched structure of ultrathin graphene nanosheets enwrapped MnO nanooctahedra with excellent lithium storage capability

• Published in: Journal of alloys and compounds 2018-06, Vol.749, p.424-432
• Main Authors: Lu, Shiyao, Gao, Yiyang, Li, Zhaoyang, Dong, Bitao, Gao, Ting, Ding, Shujiang, Bai, Yanhong, Gao, Guoxin
• Format: Article
• Language: English
• Subjects: Anodes; Discharge; Electrodes; Graphene; Graphite; Interlayers; Lithium; Lithium-ion batteries; Lithium-ion battery; Long-term cyclic stability; Manganese oxides; MnO; Nanocomposites; Nanosheets; Nanostructured materials; Rechargeable batteries; Structural hierarchy; Transition metal oxides
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2018.03.316

Graphene supported transition metal oxides (TMOs) nanocomposites have been recognized as an advisable strategy to develop the advanced electrodes for lithium-ion batteries (LIB) recently, yet the long-term cyclic stability could not be well maintained mainly due to the severe structural collapse and continuous exfoliation of active TMOs from graphene support. Herein, we successfully designed a novel sandwich-type hybrid nanostructure of reduced graphene oxide (rGO) enwrapped MnO nanooctahedra like a blanket (MnO@rGO NO) via a facile solution reflux and a post-annealing. The XRD patterns and FESEM images confirm that octahedral Mn3O4 precursor embedded among GO interlayers could be easily reduced into conformal MnO nanocrystal whilst the full reduction of GO into rGO during the subsequent calcination at 700 °C in N2. When used as a promising anode for LIBs, the sandwiched MnO@rGO NO manifests excellent lithium storage capability with high reversible discharge capacity, long-term cyclic stability and superb rate performance, mainly benefiting from the robust structure and good conductivity enhanced by rGO matrix. Even undergoing 600 cycles at the current densities of 400 and 800 mA g−1, the hybrid sandwiched MnO@rGO NO anodes could still deliver stable discharge capacities of 838 and 687 mAh g−1, respectively. •Hierarchical hybrid structure of rGO enwrapped MnO nanooctahedra is prepared.•The synergistic effect of conformal MnO NO and conductive rGO is beneficial to the electrochemical process.•Such sandwiched structure can present excellent lithium storage capability.