Highly uniform nitrogen-doped carbon decorated MoO2 nanopopcorns as anode for high-performance lithium/sodium-ion storage

ACS Appl. Energy Mater.

Guo

Zhang

et al. 2021

Self Cite

The two-dimensional layered material tin disulfide (SnS 2 ) has a high theoretical capacity for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) due to its combination of conversion and alloying reactions during the charge-storage process. However, the intrinsic poor conductivity and huge volume changes impede its practical applications. In this work, a design of in situ growth and polymerization is developed to synthesize polypyrrole wrapped SnS 2 vertical nanosheet arrays grown on nitrogen-doped three-dimensional graphene (PPy@SnS 2 @N3DG). The PPy@SnS 2 @ N3DG composite, with the unique free-standing hierarchical structure and the synergy of three components, exhibits excellent rate capability and superior cycling stability. Based on the features of high capacity, lightweight, and facile preparation, the PPy@SnS 2 @ N3DG composite can be considered as a promising electrode for energy storage devices.

Section: Resultsmentioning

confidence: 66%

Polypyrrole-Wrapped SnS₂ Vertical Nanosheet Arrays Grown on Three-Dimensional Nitrogen-Doped Porous Graphene for High-Performance Lithium and Sodium Storage

ACS Appl. Energy Mater.

Guo

Zhang

et al. 2021

Self Cite

“…On the other hand, MoO 2 crystallizes in the monoclinic structure with space group P 2 1 / c , which can be viewed as a distorted rutile phase. This structure is composed of MoO 6 octahedra joined by edge-sharing, which form a (1 × 1)-tunneling network [ 41 , 42 ]. In addition, MoO 2 has outstanding properties for energy storage applications, e.g., metal-like conductivity (~6 × 10 3 S cm −1 ), very low toxicity, cost-effectiveness, high chemical and thermal stability, high volumetric capacity due to the fact of its high density (6.5 g cm −3 ), and high theoretical capacity (838 mAh g −1 ) [ 43 , 44 , 45 ].…”

Section: Introductionmentioning

confidence: 99%

Nanostructured Molybdenum-Oxide Anodes for Lithium-Ion Batteries: An Outstanding Increase in Capacity

Hashem

et al. 2021

Nanomaterials

This work aimed at synthesizing MoO3 and MoO2 by a facile and cost-effective method using extract of orange peel as a biological chelating and reducing agent for ammonium molybdate. Calcination of the precursor in air at 450 °C yielded the stochiometric MoO3 phase, while calcination in vacuum produced the reduced form MoO2 as evidenced by X-ray powder diffraction, Raman scattering spectroscopy, and X-ray photoelectron spectroscopy results. Scanning and transmission electron microscopy images showed different morphologies and sizes of MoOx particles. MoO3 formed platelet particles that were larger than those observed for MoO2. MoO3 showed stable thermal behavior until approximately 800 °C, whereas MoO2 showed weight gain at approximately 400 °C due to the fact of re-oxidation and oxygen uptake and, hence, conversion to stoichiometric MoO3. Electrochemically, traditional performance was observed for MoO3, which exhibited a high initial capacity with steady and continuous capacity fading upon cycling. On the contrary, MoO2 showed completely different electrochemical behavior with less initial capacity but an outstanding increase in capacity upon cycling, which reached 1600 mAh g−1 after 800 cycles. This outstanding electrochemical performance of MoO2 may be attributed to its higher surface area and better electrical conductivity as observed in surface area and impedance investigations.

“…Based on the above issues, some optimization methods have been designed and studied, such as combination with conductive carbon materials, nitrogen atom doping, and expansion of interlayer spacing, to make MoS 2 show better and more stable electrochemical performance . Incorporating with conductive carbon materials, such as amorphous carbon, , graphene, , and carbon nanotubes, can improve the conductivity of the composite, helping it exhibit high capacity and superior rate capability. Graphene used as a substrate can also relieve the stacking and agglomeration of MoS 2 two-dimensional nanoflakes, which is also helpful to the improvement of electrochemical properties. , Doping nitrogen atoms in the conductive carbon materials could further boost the conductivity and interface stability of the composite, leading to more advanced lithium/sodium-ion transmission and storage performance. − In addition to electronic modulation, nitrogen atom doping can provide more reactive sites, promote reaction kinetics, and enhance the lithium/sodium storage ability. , …”

Section: Introductionmentioning

confidence: 99%

“…27,28 Based on the above issues, some optimization methods have been designed and studied, such as combination with conductive carbon materials, nitrogen atom doping, and expansion of interlayer spacing, to make MoS 2 show better and more stable electrochemical performance. 29 Incorporating with conductive carbon materials, such as amorphous carbon, 30,31 graphene, 6,32 and carbon nanotubes, 33 can improve the conductivity of the composite, helping it exhibit high capacity and superior rate capability. Graphene used as a substrate can also relieve the stacking and agglomeration of MoS 2 twodimensional nanoflakes, which is also helpful to the improvement of electrochemical properties.…”

Section: Introductionmentioning

confidence: 99%

Interlayer Expanded MoS₂/Nitrogen-Doped Carbon Hydrangea Nanoflowers Assembled on Nitrogen-Doped Three-Dimensional Graphene for High-Performance Lithium and Sodium Storage

ACS Appl. Energy Mater.

Guo

Zhang

et al. 2021

Self Cite

A combination of optimization methods has been developed to help compensate for the weak points of molybdenum disulfide (MoS2), including poor electronic conductivity and large volume expansion, for better exhibiting its advantages such as high capacity and stability in the fields of lithium/sodium-ion batteries (LIBs/SIBs). In the study, nitrogen-doped three-dimensional graphene supporting MoS2 hydrangea nanoflowers with a nitrogen-doped carbon intercalation (MoS2/NC@N3DG) hierarchical composite has been designed and prepared in a simple one-step hydrothermal and annealing way. The distinctly expanded spacing between MoS2 interlayers can facilitate the ion diffusion and the doped nitrogen atoms can markedly improve the electronic conductivity. Therefore, the MoS2/NC@N3DG composite electrode shows outstanding rate capability and excellent cycling performance for both LIBs (1497/1300 mA h g–1 at 0.2/1 A g–1 after 200/500 cycles) and SIBs (513/364 mA h g–1 at 0.2/1 A g–1 after 200/500 cycles). This work provides a promising scheme for designing advanced two-dimensional layered metal dichalcogenide materials for high-performance LIBs and SIBs.