Three-dimensional graphene–Co3O4 cathodes for rechargeable Li–O2 batteries

Zhang, Jiakai; Li, Pengfa; Wang, Zhenhua; Qiao, Jinshuo; Rooney, David; Sun, Wang; Sun, Kening

doi:10.1039/c4ta05573j

Cited by 92 publications

(46 citation statements)

References 54 publications

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“…Figure 1a show the XRD patterns of Co3O4 nanosheets and commercial and A1g. [34][35] The left shift and broadening of the peaks in Co3O4-NS indicate that the crystallization degree has become weakened and the surface electronic structure statement has changed after calcination in oxygen. indicating that the nanosheets can supply more active sites.…”

Section: Resultsmentioning

confidence: 99%

Boosting the Electrocatalytic Activity of Co₃O₄ Nanosheets for a Li-O₂ Battery through Modulating Inner Oxygen Vacancy and Exterior Co³⁺/Co²⁺ Ratio

et al. 2017

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Rechargeable Li-O2 batteries have been considered as the most promising chemical power owing to their ultrahigh specific energy density. But the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) result in the high overpotential (~1.5V), the poor rate capability and even the short cycle life, which critically hinder their practical applications. Herein, we propose a synergistic strategy to boost the electrocatalytic activity of Co3O4 nanosheets for Li-O2 battery by tuning the inner oxygen vacancies and the exterior Co 3+ /Co 2+ ratio which have been identified by Raman spectroscopy, X-ray photoelectron spectroscopy and X-ray Absorption Near Edge Structure spectroscopy. Operando X-ray diffraction and ex-situ Scanning Electron Microscope are used to probe the evolution of the discharge product. In comparison with bulk Co3O4, the cells catalyzed by Co3O4 nanosheets show a much higher initial capacity (~24051.2mAh g -1 ), better rate capability (8683.3mAh g -1 @400mA g -1 ) and cycling stability (150 cycles@400mA g -1 ), and lower overpotential. The large enhancement of the electrochemical performances can be greatly attributed to the synergistic effect of the architectured 2D nanosheets, the oxygen vacancies and Co 3+ /Co 2+ difference between the surface and the interior.Moreover, the addition of LiI in the electrolyte can further reduce the overpotential making the battery more practical. This study offers some insights into designing high performance electrocatalysts for Li-O2 batteries through the combination of the 2D nanosheets architecture, oxygen vacancy and surface electronic structure regulation.

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Section: Resultsmentioning

confidence: 99%

Boosting the Electrocatalytic Activity of Co₃O₄ Nanosheets for a Li-O₂ Battery through Modulating Inner Oxygen Vacancy and Exterior Co³⁺/Co²⁺ Ratio

et al. 2017

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“…To enhance the cathodic reaction kinetics for low charge overpotentials and high energy efficiency, it has been a prevalent approach to develop composite cathodes by loading catalysts, such as noble metal, [69] metal oxide [41,65,66,183] and others. To enhance the cathodic reaction kinetics for low charge overpotentials and high energy efficiency, it has been a prevalent approach to develop composite cathodes by loading catalysts, such as noble metal, [69] metal oxide [41,65,66,183] and others.…”

Section: Non-aqueous Lithium-oxygen Batterymentioning

confidence: 99%

Hierarchical Structures Based on Two‐Dimensional Nanomaterials for Rechargeable Lithium Batteries

Cong

Xie

2017

Advanced Energy Materials

221

125

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Two‐dimensional (2D) nanomaterials (i.e., graphene and its derivatives, transition metal oxides and transition metal dichalcogenides) are receiving a lot attention in energy storage application because of their unprecedented properties and great diversities. However, their re‐stacking or aggregation during the electrode fabrication process has greatly hindered their further developments and applications in rechargeable lithium batteries. Recently, rationally designed hierarchical structures based on 2D nanomaterials have emerged as promising candidates in rechargeable lithium battery applications. Numerous synthetic strategies have been developed to obtain hierarchical structures and high‐performance energy storage devices based on these hierarchical structure have been realized. This review summarizes the synthesis and characteristics of three styles of hierarchical architecture, namely three‐dimensional (3D) porous network nanostructures, hollow nanostructures and self‐supported nanoarrays, presents the representative applications of hierarchical structured nanomaterials as functional materials for lithium ion batteries, lithium‐sulfur batteries and lithium‐oxygen batteries, meanwhile sheds light particularly on the relationship between structure engineering and improved electrochemical performance; and provides the existing challenges and the perspectives for this fast emerging field.

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“…[5][6][7][8] The reaction mechanism in a Li-O 2 cell involves an oxygen reduction reaction (ORR) in the discharge process and an oxygen evolution reaction (OER) in the charge process, during which molecular O 2 reacts reversibly with Li + ions (Li + +O 2 +2e − ↔ Li 2 O 2 , with an equilibrium voltage of 2.96 V vs Li). 9,10 This mechanism is very different from the traditional intercalation reactions of Li-ion batteries. Although the theoretical overpotential for a Li 2 O 2 film is only 0.2 V, the practical overpotential normally reaches as high as 1.5 V, because there are limitations on charge transport through the insulating Li 2 O 2 particles to the Li 2 O 2 -electrolyte interface.…”

Section: Introductionmentioning

confidence: 99%

“…6,7,12 Various catalysts, such as metal oxides, metal nitrides and noble metals have been investigated as suitable cathode catalysts in Li-O 2 cells to reduce the charge overpotential. [13][14][15] The use of catalysts can decrease the charge potential to~3.8 V from~4.2 V. 9,16,17 Therefore, finding suitable cathode catalysts is an effective approach to solve the overpotential problem. [18][19][20] Recently, ruthenium (Ru) and RuO 2 have been reported as active catalysts towards the OER, which achieved high reversible capacity, low charge overpotential and good cycling stability.…”

Section: Introductionmentioning

confidence: 99%

“…Although the theoretical overpotential for a Li 2 O 2 film is only 0.2 V, the practical overpotential normally reaches as high as 1.5 V, because there are limitations on charge transport through the insulating Li 2 O 2 particles to the Li 2 O 2 -electrolyte interface. 9,11 Therefore, it is essential to lower the charge potential to improve Li-O 2 battery performance. So far, it has been identified that catalysts and appropriate non-aqueous electrolytes can effectively overcome these problems.…”

Section: Introductionmentioning

confidence: 99%

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Ruthenium nanocrystal decorated vertical graphene nanosheets@Ni foam as highly efficient cathode catalysts for lithium-oxygen batteries

Seo

et al. 2016

NPG Asia Mater

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The electrochemical performance of lithium-oxygen (Li-O 2 ) batteries can be markedly improved through designing the architecture of cathode electrodes with sufficient spaces to facilitate the diffusion of oxygen and accommodate the discharge products, and optimizing the cathode catalyst to promote the oxygen reduction reaction and oxygen evolution reaction (OER). Herein, we report the synthesis of ruthenium (Ru) nanocrystal-decorated vertically aligned graphene nanosheets (VGNS) grown on nickel (Ni) foam. As an effective binder-free cathode catalyst for Li-O 2 batteries, the Ru-decorated VGNS@Ni foam can significantly reduce the charge overpotential via the effects on the OER and achieve high specific capacity, leading to an enhanced electrochemical performance. The Ru-decorated VGNS@Ni foam electrode has demonstrated low charge overpotential of~0.45 V and high reversible capacity of 23 864 mAh g − 1 at the current density of 200 mA g − 1 , which can be maintained for 50 cycles under full charge and discharge testing condition in the voltage range of 2.0-4.2 V. Furthermore, Ru nanocrystal decorated VGNS@Ni foam can be cycled for more than 200 cycles with a low overpotential of 0.23 V under the capacity curtained to be 1000 mAh g − 1 at a current density of 200 mA g − 1 . Ru-decorated VGNS@Ni foam electrodes have also achieved excellent high rate and long cyclability performance. This superior electrochemical performance should be ascribed to the unique three-dimensional porous nanoarchitecture of the VGNS@Ni foam electrodes, which provide sufficient pores for the diffusion of oxygen and storage of the discharge product (Li 2 O 2 ), and the effective catalytic effect of Ru nanocrystals on the OER, respectively. Ex situ field emission scanning electron microscopy, X-ray diffraction, Raman and Fourier transform infrared measurements revealed that Ru-decorated VGNS@Ni foam can effectively decompose the discharge product Li 2 O 2 , facilitate the OER and lead to a high round-trip efficiency. Therefore, Ru-decorated VGNS@Ni foam is a promising cathode catalyst for rechargeable Li-O 2 batteries with low charge overpotential, long cycle life and high specific capacity.

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Three-dimensional graphene–Co₃O₄ cathodes for rechargeable Li–O₂ batteries

Abstract: A three-dimensional (3D) graphene–Co3O4 electrode was prepared by a two-step method and this binder-free monolithic electrode exhibited enhanced performance for rechargeable Li–O2 batteries.

Cited by 92 publications

References 54 publications

Boosting the Electrocatalytic Activity of Co₃O₄ Nanosheets for a Li-O₂ Battery through Modulating Inner Oxygen Vacancy and Exterior Co³⁺/Co²⁺ Ratio

Boosting the Electrocatalytic Activity of Co₃O₄ Nanosheets for a Li-O₂ Battery through Modulating Inner Oxygen Vacancy and Exterior Co³⁺/Co²⁺ Ratio

Hierarchical Structures Based on Two‐Dimensional Nanomaterials for Rechargeable Lithium Batteries

Ruthenium nanocrystal decorated vertical graphene nanosheets@Ni foam as highly efficient cathode catalysts for lithium-oxygen batteries

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Three-dimensional graphene–Co3O4 cathodes for rechargeable Li–O2 batteries

Abstract: A three-dimensional (3D) graphene–Co3O4 electrode was prepared by a two-step method and this binder-free monolithic electrode exhibited enhanced performance for rechargeable Li–O2 batteries.

Cited by 92 publications

References 54 publications

Boosting the Electrocatalytic Activity of Co3O4 Nanosheets for a Li-O2 Battery through Modulating Inner Oxygen Vacancy and Exterior Co3+/Co2+ Ratio

Boosting the Electrocatalytic Activity of Co3O4 Nanosheets for a Li-O2 Battery through Modulating Inner Oxygen Vacancy and Exterior Co3+/Co2+ Ratio

Hierarchical Structures Based on Two‐Dimensional Nanomaterials for Rechargeable Lithium Batteries

Ruthenium nanocrystal decorated vertical graphene nanosheets@Ni foam as highly efficient cathode catalysts for lithium-oxygen batteries

Contact Info

Product

Resources

About

Three-dimensional graphene–Co₃O₄ cathodes for rechargeable Li–O₂ batteries

Boosting the Electrocatalytic Activity of Co₃O₄ Nanosheets for a Li-O₂ Battery through Modulating Inner Oxygen Vacancy and Exterior Co³⁺/Co²⁺ Ratio

Boosting the Electrocatalytic Activity of Co₃O₄ Nanosheets for a Li-O₂ Battery through Modulating Inner Oxygen Vacancy and Exterior Co³⁺/Co²⁺ Ratio