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Carbon-based electrocatalysts for advanced energy conversion and storage.

Zhang J, Xia Z, Dai L - Sci Adv (2015)

Bottom Line: Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) play curial roles in electrochemical energy conversion and storage, including fuel cells and metal-air batteries.Having rich multidimensional nanoarchitectures [for example, zero-dimensional (0D) fullerenes, 1D carbon nanotubes, 2D graphene, and 3D graphite] with tunable electronic and surface characteristics, various carbon nanomaterials have been demonstrated to act as efficient metal-free electrocatalysts for ORR and OER in fuel cells and batteries.We present a critical review on the recent advances in carbon-based metal-free catalysts for fuel cells and metal-air batteries, and discuss the perspectives and challenges in this rapidly developing field of practical significance.

View Article: PubMed Central - PubMed

Affiliation: Center of Advanced Science and Engineering for Carbon (Case4Carbon), Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.

ABSTRACT
Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) play curial roles in electrochemical energy conversion and storage, including fuel cells and metal-air batteries. Having rich multidimensional nanoarchitectures [for example, zero-dimensional (0D) fullerenes, 1D carbon nanotubes, 2D graphene, and 3D graphite] with tunable electronic and surface characteristics, various carbon nanomaterials have been demonstrated to act as efficient metal-free electrocatalysts for ORR and OER in fuel cells and batteries. We present a critical review on the recent advances in carbon-based metal-free catalysts for fuel cells and metal-air batteries, and discuss the perspectives and challenges in this rapidly developing field of practical significance.

No MeSH data available.


Related in: MedlinePlus

Schematic representation of a hybrid Li-air battery.The enlarged image shows the basic reaction process in the air electrode based on NG. [From E. Yoo, J. Nakamura, H. Zhou, N-Doped graphene nanosheets for Li–air fuel cells under acidic conditions. Energy Environ. Sci.5, 6928–6932 (2012). Reprinted with permission from the Royal Society of Chemistry.]
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Figure 10: Schematic representation of a hybrid Li-air battery.The enlarged image shows the basic reaction process in the air electrode based on NG. [From E. Yoo, J. Nakamura, H. Zhou, N-Doped graphene nanosheets for Li–air fuel cells under acidic conditions. Energy Environ. Sci.5, 6928–6932 (2012). Reprinted with permission from the Royal Society of Chemistry.]

Mentions: For the aqueous Li-air battery, the presence of water requires a protective layer on the Li anode to prevent lithium metal from reacting with water. An aqueous electrolyte is used at the cathode (air) side, which is separated from lithium metal by a solid-state electrolyte [a lithium super-ion conductor glass film (LISICON)]. The interface between lithium and LISICON is filled with a thin buffer (electrolyte) polymer to prevent reduction of the solid electrolyte (135, 139, 157, 158). Figure 10 shows the typical configuration of a hybrid Li-air battery, in which N-doped GNSs are used as an air electrode (158). For the cathode side with aqueous electrolytes, the knowledge from conventional ORR catalysts may be straightforwardly applied. So far, however, only a few studies have been done on the use of carbon electrocatalysts in aqueous or hybrid Li-O2 cells (159). Owing to the presence of edge defect sites in GNSs, the metal-free GNS air electrodes in hybrid Li-air batteries showed a comparable and even superior discharge voltage to that of the 20 wt % Pt/C (159). It was further found that proper thermal treatment of graphene sheets could enhance the catalytic activity toward ORR and also improve the cycling stability. This is because the thermal treatment can remove adsorbed functional groups and improve the graphitization degree of the GNS electrodes.


Carbon-based electrocatalysts for advanced energy conversion and storage.

Zhang J, Xia Z, Dai L - Sci Adv (2015)

Schematic representation of a hybrid Li-air battery.The enlarged image shows the basic reaction process in the air electrode based on NG. [From E. Yoo, J. Nakamura, H. Zhou, N-Doped graphene nanosheets for Li–air fuel cells under acidic conditions. Energy Environ. Sci.5, 6928–6932 (2012). Reprinted with permission from the Royal Society of Chemistry.]
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4643813&req=5

Figure 10: Schematic representation of a hybrid Li-air battery.The enlarged image shows the basic reaction process in the air electrode based on NG. [From E. Yoo, J. Nakamura, H. Zhou, N-Doped graphene nanosheets for Li–air fuel cells under acidic conditions. Energy Environ. Sci.5, 6928–6932 (2012). Reprinted with permission from the Royal Society of Chemistry.]
Mentions: For the aqueous Li-air battery, the presence of water requires a protective layer on the Li anode to prevent lithium metal from reacting with water. An aqueous electrolyte is used at the cathode (air) side, which is separated from lithium metal by a solid-state electrolyte [a lithium super-ion conductor glass film (LISICON)]. The interface between lithium and LISICON is filled with a thin buffer (electrolyte) polymer to prevent reduction of the solid electrolyte (135, 139, 157, 158). Figure 10 shows the typical configuration of a hybrid Li-air battery, in which N-doped GNSs are used as an air electrode (158). For the cathode side with aqueous electrolytes, the knowledge from conventional ORR catalysts may be straightforwardly applied. So far, however, only a few studies have been done on the use of carbon electrocatalysts in aqueous or hybrid Li-O2 cells (159). Owing to the presence of edge defect sites in GNSs, the metal-free GNS air electrodes in hybrid Li-air batteries showed a comparable and even superior discharge voltage to that of the 20 wt % Pt/C (159). It was further found that proper thermal treatment of graphene sheets could enhance the catalytic activity toward ORR and also improve the cycling stability. This is because the thermal treatment can remove adsorbed functional groups and improve the graphitization degree of the GNS electrodes.

Bottom Line: Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) play curial roles in electrochemical energy conversion and storage, including fuel cells and metal-air batteries.Having rich multidimensional nanoarchitectures [for example, zero-dimensional (0D) fullerenes, 1D carbon nanotubes, 2D graphene, and 3D graphite] with tunable electronic and surface characteristics, various carbon nanomaterials have been demonstrated to act as efficient metal-free electrocatalysts for ORR and OER in fuel cells and batteries.We present a critical review on the recent advances in carbon-based metal-free catalysts for fuel cells and metal-air batteries, and discuss the perspectives and challenges in this rapidly developing field of practical significance.

View Article: PubMed Central - PubMed

Affiliation: Center of Advanced Science and Engineering for Carbon (Case4Carbon), Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.

ABSTRACT
Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) play curial roles in electrochemical energy conversion and storage, including fuel cells and metal-air batteries. Having rich multidimensional nanoarchitectures [for example, zero-dimensional (0D) fullerenes, 1D carbon nanotubes, 2D graphene, and 3D graphite] with tunable electronic and surface characteristics, various carbon nanomaterials have been demonstrated to act as efficient metal-free electrocatalysts for ORR and OER in fuel cells and batteries. We present a critical review on the recent advances in carbon-based metal-free catalysts for fuel cells and metal-air batteries, and discuss the perspectives and challenges in this rapidly developing field of practical significance.

No MeSH data available.


Related in: MedlinePlus