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Simple synthesis of highly catalytic carbon-free MnCo2O4@Ni as an oxygen electrode for rechargeable Li-O2 batteries with long-term stability.

Kalubarme RS, Jadhav HS, Ngo DT, Park GE, Fisher JG, Choi YI, Ryu WH, Park CJ - Sci Rep (2015)

Bottom Line: The highly porous structure of the electrode allows the electrolyte and oxygen to diffuse effectively into the catalytically active sites and hence improve the cell performance.The Li-O2 cell has demonstrated a cyclability of 119 cycles while maintaining a moderate specific capacity of 1000 mAh g(-1).Furthermore, the synergistic effect of the fast kinetics of electron transport provided by the free-standing structure and the high electro-catalytic activity of the spinel oxide enables excellent performance of the oxygen electrode for Li-O2 cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Material Science and Engineering, Chonnam National University, 77, Yongbongro, Bukgu, Gwangju 500-757, South Korea.

ABSTRACT
An effective integrated design with a free standing and carbon-free architecture of spinel MnCo2O4 oxide prepared using facile and cost effective hydrothermal method as the oxygen electrode for the Li-O2 battery, is introduced to avoid the parasitic reactions of carbon and binder with discharge products and reaction intermediates, respectively. The highly porous structure of the electrode allows the electrolyte and oxygen to diffuse effectively into the catalytically active sites and hence improve the cell performance. The amorphous Li2O2 will then precipitate and decompose on the surface of free-standing catalyst nanorods. Electrochemical examination demonstrates that the free-standing electrode without carbon support gives the highest specific capacity and the minimum capacity fading among the rechargeable Li-O2 batteries tested. The Li-O2 cell has demonstrated a cyclability of 119 cycles while maintaining a moderate specific capacity of 1000 mAh g(-1). Furthermore, the synergistic effect of the fast kinetics of electron transport provided by the free-standing structure and the high electro-catalytic activity of the spinel oxide enables excellent performance of the oxygen electrode for Li-O2 cells.

No MeSH data available.


Related in: MedlinePlus

(a) Cathodic linear sweep voltammogram and (b) anodic linear sweep voltammogram for the free-standing MnCo2O4 (FSMCO), MnCo2O4 (MCO)+Ketjen Black (KB), and Ketjen black (KB) electrodes in non-aqueous electrolyte containing 1 M LiTFSI in TEGDME.
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f3: (a) Cathodic linear sweep voltammogram and (b) anodic linear sweep voltammogram for the free-standing MnCo2O4 (FSMCO), MnCo2O4 (MCO)+Ketjen Black (KB), and Ketjen black (KB) electrodes in non-aqueous electrolyte containing 1 M LiTFSI in TEGDME.

Mentions: The ORR and OER catalytic activities of the free-standing MnCo2O4 (FSMCO) nanorod arrays formed on Ni foam were assessed in an O2-saturated non-aqueous electrolyte of 1 M Bis(trifluoromethane) sulfonimide lithium salt (LiTFSI) in tetra-ethylene glycol dimethyl ether (TEGDME). In addition, the results were compared with the data obtained for the electrode composed of Ketjen black (KB) and the electrode composed of a physical blend of KB and MnCo2O4 (1:1) (KB-MCO). A commercial three-electrode cell (ECC-air; EL-CELL®) using the working electrode of interest, the counter electrode of Li metal and the reference electrode, also of Li metals were used for the tests23. Figure 3a shows the cathodic linear sweep voltamograms (LSV) for KB, KB-MCO, and FSMCO measured in 1M LiTFSI in TEGDME at a scan rate of 0.5 mV·s−1 in the potential range of 3.1 ~ 1.8 V vs Li/Li+. It can be seen that the addition of MnCo2O4 to the KB electrode resulted in higher ORR onset potential and higher ORR peak current density. Nevertheless, the ORR onset potential and ORR peak current density for the FSMCO electrode were higher than those of the other two electrodes. In particular, the peak current density for the FSMCO electrode (−6.39 mA·cm−2) was approximately 3 times higher than that of the KB-MCO electrode (−2.19 mA·cm−2) and 5 times higher than that of the KB electrode (−1.25 mA·cm−2). Apparently, the free-standing MnCo2O4 nanorod arrays demonstrated higher activity for ORR compared to KB blended with MnCo2O4.


Simple synthesis of highly catalytic carbon-free MnCo2O4@Ni as an oxygen electrode for rechargeable Li-O2 batteries with long-term stability.

Kalubarme RS, Jadhav HS, Ngo DT, Park GE, Fisher JG, Choi YI, Ryu WH, Park CJ - Sci Rep (2015)

(a) Cathodic linear sweep voltammogram and (b) anodic linear sweep voltammogram for the free-standing MnCo2O4 (FSMCO), MnCo2O4 (MCO)+Ketjen Black (KB), and Ketjen black (KB) electrodes in non-aqueous electrolyte containing 1 M LiTFSI in TEGDME.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4543937&req=5

f3: (a) Cathodic linear sweep voltammogram and (b) anodic linear sweep voltammogram for the free-standing MnCo2O4 (FSMCO), MnCo2O4 (MCO)+Ketjen Black (KB), and Ketjen black (KB) electrodes in non-aqueous electrolyte containing 1 M LiTFSI in TEGDME.
Mentions: The ORR and OER catalytic activities of the free-standing MnCo2O4 (FSMCO) nanorod arrays formed on Ni foam were assessed in an O2-saturated non-aqueous electrolyte of 1 M Bis(trifluoromethane) sulfonimide lithium salt (LiTFSI) in tetra-ethylene glycol dimethyl ether (TEGDME). In addition, the results were compared with the data obtained for the electrode composed of Ketjen black (KB) and the electrode composed of a physical blend of KB and MnCo2O4 (1:1) (KB-MCO). A commercial three-electrode cell (ECC-air; EL-CELL®) using the working electrode of interest, the counter electrode of Li metal and the reference electrode, also of Li metals were used for the tests23. Figure 3a shows the cathodic linear sweep voltamograms (LSV) for KB, KB-MCO, and FSMCO measured in 1M LiTFSI in TEGDME at a scan rate of 0.5 mV·s−1 in the potential range of 3.1 ~ 1.8 V vs Li/Li+. It can be seen that the addition of MnCo2O4 to the KB electrode resulted in higher ORR onset potential and higher ORR peak current density. Nevertheless, the ORR onset potential and ORR peak current density for the FSMCO electrode were higher than those of the other two electrodes. In particular, the peak current density for the FSMCO electrode (−6.39 mA·cm−2) was approximately 3 times higher than that of the KB-MCO electrode (−2.19 mA·cm−2) and 5 times higher than that of the KB electrode (−1.25 mA·cm−2). Apparently, the free-standing MnCo2O4 nanorod arrays demonstrated higher activity for ORR compared to KB blended with MnCo2O4.

Bottom Line: The highly porous structure of the electrode allows the electrolyte and oxygen to diffuse effectively into the catalytically active sites and hence improve the cell performance.The Li-O2 cell has demonstrated a cyclability of 119 cycles while maintaining a moderate specific capacity of 1000 mAh g(-1).Furthermore, the synergistic effect of the fast kinetics of electron transport provided by the free-standing structure and the high electro-catalytic activity of the spinel oxide enables excellent performance of the oxygen electrode for Li-O2 cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Material Science and Engineering, Chonnam National University, 77, Yongbongro, Bukgu, Gwangju 500-757, South Korea.

ABSTRACT
An effective integrated design with a free standing and carbon-free architecture of spinel MnCo2O4 oxide prepared using facile and cost effective hydrothermal method as the oxygen electrode for the Li-O2 battery, is introduced to avoid the parasitic reactions of carbon and binder with discharge products and reaction intermediates, respectively. The highly porous structure of the electrode allows the electrolyte and oxygen to diffuse effectively into the catalytically active sites and hence improve the cell performance. The amorphous Li2O2 will then precipitate and decompose on the surface of free-standing catalyst nanorods. Electrochemical examination demonstrates that the free-standing electrode without carbon support gives the highest specific capacity and the minimum capacity fading among the rechargeable Li-O2 batteries tested. The Li-O2 cell has demonstrated a cyclability of 119 cycles while maintaining a moderate specific capacity of 1000 mAh g(-1). Furthermore, the synergistic effect of the fast kinetics of electron transport provided by the free-standing structure and the high electro-catalytic activity of the spinel oxide enables excellent performance of the oxygen electrode for Li-O2 cells.

No MeSH data available.


Related in: MedlinePlus