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Catalytic properties of Co3O4 nanoparticles for rechargeable Li/air batteries.

Kim KS, Park YJ - Nanoscale Res Lett (2012)

Bottom Line: The electrochemical property of the air electrodes containing Co3O4 nanoparticles is significantly associated with the shape and size of the nanoparticles.It appears that the capacity of electrodes containing villiform-type Co3O4 nanoparticles is superior to that of electrodes containing cube- and flower-type Co3O4 nanoparticles.This is probably due to the sufficient pore spaces of the villiform-type Co3O4 nanoparticles.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Advanced Materials Engineering, Kyonggi University, San 94-6, Yiui-dong, Yeongtong-gu, Suwon, Gyeonggi-do, 443-760, Republic of Korea. yjpark2006@kyonggi.ac.kr.

ABSTRACT
Three types of Co3O4 nanoparticles are synthesized and characterized as a catalyst for the air electrode of a Li/air battery. The shape and size of the nanoparticles are observed using scanning electron microscopy and transmission electron microscopy analyses. The formation of the Co3O4 phase is confirmed by X-ray diffraction. The electrochemical property of the air electrodes containing Co3O4 nanoparticles is significantly associated with the shape and size of the nanoparticles. It appears that the capacity of electrodes containing villiform-type Co3O4 nanoparticles is superior to that of electrodes containing cube- and flower-type Co3O4 nanoparticles. This is probably due to the sufficient pore spaces of the villiform-type Co3O4 nanoparticles.

No MeSH data available.


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Electrochemical properties of the air electrode containing Co3O4 nanoparticles. Air electrode containing Co3O4 nanoparticles at a constant current density of 0.4 mA·cm-2 (voltage range of 4.35 to 2.3 V). (a) Initial voltage profile and (b) cyclic performance.
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Figure 3: Electrochemical properties of the air electrode containing Co3O4 nanoparticles. Air electrode containing Co3O4 nanoparticles at a constant current density of 0.4 mA·cm-2 (voltage range of 4.35 to 2.3 V). (a) Initial voltage profile and (b) cyclic performance.

Mentions: The electrochemical properties of the air electrodes containing Co3O4 nanoparticles were characterized at a constant current density of 0.4 mA·cm-2 at 30°C. Figure 3a shows the initial voltage profile of the electrodes containing the Co3O4 nanoparticles in the voltage range of 4.35 to 2.3 V. The discharge capacity shown in Figure 3 is based on the weight of carbon (Ketjen black) in the air electrode, which has generally been used for expressing the capacity of an air electrode [1,8,9,12]. The average charge and discharge voltages of the air electrode containing the Co3O4 nanoparticles were approximately 4.2 and 2.6 V, respectively. The initial discharge capacity of the electrode was highly dependent upon the type of Co3O4 nanoparticles. The electrode containing villiform-type Co3O4 nanoparticles showed a relatively higher initial discharge capacity (approximately 2, 900 mA h·g-1) than with the other electrodes. In contrast, the initial discharge capacities of the electrodes containing flower-type Co3O4 nanoparticles were just about 1, 800 mA h·g-1 although they have a shape very similar to the villiform-type Co3O4 nanoparticles. As shown in Figure 3b, the cyclic performance of the air electrodes was not satisfactory. Actually, capacity fading has been a typical feature of all previous results about air electrodes [8,12,13]. It has been known that cycle degradation is associated with irreversible reaction products, which accumulate in the pores of the electrode at a discharged state [13,14]. It seems that the practical rechargeability of air electrodes has yet to be achieved before these can be put to practical use.


Catalytic properties of Co3O4 nanoparticles for rechargeable Li/air batteries.

Kim KS, Park YJ - Nanoscale Res Lett (2012)

Electrochemical properties of the air electrode containing Co3O4 nanoparticles. Air electrode containing Co3O4 nanoparticles at a constant current density of 0.4 mA·cm-2 (voltage range of 4.35 to 2.3 V). (a) Initial voltage profile and (b) cyclic performance.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3275460&req=5

Figure 3: Electrochemical properties of the air electrode containing Co3O4 nanoparticles. Air electrode containing Co3O4 nanoparticles at a constant current density of 0.4 mA·cm-2 (voltage range of 4.35 to 2.3 V). (a) Initial voltage profile and (b) cyclic performance.
Mentions: The electrochemical properties of the air electrodes containing Co3O4 nanoparticles were characterized at a constant current density of 0.4 mA·cm-2 at 30°C. Figure 3a shows the initial voltage profile of the electrodes containing the Co3O4 nanoparticles in the voltage range of 4.35 to 2.3 V. The discharge capacity shown in Figure 3 is based on the weight of carbon (Ketjen black) in the air electrode, which has generally been used for expressing the capacity of an air electrode [1,8,9,12]. The average charge and discharge voltages of the air electrode containing the Co3O4 nanoparticles were approximately 4.2 and 2.6 V, respectively. The initial discharge capacity of the electrode was highly dependent upon the type of Co3O4 nanoparticles. The electrode containing villiform-type Co3O4 nanoparticles showed a relatively higher initial discharge capacity (approximately 2, 900 mA h·g-1) than with the other electrodes. In contrast, the initial discharge capacities of the electrodes containing flower-type Co3O4 nanoparticles were just about 1, 800 mA h·g-1 although they have a shape very similar to the villiform-type Co3O4 nanoparticles. As shown in Figure 3b, the cyclic performance of the air electrodes was not satisfactory. Actually, capacity fading has been a typical feature of all previous results about air electrodes [8,12,13]. It has been known that cycle degradation is associated with irreversible reaction products, which accumulate in the pores of the electrode at a discharged state [13,14]. It seems that the practical rechargeability of air electrodes has yet to be achieved before these can be put to practical use.

Bottom Line: The electrochemical property of the air electrodes containing Co3O4 nanoparticles is significantly associated with the shape and size of the nanoparticles.It appears that the capacity of electrodes containing villiform-type Co3O4 nanoparticles is superior to that of electrodes containing cube- and flower-type Co3O4 nanoparticles.This is probably due to the sufficient pore spaces of the villiform-type Co3O4 nanoparticles.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Advanced Materials Engineering, Kyonggi University, San 94-6, Yiui-dong, Yeongtong-gu, Suwon, Gyeonggi-do, 443-760, Republic of Korea. yjpark2006@kyonggi.ac.kr.

ABSTRACT
Three types of Co3O4 nanoparticles are synthesized and characterized as a catalyst for the air electrode of a Li/air battery. The shape and size of the nanoparticles are observed using scanning electron microscopy and transmission electron microscopy analyses. The formation of the Co3O4 phase is confirmed by X-ray diffraction. The electrochemical property of the air electrodes containing Co3O4 nanoparticles is significantly associated with the shape and size of the nanoparticles. It appears that the capacity of electrodes containing villiform-type Co3O4 nanoparticles is superior to that of electrodes containing cube- and flower-type Co3O4 nanoparticles. This is probably due to the sufficient pore spaces of the villiform-type Co3O4 nanoparticles.

No MeSH data available.


Related in: MedlinePlus