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NiCo2O4 @Ni As the New Air Electrode Material to Enhance the Performance in Rechargeable Zinc–Air Batteries Application

Wednesday, 4 October 2017
Prince George's Exhibit Hall D/E (Gaylord National Resort and Convention Center)

ABSTRACT WITHDRAWN

In recent years, pollution and shortage of fossil fuels in the environment have made it a popular trend to develop portable electronic devices, use renewable energy and grid-scale energy storage in electric vehicles. Batteries have long been recognized for their capacity to convert and store electrical energy efficiently. In the present work, rechargeable metal−air batteries such as Zn-air batteries could be idealized energy storage devices which have attracted much attention compared with lithium-ion batteries ,because Zn-air batteries possess high power density, economic viability and high safety.[1-2] Active and durable electrocatalysts on the cathode side are required to catalyse oxygen reduction reaction during discharge and oxygen evolution reaction during charge for rechargeable batteries.[3]

The aim of experiment is to synthesize mesoporous NiCo2O4@Ni. All the reagents used in this experiment were analytical grade and were used without further purification. In a typical synthetic procedure, a piece of nickel foam was thoroughly cleaned with 3 M HCl solution in an ultrasound bath for 30 minutes in order to remove the NiO layer on the surface and then washed by deionized water and absolute ethanol. Put it into watch glasses for drying. C4H6NiO4 • 4H2O (0.3 g), Co(NO3)2 • 6H2O (0.6 g) and hexamethylenetetramine (HMT, 0.8 g) were dissolved into a mixed solution of deionized water (30 mL) and ethanol (20 mL) under vigorous magnetic stirring. After stirring for 30 min, the as-obtained solution was transferred into a 60 mL polytetra-fluoroethylene (PTFE) (Teflon)-lined autoclave, and then use the cleaned nickel foam which has been worked to immerse into the reaction solution. The autoclave was sealed and maintained at 95 °C for 8 hours in an electric oven. After cooling to room temperature, the products on the nickel foam were washed with deionized water and absolute ethanol for several times respectively and then dried the nickel foam at 60°C overnight. Afterward, the samples were annealed at 250° C, 350° C and 450° C for 1h at a ramping rate of 1°C min-1 to transform into NiCo2O4@Ni-250, NiCo2O4@Ni-350 and NiCo2O4@Ni-450.

NiCo2O4@Ni-350 is a new air electrode material which has been synthesized via a hydrothermal method. This nanomaterial displays good bifunctional ORR/OER activity, cyclic stability, low cost and high energy density in the discharge and charge process. Further studies are ongoing to improve the Zn-Air batteries performance by manipulating the structure.

References

[1] D.U. Lee, J.Y. Choi, K. Feng, H.W. Park, Z.W. Chen, Advanced Energy Materials, 4,1301389(2014).

[2] P.C. Pei, Z. Ma, K.L. Wang, X.Z. Wang, M.C.Song, H.C.Xu, Journal Of Power Sources, 249,3(2014)

[3] V. Neburchilov, H.J. Wang, J.J. Martin, W. Qu, J. Power Sources 195,1271 (2010).