Electrospinning in solid oxide fuel cells – A review

Diameter of nanofibers depend on a number of processing parameters which can be divided into three categories:

1)Solution properties

2)Processing conditions

3)Operating conditions

Electrospinning in solid oxide fuel cells – A review

S.T. Aruna n, L.S. Balaji, S. Senthil Kumar, B. Shri Prakash

Future Challenges

1)Changes the microstructures of nanofibers when treated at elevated temperature.

2)If we used conventional powder-based anode resulting low power density.

Thank you!

Ni-based nanofiber anode:

1)Few applications of electrospinning for anode fabrication.

Ni based YSZ nanofibers.

2)Commonly 8YSZ with ethanol solution.

3)Higher power density than conventionally powder-derived anode in SOFC.

4)Due to nanofibers are well structured and interconnected with each other.

5)Nickel oxide-gadolinium doped ceria

(NiO–Ce 0.8Gd0.2O1.9)

Lanthanum Strontium Cobalt Ferrite (La0.6Sr0.4Co0.2Fe0.8O3-δ

1)Provides high density ,low polarization resistances.

2)Diameter range 250-300 nm.

3)Diameter can be reduced to 100 nm as shown

Types & properties of Polymers used in SOFC

1)polyvinyl pyrrolidone (PVP)

2)polyvinyl alcohol (PVA)

3)polyacrylo nitrile (PAN)

Properties of polymers:

1)less toxic

2)impart high viscosity

3)Facilitate high solubility

Steps involved in electrospining to final SOFC testing

Preparation of SSC –SDC amalgam

1)samarium nitrate (Sm(NO3)3 6H2O), cobalt nitrate (Co(NO3)3 6H2O) and cerium nitrate (Ce(NO3)3 H2O) precursors at 12 kV

2)For the precursor preparation, poly vinyl alcohol (PVA) is used at 15 wt% in some cases and polyvinylpyrrolidone (PVP) in other cases.

Types of ceramic materials used in electrospining:

1)lanthanum strontium cobalt ferrite (La0.6Sr0.4Co0.2Fe0.8O3-δ)

2)samarium strontium cobaltite (Sm0.5Sr0.5CoO3-δ)

3)samaria doped ceria (Sm0.2Ce0.8O1.9)

4)barium strontium cobalt ferric oxide (Ba0.5Sr0.5Co0.2Fe0.8O3-δ),

5)strontium yttria cobalt oxide (Sr0.7Y0.3CoO2.65-δ)

lanthanum strontium nickel oxide (La0.6Sr0.4NiO4).

A schematic representation of an electrospinning setup

key components are

1)high voltage power supply .

2)syringe with a needle.

3)metal collector .

Effect of applied voltage:

1)diameter of the nanofibers deposited on the collector 2)varies with the voltage supplied

3)diameter of the nanofiber decrease with the increase in voltage

4)Higher voltages tend to creates bead

5)Beads formation is the reduction of active surface area

LSCF VS LSCF-GDC

1)The power density of SOFC having LSCF-GCD nanofibres cathodes at 650 °C equals 850 mW/cm2 as compared to 450 mW/cm2 of LSCF powder cathodes.

2)Due to,higher porosity /mass as well as continuous porous channels which ease flow of ions.

3)Gadolinia doped ceria (GDC) improves electro-catalytic activity reducing polarization resistance.

4)The activation energy is relatively low fr LSCF-GDC cathodes.

5)Polarization resitances of LSCF-GCD lower than LSCF

Polymers used in Electrospinning

Research contribution to this technology

SOLID OXIDE FUEL CELL

1)Nylon, polyurethanes, polycarbonate, poly vinyl alcohol, poly lactic acid, polyethylene-o-vinyl acetate, poly- methacrylate, polyethylene oxide, collagen, polyaniline and cellulose are Electrospun in solution form.

2)polyethylene, polypropylene nylon 12, polyethylene terephthalate are electrospun in melt form.

3)water, formic acid, toluene,acetone, ethanol and HCl are the Solvents.

Samarium strontium cobaltite (Sm0.5Sr0.5CoO3-δ) and samaria doped ceria (Sm0.2Ce0.8O1.9

Electrospining

1)These increase performance of SOFC at lower temperatures.

2)SDC embedded in SSC provides low polarization resistance.

a)highly ionic conducting nature of SDC

b)mixed ionic/electronic conducting SSC

3)Diameter ranges from 20-100 nm after sintering .

4)Reduction in diameter (10-40 nm) is possible subjecting the electrospun and calcined fiber to ultrasonic vibration

Effect of distance between needle and collector:

1)distance between the needle and the collector directly affects the electric field on the precursor solution

2)increase in the diameter of the nanofibers is not substantial

3)Increase in the distance between the needle tip and the metal collector increases diameter of the circular nanofiber effectively

4)The optimum distance between the needle and the collector is found to be 10 cm

Article history:

Received 30 December 2015

Received in revised form

25 July 2016

Accepted 3 September 2016

Available online 25 October 2016

Group Members

Effect of polymer concentration

summary

Electrospinning parameters

Abstract

1)Useful technique having lot more advantages over conventional methods.

2)Cost Effective

3)May have potential to become main stream technology for SOFC.

1.Bilal Bashir

2.Muhammad Zeeshan

3.Muhammad Zulqarnain Arif.

4.Hafiz Ijaz Tahir

1)determines the spin ability

2)Changes the physical and morphological properties of the nanofibers

3)Optimum polymer concentration should be used

4)Polymer concentration required for electrospinning varies with different polymers

Electrospinning is an efficient technique for the fabrication of polymer/ceramic nanofibers. Efforts are made to increase the performance of SOFCs and also decreasing the cost by different approaches and strategies. The performance of a SOFC can be altered by changing the composition and microstructure of the cathode. The research activities in this field is presented along with the challenges and future prospects of electrospinning in SOFCs.