6

Technical Report

Pb-Sb Pb-Sb 2, 3.

1

Pb-Ca 1)

Electrochemical Property of Lead Dioxide Formed on Various Lead Alloy Substrates

* * *

** **

Masashi ShiotaTsuyoshi KamedaKazumasa MatsuiNobumitsu HiraiToshihiro Tanaka

Electrochemical properties of lead dioxides, formed on various lead alloy substrates of Pb-Al, Pb-Ga, Pb-Ge, Pb-In, Pb-Sn, Pb-Sb, Pb-Tl, and Pb-Bi, have been investigated using electrochemical techniques with X-ray diffraction (XRD) and electron probe micro analyzer (EPMA). It was found that the reduction capacity of lead dioxides was increased with the additive element of Al, Ga, In, Tl, and Bi, while its capasity was decreased with the element of Ge, Sn, and Sb. The mechanism of the capacity change was also investigated by the careful consideration on the change of the lattice constant of -lead dioxides and the distribution of additive elements in the lead dioxide layer. In conclusion, the reduction capacity of lead dioxides is found to be strongly depedent on the change in value of columbic bonding strength between metallic ion and oxygen ion.

Abstract

*

** 2005 GS Yuasa Corporation, All rights reserved.

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GS Yuasa Technical Report 2005 6 2 1

2

2.1

Ar-10% H2 Fig. 1 AlGaGeInSnSbTl Bi Ar-10% H2 30 100 10 470 170 100 mm 20 mm 2 mm2.2 Fig. 2

#240 #400 #600 #800 #1000

1.250 g cm-3 (Hg / Hg2SO4) (PbO2) HZ- 3000 -1400 mV (vs. Hg / Hg2SO4 ) -1200 mV 10 25 2.32.2 1250 mV 10

Polishing with abrasive papers followed by buffingwith fine Al2 O3 powder

Polishing chemically with mixed solutionof CH3COOH and H2O2

Wiping with cloth absorbed ethanol

Reduction at -1400 mV vs. Hg / Hg 2 SO4 for 10 min. followed by -1200 mV vs. Hg / Hg2SO4 for 10 min.

Assembling the test cell with electrode followed by filling electrolyte

Fig. 2Procedure of pretreatment of lead alloy elec-trode.

Ar -10% H2

Heating inductor

Thermocouple (CA -K type)

Crucible (Carbon)

O-ring

Sample

Quartz glassCoolant circulationunit

High frequencyGenerator

Matching sectionoutput transformer

Fig. 1High frequency induction heating device for preparation of lead alloy substrates.

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GS Yuasa Technical Report 2005 6 2 1

950 mV 30 10 10 1250 mV (PbO2 ) 950 mV (PbSO4 ) 2.4XRD EPMA

XRD (RINT 2500 V)

20 60 0.5 min-1 0.002 40 kV 200 mA

EPMA (EPMA- 8705)

3

3.1 2.3 Fig. 3 1 atom% Table 1

0

20

40

60

0

20

40

60

0

20

40

60

0

20

40

60

0

20

40

60

0

20

40

60

0

20

40

60

0.0 2.0 4.0 6.0

0

20

40

60

Aluminium concentration / atom%

Red

uctio

n ca

paci

ty/

Ah c

m-2

Gallium concentration / atom%

Red

uctio

n ca

paci

ty/

Ah c

m-2

Germanium concentration / atom%

Red

uctio

n ca

paci

ty/

Ah c

m-2

Indium concentration / atom%

Red

uctio

n ca

paci

ty/

Ah c

m-2

Tin concentration / atom%

Red

uctio

n ca

paci

ty/

Ah c

m-2

Thallium concentration / atom%

Red

uctio

n ca

paci

ty/

Ah c

m-2

Bismuth concentration / atom%

Red

uctio

n ca

paci

ty/

Ah c

m-2

Antimony concentration / atom%

Red

uctio

n ca

paci

ty/

Ah c

m-2

0.0 2.0 4.0 6.0

0.0 2.0 4.0 6.0

0.0 2.0 4.0 6.0

0.0 2.0 4.0 6.0

0.0 2.0 4.0 6.0

0.0 2.0 4.0 6.0 0.0 2.0 4.0 6.0

Fig. 3Electrochemical reduction capacity of lead dioxide formed on various lead alloy substrates.

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GS Yuasa Technical Report 2005 6 2 1

Pb-GePb-Sb Pb-Sn Pb-AlPb-GaPb-InPb-Tl Pb-Bi 3.2

( HF VH-8000 ) Pb-InPb-SnPb-SbPb-Tl Pb-Bi Fig. 4 Pb-3 mass% InPb-3 mass% Sn Pb-3 mass% Tl Pb-3 mass% Sb Pb-3 mass% Bi 3.3XRD3.3.1 -PbO2 -PbO2 -PbO2 -PbO2 4)-PbO2 -PbO2 Pb-InPb-SnPb-

SbPb-Tl Pb-Bi -PbO2 -PbO2 XRD-PbO2 (111) -PbO2 (101)

Pb-3 mass% In Pb-3 mass% Sn Pb-3 mass% Sb

Pb-3 mass% Tl Pure Pb Pb-3 mass% Bi100

Fig. 4Microstructure of pure lead and its alloy substrates.

Element Reduction capacity/ Ah cm-2

Pb 32.3

Al 33.7

Ga 33.4

Ge 32.2

In 34.5

Sn 31.2

Sb 27.9

Tl 39.5

Bi 41.3

Table 1Interpolated reduction capacity* of lead dioxide with 1 atom% addition of each additive.

*Obtained by linear relation of Fig. 3.

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GS Yuasa Technical Report 2005 6 2 1

Table 2 -PbO2/-PbO2 Pb-In > Pb-Sn = Pb-Bi > Pb-Tl > pure Pb = Pb-Sb -PbO2 -PbO2 -PbO2 3.3.2-PbO2 Pb-InPb-SnPb-SbPb-Tl Pb-Bi

-PbO2 101211Fig. 5-PbO2 ca, b -PbO2 -PbO2 a, b Pb-Sb Pb-Sn a, b Pb-InPb-Tl Pb-Bi

Fig. 3 -PbO2 3.4EPMA (Sb, Sn, In, Tl, Bi) EPMAFig. 6 3.5XRD EPMA (1) (2) PbO2+4H++2e-Pb

2++2H2O ( 1 )

Pb2++SO42-PbSO4 ( 2 )

- - - - -Lux 5) -Ai* (3)

)3()40.1(2

)( 22*

2

2

+

=+

=

-

-

i

i

Oi

Oii r

Zrr

ZZA

( 3 )

Zi ZO2- (2)r i rO2- (1.40 ) -Bi* (4)

Substrate -PbO2 (101)/-PbO2 (111)

Pure Pb 1.3

Pb-3 mass% In 2.5

Pb-3 mass% Sn 1.9

Pb-3 mass% Sb 1.3

Pb-3 mass% Tl 1.7

Pb-3 mass% Bi 1.9

Table 2Ratio of -PbO2 to -PbO2.

4.944.96

4.985.00

5.025.04

5.065.08

Pb-Sb Pb-Sn Pure Pb Pb-In Pb-Tl Pb-Bi3.303.32

3.343.36

3.383.40

3.423.44

a, b

/

c /

Fig. 5Lattice constant of -PbO2 formed on sur-face of various alloy substrates.

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GS Yuasa Technical Report 2005 6 2 1

)4(1*

*

ii AB = ( 4 )

Bi* -

Fig. 6Distribution of various elements in alloy substrate (a) and lead dioxide layer (b) formed on its substrate.

Bi* Table 3 Bi* Fig. 7 pH diagram6) pH=-1

Sn distributionon lead dioxide

Sn distributionon substrate

In distributionon lead dioxide

In distributionon substrate

Sb distributionon lead dioxide

Sb distributionon substrate

Low Element conc. High

Tl distributionon substrate

Bi distributionon substrate

Tl distributionon lead dioxide

Bi distributionon lead dioxide

10 m

(a) (b)

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GS Yuasa Technical Report 2005 6 2 1

4

XRDEPMA(1) , Pb-Sb, Pb-Sn, Pb-In, Pb-Tl Pb-Bi-PbO2 c -PbO2 a, b

(2) , Pb-Sb, Pb-Sn, Pb-In, Pb-Tl Pb-Bi-PbO2 a, b a, b

(3) AlGaGeInSnSbTl Bi -Bi*

1) M. Torralba, Journal of Power Sources , 1, 301 (1976/77).

2) M. Shiota, Y. Yamaguchi, Y. Nakayama, N. Hirai, and S. Hara, Journal of Power Sources, 113, 277 (2003).

3) M. Shiota, Y. Yamaguchi, Y. Nakayama, N. Hirai, and S. Hara, YUASA JIHO, 94, 5 (2003).

4) Y. Matsuda and Z. Takehara , P.191 (1990)

5) H. Lux, Z. Electrochem., 45, 303 (1939).6) M. Pourbaix, Atlas of Electrochemical Equilibria in Aqueous Solutions , 2nd edition, National Associa-tion of Corrosion Engineers, Houston TX (1974).

7) R. D. Shannon, Acta Crystallogr.Sect.A, 32, 751 (1976).

1600 mV vs. NHE (pH=-1 / ) (Table 3 ) 6Shannon7) (Table 3 )Fig. 7 AlGaGeInSnSbTl Bi Bi* -

20

30

40

50

0.0 0.5 1.0 1.5

Pb4+

Sb5+

In3+

Tl3+Bi 3+

Ga3+Al3+

Sn4+

Ge4+

Red

uctio

n ca

paci

ty/

Ah c

m-2

Index i*B

Fig. 7Relationship between electrochemical re-duction capacity and reciprocal value of columbic bonding strength for metallic ion and oxygen ion ex-pressed by formula of (ri+1.40)2/2 Zi. ri : Radius of metallic ionZi : Valence of metallic ion

Element Oxide Valence Ion radius/

IndexBi*

Al Al2O3 3 0.535 0.62

Ga Ga2O3 3 0.62 0.68

Ge GeO2 4 0.53 0.47

In In2O3 3 0.80 0.81

Sn SnO2 4 0.69 0.55

Sb Sb2O5 5 0.60 0.40

Tl Tl2O3 3 0.885 0.87

Pb PbO 4 0.775 0.59

Bi Bi2O3 3 1.030 0.98

Table 3Index value of Bi* for bonding strength of metallic ion and oxygen.