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Publication numberUS3854940 A
Publication typeGrant
Publication dateDec 17, 1974
Filing dateAug 27, 1973
Priority dateJun 8, 1970
Publication numberUS 3854940 A, US 3854940A, US-A-3854940, US3854940 A, US3854940A
InventorsHoekje H
Original AssigneePpg Industries Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Electroconductive, corrosion resistant high silicon alloy
US 3854940 A
Abstract
Disclosed is a silicon base alloy containing sufficient dopant to provide an electrical conductivity in excess of 100 (ohm-centimeters)<->1, and sufficient transition group metal to provide a volumetric coefficient of expansion upon solidification of less than about 10 percent, and balance silicon.
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United States Patent Related US. Application Data US. Cl 75/134 S, 204/293 Int. Cl. B01k 3/06, COld 1/08, COlb 11/25 Field of Search 75/134 S, 122, 123 L;

References Cited UNITED STATES PATENTS 1/1970 Bianchi et a1 204/293 X Hoek'e Dec. 17 1974 .l 9

[54] fi g iggfigg iig g ffifg FOREIGN PATENTS OR APPLICATIONS 7,003,774 9/1970 Netherlands 204/292 [75] Inventor: Howard H. Hoekje, Akron, Ohio [73] Assignee: PPG Industries, Inc., Pittsburgh, Pa. OTHER PUBLICATIONS Filedi g- 1973 Effect of Boron on the Resistivity and Rectification [21] AppL No 391,118 Characteristics of Silicon," Metal Transactions, Vol.

185, June 1949, Pp- 385-388.

Primary ExaminerL. Dewayne Rutledge Assistant Examiner-Arthur J. Steiner Attorney, Agent, orFirm-Richard M. Goldman [5 7] ABSTRACT Disclosed is a silicon base alloy containing sufficient dopant to provide an electrical conductivity in excess of 100 (ohm-centimeters), and sufficient transition group metal to provide a volumetric coefficient of expansion upon solidification of less than about 10 percent. and balance silicon.

16 Claims, 5 Drawing Figures PATENTED 5531 71974 3,854, 940

SHEET 1 [1F 5 PATENTEI] DEC] 7 I974 SHEET 2 BF 5 FIG PATENTED mm 7 m4 SHEET 5 OF 5 FIG ELECTROCONDUCTIVE, CORROSION RESISTANT HIGH SILICON ALLOY CROSS-REFERENCE TO RELATED APPLICATIONS This is a continuation-in-part of my commonly assigned copending U.S. Application Ser. No. 260,790 filed June 8, 1972, of my commonly assigned copending U.S. Application Ser. No. 336,288 filed Feb. 27, 1973 which is in turn a continuation-in-part of said U.S. Application Ser. No. 260,790, and of my commonly assigned co-pending U.S. Application Ser. No. 356,972 filed May 3, 1973, which is in turn a continuation-in-part of said U.S. Application Ser. No. 336,288 and of said U.S. Application Ser. No. 260,790.

BACKGROUND OF THE INVENTION Elemental silicon and alloys containing large amounts of elemental silicon have been found to provide a particularly outstanding electroconductive material for use in acidic media, such as anodes for electrolytic cells. Such anodes are particularly described in my commonly assigned, co-pending applications for Electrodes Having Silicon Base Members" filed June 8, 1972, Ser. No. 260,790. Such silicon anodes, while having satisfactory electrochemical properties, have been difficult to cast, and have been characterized by a higher degree of brittleness, i.e., a lower impact strength, than is desired for such service.

SUMMARY It has surprisingly now been found that a particularly satisfactory electrode may be provided by a silicon alloy containing sufficient dopant to provide an electrical conductivity of greater than about 100 (ohmcentimeters) and sufficient transition metal to provide a volumetric expansion coefficient, upon solidification, of less than the plus percent expansion characteristic of silicon itself. Such alloys are characterized by a predominant, discontinuous, silicon-rich phase, substantially continuous rivulets of a transition metalrich phase surrounding the silicon rich phase and forming the boundaries thereof, and discrete nodules of a dopant-rich phase.

DESCRIPTION According to this invention, en electroconductive, corrosion-resistance, castable, high silicon alloy is provided. The alloy is particularly useful for providing electroconductive elements for use in acidic media, e.g., as anodes in electrolytic cells such as chlorine cells. Such anodes are particularly described in my commonly assigned, co-pending applications Ser. No. 260,790, filed June 8, 1972 for Electrodes Having Silicon Base Members and Ser. No. 356,972, filed May 3, 1973, for Electrolytic Cell for the Electrolysis of alkali Metal Chlorides Having Bipolar Electrodes."

The silicon alloy described herein has an electroconductivity greater than 100 (ohm-centimeter), and preferably in excess in 1,000 or more (ohmcentimeter), and frequently as high as 1,500 (ohmcentimeter). The alloy is further characterized by its resistance to corrosion, particularly in acidic media,

such as in acidified brine solutions where nascent chlo- I rine is evolved.

The silicon alloy described herein is characterized by its ready castability. Elemental silicon alloys having particularly low contents of alloying elements are characterized by expansion upon solidification. The coefficient of expansion of elemental upon solidification, i.e., AV/Vo where V0 is the initial volume, and AV is the volumetric expansion in consistent units, is on the order of about 10 percent. This expansion upon solidification sets up internal stresses and thermal stresses which can result in the failure of the casting. The silicon alloy of this invention is characterized by the substantial absence of such stresses. ln one exemplification, the silicon alloy of this invention has a reduced co-efficient of expansion upon solidification, for example +5 percent or less.

On an elemental basis, the alloy of this invention contains silicon, a transition metal, and a dopant. The dopant and the transition metal are generally present as silicides and solid solutions with silicon.

The dopant is generally nitrogen, phosphorous, aluminum, or boron. Most commonly boron or phosphorous is the dopant. Boron is the preferred dopant. The amount of dopant is sufficient to provide an electroconductivity greater than (ohm-centimeter). This is on the order of about 0.2 weight percent or more.

Lesser amounts of dopant, e.g., less than about 0.2 weight percent, while beneficial in increasing the conductivity of the alloy, generally do not raise the conductivitiy to above 100 (ohm-centimeter). As a practical matter, the concentration of the dopant will be greater than the solubility of the dopant in molten silicon. This is generally on the order of about 0.5 weight percent. The concentration of dopant will, however, not be great enough-to increase the susceptibility of the alloy to corrosion or spalling. As a practical matter, this is on the order of about 2 weight percent,

Whenever a transition metal rich phase or transition metal silicide rich'phase, is referred to herein, it is to be understood that the phase referred to is the phase in the alloy having the higher or highest content of transition metal either as the metal or as a silicide thereof, expressed on an elemental basis. The transition metal rich phase generally contains twenty or more atomic percent of the transition metal, elemental basis, most frequently as the silicide.

The transition metal will generally be present as a silicide of the transition metal such as manganese disilicide, chromium disilicide, iron disilicide, cobalt trisilicide, nickel disilicide, or molybdenum disilicide. Most frequently, the transition metal silicide is present in a transition metal rich phase which is a solid solution of the transition metal silicide and elemental silicon.

The transition metal used to provide the transition metal rich phase or the transition metal silicide rich phase in the alloy may be any metal which is either so]- uble in silicon, or in'which silicon is soluble, or which forms a silicide in which silicon is soluble. Suitable transition metals useful in providing the alloy of this invention include scandium, yttrium, the lanthanides, titanium, lanthanides, hafnium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, the iron triad, e.g., iron, cobalt, and nickel, the ruthenium triad, e.g., ruthenium, rhodium, and palladium, the platinum triad, e.g., osmium, iridium, and platinum; copper, silver, and gold.

The transition metal used to provide the silicide in the alloy is generally iron, cobalt, nickel, chromium, manganese, or molybdenum. Most frequently iron, co-

balt, or nickel is the transition metal used. Iron is the preferred transition metal. However, it should be understood that the other transition metals referred to hereinabove may be used interchangeably therewith.

The concentration of transition metal should be sufficient to provide a substantially continuous phase surrounding the regions of the silicon rich phase of the alloy when examined by an optical microscope at magnifications of greater than about 200 times.

The minimum elemental concentration of transition metal in the alloy is the amount necessary to give rise' to the second or transition metal rich phase. This will generally be an amount at or just above the solubility limit of the transition metal silicide in the silicon, i.e., the concentration at which the transition metal silicide first appears as a separate phase. For iron, this is approximately 4 weight percent iron; for cobalt, approximately 9 weight percent cobalt; for molybdenum, approximately weight percent molybdenum. For nickel,

' or chromium, or manganese, the amount necessary is at the trace level, e.g., l weight percent or more.

The concentration of the transition metal should be sufficient to provide a liquidus phase around the solid silicon phase during the early stages of solidification, thereby relieving the thermal stresses within the silicon phase created upon solidification. Preferably, the concentration of transition metal should be sufficient to provide an alloy having a co-efficient of expansion upon solification of less than about plus 10 percent, e.g., on the order of about 5 percent or less.

As a practical matter, the concentration of transition metal in the alloy should be sufficient to maintain the corrosion resistance at the levels provided by the elemental silicon. Accordingly, the silicon rich phase should be maintained as the metallographicallypredominant phase within the alloy with about twothirds, and preferably three quarters or more of the silicon being present in the silicon rich phase. When the transition metal is iron, and the concentrations are in weightpercents as the elements, the iron content should be less than 39 percent, generally less than about l8 percent, and preferably less than about l4 percent. When the transition metal is cobalt, the concentration of cobalt should be less than about 38 weight percent, generally less than 18 weight percent. and preferably less than about 12 weight percent. When the transition metal is nickel, the concentration of nickel should be less than 50 weight percent and preferably less than about 15 weight percent, and generally less than about 7 weight percent. When the transition metal is manganese, the concentration of manganese should be less than weight percent, generally less than l5 weight percent, and preferably less than about 6 weight percent. When the transition series metal is chromium, the concentration of the chromium should be less than about 28 weight percent, generally less than about I8 weight percent, and preferably less than about 6 weight percent.

In the alloys herein contemplated, when the transition metal is iron, the concentration of the iron should be from about 4 weight percent to about I4 weight percent, preferably about 8 weight percent. When the transition metal is cobalt. the concentration of cobalt should be from about 9 weight percent to about l2 weight percent and preferably about 10 weight percent. When the transition metal is nickel, the concentration of nickel should be about I weight percent to about 7 weight percent, and preferably about 6 weight percent. When the transition metal is chromium, the concentration of the chromium should be from about 1 weight percent to about 6 or 7 weight percent and preferably from about 6 weight percent. When the transition metal is manganese, the concentration of manganese should be from about I to about 6 weight, and preferably about 6 weight percent.

When scandium, yttrium, ora lanthanide is the transition metal, the transition metal, in whatever form it is present, should be from I to about l8 atomic percent of the alloy. When titanium, zirconium, or hafnium is the transition metal, the transition metal is whatever form it is present, should be from L5 to 7 atomic percent of the alloy. When vanadium, columbium, or tantalum is the transition metal, the transition metal, in whatever form it is present, should be from about I6 to 1 atomic percent. A particularly outstanding alloy is one containing from about 1.0 to about 2.0 atomic percent tantalum. When. the transition metal is tungsten the tungsten content should be about 1 atomic percent in whatever form the tungsten is present. When the transition metal is copper, silver, or gold, the transition metal content is from about 1 to 20 atomic percent.

The preferred alloys of this invention are three phase alloys, containing a transition metal or transition metal silicide rich phase, a dopant or dopant silicide rich phase, and a silicon rich phase. The silicon rich phase is the predominant phase and is substantially discontinuous, broken into numerous individual regions of a silicon rich phase. In a preferred exemplification of this invention, the transition metal rich phase forms narrow rivulets around the boundaries of the regions of the silicon rich phase. Preferably, the rivulets are substantially continuous around all of the regions of the silicon rich phase. The dopant rich phase is present as nodules at the boundaries between the phases and within the individual phases.

The photomicrographs of one particularly preferred exemplification of this invention are shown in the Figures. 1

FIG. I is a scanning electron microscope photomicrograph of a polished section of an alloy containing 8 percent iron, 0.3 weight percent boron, balance silicon at the magnification shown in the lower left hand corner thereof.

FIG. 2 is a section of FIG. I at higher magnification.

FIG. 3 is a section of FIG. 2 at higher magnification.

FIG. 4 is a scanning electron microscope photomicrograph of a polished section of an alloy containing less than 0.5 weight percent iron, 0.3 weight percent boron, balance silicon, at the same degree of magnification as FIG. 2. 7

FIG. 5 is a scanning electron microscope photomi crograph of a polished section of an alloy containing 30 weight percent iron, 0.5 weight percent boron, and balance silicon, at the same magnification as FIGS. 2 and 4.

As shown in FIGS. 1, 2, and 3, the predominant phase is a discontinuous silicon rich phase. The phase has well-defined phase boundaries. The exact composition of the phase is not known, but it is believed to be a solid solution of elemental silicon and an iron silicide containing in excess of percent silicon, the phase is predominantly silicon with less than about 2 percent total silicides, e.g., iron silicide and boron silicide, therein. Within the discontinuous silicon-rich phase, i.e., the solid solution and silicides, the silicides are present at or below the solubility limit of the silicides in the silicon.

The silicon-rich phase is seen to be surrounded by substantially continuous rivulets of a transition metal rich phase. The rivulets of the transition metal rich phase surrounding the silicon rich phase are believed to contain iron disilicide, FeSi in the form of a solid solution of the disilicide and elemental silicon. The elemental silicon is present at or below the solubility limit of elemental silicon in the silicide. This is the material referred to in the literature as lebeauite.

The rivulets generally are of a width of microns or less, separating regions of the silicon-rich phase. Frequent pools of 100, 200 or more microns in diameter are observed between the silicon rich phases.

Nodules of the dopant rich phase are observed to be present in both phases and at the boundaries thereof. The nodules are of particularly high melting constituent of the alloy and are silicon-boron phase, e.g., a boron silicide or silicon boride.

As can further be seen, the silicon rich phase is a predominant although discontinuous phase containing many regions that are several thousand microns or more in their greatest dimension, i.e., in length or in diameter.

ln the alloy having the grain structure shown in FIG. 4, containing less than 0.5 weight percent iron, and 0.3 weight percent boron, elemental basis, the silicon rich phase is not only the predominant phase, but is a substantially continuous phase. The iron silicide phase is both a minor phase and a discontinuous phase.

The alloy having the'grain structure shown in FIG. 2, discussed above with reference to FIGS. 1 through 3, is characterized by a predominant, discontinuous silicon rich phase, a minor, continuous iron silicide phase, and nodules of a boride phase.

in the alloy having the grain structure shown in FIG. 5, containing 30 weight percent iron, and 0.3 weight percent boron, elemental basis, the iron silicide phases are seen to be continuous. They are also seen to be the predominant phases, providing an alloy that is predominantly a ferro-silicon with only a minor silicon phase.

The following Examples are illustrative.

EXAMPLE 1 To determine the effect of the absence of the dopant, a silicon alloy ingot was prepared containing 8 percent weight iron, 0.3 weight percent boron, and balance silicon. The ferro-silicon used in this test was Ohio Ferro Alloys ferro-silicon having a nominal iron content of 35 weight percent and an actual iron content of 30 weight percent. Seven hundred grams of the ferro-silicon was placed in a No. 10 graphite crucible. The crucible was heated to l,580C., for approximately 65 minutes. The molten alloy was then poured into a 1 inch by 1 inch by 5 inch graphite mold. After the ferro-silicon solidified and cooled, the electroconductivity of the ingot was measured using a Weston Model 91 1 milliameter with power supplied through a Kokour Company silicon rectifier. The electrical conductivity was found to be 32 (ohm-centimeter)". The ingot does not crack or develop stress fractures, indicating a coefficient of volumetric expansion upon solidification of less than 10 percent.-

An alloy was then prepared to test the effect of the dopant, containing 8 weight percent iron, 0.3 weight percent boron, balance silicon. In preparing this alloy, 12 pounds ferro-silicon, containing weight percent silicon, 12 pounds of silicon, and 152 grams of fused sodium tetraborate (Na B O were placed in a graphite crucible. The crucible was placed in a furnace and heated to 1,435C. for approximately 50 minutes. Then, the molten iron-boron-silicon alloy was poured into a mold that had been pre-heated to l,0O0C. After the metal had solidified, and cooled its electroconductivity was measured using a Weston Model 911 Milliameter with power supplied through a Kokour Company silicon rectifier. The electrical conductivity was found to be 1,090 (ohm-centimeters)". The ingot did not crack or develop stress fractures, indicating a coefficient of volumetric expansion upon solidification of less than 10 percent.

Thereafter, the sample was cut, and the uncut surface of the sample was sandblasted and washed with Comet (TM) household cleanser. The sample was then etched for 5 minutes in a 2.5 normal sodium hydroxide solution of C., rinsed in water, and airdried.

Two costs of an undercoating solution of 20 grams of Englehard Industries ruthenium trichloride containing 39.71 weight percent of ruthenium, elemental basis, in

I 380 grams of US. Industrial Chemical Co. absolute ethyl alcohol were applied to the uncut surface of each sample. After each cost, the sample was heated to 350C. for 15 minutes.

Thereafter three coats of an outer coating solution were applied above the undercoating. The outer coating solution was prepared by first dissolving 54.3 grams of K and K Laboratories titanium chloride in 154.5 grams of a 15 weight percent aqueous solution of Fisher Scientific Company hydrochloric acid. One hundred grams of this composition were mixed with 50 grams of a Mallinckrodt absolute methyl alcohol and sufficient Baker and Adams 30 weight percent hydrogen peroxide to cause the liquid to turn brown. This was then mixed with 60 grams of a liquid composition that had been prepared from 15 grams of Englehard Industries ruthenium trichloride and 60 grams of Mallinckrodt absolute methyl alcohol. Five coats of the resulting liquid composition were applied to the previously coated surface of the sample. After each of the coats the electrode was heated to 350C. for 10 minutes. After the last coat, the electrode was heated to 450C. for 16 hours. The electrode had a chlorine overvoltage of 0.03 to 0.06 volts at 200 amperes per squre foot in a chlorinated brine solution containing 315 grams per liter of sodium chloride.

EXAMPLE ll lron-boron-silicon alloys were prepared containing 12 percent iron, varying amounts of boron, and the balance silicon.

The ferro-silicon used in this test was Ohio Ferro Alloys ferro-silicon having a nominal iron content of 15 weight percent and an actual content of 12 weight percent.

Seven hundred grams of the ferro-silicon was placed in a No. 10 graphite crucible. The crucible of ferrosilicon was heated to 1,580C. for approximately 1 Two electrodes were prepared having bases containing 12 weight percent iron, 0.5 weight percent boron, and the balance silicon. In preparing these electrodes, 1,800 grams of ferro-silicon and 42 grams of fused sodium tetraborate (Na B O were placed in a No. 10 graphite crucible. The crucible was placed in a furnace and heated to 1,580C. for approximately 1 hour. Then the molten ferro-silicon, containing boron, was poured into a pre-heated, 3- 4 inch X 1 inch X 6 inch graphite mold.

After the metal had solidified and cooled, two inch X inch X inch samples were cut from the ingot. The samples showed no signs of cracking or stress fractures, indicating a coefficient of volumetric expansion upon solidification of less than 10 percent. The uncut surface of each sample was sandblasted and washed with Comet" (TM) household cleanser. Each sample was then etched for 5 minutes in a 2.5 normal sodium hydroxide solution at 90C., rinsed in water, and air dried.

Three coats of an undercoating solution of 2 grams of Englehard Industries ruthenium trichloride in 18 grams of U.S. Industrial Chemical absolute ethyl alcohol were applied to the uncut surface of each sample.

which are in the full intended scope of this invention as defined by the appended claims. i

1 claim: V

l. A silicon base alloy having an electroconductivity greater than 100 (ohm-centimeters), consisting essentially of silicon,- a dopant, and a transition metal present as the silicide thereof, and comprising:

After each coat,- the sample was heated to 350C. for

10 minutes.

Thereafter three coats of an outer coating solution were applied above the undercoating. The outer coating solution was prepared by dissolving 18.1 grams of K and K Laboratories titanium chloride in 51.5 grams of a 15 weight percent aqueous solution of Fisher Scientific Company hydrochloric acid. Two grams of this liquid composition were mixed with 1 gram of Mallinckrodt absolute methyl alcohol and 0.5 gram of Baker and Adams 30 weight percent hydrogen peroxide. This liquid composition was then mixed with 1.2 grams of a liquid compositionthat had been prepared from 1 gram of Englehard Industries ruthenium trichloride and 4 grams of Mallinckrodt absolute methyl alcohol. Three coats of this liquid composition were applied to the previously undercoated surfaces of each sample. After each of the first two coats, the electrode was heated to 350C. for 10 minutes. After the last coat, each electrode was heated to 450C. for 30 minutes.

The resulting electrodes had bulk electroconductivities of 1,500 (ohm-centimeters)". Each of the electrodes had 'a chlorine overvoltage of 0.08 to 0.10 volts at 200 amperes per square foot in a chlorinated solution containing 3 l 5, grams per liter of sodium chloride.

It is to be understood that although the invention has been described with specific reference to details of particular embodiments thereof, it is not to be so limited since changes and alterations therein may be made a predominant, discontinuous silicon rich phase; discrete nodules of a dopant rich phase; and substantially continuous rivulets of a transition metal silicide rich phase surrounding the silicon richphase and forming the boundaries thereof. 2. The alloy of claim 1 wherein the dopant is chosen from the group consisting of boron and phosphorous.

3. The alloy of claim 2 wherein the dopant content is greater than the solubility of the dopant in silicon.

4. The alloy of claim 2 wherein the dopant content is from 0.2 to 2.0weight percent.

5. The alloy of claim 1 wherein the transition metal is chosen from the group consisting of iron, cobalt, nickel, chromium, molybdenum and manganese.

6. The alloy of claim 5 wherein the transition metal content is greater than the solubility of the transition metal in silicon.

7. The alloy of claim 5 wherein the transition metal is iron and the iron content is from about 4 to about 14 weight percent.

8. The alloy of claim 1 wherein the alloy has a volumetric coefficient of expansion upon solidification of less than 10 percent.

9. A silicon alloy'consisting essentially of sufficient dopant to provide an electrical conductivity of greater than about .100 (ohm-centimeters), sufficient transition metal silicide to provide an expansion on solidification of less than 5 percent, and balance silicon.

10. The alloy of claim 9 wherein the dopant content .is chosen from the group consisting of boron and phosphorous. I

11. The alloy of claim 10 wherein the dopant content is greater than the solubility of the dopant is silicon.

12. The alloy of claim 11 wherein the dopant is boron and the dopant content is from about 0.1 to about 2.0 weight percent.

13. The alloy of claim 9 wherein the transition metal silicide is chosen from thhe group consisting of the silicides of iron, cobalt, nickel, chromium, and manganese.

14. The alloy of claim 13 wherein the content of the transition metal silicide is greater than the solubility of the transition metal silicide in silicon but insufficient to form a predominant transition metal silicide phase.

15. The alloy of claim 14 wherein the transition metal is iron and the content of the transition metal in the alloy, elemental basis, is from about 4 to about 14 weight percent.

16. The alloy of claim 9 wherein the alloy comprises:

phase and forming the boundaries thereof.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3491014 *Jan 16, 1969Jan 20, 1970Oronzio De Nora ImpiantiComposite anodes
NL7003774A * Title not available
Non-Patent Citations
Reference
1 * Effect of Boron on the Resistivity and Rectification Characteristics of Silicon, Metal Transactions, Vol. 185, June 1949, pp. 385 388.
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3988221 *Mar 20, 1975Oct 26, 1976Occidental Petroleum CorporationElectrolytic removal of heavy metal ions using particulate silicon alloys
US4197218 *Jan 23, 1978Apr 8, 1980Hooker Chemicals & Plastics Corp.Electrically conductive articles
US4390458 *Feb 28, 1980Jun 28, 1983Occidental Chemical CorporationElectrically conductive articles
US4687606 *Oct 15, 1984Aug 18, 1987Ford Motor CompanyMetalloid precursor powder and method of making same
US4721991 *May 6, 1985Jan 26, 1988Kabushiki Kaisha ToshibaRefractory silicide conductor containing iron
US5547598 *Aug 2, 1994Aug 20, 1996Technova, Inc.Thermoelectric semiconductor material
EP0002017A1 *Nov 4, 1978May 30, 1979BASF AktiengesellschaftAnodes for electrochemical purposes
EP0820110A2 *Jul 15, 1997Jan 21, 1998Sony CorporationNegative electrode material and non-aqueous liquid electrolyte secondary cell employing same
EP1096583A1 *Jan 31, 2000May 2, 2001Matsushita Electric Industrial Co., Ltd.Non-aqueous electrolyte secondary cell and material for negative plate used therefor
Classifications
U.S. Classification420/578, 204/293, 257/734
International ClassificationC25B11/04, C22C28/00, C25B11/00
Cooperative ClassificationC22C28/00, C25B11/04
European ClassificationC22C28/00, C25B11/04