Rechargeable cell having ceramic-metal terminal seal resistant to alkali electrolyte

Claim 2

A SEALED, RECHARGEABLE CELL STRUCTURE FOR AN ALKALIELECTROLYTE CELL CONTAINING POSITIVE AND NEGATIVE ELECTRODES THEREIN COMPRISING AN ALKALI-RESISTANT METAL CASING HAVING AN ALKALI-RESISTANT COVER BONDED THERETO, TERMINAL MEANS CARRIED BY SAID COVER AND ELECTRICALLY COMMUNICATING THERETHROUGH WITH AT LEAST ONE OF SAID ELECTRODES, SAID TERMINAL MEANS COMPRISING A TERMINAL ROD MEMBER DEFINING AN AXIS, A FIRST NICKEL SLEEVE COAXIAL WITH AND SPACED FROM SAID ROD MEMBER AND HAVING AN INWARDLY EXTENDING SHOULDER FORMED THEREON AND AN OUTER PORTION BONDED TO SAID COVER, CYLINDRICAL CERAMIC WASHER MEANS COAXIAL WITH SAID ROD MEMBER AND COMPRISING HIGH-PURITY ALUMINA HAVING ONE END THEREOF BONDED TO SAID SHOULDER WITH A CERAMIC-TO-METAL BONDING AGENT, A SECOND NICKEL SLEEVE COAXIAL WITH AND SEALED TO SAID ROD MEMBER AND HAVING AN OUTWARDLY FORMED SHOULDER THEREOF BONDED TO THE OPPOSITE END OF SAID CERAMIC WASHER WITH AN ALKALI-RESISTANT CERAMIC-TO-METAL BONDING AGENT TO FORM PARALLEL, AXIALLY SPACED APART, BUTT SEALS ON BOTH ENDS OF SAID CYLINDRICAL CERAMIC WASHER, SAID SECOND SLEEVE BEING ELECTICALLY COUPLED TO ONE OF SAID ELECTRODE WITHIN SAID CELL.

Claim 3

The cell structure of claim 1 wherein a second cylindrical ceramic washer is bonded to the opposite side of said shoulder of said first nickel sleeve and a third cylindrical ceramic washer is bonded to the opposite side of said shoulder on said second nickel sleeve, said additional ceramic washers strengthening the bonds of said nickel sleeves to said first cylindrical ceramic washer.

Claim 4

The cell structure of claim 1 wherein said terminal rod member passes freely through a central opening in said ceramic washer to communicate with the interior of said cell.

Claim 5

The cell structure of claim 3 wherein portions of said washer adjacent said rod are cutaway to inhibit contact by said bonding agent with said rod.

Claim 6

An improved sealed cell structure for a rechargeable cell containing active electrodes and an alkali electrolyte comprising an alkali-resistant metal casing; an alkali-resistant cover bonded to said cover, said cover having an opening therein; and sealed terminal means sealing said opening, communicating with at least one of said electrodes therein and comprising an axially stacked array of metal sleeves and ceramic cylindrical washers bonded together with a bonding agent consisting essentially of a predominantly TiNi3 alloy, said array of sleeves and washers including first and second nickel metal sleeves having a high-purity alumina ceramic washer therebetween to insulate said first and second metal sleeves from one another, said first metal sleeve bonded and electrically connected to said casing and said second metal sleeve electrically connected to one of said electrodes, said first metal sleeve being in a spaced, non-conductive relationship with said one electrode.

Claim 7

An improved sealed cell structure for a rechargeable cell containing active electrodes and an alkali electrolyte comprising an alkali-resistant metal casing; an alkali-resistant cover bonded to said cover, said cover having an opening therein; and sealed terminal means sealing said opening, communicating with at least one of said electrodes therein and comprising an axially stacked array of metal sleeves and ceramic cylindrical washers bonded together with a bonding agent consisting essentially of a predominantly TiNi3 alloy, said array of sleeves and washers including first and second nickel metal sleeves having a high-purity alumina ceramic washer therebetween to insulate said first and second metal sleeves from one another, said first metal sleeve bonded and electrically connected to said casing and said second metal sleeve electrically connected to one of said electrodes, said first metal sleeve being in a spaced, non-conductive relationship with said one electrode.

Claim 8

The cell structure of claim 5 wherein said metal and ceramic washers form substantially spaced parallel butt seals.

Claim 9

The cell structure of claim 6 wherein said casing is constructed of an alkali resistant metal selected from the class consisting of nickel and stainless steel.

Claim 10

The cell structure of claim 5 wherein said electrodes comprise negative and positive electrodes and each electrode is connected to terminal means on said cover.

Claim 11

The cell structure of claim 5 wherein said high purity alumina comprising from 95-97 percent alumina and is further characterized by a low silica content to improve the resistant of the ceramic to an alkali electrolyte.

Claim 12

An improved sealed cell structure for a rechargeable cell containing active electrodes and an alkali electrolyte comprising an alkali-resistant metal casing having a cover of alkali-resistant metal thereon, said alkali-resistant metal being selected from the class consisting of nickel and stainless steel, said cover having an opening therein and having terminal means thereon sealing said opening formed by: a. brazing together an axially stacked array of nickel sleeves, each said sleeve having a substantially planar portion, said planar portions being substantially parallel to each other, and at least one high purity alumina washer with titanium metal interposed between said planar portions at a temperature of about 1300* C to form ceramic-to-metal butt seals consisting essentially of a predominantly TiNi3 alloy, b. electrically connecting one of said metal sleeves to one of said electrodes, and c. bonding another of said metal sleeves to said cover in a spaced non-conductive relationship with said one electrode.

Claim 13

An improved sealed cell structure for a rechargeable cell containing active electrodes and an alkali electrolyte comprising an alkali-resistant metal casing having a cover of alkali-resistant metal thereon, said alkali-resistant metal being selected from the class consisting of nickel and stainless steel, said cover having an opening therein and having terminal means thereon sealing said opening formed by: a. brazing together an axially stacked array of nickel sleeves, each said sleeve having a substantially planar portion, said planar portions being substantially parallel to each other, and at least one high purity alumina washer with titanium metal interposed between said planar portions at a temperature of about 1300* C to form ceramic-to-metal butt seals consisting essentially of a predominantly TiNi3 alloy, b. electrically connecting one of said metal sleeves to one of said electrodes, and c. bonding another of said metal sleeves to said cover in a spaced non-conductive relationship with said one electrode.

Claim 14

An electrochemical device having a casing containing an electrolyte and active electrode elements immersed in said electrolyte; and a cover and terminal assembly, said assembly comprising a conductive terminal of inverted cup-shaped configuration including a bright portion and free end portions depending therefrom, the free end portions of said terminal being provided with outwardly extending flange portions which are connected to one of said active elements; an apertured conductive closure coaxially disposed about said terminal member, portions of said closure being arranged in spaced, partly overlapping relation to said flange portions, other portions of said closure being connected to said casing, an annular ceramic washer coaxial with said terminal, the inner wall of said washer spaced from said free end portions, a bonding agent consisting essentially of a predominantly TiNi3 alloy on one face of said washer bonding said washer to said overlapping portion of said closure, said bonding agent on another face of said washer bonding said washer to said flange portion of said terminal, said washer being supported only between said overlapping portions of said closure and said flange portion in substantially radial compression-free relationship.

Claim 15

An electrochemical device having a casing containing an electrolyte and active electrode elements immersed in said electrolyte; and a cover and terminal assembly, said assembly comprising a conductive terminal of inverted cup-shaped configuration including a bright portion and free end portions depending therefrom, the free end portions of said terminal being provided with outwardly extending flange portions which are connected to one of said active elements; an apertured conductive closure coaxially disposed about said terminal member, portions of said closure being arranged in spaced, partly overlapping relation to said flange portions, other portions of said closure being connected to said casing, an annular ceramic washer coaxial with said terminal, the inner wall of said washer spaced from said free end portions, a bonding agent consisting essentially of a predominantly TiNi3 alloy on one face of said washer bonding said washer to said overlapping portion of said closure, said bonding agent on another face of said washer bonding said washer to said flange portion of said terminal, said washer being supported only between said overlapping portions of said closure and said flange portion in substantially radial compression-free relationship.

Claim 16

The device as defined in claim 11 wherein said bight portion comprises a substantially planar disc, and said overlapping closure portions are substantially coplanar with and electrically isolated from said bight portion.

Claim 17

The device as defined in claim 11 wherein said terminal is formed of a material selected from the class comprising nickel and stainless steel, and said ceramic washer is of a high-alumina ceramic material having low silica content, the ceramic-to-metal bond being effected at a temperature ranging between 1,250*C and 1,350*C.

Claim 18

A cover and terminal assembly for an electrochemical device having a casing containing an electrolyte and active electrode elements immersed in said electrolyte; said assembly comprising a conductive terminal of inverted cup-shaped configuration including free end portions depending therefrom, the free end portions of said terminal being provided with outwardly extending flange portions which are adApted to be connected to one of said active elements; an apertured conductive closure coaxially disposed about said terminal member, portions of said closure being arranged in spaced, partly overlapping relation to said flange portions, other portions of said closure being adapted for connection to said casing, an annular ceramic washer coaxial with said terminal, the inner wall of said washer being spaced from said free end portions, one face of said washer bonded to said overlapping portion of said closure, another face of said washer bonded to said flange portion of said terminal, the ceramic-to-metal bonds consisting essentially of a predominantly TiNi3 alloy formed at a temperature ranging between 1,250*C and 1,350*C, said washer being supported only between said overlapping portions of said closure and said flange portion in substantially radial compression-free relationship.

Claim 19

A cover and terminal assembly for an electrochemical device having a casing containing an electrolyte and active electrode elements immersed in said electrolyte; said assembly comprising a conductive terminal of inverted cup-shaped configuration including free end portions depending therefrom, the free end portions of said terminal being provided with outwardly extending flange portions which are adApted to be connected to one of said active elements; an apertured conductive closure coaxially disposed about said terminal member, portions of said closure being arranged in spaced, partly overlapping relation to said flange portions, other portions of said closure being adapted for connection to said casing, an annular ceramic washer coaxial with said terminal, the inner wall of said washer being spaced from said free end portions, one face of said washer bonded to said overlapping portion of said closure, another face of said washer bonded to said flange portion of said terminal, the ceramic-to-metal bonds consisting essentially of a predominantly TiNi3 alloy formed at a temperature ranging between 1,250*C and 1,350*C, said washer being supported only between said overlapping portions of said closure and said flange portion in substantially radial compression-free relationship.