Sealed storage battery and method for making its electrode

Claim 2

A sealed storage battery comprising: (a) a positive electrode including a metallic oxide; (b) a negative electrode including hydrogen-storage-alloy powder having a crystal structure of CaCu 5 , being provided with numerous irregularities on a surface, and having an SF-value of 2.5 or below, said SF-value representing a plateau characteristic of equilibrium pressure of released hydrogen; (c) an alkaline electrolyte; and (d) separator means for separating said positive electrode from said negative electrode, and for absorbing and retaining said alkaline electrolyte.

Claim 3

A sealed storage battery as claimed in claim 1, wherein a composition of said hydrogen-storage-alloy powder is represented by the formula, M Nix M'(5-x), wherein M is a single element or combined elements selected from the group consisting of Mm, Ca, Zr and Ti, said M' being a single element or combined elements selected from the group consisting of Co, Al, Mn, Cu, Cr and Fe, and the value of x being 3 or above.

Claim 4

A sealed storage battery as claimed in claim 1, wherein said positive electrode is nickel oxide.

Claim 5

A sealed storage battery as claimed in claim 1, wherein said separator means is made of a polyolefin resin containing a sulfonic acid group or its alkali metal salts.

Claim 6

A sealed storage battery as claimed in claim 1, wherein irregularities on a surface of said hydrogen-storage-alloy powder are made by mechanical grinding or eluting a part of alloy components into acid solution or alkaline solution.

Claim 7

A sealed storage battery comprising: (a) a positive electrode including a sintered nickel electrode or a non-sintered nickel electrode comprising a metallic porous body filled with nickel compounds or a nickel oxide; (b) a negative electrode including a hydrogen-storage-electrode comprising an alloy having a crystal structure CaCu 5 and represented by the formula, Mm 1-x M 1x Ni y M 2z , having an SF value of 2.5 or below, and having numerous irregularities on a surface layer of a powder of said alloy, said SF-value representing a plateau characteristic of equilibrium pressure of released hydrogen; (c) an alkaline electrolyte; and (d) separator means for separating said positive electrode from said negative electrode, and for absorbing and retaining said alkaline electrolyte, wherein in said formula, Mm is misch metal, M 1 is a single element or combined elements selected from the group consisting of Ca, Ti and Zr with which said misch metal is replaced, M 2 being a single element or combined elements selected from the group consisting of Co, Al, Mn, Cu, Cr, and Fe with which a part of nickel is replaced, x, y, and z being restricted by l>x≧0, y>3.0, z>0 and 4.7≦y+z≦5.3, said SF-value representing a plateau characteristic of equilibrium pressure of released hydrogen calculated by an equality SF-value=ln (P G/M =0.75/P H/M =0.25.

Claim 8

A sealed storage battery comprising: (a) a positive electrode including a sintered nickel electrode or a non-sintered nickel electrode comprising a metallic porous body filled with nickel compounds or a nickel oxide; (b) a negative electrode including a hydrogen-storage-electrode comprising an alloy having a crystal structure CaCu 5 and represented by the formula, Mm 1-x M 1x Ni y M 2z , having an SF value of 2.5 or below, and having numerous irregularities on a surface layer of a powder of said alloy, said SF-value representing a plateau characteristic of equilibrium pressure of released hydrogen; (c) an alkaline electrolyte; and (d) separator means for separating said positive electrode from said negative electrode, and for absorbing and retaining said alkaline electrolyte, wherein in said formula, Mm is misch metal, M 1 is a single element or combined elements selected from the group consisting of Ca, Ti and Zr with which said misch metal is replaced, M 2 being a single element or combined elements selected from the group consisting of Co, Al, Mn, Cu, Cr, and Fe with which a part of nickel is replaced, x, y, and z being restricted by l>x≧0, y>3.0, z>0 and 4.7≦y+z≦5.3, said SF-value representing a plateau characteristic of equilibrium pressure of released hydrogen calculated by an equality SF-value=ln (P G/M =0.75/P H/M =0.25.

Claim 9

A sealed storage battery as claimed in claim 6, wherein the hydrogen-storage alloy powder is represented by the formula MmNi 3 .95-x Mn x Al 0 .3 Co 0 .75, in which 0.8≧x≧0.2.

Claim 10

A sealed storage battery as claimed in claim 6, wherein said separator means is a porous body of a polyolefin resin containing a sulfonic acid group or its alkali metal salts.

Claim 11

A sealed storage battery as claimed in claim 6, wherein said separator means is made of a polyolefin resin containing a sulfonic acid group or its salts, and the number of monomers of polyolefin to each sulfonic acid group or its salts is limited from 20 to 250.

Claim 12

A sealed storage battery as claimed in claim 6, wherein said separators means is made of a e polyolefin resin containing a sulfonic acid group or its salts and has a porosity of 40 to 70%.

Claim 13

A sealed storage battery comprising: (a) a positive electrode including a metallic oxide; (b) a negative electrode including a hydrogen-storage-alloy powder having a CaCu 5 crystal structure, and provided with numerous irregularities on a surface thereof, said hydrogen-storage-alloy powder being represented by a formula Mn 1-x M 1x Ni y M 2z wherein m 1 is one of Ca, Ti, and Zr; M 2 is one of Co, Al, Mn, Cu, Cr, and Fe; 1<×≦0, y<3.0, z<0 and 4.7≦y+z≦5.3, said numerous irregularities being made by mechanical grinding or eluting a portion of alloy components into acid solution and/or alkaline solution; (c) an alkaline electrolyte; and (d) separator means for separating said positive electrode from said negative electrode, and for absorbing and retaining said alkaline electrolyte.

Claim 14

A sealed storage battery comprising: (a) a positive electrode including a metallic oxide; (b) a negative electrode including a hydrogen-storage-alloy powder having a CaCu 5 crystal structure, and provided with numerous irregularities on a surface thereof, said hydrogen-storage-alloy powder being represented by a formula Mn 1-x M 1x Ni y M 2z wherein m 1 is one of Ca, Ti, and Zr; M 2 is one of Co, Al, Mn, Cu, Cr, and Fe; 1<×≦0, y<3.0, z<0 and 4.7≦y+z≦5.3, said numerous irregularities being made by mechanical grinding or eluting a portion of alloy components into acid solution and/or alkaline solution; (c) an alkaline electrolyte; and (d) separator means for separating said positive electrode from said negative electrode, and for absorbing and retaining said alkaline electrolyte.