Non-sintered type thin electrode for battery, battery using same and process for same

Abstract

An electrode substrate is formed by mechanically processing a nickel foil so as to be made three dimensional through the creation of concave and convex parts, and then, this substrate is filled with active material or the like so that an electrode is manufactured, wherein the above described concave and convex parts are rolling pressed so as to incline in one direction. Furthermore, an electrode for secondary battery is formed by using the above described method.

1 - 10 . (cancelled)  
     
     
         11 . Process for producing a non-sintered thin electrode for batteries, which comprises the steps of: 
 filling into or coating on conductive electrode substrate in a wide belt-like form with the paste of powders that contain mainly active material or pseudo-materials;    pressing the filled or coated conductive electrode substrate between a pair of rollers; and    cutting into a desirable size; wherein    (a) the conductive electrode substrate has an unevenness produced on the conductive electrode substrate by unevenness processing except for a part which remains even with a desirable width at least on both sides along the longitudinal direction,    (b) the conductive electrode substrate has innumerable hollow concave and convex parts formed by the unevenness processing,    (c) the thickness of the conductive electrode substrate which made a thin electrolyte-proof metal plate into a three dimensional form with said concave and convex parts is 0.5 to 2.0 times as large as the thickness of the final electrode, and    (d) the number of concave parts is not less than half the number of concave and convex parts, wherein the said concave parts are adjacent and closest to a convex part, 
 the number of groups of concave parts is not less than half the number of groups of concave and convex parts, wherein the said groups of concave parts are adjacent and closest groups of convex parts,  
 the number of convex parts is not less than half the number of concave and convex parts wherein the said concave and convex parts are adjacent and closest to a concave part, and  
 the number of groups of convex parts is not less than half the number of groups of concave and convex parts, wherein the said concave and convex groups parts are adjacent and closest to groups of concave parts.  
   
     
     
         12 . Process for producing a non-sintered thin electrode for batteries according to  claim 11 , wherein said conductive electrode substrate: 
 is processed to produce said unevenness by means of 
 pressing between dies in which the upper and the lower dies are formed to have the same unevenness so as to engage with each other,  
 pressing between rollers in which the upper and the lower rollers are formed to have the same unevenness so as to engage with each other, or  
 depositing nickel with the electrolytic nickel deposition method; and is provided with alternating columns of numerous concave parts or concave part groups and columns of numerous convex parts or convex part groups which are substantially in parallel and spaced at a constant interval while making an angle in a range of about 30 to 60 degrees with respect to longitudinal direction of the substrate.  
   
     
     
         13 . Process for producing a non-sintered thin electrode for batteries according to  claim 12 , wherein said conductive electrode substrate employed to form the non-sintered thin electrode is roll pressed and contoured in one direction in the vicinity of both surfaces of the said conductive electrode substrate.  
     
     
         14 . Process for producing a non-sintered thin electrode for batteries according to  claim 11 , wherein the formation process applies a rolling press operation at least twice, wherein a first rolling press operates at a relatively high speed and with low pressure in an opposite rolling direction to the direction in which the electrode proceeds while a second press operates between rollers with larger diameters than those of the first rolling press at a lower speed than the first rolling press and with higher pressure than the first rolling press in the same direction that the electrode proceeds.  
     
     
         15 . Process for producing a non-sintered thin electrode for batteries according to  claim 11 , wherein the process comprises the step of; 
 pressing slightly by rubbing the surfaces of the conductive electrode between a slit with a brush, while being filled in or coated on with active material or pseudo-active material, before pressing the filled or coated conductive electrode substrate between a pair of rollers.    
     
     
         16 . Process for producing a non-sintered thin electrode for batteries according to  claim 11 , wherein after being cut into a desirable size, the said electrode is immersed in a liquid wherein a fine powder of synthetic resin is dispersed or the same liquid is sprayed onto the surfaces of said electrode so that said electrode is thinly coated with the fine powder of said synthetic resin.  
     
     
         17 . Process for producing a non-sintered thin electrode for batteries according to  claim 16 , wherein said synthetic resin is any of fluoride resin, polyolefin, polyvinyl-type and polysulfone resin powders or copolymers of which the main material is the above resins.  
     
     
         18 . A secondary battery wherein electrodes, at least one thin electrode obtained by filling or coating a power of which a main component is active material powders or pseudo-active material powders to the conductive electrode substrate which has a three dimensional structures and an opposite electrode with separator are sealed in a battery case, wherein: 
 (a) the conductive electrode substrate has an innumerable number of hollow concave and convex parts;    (b) a thickness of the conductive electrode substrate, made of a metal foil with electrolyte-proof resistance properties in a three dimensional form with said concave and convex parts, is nearly the same as the thickness of the final electrode;    (c) the number of concave parts is not less than half the number of concave and convex parts wherein the said concave and convex parts are adjacent and closest to a convex part, the number of groups of concave parts is not less than half the number of concave and convex parts, wherein the said concave and convex parts are adjacent and closest to a convex part, 
 the number of convex parts is not less than half the number of concave and convex parts, wherein the said concave and convex parts are adjacent and closest to a concave part, and  
 the number of groups of convex parts is not less than half the number of groups of concave and convex parts, wherein the said concave and convex parts are adjacent and closest to groups of concave parts; and  
   (d) the walls of said concave and convex parts bend in the direction of the thickness of said conductive electrode substrate so as to incline to a greater extent in one direction in relation to proximity to the edges of the concave and convex parts.    
     
     
         19 . The secondary battery according to  claim 18 , wherein said battery case has a bottom whose thickness (t 2 ) can withstand welding and a ratio (t 1 /t 2 ) of the thickness (t 2 ) of the bottom to a thickness (t 1 ) of the side walls is 1.5 or more.  
     
     
         20 . The secondary battery according  claim 19 , wherein a thicker part is provided inside of the battery case along the border between the wall surface and the bottom in said battery case.  
     
     
         21 . The secondary battery according to  claim 19 , wherein a positive terminal of an adjoining secondary battery is welded directly, or via a metal connector, to the bottom of said battery case.