Electrode for lead-acid battery and method for producing such an electrode

Abstract

An electrode for lead-battery comprises a current collector covered by an active layer of lead-containing paste. The current is formed by a glassy carbon substrate on which is deposited an intermediate layer. The glassy carbon substrate has preferably a thickness comprised between 1 mm and 3 mm whereas the thickness of the intermediate layer is advantageously comprised between 50 μm and 200 μm. In a particular embodiment, the glassy carbon substrate is in form of a comb.

1 - 9 . (canceled) 
     
     
         10 . A method for producing an electrode for lead-acid battery comprising at least the following steps:
 formation of a glassy carbon substrate by plastic molding of a thermosetting resin in a predetermined shape followed by carbonizing the thermosetting resin in inert atmosphere,   formation of a compact intermediate layer made from a lead-tin alloy with a percent of tin in the lead-tin alloy of about 2.5% in weight on at least one part of a surface of the glassy carbon substrate, by an operation of electroplating with an electrolyte comprising Pb(II) salt of the 4-hydroxybenzensulfonic acid, Sn(II) salt of the 4-hydroxybenzenesulfonic acid and p-phenolsulfonic acid,   and formation of an active layer of lead-containing paste by covering the intermediate layer with the lead-containing paste,   wherein the glassy carbon substrate presents an apparent volume and a volume of pores, the volume of pores of the glassy carbon substrate being comprised between 0% and 10% of its apparent volume.   
     
     
         11 . The method according to  claim 10 , wherein formation of the glassy carbon substrate is followed by a surface treatment step of the glassy carbon substrate comprising a mechanical treatment, an electrochemical etching and a water rinsing. 
     
     
         12 . The method according to  claim 10 , wherein that the glassy carbon substrate comprises a tab and wherein an electroplating operation of the tab with copper is achieved before the formation of the compact intermediate layer. 
     
     
         13 . The method according to  claim 10 , wherein the volume of the pores in the glassy carbon substrate is comprised between 1% and 6% of its apparent volume. 
     
     
         14 . The method according to  claim 10 , wherein the predetermined shape of the glassy carbon substrate is a comb. 
     
     
         15 . The method according to  claim 14 , wherein the glassy carbon substrate comprises a plurality of branches, having a round, rectangular, square or elliptic cross-section. 
     
     
         16 . The method according to  claim 10 , wherein the glassy carbon substrate has a thickness comprised between 1 mm and 3 mm. 
     
     
         17 . The method according to  claim 10 , wherein the compact intermediate layer has a thickness comprised between 50 μm and 200 μm. 
     
     
         18 . The method according to  claim 10 , wherein the electrolyte is obtained by mixing:
 140 g.L −1  of Pb(p-C 6 H 4 OHSO 3 ) 2 ,   40 g.L −1  of p-C 5 H 4 OHSO 3 H,   4 g.L −1  of Sn(p-C 6 H 4 OHSO 3 ) 2 , and   4 g.L −1  of gelatin.