Binary lead-tin alloy substrate for lead-acid electrochemical cells
AssigneeGates Energy Products, Inc.
InventorsRobert F. Nelson, David M. Wisdom
Life of this patent
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Abstract
A binary lead-tin alloy substrate for support of the electrochemically active material in lead-acid cells is disclosed having a tin concentration from about 0.3 to about 0.9 weight percent, the balance being lead. The tin impedes the formation of a passivation layer at the interface between the grid material and the active material improving cell recovery from deep discharge and improving cold cranking amperes performance.
Claims14
A substrate which services as the current collector and mechanical support for the electrochemically active material of an electrode of the pasted typed, comprising:
- a binary lead-tin alloy consisting essentially of from about 0.3 to about 0.9 weight percent tin, any other metals present in the alloy aggregating no more than about 0.01 weight percent of the alloy, the balance being essentially lead;
- the alloy of the substrate having a grain structure defined by a central grain body and boundary surrounding the central grain body and boundary surrounding the central grain body such that the tin is contained generally homogeneously and free from being concentrated at the boundary.
A normally sealed lead-acid electrochemical cell of the oxygen recombinant type comprising:
- a porous pasted positive electrode;
- a porous pasted negative electrode;
- the positive electrode employing an electrically conductive substrate formed from a binary lead-tin alloy consisting essentially of from about 0.3 to about 0.9 weight percent tin, the balance being essentially lead, wherein the alloy of the substrate has a grain structure defined by a central grain body and boundary surrounding the central grain body such that the tin is contained generally homogeneously within the grain body, and free from being concentrated at the boundary;
- porous compressible separator interposed between the positive and negative electrodes and existing under firm mutual stacking pressure with the electrodes;
- an acid electrolyte in liquid form absorbed within the electrode plates and separator and present in an amount such that the total pore volume of the plates and separator is less than fully filled with the electrolyte;
- and
- a cell housing in which is disposed the electrodes, separator and electrolyte.
Dependencies are inferred from the claim text.