Laminated oxidation protected separator

Abstract

A battery separator for a lead acid battery addresses the issues of acid stratification and separator oxidation arising from contaminants. The separator includes a microporous membrane and a diffusive mat affixed thereto. The diffusive mat has a three hour wick of: at least about 2.5 cm. The diffusive mat may be made of synthetic fibers, glass fibers, natural fibers, and combinations thereof. The diffusive mat may include silica. The separator may include a rubber.

1 - 17 . (canceled) 
     
     
         18 . A battery separator for a flooded lead acid battery, wherein the battery separator comprises:
 a microporous membrane comprising polyethylene and silica; and   a positive active material (PAM) retention mat, said PAM retention mat comprising fine glass fibers, wherein said PAM retention mat is a nonwoven mat or a woven mat, and wherein said PAM retention mat faces or is in contact with a positive electrode or PAM of said flooded lead acid battery,   wherein the battery separator decelerates corrosion of at least one electrode of the flooded lead acid battery and/or prevents shedding of PAM from the positive electrode of the flooded lead acid battery, and   wherein the flooded lead acid battery operates at a high depth of discharge (DoD).   
     
     
         19 . The battery separator according to  claim 18 , wherein the flooded lead acid battery is selected from the group consisting of a dry charge battery, an inverter battery, an enhanced flooded battery (EFB), an ISS battery, a stationary battery, a golf cart battery, and combinations thereof. 
     
     
         20 . The battery separator according to  claim 18 , wherein the PAM retention mat has a thickness of about 0.2 mm to less than about 0.5 mm. 
     
     
         21 . The battery separator according to  claim 18 , wherein the PAM retention mat comprises a particulate filler, and said filler includes silica. 
     
     
         22 . The battery separator according to  claim 18 , wherein the PAM retention mat further includes a coating. 
     
     
         23 . The battery separator according to  claim 18 , wherein the microporous membrane further comprises rubber and/or latex. 
     
     
         24 . The battery separator according to  claim 18 , wherein the battery separator is an envelope separator and envelopes a positive plate, a negative plate, or both a positive plate and a negative plate of the flooded lead acid battery. 
     
     
         25 . The battery separator according to  claim 18 , wherein the battery separator is a pocket, a sleeve, a leaf, or an “S” wrap. 
     
     
         26 . An EFB or a golf cart battery comprising the battery separator of  claim 18 . 
     
     
         27 . An EFB or a golf cart battery with increased cycle life comprising the battery separator of  claim 18 . 
     
     
         28 . The battery separator according to  claim 18 , wherein the microporous membrane has a ribbed profile. 
     
     
         29 . The battery separator according to  claim 28 , wherein the ribbed profile includes ribs running in a machine direction on a side of the microporous membrane facing the positive electrode or PAM of the flooded lead acid battery. 
     
     
         30 . The battery separator according to  claim 29 , wherein the ribbed profile further includes ribs running in a cross machine direction on a side of the microporous membrane facing a negative electrode or negative active material (NAM) of the flooded lead acid battery. 
     
     
         31 . The battery separator according to  claim 18 , wherein the battery separator reduces acid stratification in the flooded lead acid battery. 
     
     
         32 . The battery separator according to  claim 18 , wherein the PAM retention mat has a three hour wick of at least about 2.5 cm. 
     
     
         33 . The battery separator according to  claim 18 , wherein the PAM retention mat has a three hour wick in a range of about 2.5 cm to about 10.0 cm. 
     
     
         34 . The battery separator according to  claim 18 , wherein the PAM retention mat further comprises synthetic fibers, synthetic wood pulp, glass fibers, natural fibers, coated fibers, or combinations thereof. 
     
     
         35 . The battery separator according to  claim 18 , wherein the microporous membrane is laminated to the PAM retention mat. 
     
     
         36 . The battery separator according to  claim 18 , wherein the PAM retention mat is a nonwoven mat. 
     
     
         37 . The battery separator according to  claim 18 , wherein the PAM retention mat is a woven mat. 
     
     
         38 . The battery separator according to  claim 18 , wherein the PAM retention mat has at least one of: a pore size of greater than about 1 micron; an MD stiffness of greater than about 90 mN; a CMD stiffness of greater than about 45 mN; a thickness of equal to or greater than about 0.2 mm; and a basis weight of greater than about 35 gsm. 
     
     
         39 . A flooded lead acid battery comprising:
 a negative electrode,   a positive electrode,   an electrolyte, and   a battery separator, wherein said battery separator comprises   a microporous membrane comprising polyethylene and silica, and   a positive active material (PAM) retention mat affixed or laminated thereto, said PAM retention mat comprising fine glass fibers, wherein said PAM retention mat is a nonwoven mat or a woven mat, wherein said PAM retention mat faces or is in contact with said positive electrode or PAM of said battery, wherein the PAM retention mat has a three hour wick of at least about 2.5 cm, and wherein the battery separator prevents shedding of PAM from the positive electrode of the battery.   
     
     
         40 . The flooded lead acid battery of  claim 39 , wherein said battery is a dry charge battery, an inverter battery, an enhanced flooded battery (EFB), an ISS battery, a stationary battery, or a golf cart battery. 
     
     
         41 . The flooded lead acid battery of  claim 39 , wherein said PAM retention mat is a nonwoven mat less than about 0.5 mm thick. 
     
     
         42 . The flooded lead acid battery of  claim 39 , wherein said PAM retention mat is a woven mat less than about 0.5 mm thick. 
     
     
         43 . A battery separator for a flooded lead acid battery, wherein said battery separator comprises
 a microporous polymer membrane, and   a positive active material (PAM) retention mat affixed or laminated thereto, said PAM retention mat comprising fine glass fibers, wherein said PAM retention mat is a nonwoven mat or a woven mat less than about 0.5 mm thick, wherein said PAM retention mat faces or is in contact with said positive electrode or PAM of said battery, and   
       wherein the battery separator prevents shedding of PAM from the positive electrode of the battery when it operates at a high depth of discharge (DoD) and wherein the battery operating at a high DoD is selected from the group consisting of a dry charge battery, an inverter battery, an enhanced flooded battery (EFB), an ISS battery, a stationary battery, a golf cart battery, and combinations thereof.