Battery separator with improved oxidation stability

Abstract

The invention relates to a thermoplastic polymer-based battery separator, which contains a compound of formula R (OR 1 ) n (COOM x+ 1/x ) m . In said formula, R represents a non-aromatic hydrocarbon group comprising between 10 and 4,200 carbon atoms, which can be interrupted by oxygen atoms, R 1 represents H, —(CH 2 ) k COOM x+ 1/x or —(CH 2 ) k —SO 3 M x+ 1/x , whereby k stands for 1 or 2, M represents an alkali or earth alkaline metal ion, H + or NH 4 + , whereby not all variables of M are defined simultaneously as H + , n stands for 0 or 1, m stands for 0 or a whole number from 10 to 1,400 and x stands for 1 or 2. The ratio of oxygen atoms to carbon atoms in the compound according to the aforementioned formula ranges between 1:1.5 and 1:30 and n and m cannot simultaneously represent zero.

1 . Lead-sulphuric acid accumulator with at least two oppositely-charged electrode plates, comprising at least one battery separator, wherein the battery separator is based on thermoplastic, ultra-high molecular-weight polyolefin with an average molecular weight by weight of at least 300,000, comprising, relative to the sum of the weights of filler and polyolefin, 10 to 100 wt.-% polyolefin and 0 to 90 wt.-% filler, and, relative to the weight of the separator, 5 to 35 wt.-% oil and 0.5 to 5.0 wt.-% of a compound according to the Formula (I)
   ROR 1    (I)   
       in which
 R is a hydrocarbon radical of the formula R 2 —[(OC 2 H 4 ) p ]—, in which
 R 2  is an alkyl radical with 10 to 30 carbon atoms, 
 p is an integer from 0 to 30, 
 
 R 1  is H, —(CH 2 ) k COOM X+   1/x  or —(CH 2 ) k —SO 3 M X+   1/x , where k is 1 or 2,
 M is an alkali metal or alkaline-earth metal ion, H +  or NH 4   + , where not all the M variables simultaneously have the meaning H + , 
 x is 1 or 2. 
 
 
     
     
         2 . Accumulator according to  claim 1 , wherein p is an integer from 0 to 10. 
     
     
         3 . Accumulator according to  claim 2 , wherein p is an integer from 0 to 4. 
     
     
         4 . Accumulator according to  claim 3 , wherein p is an integer from 1 to 4. 
     
     
         5 . Accumulator according to  claim 1 , wherein R 2  is an alkyl radical with 12 to 25 3 0 carbon atoms. 
     
     
         6 . Accumulator according to  claim 5 , wherein R 2  is an alkyl radical with 14 to 20 carbon atoms. 
     
     
         7 . Accumulator according to  claim 1 , wherein R 1  is H. 
     
     
         8 . Lead-sulphuric acid accumulator with at least two oppositely-charged electrode plates, comprising at least one battery separator, wherein the battery separator is based on thermoplastic, ultra-high molecular-weight polyolefin with an average molecular weight by weight of at least 300,000, comprising, relative to the sum of the weights of filler and polyolefin, 10 to 100 wt.-% polyolefin and 0 to 90 wt.-% filler, and, relative to the weight of the separator, 5 to 35 wt.-% oil, and a component which when the separator is used for the intended purpose can form a compound according to the Formula (I)
   ROR 1    (I)   
       in which
 R is a hydrocarbon radical of the formula R 2 —[(OC 2 H 4 ) p ]—, in which
 R 2  is an alkyl radical with 10 to 30 carbon atoms, 
 p is an integer from 0 to 30, 
 
 R 1  is H, —(CH 2 ) k COOM X+   1/x  or —(CH 2 ) k —SO 3 M X+   1/x , where k is 1 or 2,
 M is an alkali metal or alkaline-earth metal ion, H +  or NH 4 ’, where not all the M variables simultaneously have the meaning H + , 
 x is 1 or 2. 
 
 
     
     
         9 . Method for the improvement of the oxidation resistance of a battery separator of a lead-sulphuric acid accumulator comprising the addition to the separator of a compound with the Formula (I)
   ROR 1    (I)   
       in which
 R is a hydrocarbon radical of the formula R 2 —[(OC 2 H 4 ) p ]—, in which
 R 2  is an alkyl radical with 10 to 30 carbon atoms, 
 p is an integer from 0 to 30, 
 
 R 1  is H, —(CH 2 ) k COOM X+   1/x  or —(CH 2 ) k —SO 3 M X+   1/x , where k is 1 or 2,
 M is an alkali metal or alkaline-earth metal ion, H +  or NH 4   + , where not all the M variables simultaneously have the meaning H + , 
 x is 1 or 2.