Patent ID: 6896996

Claim:
Electrolytic compositions comprising a perfluoropolyether additive of formula (I): wherein: d, e, f are integers; a, b, c can be zero or integers; said units being statistically distributed along the chain, a+b+c+d+e+f such that the number average molecular weight ranges from 500 to 5×10 5 , preferably from 1,000 to 50,000; T are end groups selected from —CF 2 X(X═F, CF 3 , C1), —C 3 F 7 , —CF(CF 3 )COO − (1/n)M n+ , —CF 2 COO − (1/n)M n+ , —CF 2 C(O(1/n)M n+ ) 2 CF 3 ; M n+ is a cation having valence n=1-4 selected from Li + , Na + , K + , Cs + , Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ , metal cations of the group IIIA such as Al 3+ ; transition metal cations, such as Fe 2+ , Fe 3+ , Zn 2+ , Ti 4+ , Cu 2+ ; tetraalkylammonium NR 4 + cations, trialkylammonium NR 3 + cations, wherein R is selected from H, a linear or branched when possible C 1 -C 4 lower alkyl.