Binder compound and method for preparing same

A method for preparing a binder compound of formula (I),

• wherein
• R1, R2, and R3 each independently represents an unsubstituted or substituted linear or branched alkyl with 1-6 carbon atoms, or an unsubstituted or substituted aryl with 6-20 carbon atoms;
• R4 represents —COOM,
• R5 represents a bridging oxo or bridging imino;
• each M independently represents one of Li, Na, K, Rb, and Cs;
• Z represents a linear or branched alkylene with 1-6 carbon atoms;
• m is an integer selected from 7,600 to 47,000;
• n is an integer selected from 1,520 to 94,000;
• and
• m/n=0.1-10;
• the method comprising following steps:
• (i) allowing a polymerization reaction of a vinylidene fluoride monomer in the presence of a chain transfer agent of formula (II) to obtain a polymer of formula (III):
• wherein R1, R3, Z, and m are defined as above respectively;
• and
• optionally, the chain transfer agent of formula (II) is 4-cyano-4-thioylthiopropylsulfanyl pentanoic acid;
• (ii) allowing a polymerization reaction between a glucose acrylic acid derivative of formula (IV) and polyvinylidene fluoride of formula (III) to obtain a polymer of formula (I′):
• wherein R1, R2, R3, Z, m, n, and m/n are as defined above respectively,
• R5 represents a bridging oxo or bridging imino, and
• R6 represents acetyl;
• and (iii) reacting the polymer obtained in the step (ii) with an alkali metal alkoxide R7OM to obtain the binder compound of formula (I):
• wherein R7 is selected from a linear or branched alkyl with 1-6 carbon atoms.