Binder compound and method for preparing same

1. A binder compound of formula (I):

wherein

R 1 , R 2 , and R 3 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;

R 4 represents —COOM;

R 5 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.

2. The binder compound according to claim 1 , wherein R 1 and R 3 each independently represents an unsubstituted linear or branched alkyl with 1-6 carbon atoms.

3. The binder compound according to claim 1 , wherein R 2 represents an unsubstituted linear or branched alkyl with 1-6 carbon atoms or phenyl.

4. The binder compound according to claim 1 , wherein m is an integer selected from 7,600 to 30,000.

5. The binder compound according to claim 1 , wherein n is an integer selected from 1,520-46,000.

6. The binder compound according to claim 1 , wherein m/n=0.3-7.5.

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

wherein

R 1 , R 2 , and R 3 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;

R 4 represents —COOM,

R 5 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 R 1 , R 3 , 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 R 1 , R 2 , R 3 , Z, m, n, and m/n are as defined above respectively,

R 5 represents a bridging oxo or bridging imino, and

R 6 represents acetyl;

and (iii) reacting the polymer obtained in the step (ii) with an alkali metal alkoxide R 7 OM to obtain the binder compound of formula (I):

wherein R 7 is selected from a linear or branched alkyl with 1-6 carbon atoms.

8. The method according to claim 7 , wherein the glucose acrylic acid derivative of formula (IV) is obtained from glucose or 6-aminoglucose by:

(1) reacting glucose or 6-aminoglucose with a first protective reagent, so that 6-primary hydroxyl or primary amino thereof is protected by a first protective group;

(2) reacting the product in the step (1) with acetic anhydride, so that 1-hydroxyl to 4-hydroxyl thereof are protected by acetyl;

(3) removing the first protective group from the product in the step (2); and

(4) reacting the product in the step (3) with acryloyl chloride or a derivative thereof to obtain the glucose acrylic acid derivative of formula (IV).

9. The method according to claim 8 , wherein the first protective reagent is triphenylchoromethane, and the first protective group is triphenylmethyl.

10. The method according to claim 8 , wherein the step (3) is performed in the presence of hydrogen bromide.

11. An electrode sheet, comprising a current collector and an electrode sheet material layer provided on at least one surface of the current collector, wherein the electrode sheet material layer comprises the binder compound according to claim 1 .

12. The electrode sheet according to claim 11 , wherein the electrode sheet is a negative electrode sheet.

13. The electrode sheet according to claim 12 , wherein the electrode sheet material layer of the negative electrode sheet comprises 0.1-10 wt % of the binder compound based on a total weight of the electrode sheet material layer.

14. A secondary battery, comprising the binder compound according to claim 1 .

15. A battery module, comprising the secondary battery according to claim 14 .

16. A battery pack, comprising the battery module according to claim 15 .

17. An electrical apparatus, comprising the battery pack according to claim 16 .