Polyimide binder precursor composition, and power storage device using same

1 . A polyimide binder precursor composition for a power storage device electrode, comprising a reaction product of a tetracarboxylic acid component and a diamine component, and a solvent,

wherein a polyimide binder obtained from the polyimide binder precursor composition has an irreversible capacity of 1200 mAh/g or less, wherein

the tetracarboxylic acid component comprises more than 80 mol % of an alicyclic tetracarboxylic dianhydride based on the total amount of the tetracarboxylic acid component, wherein the alicyclic tetracarboxylic dianhydride is selected from the group consisting of:

wherein R 31 is a direct bond or a divalent organic group, and R 41 , R 46 and R 47 are each independently selected from the group consisting of —CH 2 —, —CH═CH—, —CH 2 CH 2 —, —O— and —S—; and

the diamine component comprises, based on the total amount of the diamine component,

more than 80 mol % of an aromatic diamine compound, wherein the aromatic diamine compound is selected from compounds represented by formula:

wherein W 1 is a divalent group selected from the group consisting of:

and a divalent group selected from formula (6):

wherein R 61 to R 68 each independently represents any one of the divalent groups selected from the group consisting of:

n12 and n13 each independently represent an integer of 0 to 4; and

R 52 and R 53 are each independently an alkyl group having 1 to 6 carbon atoms, a halogen group, a hydroxyl group, a carboxyl group, or a trifluoromethyl group.

2 . A negative electrode mixture paste for an electrical storage device, comprising the polyimide binder precursor composition according to claim 1 and an active material comprising a silicon-containing material and/or a graphite.

3 . A negative electrode for a power storage device comprising:

(a) an electrode active material layer comprising an active material comprising a silicon-containing material and/or a graphite, and a polyimide binder that is a heated product of a polyimide precursor in the polyimide binder precursor composition according to claim 1 ; wherein the polyimide binder binds the active material; and

(b) a current collector.

4 . A power storage device comprising the negative electrode for a power storage device according to claim 3 .

5 . A method for producing a negative electrode for a power storage device comprising the steps of:

casting or applying the negative electrode mixture paste according to claim 2 onto a current collector; and

heating the applied layer of the negative electrode mixture paste to form a negative electrode active material layer.

6 . A method for producing a power storage device, comprising the method for producing a negative electrode according to claim 5 as one step.

7 . The polyimide binder precursor composition according to claim 1 , wherein the aromatic diamine compound is selected from compounds represented by formula:

wherein W 1 is a divalent group selected from formula (5d):

or a divalent group selected from formula (6):

wherein R 61 to R 68 each independently represent any one of the divalent groups represented by formula (5d):

n12 and n13 each independently represent an integer of 0 to 4; and

R 52 and R 53 are each independently an alkyl group having 1 to 6 carbon atoms.

8 . The polyimide binder precursor composition according to claim 7 , wherein n12 and n13 represent 0.

9 . The polyimide binder precursor composition according to claim 1 , wherein

the alicyclic tetracarboxylic dianhydride is selected from the group consisting of cyclohexane-1,2,4,5-tetracarboxylic dianhydride (H-PMDA), 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), norbornane-2-spiro-a-cyclopentanone-α′-spiro-2″-norbornane 5,5″,6,6″-tetracarboxylic dianhydride (CpODA), (4arH,8acH)-decahydro-1t,4t:5c,8c-dimethanonaphthalene-2t,3t,6c,7c-tetracarboxylic dianhydride (DNDAxx), bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BTA), [1,1′-bi(cyclohexane)]-3,3′,4,4′-tetracarboxylic dianhydride (H-sBPDA), and (octahydro-1,3-dioxo-5-isobenzofurancarboxylic acid) 1,4-phenylenediamide (PPHT), and

the aromatic diamine compound is selected from the group consisting of 4,4′-diaminodiphenyl ether (ODA), 1,3-bis(4-aminophenoxy)benzene (TPE-R), and 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP).

10 . The polyimide binder precursor composition according to claim 1 , wherein the diamine component consists essentially of the aromatic diamine compound.

11 . The polyimide binder precursor composition according to claim 1 , wherein the tetracarboxylic acid component consists essentially of the alicyclic tetracarboxylic dianhydride.

12 . The polyimide binder precursor composition according to claim 1 , wherein the polyimide binder has an irreversible capacity of 800 mAh/g or less.