Dispersant for power storage device positive electrode
An aspect of the present disclosure relates to a dispersant for a positive electrode of a power storage device, the dispersant being a copolymer containing a constitutional unit represented by the following formula (1), a constitutional unit represented by the following formula (2), and a constitutional unit represented by the following formula (3). Also, an aspect of the present disclosure relates to a dispersant composition, a conductive material slurry for a battery and a method for producing the conductive material slurry a positive electrode paste for a battery or a positive electrode for a battery, each of which contains the dispersant for a positive electrode of a power storage device.
1 . A dispersant for a positive electrode of a power storage device, the dispersant being a copolymer comprising:
a constitutional unit represented by the following formula (1);
a constitutional unit comprising at least one monomer selected from the group consisting of 4-vinylpyridine and 2-vinylpyridine; and
a constitutional unit represented by the following formula (3), wherein
in the formula (1), R 1, R 2, and R 3 are the same or different and represent a hydrogen atom, a methyl group, or an ethyl group, and R 4 represents a hydrocarbon group having 8 to 30 carbon atoms, and
in the formula (3), R 8, R 9, and R 10 are the same or different and represent a hydrogen atom, a methyl group, or an ethyl group, and
wherein:
a content of the constitutional unit represented by formula (1) in all the constitutional units of the dispersant for a positive electrode of a power storage device is 39% by mass or more and 50% by mass or less;
a content of the constitutional unit comprising at least one monomer selected from the group consisting of 4-vinylpyridine and 2-vinylpyridine in all the constitutional units of the dispersant for a positive electrode of a power storage device is 24% by mass or more and 38% by mass or less; and
a content of the constitutional unit represented by formula (3) in all the constitutional units of the dispersant for a positive electrode of a power storage device is 20% by mass or more and 35% by mass or less.
2 . A dispersant for a positive electrode of a power storage device, the dispersant being a copolymer comprising:
a constitutional unit represented by the following formula (1); and
a constitutional unit represented by the following formula (2); and
a constitutional unit represented by the following formula (3), wherein
in the formula (1), R 1, R 2, and R 3 are the same or different and represent a hydrogen atom, a methyl group, or an ethyl group, and R 4 represents a hydrocarbon group having 8 to 30 carbon atoms,
in the formula (2), R 5, R 6, and R 7 are the same or different and represent a hydrogen atom, a methyl group, or an ethyl group, and a functional group X 1 is a pyridinyl group or a pyrrolidone group, and
in the formula (3), R 8, R 9, and R 10 are the same or different and represent a hydrogen atom, a methyl group, or an ethyl group, and
wherein:
a content of the constitutional unit represented by formula (1) in all the constitutional units of the dispersant for a positive electrode of a power storage device is 39% by mass or more and 50% by mass or less;
a content of the constitutional unit represented by formula (2) in all the constitutional units of the dispersant for a positive electrode of a power storage device is 24% by mass or more and 38% by mass or less; and
a content of the constitutional unit represented by formula (3) in all the constitutional units of the dispersant for a positive electrode of a power storage device is 20% by mass or more and 35% by mass or less.
3 . The dispersant for a positive electrode of a power storage device according to claim 2 ,
wherein a mass ratio of the constitutional unit represented by the formula (1) to the constitutional unit represented by the formula (2) is 1.00 or more and 2.10 or less.
4 . The dispersant for a positive electrode of a power storage device according to claim 2 ,
wherein a total content of the constitutional unit represented by the formula (2) and the constitutional unit represented by the formula (3) in all the constitutional units of the dispersant for a positive electrode of a power storage device is 45% by mass or more and 60% by mass or less.
5 . The dispersant for a positive electrode of a power storage device according to claim 2 ,
wherein the dispersant for a positive electrode of a power storage device has a weight average molecular weight of 5000 or more and 500000 or less.
6 . A dispersant composition comprising:
the dispersant for a positive electrode of a power storage device according to claim 2 ; and
a solvent.
7 . A conductive material slurry for a battery, comprising:
the dispersant for a positive electrode of a power storage device according to claim 2 ;
a carbon material-based conductive material; and
a solvent.
8 . The conductive material slurry for a battery according to claim 7 , wherein the carbon material-based conductive material is at least one selected from carbon black, carbon nanotubes, and graphene.
9 . A method for producing a conductive material slurry for a battery, comprising
dispersing components in a mixture containing the dispersant for a positive electrode of a power storage device according to claim 2 , a carbon material-based conductive material, and a solvent, using a ball mill, bead mill, or sand mill.
10 . A positive electrode paste for a battery, comprising:
the dispersant for a positive electrode of a power storage device according to claim 2 ;
a carbon material-based conductive material;
a positive electrode active material;
a binder; and
a solvent.
11 . A positive electrode for a battery, comprising
the dispersant for a positive electrode of a power storage device according to claim 2 .