Battery, positive electrode plate, positive electrode slurry, and dispersant and preparation method thereof
View Patent ↗A battery, a positive electrode plate, a positive electrode slurry, a dispersant and its preparation method, and an electric device are disclosed. The battery includes a positive electrode plate having a current collector and a positive electrode material layer on at least one side. The material layer contains a positive electrode active material and a dispersant. The dispersant comprises a polyester compound that includes structural unit A and/or structural unit B. Structural unit A and B are defined by specific chemical formulas, where R1 and R2 are each selected from and C0, C1-C18 alkyl, and C6-C18 aryl groups; R3 and R4 are each selected from H, C1-C18 alkyl, C6-C18 aryl, or ester groups aryl, or ester groups. The dispersant improves the dispersion performance of the positive electrode slurry and enhances the uniformity and flexibility of the positive electrode plate, thereby contributing to higher capacity and improved stability of the battery.
1 . A battery, wherein the battery comprises a positive electrode plate, the positive electrode plate comprises a current collector and a positive electrode material layer provided on at least one side of the current collector, the positive electrode material layer comprises a positive electrode active material and a dispersant, the dispersant comprises a polyester compound, the polyester compound comprises a structural unit A and/or a structural unit B, the structural unit A has a chemical formula of
and the structural unit B has a chemical formula of
wherein
R1 and R2 are each selected from C0, a C1-C18 alkyl group, a C6-C18 aryl group, and an ester group; and R3 and R4 are each selected from at least one of H, a C1-C18 alkyl group, a C6-C18 aryl group, and an ester group.
2 . The battery according to claim 1 , wherein the ester group has a chemical formula of
wherein 0≤a≤6, and R′ is selected from any one of a C1-C18 alkyl group, a C6-C18 aryl group, a polyoxyethylene ether segment, and a polyoxyethylene ether polyoxypropylene ether copolymer segment.
3 . The battery according to claim 2 , wherein the polyoxyethylene ether polyoxypropylene ether copolymer segment comprises
wherein 3<b≤60 and 0<c≤60.
4 . The battery according to claim 1 , wherein
the positive electrode active material comprises one or more of lithium iron phosphate and lithium manganese iron phosphate.
5 . The battery according to claim 1 , wherein
a coating weight of the positive electrode material layer is in a range of 300 g/1540.25 mm 2 -450 g/1540.25 mm 2 ;
a compacted density of the positive electrode material layer is in a range of 2.4 g/cm 3 -2.8 g/cm 3 ; and/or
a sheet resistance of the positive electrode plate is in a range of 0.05Ω-0.30Ω.
6 . The battery according to claim 1 , wherein the polyester compound comprises a structural unit C and/or a structural unit D, the structural unit C has a chemical formula of
and the structural unit D has a chemical formula of
wherein
R5 is selected from any one of a C1-C18 alkyl group, a C6-C18 aryl group, and an ester group.
7 . The battery according to claim 1 , wherein the polyester compound further comprises at least one substituent group G, and G comprises any one of a carboxyl group and a derivative thereof, a sulfonic acid group and a derivative thereof, and a phosphonic acid group and a derivative thereof, wherein
G is a terminal group of the polyester compound;
the carboxyl group and the derivative thereof have a chemical formula of
and/or
the sulfonic acid group and the derivative thereof have a chemical formula of
wherein
a value of d ranges from greater than 1 and less than or equal to 12, and R6 is selected from any one of H, an alkyl group, alkyl alcohol, alkyl hydroxylamine, a fatty ester group, and an aromatic ester group; wherein
the alkyl group has a chemical formula of
the alkyl alcohol has a chemical formula of
the alkyl hydroxylamine has a chemical formula of
the fatty ester group has a chemical formula of
the aromatic ester group has a chemical formula of
a value of e is in a range of 1-12, a value of f is in a range of 1-16, and carbon atoms in Ar have a quantity of not exceeding 12.
8 . The battery according to claim 7 , wherein
the phosphonic acid group and the derivative thereof have a chemical formula of
wherein
R6 is selected from any one of H, an alkyl group, alkyl alcohol, alkyl hydroxylamine, a fatty ester group, and an aromatic ester group; where
the alkyl group has a chemical formula of
the alkyl alcohol has a chemical formula of
the alkyl hydroxylamine has a chemical formula of
the fatty ester group has a chemical formula of
the aromatic ester group has a chemical formula of
a value of is in a range of 1-12, a value of f is in a range of 1-16, and carbon atoms in Ar have a quantity of not exceeding 12.
9 . The battery according to claim 1 , wherein the dispersant comprises a structure shown in formula (1) or a structure shown in formula (2):
wherein
a value of n is in a range of 3-100, and A is a capping group, wherein the capping group comprises one or more of an alkoxy group
a phenylalkoxy group
an ester group
an ester group
an amide group
hydroxyl-OH, amino-NH 2 , and carboxyl-COOH, a value of g is in a range of 1-12, C h is an alkyl segment or an aryl-containing segment, a value of h is in a range of 1-18, and R is H, a C1-C12 alkyl group, or a C6-C12 aryl group,
R1 and R2 are each selected from C0, a C1-C18 alkyl group, a C6-C18 aryl group, and an ester group; and R3 and R4 are each selected from at least one of H, a C1-C18 alkyl group, a C6-C18 aryl group, and an ester group,
R5 is selected from any one of a C1-C18 alkyl group, a C6-C18 aryl group, and an ester group,
G is a substituent group comprising at least one of a carboxyl group and a derivative thereof, a sulfonic acid group and a derivative thereof, and a phosphonic acid group and a derivative thereof, wherein
in the polyester compound, a weight percentage of the substituent group G is less than 15%, a weight percentage of solvated segments R1, R2, R3, R4, and R5 is less than 65%, and a weight percentage of a polyester group is 3%-30%, wherein a weight-average molecular weight of the polyester compound is in a range of 500-100000, wherein the weight-average molecular weight of the polyester compound is in a range of 2000-50000.
10 . A positive electrode slurry, comprising a positive electrode active material, a dispersant, and a solvent, wherein the dispersant comprises a polyester compound, the polyester compound comprises a structural unit A and/or a structural unit B, the structural unit A has a chemical formula of
and the structural unit B has a chemical formula of
wherein
R1 and R2 are each selected from at least one of C0, a C1-C18 alkyl group, and a C6-C18 aryl group; and R3 and R4 are each selected from H, a C1-C18 alkyl group, a C6-C18 aryl group, and an ester group, wherein the dispersant accounts for 0.01%-3.0% of a total weight of the positive electrode slurry, wherein the dispersant accounts for 0.03%-2.0% of the total weight of the positive electrode slurry.
11 . The positive electrode slurry according to 10 , wherein a viscosity of the positive electrode slurry is in a range of 4000 mPa·s-30000 mPa·s.
12 . The positive electrode slurry according to claim 10 , wherein a solid content of the positive electrode slurry is in a range of 55%-65%.
13 . A dispersant, comprising a polyester compound, wherein the polyester compound comprises a structural unit A and/or a structural unit B, the structural unit A has a chemical formula of
and the structural unit B has a chemical formula of
wherein
R1 and R2 are each selected from at least one of C0, a C1-C18 alkyl group, and a C6-C18 aryl group; and R3 and R4 are each selected from H, a C1-C18 alkyl group, a C6-C18 aryl group, and an ester group,
wherein the polyester compound further comprises at least one substituent group G, and G comprises at least one of a sulfonic acid group and a derivative thereof, and a phosphonic acid group and a derivative thereof, wherein
G is a terminal group of the polyester compound;
the sulfonic acid group and the derivative thereof have a chemical formula of
the phosphonic acid group and the derivative thereof have a chemical formula of
wherein
R6 is selected from any one of H, an alkyl group, alkyl alcohol, alkyl hydroxylamine, a fatty ester group, and an aromatic ester group; where
the alkyl group has a chemical formula of
the alkyl alcohol has a chemical formula of
the alkyl hydroxylamine has a chemical formula of
the fatty ester group has a chemical formula of
the aromatic ester group has a chemical formula of
a value of e is in a range of 1-12, a value of f is in a range of 1-16, and carbon atoms in Ar have a quantity of not exceeding 12,
wherein a value of d ranges from greater than 1 and less than or equal to 12.
14 . The dispersant according to claim 13 , wherein the polyester compound comprises a structural unit C and/or a structural unit D, the structural unit C has a chemical formula of
and the structural unit D has a chemical formula of
wherein
R5 is selected from any one of a C1-C18 alkyl group and a C6-C18 aryl group.
15 . An electric device, wherein the electric device comprises the battery according to claim 1 .
16 . The dispersant according to claim 13 , wherein the ester group has a chemical formula of
wherein 0≤a≤6, and R′ is selected from any one of a C1-C18 alkyl group, a C6-C18 aryl group, a polyoxyethylene ether segment, and a polyoxyethylene ether polyoxypropylene ether copolymer segment.
17 . The dispersant according to claim 16 , wherein the polyoxyethylene ether polyoxypropylene ether copolymer segment comprises
wherein 3<b≤60 and 0<c≤60.
18 . The dispersant according to claim 13 , wherein the dispersant comprises a structure shown in formula (1) or a structure shown in formula (2):
wherein
a value of n is in a range of 3-100, and A is a capping group, wherein the capping group comprises one or more of an alkoxy group
a phenylalkoxy group
an ester group
an ester group
an amide group
hydroxyl-OH, amino-NH 2 , and carboxyl-COOH, a value of g is in a range of 1-12, C h is an alkyl segment or an aryl-containing segment, a value of h is in a range of 1-18, and R is H, a C1-C12 alkyl group, or a C6-C12 aryl group,
R5 is selected from any one of a C1-C18 alkyl group, a C6-C18 aryl group, and an ester group,
wherein in the polyester compound, a weight percentage of the substituent group G is less than 15%, a weight percentage of solvated segments R1, R2, R3, R4, and R5 is less than 65%, and a weight percentage of a polyester group is 3%-30%, wherein a weight-average molecular weight of the polyester compound is in a range of 500-100000, wherein the weight-average molecular weight of the polyester compound is in a range of 2000-50000.