BINDER AND PREPARATION METHOD THEREOF, SEPARATOR, ELECTRODE PLATE, ELECTRODE ASSEMBLY, BATTERY CELL, BATTERY, AND ELECTRIC APPARATUS
This application discloses a binder and a preparation method thereof, a separator, an electrode plate, an electrode assembly, a battery cell, a battery, and an electric apparatus, and relates to the field of battery technologies. The binder includes a coating layer and a core disposed in the coating layer, where the coating layer includes a polyacrylate copolymer, and the core includes ceramic. The binder is applied onto the separator and used in the battery, providing strong adhesion. This enhances the pre-cold pressing adhesion force and hardness of the battery cell, and reduces electrochemical impedance, thus improving the cycling performance of the battery.
1 . A binder comprising a coating layer and a core disposed in the coating layer, wherein the coating layer comprises a polyacrylate copolymer, and the core comprises ceramic.
2 . The binder according to claim 1 , wherein monomers of the polyacrylate copolymer comprise an acrylate monomer, an acrylonitrile monomer, and an acrylamide monomer.
3 . The binder according to claim 2 , wherein the acrylate monomer comprises at least one of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, n-propyl acrylate, cyclohexyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, isobornyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate; and/or
the acrylonitrile monomer comprises at least one of acrylonitrile and methacrylonitrile; and/or
the acrylamide monomer comprises at least one of acrylamide, N-methylolacrylamide, and N-butoxymethacrylamide; and/or
a molar ratio of the acrylate monomer, acrylonitrile monomer, and acrylamide monomer is 1:(0.01-0.8):(0.01-0.15), optionally 1:(0.05-0.7):(0.05-0.12).
4 . The binder according to claim 1 , wherein a mass ratio of the polyacrylate copolymer to the ceramic is (20-50):(50-80).
5 . The binder according to claim 1 , wherein the ceramic comprises at least one of titanium dioxide, silicon oxide, boehmite, magnesium oxide, and aluminum oxide; and/or
a median particle size by volume D v 50 of the ceramic is 0.01 μm to 2 μm.
6 . The binder according to claim 1 , wherein a median particle size by volume D v 50 of the binder is 5 μm to 100 μm, optionally, 7 μm to 8 μm.
7 . A method for preparing a binder comprising the steps of:
adding monomers of a polyacrylate copolymer into a solution containing an emulsifier, to obtain a pre-emulsion;
adding an initiator into the pre-emulsion for reaction, and adjusting a pH value to 7 to 8, to obtain a reaction solution; and
mixing the reaction solution and ceramic into uniformity and drying the mixture to obtain the binder.
8 . The according to claim 7 , wherein the reaction is conducted at 20° C. to 90° C., optionally, 75° C. to 85° C.; and/or
the reaction is conducted for 20 min to 40 min; and/or
the drying comprises spray-drying.
9 . The method according to claim 7 , wherein monomers of the polyacrylate copolymer comprise an acrylate monomer, an acrylonitrile monomer, and an acrylamide monomer.
10 . The method according to claim 9 , wherein the acrylate monomer comprises at least one of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, n-propyl acrylate, cyclohexyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, isobornyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate; and/or
the acrylonitrile monomer comprises at least one of acrylonitrile and methacrylonitrile; and/or
the acrylamide monomer comprises at least one of acrylamide, N-methylolacrylamide, and N-butoxymethacrylamide; and/or
a molar ratio of the acrylate monomer, acrylonitrile monomer, and acrylamide monomer is 1:(0.01-0.8):(0.01-0.15), optionally 1:(0.05-0.7):(0.05-0.12).
11 . The method according to claim 7 , wherein a mass ratio of the polyacrylate copolymer to the ceramic is (20-50):(50-80).
12 . The method according to claim 7 , wherein the ceramic comprises at least one of titanium dioxide, silicon oxide, boehmite, magnesium oxide, and aluminum oxide; and/or
a median particle size by volume D v 50 of the ceramic is 0.01 μm to 2 μm.
13 . The method according to claim 7 , wherein a median particle size by volume D v 50 of the binder is 5 μm to 100 μm, optionally, 7 μm to 8 μm.
14 . A separator comprising a binder according to claim 1 .
15 . An electrode plate comprising a binder according to claim 1 .
16 . An electrode assembly comprising at least one binder according to claim 1 .
17 . A battery cell comprising the electrode assembly according to claim 16 .
18 . A battery comprising the battery cell according to claim 17 .
19 . An electric apparatus comprising the battery cell according to claim 17 .