A separator and a lithium ion battery comprising the separator

Abstract

The invention provides a diaphragm and a lithium ion battery including the diaphragm. In the past, improving the infiltration of the positive electrode active material by the electrolyte generally starts with the electrolyte, and adds additives with high liquid absorption capacity in the electrolyte, but the side reactions of the electrolyte are relatively low. If it is too much, the added additives will be consumed by the reaction at the negative electrode, which increases the burden of the electrolyte to a certain extent. The dispersing aid of the present invention is added to the rubber coating layer and / or ceramic layer of the separator, so as to ensure the infiltration effect of the electrolyte, and at the same time, it can stabilize the coating and bonding effect of the inorganic nanoparticles and the binder, and ensure the effective performance of the ceramic layer. play. Using the intermolecular force between the imino group of the dispersing aid and O in the inorganic nanoparticles and between the active hydrogen on the aromatic ring and PVDF, the adhesiveness and dispersion uniformity of the ceramic layer of the coating separator are effectively improved .

Description

technical field

[0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a separator and a lithium ion battery including the separator. Background technique

[0002] Lithium-ion batteries are widely used in 3C digital and aerospace, automotive, medical and other fields due to their high energy density, high operating voltage, and good cycle storage performance.

[0003] The separator is an important part of the lithium-ion battery. It is located between the positive and negative electrodes inside the battery. It prevents the electron transport while ensuring the passage of lithium ions. The performance of the separator determines the interface structure and internal resistance of the battery, which directly affects the cycle and safety performance of the battery. The separator with excellent performance plays an important role in improving the overall performance of the battery. In order to improve the interfacial adhesion b...

Examples

Embodiment 1

[0097] (1) Preparation of positive electrode sheet

[0098] The positive active material NCM622, the binder PVDF, conductive carbon black and carbon nanotubes were dispersed in N-methylpyrrolidone, and a uniform positive electrode slurry was obtained after stirring, and the solid content contained 93wt% NCM622, 4wt% conductive carbon black and 1wt% % carbon nanotubes and 2 wt% binder PVDF, the solid content of the positive electrode slurry is 51%, and the viscosity is 5360 mPa·s. The positive electrode slurry is uniformly coated on both sides of the carbon-coated aluminum foil, and is baked at 100 ~ 130 ℃ for 4 hours. Roll compaction to 2.5g / cm 3 , get the positive electrode sheet;

[0099] (2) Preparation of negative electrode sheet

[0100] Disperse the negative electrode active material artificial graphite, SBR binder, conductive carbon black and sodium carboxymethyl cellulose in solvent water, and stir to obtain a uniform negative electrode slurry, wherein the solid cont...

Embodiment 2

[0107] The difference from Example 1 is that in Example 2, ① in step (3) prepares a separator coated with ceramic layers on both sides.

Embodiment 3

[0109] The difference from Example 1 is that the auxiliary agent added in ① and ② in step (3) in Example 3 is p-acetamido naphthol acetate.

technical field

[0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a separator and a lithium ion battery including the separator. Background technique

[0002] Lithium-ion batteries are widely used in 3C digital and aerospace, automotive, medical and other fields due to their high energy density, high operating voltage, and good cycle storage performance.

[0003] The separator is an important part of the lithium-ion battery. It is located between the positive and negative electrodes inside the battery. It prevents the electron transport while ensuring the passage of lithium ions. The performance of the separator determines the interface structure and internal resistance of the battery, which directly affects the cycle and safety performance of the battery. The separator with excellent performance plays an important role in improving the overall performance of the battery. In order to improve the interfacial adhesion b...

Examples

Embodiment 1

[0097] (1) Preparation of positive electrode sheet

[0098] The positive active material NCM622, the binder PVDF, conductive carbon black and carbon nanotubes were dispersed in N-methylpyrrolidone, and a uniform positive electrode slurry was obtained after stirring, and the solid content contained 93wt% NCM622, 4wt% conductive carbon black and 1wt% % carbon nanotubes and 2 wt% binder PVDF, the solid content of the positive electrode slurry is 51%, and the viscosity is 5360 mPa·s. The positive electrode slurry is uniformly coated on both sides of the carbon-coated aluminum foil, and is baked at 100 ~ 130 ℃ for 4 hours. Roll compaction to 2.5g / cm 3 , get the positive electrode sheet;

[0099] (2) Preparation of negative electrode sheet

[0100] Disperse the negative electrode active material artificial graphite, SBR binder, conductive carbon black and sodium carboxymethyl cellulose in solvent water, and stir to obtain a uniform negative electrode slurry, wherein the solid cont...

Embodiment 2

[0107] The difference from Example 1 is that in Example 2, ① in step (3) prepares a separator coated with ceramic layers on both sides.

Embodiment 3

[0109] The difference from Example 1 is that the auxiliary agent added in ① and ② in step (3) in Example 3 is p-acetamido naphthol acetate.

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