Polyamide-imide binder for lithium ion battery and electrode plate

Abstract

The invention discloses a polyamide-imide binder for a lithium ion battery and an electrode plate, and relates to the field of lithium ion battery materials. The binder contains a polyamide-imide copolymer with the following structural general formula: n: m = 30: 70-95: 5; R1 is a unit derived from aliphatic amino acid containing 2-16 carbon atoms; R3 is a unit derived from aliphatic dicarboxylic acid containing 4 to 24 carbon atoms; R2 and R4 are same or different and are selected from units derived from p-phenylenediamine, m-phenylenediamine, o-phenylenediamine and the like. The electrode plate comprises the following components in parts by weight: 1-8 parts of the binder and 92-99 parts of an electrode active material. The binder provided by the invention has stronger bonding strength and flexibility, and can ensure the mechanical properties of the prepared battery pole piece.

Description

technical field

[0001] The invention relates to the field of lithium-ion battery materials, in particular to a polyamide-imide binder and battery pole pieces for lithium-ion batteries. Background technique

[0002] As a clean energy source, lithium-ion batteries are widely used in various electronic devices and electric vehicles. As a member of the lithium battery components, although the amount of electrode binder is small, it ensures the good mechanical properties and processability of the electrode sheet, maintains the integrity of the conductive network of the electrode during charging and discharging, and has a positive effect on the electrical properties of the lithium ion battery electrode. Chemical properties have a significant impact.

[0003] Currently, the most widely used binders in Li-ion batteries are polyvinylidene fluoride (PVDF) and acrylic polymer (PAA). However, it has a series of obvious deficiencies. For example, the bonding force of PVDF is mainly de...

Examples

Embodiment 1

[0038] In the present embodiment, the electrode binder used contains the polyamide-imide copolymer of following structural formula:

[0039]

[0040] Wherein, n:m=75:25 in the synthesized polyamide-imide copolymer.

[0041] Its preparation method is:

[0042] Put 384.3g of trimellitic anhydride, 402.6g of aminoundecanoic acid and 2.50L of glacial acetic acid into a 5L reactor, heat up to 120°C and react for 2 hours, then cool and stand still, filter out the white precipitate, and wash it fully with ethanol to obtain Diacid monomer TMA-11.

[0043] Put 212.3g of 4,4-diaminobenzophenone, 281.6g of TMA-11 and 57.6g of 1,12-dodecanedioic acid into the autoclave, add 165g of deionized water, through repeated vacuuming and Fill the reactor with nitrogen to replace the gas. Seal the reaction kettle and raise the temperature to 230°C while stirring. At this time, discharge water vapor through the exhaust valve to keep the pressure in the kettle constant. The reaction was carried...

Embodiment 2

[0045] In the present embodiment, the electrode binder used contains the polyamide-imide copolymer of following structural formula:

[0046]

[0047] Wherein, n:m=75:25 in the synthesized polyamide-imide copolymer.

[0048] In the preparation, except that 4,4-diaminobenzophenone was replaced by p-phenylenediamine in Example 1, the same method as in Example 1 was used to obtain the polyamideimide described in this example copolymer.

Embodiment 3

[0050] In the present embodiment, the electrode binder used contains the polyamide-imide copolymer of following structural formula:

[0051]

[0052] Wherein, n:m=75:25 in the synthesized polyamide-imide copolymer.

[0053] In the preparation, except that aminoundecanoic acid in Example 1 was replaced with 2-aminodecanoic acid, the same method as in Example 1 was used to obtain the polyamideimide copolymer described in this example.

technical field

[0001] The invention relates to the field of lithium-ion battery materials, in particular to a polyamide-imide binder and battery pole pieces for lithium-ion batteries. Background technique

[0002] As a clean energy source, lithium-ion batteries are widely used in various electronic devices and electric vehicles. As a member of the lithium battery components, although the amount of electrode binder is small, it ensures the good mechanical properties and processability of the electrode sheet, maintains the integrity of the conductive network of the electrode during charging and discharging, and has a positive effect on the electrical properties of the lithium ion battery electrode. Chemical properties have a significant impact.

[0003] Currently, the most widely used binders in Li-ion batteries are polyvinylidene fluoride (PVDF) and acrylic polymer (PAA). However, it has a series of obvious deficiencies. For example, the bonding force of PVDF is mainly de...

Examples

Embodiment 1

[0038] In the present embodiment, the electrode binder used contains the polyamide-imide copolymer of following structural formula:

[0039]

[0040] Wherein, n:m=75:25 in the synthesized polyamide-imide copolymer.

[0041] Its preparation method is:

[0042] Put 384.3g of trimellitic anhydride, 402.6g of aminoundecanoic acid and 2.50L of glacial acetic acid into a 5L reactor, heat up to 120°C and react for 2 hours, then cool and stand still, filter out the white precipitate, and wash it fully with ethanol to obtain Diacid monomer TMA-11.

[0043] Put 212.3g of 4,4-diaminobenzophenone, 281.6g of TMA-11 and 57.6g of 1,12-dodecanedioic acid into the autoclave, add 165g of deionized water, through repeated vacuuming and Fill the reactor with nitrogen to replace the gas. Seal the reaction kettle and raise the temperature to 230°C while stirring. At this time, discharge water vapor through the exhaust valve to keep the pressure in the kettle constant. The reaction was carried...

Embodiment 2

[0045] In the present embodiment, the electrode binder used contains the polyamide-imide copolymer of following structural formula:

[0046]

[0047] Wherein, n:m=75:25 in the synthesized polyamide-imide copolymer.

[0048] In the preparation, except that 4,4-diaminobenzophenone was replaced by p-phenylenediamine in Example 1, the same method as in Example 1 was used to obtain the polyamideimide described in this example copolymer.

Embodiment 3

[0050] In the present embodiment, the electrode binder used contains the polyamide-imide copolymer of following structural formula:

[0051]

[0052] Wherein, n:m=75:25 in the synthesized polyamide-imide copolymer.

[0053] In the preparation, except that aminoundecanoic acid in Example 1 was replaced with 2-aminodecanoic acid, the same method as in Example 1 was used to obtain the polyamideimide copolymer described in this example.

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