阅读说明：本技术 电极粘接剂及其制备方法和锂离子电池负极及锂离子电池 (Electrode binder and preparation method thereof and negative electrode of lithium ion battery and lithium ion battery ) 是由 姜猛进 高慧慧 徐建军 李大哲 喻媛媛 毛建昭 齐世凯 刘鹏清 游彦 于 2019-08-30 设计创作，主要内容包括：本申请涉及一种电极粘接剂及其制备方法和锂离子电池负极及锂离子电池,属于电极粘接剂技术领域。一种电极粘接剂,包括聚噁二唑磺酸锂聚合物。该聚合物包括噁二唑结构和磺酸锂基团,噁二唑结构可以与聚合物中的其他结构形成共轭结构,可以为活性物质提供电子运输的通道,体现电子导电性。磺酸锂基团可作为单离子导体为活性物质提供锂离子跳跃点,体现离子导电性。将该聚合物其作为粘接剂时,可体现出电子-离子双导的特性,可以提高电极的循环性能。该电极粘接剂可以用于制备锂离子电池,制得的锂离子电池可以为纽扣电池、软包电池或其他类型的电池。(This application involves a kind of electrode binders and preparation method thereof and negative electrode of lithium ion battery and lithium ion battery, belong to electrode binder technical field.A kind of electrode binder, including polyoxadiazoles sulfonic acid lighium polymer.The polymer includes oxadiazoles structure and Sulfonic Lithium group, and oxadiazoles structure can form conjugated structure with the other structures in polymer, the channel of electronics transport can be provided for active material, embodies electron conduction.Sulfonic Lithium group can be used as single ion conductor and provide lithium ion jump for active material, embody ionic conductivity.Using the polymer its as the double characteristics led of electron-ion when bonding agent, are reflected, the cycle performance of electrode can be improved.The electrode binder can be used for preparing lithium ion battery, and lithium ion battery obtained can be button cell, soft-package battery or other kinds of battery.)

1. a kind of electrode binder, which is characterized in that including polyoxadiazoles sulfonic acid lighium polymer, the polyoxadiazoles Sulfonic Lithium is poly- Close the structural formula of object are as follows:

Wherein, R is selected from AndOne of, m and n are positive integer.

2. electrode binder according to claim 1, which is characterized in that the structure of the polyoxadiazoles sulfonic acid lighium polymer Formula are as follows:

3. a kind of preparation method of electrode binder as claimed in claim 2 characterized by comprising to by hydrazine sulfate and The polymer that at least two diacid monomers polymerize carries out lithiumation, and obtained polyoxadiazoles sulfonic acid lighium polymer is dissolved in solvent In obtain the electrode binder；

Wherein, at least two diacid monomer includes terephthalic acid (TPA) and Biphenyl Ether dioctyl phthalate, the terephthalic acid (TPA) and institute The molar ratio for stating Biphenyl Ether dioctyl phthalate is 1:9 to 9:1.

4. the preparation method of electrode binder according to claim 3, which is characterized in that the terephthalic acid (TPA) and described The molar ratio of Biphenyl Ether dioctyl phthalate is (5-9): (5-1).

5. the preparation method of electrode binder according to claim 3 or 4, which is characterized in that the hydrazine sulfate and described The molar ratio of diacid monomer is (1-1.5): 1.

6. the preparation method of electrode binder according to claim 3 or 4, which is characterized in that the solvent is that diformazan is sub- Any one or a few mixture in sulfone, DMF, DMAC and NMP.

7. a kind of negative electrode of lithium ion battery, which is characterized in that including negative electrode active material, conductive agent and such as claims 1 or 2 institute The electrode binder stated.

8. negative electrode of lithium ion battery according to claim 7, which is characterized in that the negative electrode active material, the conduction The mass ratio of agent and the electrode binder is (5-9.8): (0.1-3): (0.1-4).

9. a kind of lithium ion battery, which is characterized in that including negative electrode of lithium ion battery as claimed in claim 7 or 8.

Technical field

This application involves electrode binder technical fields, and in particular to a kind of electrode binder and preparation method thereof and lithium Ion battery cathode and lithium ion battery.

Background technique

In electrode composition, bonding agent has significant impact to electrode and battery performance.In common bonding agent, For PVDF (Kynoar) because it is weaker with the active force of silicon particle, bonding force is insufficient, and electrode is easy to fall off, and capacity is caused to decline Subtract rapidly.The electric conductivity of CMC (sodium carboxymethylcellulose) is weaker, and intensity is lower, does not adapt to the large volume expansion of silicon electrode.

Summary of the invention

In view of the deficiencies of the prior art, the purpose of the embodiment of the present application includes providing a kind of electrode binder and its preparation side Method and negative electrode of lithium ion battery and lithium ion battery, the technical issues of to improve electrode binder poorly conductive.

In a first aspect, the embodiment of the present application proposes a kind of electrode binder, including polyoxadiazoles sulfonic acid lighium polymer, gather The structural formula of oxadiazoles sulfonic acid lighium polymer are as follows:

Wherein, R is selected from AndOne of, m and n are positive integer.

The polymer that the application uses includes oxadiazoles structure and Sulfonic Lithium group.Oxadiazoles structure has electrophilic spy Property, conjugated structure can be formed with R, it is doped in conjunction with electronically forming, it can be active material when being used for bonding agent The channel of electronics transport is provided, electron conduction is embodied.Sulfonic Lithium group can be used as single ion conductor as active material and provide lithium Ion jump embodies ionic conductivity.Using the polymer, it is double as preferable electron-ion when bonding agent, is reflected The cycle performance of electrode can be improved in the characteristic led.

In the section Example of the application, the structural formula of polyoxadiazoles sulfonic acid lighium polymer are as follows:

The conjugation section that oxadiazoles structure and terephthalic acid (TPA) structure are formed in the structure is longer, so that polyoxadiazoles Sulfonic Lithium The electric conductivity of polymer is stronger.

Second aspect, the embodiment of the present application propose the preparation method of above-mentioned electrode binder, comprising: to by hydrazine sulfate and The polymer that diacid monomer polymerize carries out lithiumation, and obtained polyoxadiazoles sulfonic acid lighium polymer is dissolved in solvent and obtains electricity Pole bonding agent.Wherein, diacid monomer includes terephthalic acid (TPA) and Biphenyl Ether dioctyl phthalate, terephthalic acid (TPA) and Biphenyl Ether dioctyl phthalate Molar ratio is 1:9 to 9:1.

This method can make its strand carry sulfonic acid group by condensation polymerization while obtaining polyoxadiazoles, then pass through Lithiumation process obtains polyoxadiazoles Sulfonic Lithium.It is strong to react controllability.It should be noted that other polyoxadiazoles provided by the present application The method that sulfonic acid lighium polymer prepares electrode binder is identical as above-mentioned preparation method.

In the section Example of the application, the molar ratio of terephthalic acid (TPA) and Biphenyl Ether dioctyl phthalate is (5-9): (5-1).

It, can be with accuracy controlling polymer by adjusting the ratio of two kinds of diacid monomers of terephthalic acid (TPA) and Biphenyl Ether dioctyl phthalate Middle Sulfonic Lithium radical amount, and the electron-withdrawing group nitrogen-atoms in molecule can make sulfonic acid group delocalized, the two synergistic effect, The dissociation for promoting lithium ion, to improve the ionic conductivity of polyoxadiazoles Sulfonic Lithium.

In the section Example of the application, the molar ratio of hydrazine sulfate and diacid monomer is (1-1.5): 1.

By adjusting the molar ratio of hydrazine sulfate and diacid monomer, and then adjust rubbing for terephthalic acid (TPA) and Biphenyl Ether dioctyl phthalate The electric conductivity of polyoxadiazoles Sulfonic Lithium can be improved in that ratio, the dosage increase of terephthalic acid (TPA), so that polyoxadiazoles Sulfonic Lithium has There are preferable electron-ion is double to lead characteristic.

The third aspect, the embodiment of the present application propose a kind of negative electrode of lithium ion battery, including negative electrode active material, conductive agent With above-mentioned electrode binder.

The negative electrode of lithium ion battery uses electrode binder provided by the present application, has good cohesive force, active material Between can keep closely contacting, and the stabilization of pattern can be kept before and after circulation.

In the section Example of the application, the mass ratio of negative electrode active material, conductive agent and electrode binder is (5- 9):(0.1-3):(0.1-4)。

Due to using electrode binder provided by the present application, which has preferable electron-ion is double to lead characteristic, because The dosage of conductive agent in the negative electrode of lithium ion battery of this application appropriate can be reduced, and increase the dosage of other compositions, into And improve the electrical property of cathode.

Fourth aspect, the embodiment of the present application propose a kind of lithium ion battery, including above-mentioned negative electrode of lithium ion battery.

Lithium ion battery battery capacity with higher, capacity retention ratio are higher.The lithium ion battery can be button Battery, soft-package battery or other kinds of battery.

Detailed description of the invention

Technical solution in ord to more clearly illustrate embodiments of the present application, below will be to needed in the embodiment attached Figure is briefly described, it should be understood that the following drawings illustrates only some embodiments of the application, therefore is not construed as pair The restriction of range for those of ordinary skill in the art without creative efforts, can also be according to this A little attached drawings obtain other relevant attached drawings.

Fig. 1 is the reaction equation of polyoxadiazoles sulfonic acid lighium polymer provided by the embodiments of the present application；

Fig. 2 is the cycle performance curve graph for the electrode that the embodiment of the present application 5-8 is provided；

Fig. 3 is the electrode cycle performance detection figure that the application test example 3 provides.

Specific embodiment

It, below will be in the embodiment of the present application to keep the purposes, technical schemes and advantages of the embodiment of the present application clearer Technical solution be clearly and completely described.The person that is not specified actual conditions in embodiment, according to normal conditions or manufacturer builds The condition of view carries out.Reagents or instruments used without specified manufacturer is the conventional production that can be obtained by commercially available purchase Product.

Silicium cathode is as many as 10 times of common graphite capacity because its theoretical specific capacity is relatively high, and is had lower Operating potential, the rich content in the earth's crust, it is nontoxic the advantages that, become most potential lithium ion battery negative material. But silicon electrode because of the continuous insertion of lithium ion and is deviate from cyclic process, volume expansion is larger (300%-400%), meeting So that electrode falls off from copper foil, dusting loses electrical connection, leads to battery capacity rapid decay, limits the use of silicon materials.

Bonding agent accounting is very small in electrode composition, but is to maintain the important composition portion of the structural intergrity of electrode Point.Due to silicon electrode volume expansion, the bonding force of current bonding agent is not sufficient to ensure that the firm of silicon electrode, causes electrode de- It falls.The bonding force of CMC-Li bonding agent is stronger, and the stability of electrode can be improved, but electric conductivity is weaker, and intensity is lower, cannot Adapt to the large volume expansion of silicon electrode.

In view of the above-mentioned problems, present inventor proposes a kind of electrode binder, bonding force with higher it is same When, also with the double characteristics led of preferable electron-ion, the cycle performance of electrode can be improved.

Below to a kind of electrode binder of the embodiment of the present application and preparation method thereof and negative electrode of lithium ion battery and lithium from Sub- battery is specifically described.

A kind of electrode binder, including polyoxadiazoles sulfonic acid lighium polymer, structural formula are as follows:

Wherein, R is selected from AndOne of, m and n are positive integer.

In the section Example of the application, electrode binder is polyoxadiazoles sulfonic acid lighium polymer, and structural formula is

Oxadiazoles structure in the structure has electrophilic characteristic, conjugated structure can be formed with phenyl ring, in conjunction with electricity Son formation is doped, and when being used for bonding agent, the channel of electronics transport can be provided for active material, embodies electronic conduction Property.And the Sulfonic Lithium group in structure, it can be used as single ion conductor as active material and lithium ion jump be provided, embody ion and lead Electrically.Using polyoxadiazoles sulfonic acid lighium polymer as the double characteristics led of electron-ion when bonding agent, are reflected, can be improved The cycle performance of electrode.

The application prepares electrode binder by raw material of polyoxadiazoles sulfonic acid lighium polymer, and diacid monomer is terephthalic acid (TPA) When with Biphenyl Ether dioctyl phthalate, the preparation method of electrode binder includes:

By hydrazine sulfate and diacid monomer at a temperature of 60-100 DEG C pre-polymerization 2-4h.Wherein, hydrazine sulfate and diacid monomer are rubbed Your proportion is (1-1.5): 1.The molar ratio of terephthalic acid (TPA) and Biphenyl Ether dioctyl phthalate is 1:9 to 9:1.Further, to benzene two The molar ratio of formic acid and Biphenyl Ether dioctyl phthalate is (5-9): (5-1).Optionally, the mol ratio of hydrazine sulfate and diacid monomer is The molar ratio of 1.05:1, terephthalic acid (TPA) and Biphenyl Ether dioctyl phthalate is 1:9,2:8,3:7,4:6,5:5,6:4,7:3,8:2 or 9: 1。

Then under the conditions of temperature is 80-130 DEG C, it polymerize 5-8h, end-capping reagent is added after completing in polymerization.In the application portion Divide in embodiment, end-capping reagent is benzoic acid.

Then under the conditions of temperature is 120-170 DEG C, it is cyclized 3-5h, obtains polymer.

By obtained polymer in water coagulating bath coagulation forming, after being washed to neutrality, be immersed in Aqueous Lithium Salts It middle 1-5 days, completes lithiumation process and forms lithiated product, the reaction equation of lithiumation process is as shown in Figure 1.

Lithiated product is dried, is re-dissolved in solvent, uniform solution is formed, obtains electrode binder.In the application In section Example, solvent is dimethyl sulfoxide (DMSO).In the application other embodiments, solvent can be DMF (N-N ' diformazan Base formamide), DMAC (N-N ' dimethyl acetamide) or NMP (N methyl pyrrolidone).

The embodiment of the present application can make its strand carry sulfonic acid by condensation polymerization method while obtaining polyoxadiazoles Group, then polyoxadiazoles Sulfonic Lithium (lithiated product) is obtained by lithiumation process.During the preparation process, by adjusting terephthaldehyde The ratio of acid and two kinds of dioctyl phthalate monomers of Biphenyl Ether dioctyl phthalate, can be with Sulfonic Lithium radical amount in accuracy controlling polymer, and divides Electron-withdrawing group nitrogen-atoms in son can make sulfonic acid group delocalized, and the two synergistic effect promotes the dissociation of lithium ion, thus Improve the ionic conductivity of polyoxadiazoles Sulfonic Lithium.By adjusting the molar ratio of hydrazine sulfate and diacid monomer, and then adjust to benzene The conduction of polyoxadiazoles Sulfonic Lithium can be improved in the molar ratio of dioctyl phthalate and Biphenyl Ether dioctyl phthalate, the dosage increase of terephthalic acid (TPA) Property, so that polyoxadiazoles Sulfonic Lithium has preferable electron-ion is double to lead characteristic.

The third aspect, the embodiment of the present application propose a kind of negative electrode of lithium ion battery, including negative electrode active material, conductive agent With above-mentioned electrode binder.Due to using electrode binder provided by the present application, which has preferable electron-ion double Characteristic is led, therefore the dosage of the conductive agent in the negative electrode of lithium ion battery of the application appropriate can be reduced, increases other compositions Dosage, and then improve cathode electrical property.In the section Example of the application, negative electrode active material, conductive agent and electrode The mass ratio of bonding agent is (5-9): (0.1-3): (0.1-4).Optionally, negative electrode active material, conductive agent and electrode binder Mass ratio be 9:0.9:0.1,8:1:1,7:2:1,7:1:2,6:3:1,6:2:2,6:1:3,5:4:1,5:3:2,5:2:3 or 5: 1:4, it should be noted that the ratio of negative electrode active material, conductive agent and electrode binder in the application and be 10, wherein The accounting of active material is greater than 50%, and the ratio of negative electrode active material, conductive agent and electrode binder can be that integer can also Decimal is thought, such as 7.5:1.5:1,6:2.4:1.6.Negative electrode active material can be at least one in nano silica fume, nano silica fume Kind, conductive agent can in conductive black, electrically conductive graphite, carbon fiber, carbon nanotube, graphene or hybrid conductive slurry at least It is a kind of.

In the section Example of the application, the preparation method of negative electrode of lithium ion battery includes:

Negative electrode active material, conductive agent and above-mentioned electrode binder are mixed in proportion, the grinding of solvent dimethyl sulfoxide is added At uniform slurry.Coated on smooth copper foil and dry.Dry mode for example can using successively in convection oven and It is dry in vacuum drying oven.It is possible to further which the electrode after drying is cut into the disk that diameter is 13mm, battery pack is carried out Dress.

Negative electrode of lithium ion battery provided by the present application has good cohesive force, can keep close between active material It contacts, and the stabilization of pattern can be kept before and after circulation.

Fourth aspect, the embodiment of the present application propose a kind of lithium ion battery, including above-mentioned negative electrode of lithium ion battery.At this Apply in section Example, the assemble method of battery includes: by collector, lithium piece, diaphragm, electrolyte, electrode and collector group Dress, finally forms complete battery for battery seal.

The lithium ion battery has high coulombic efficiency.

The feature of the application and performance are described in further detail with reference to embodiments.