阅读说明：本技术 一种锂离子电池负极片的制备方法 (A kind of preparation method of anode plate for lithium ionic cell ) 是由 李金娣 于 2019-08-22 设计创作，主要内容包括：本发明涉及锂离子电池领域,更具体地,本发明涉及一种锂离子电池负极片,按重量份计,包括以下原料：二氧化硅气凝胶70-75份、石墨烯70-75份、粘结剂1-2.5份、导电剂0.5-1份、分散剂0-1份,增稠剂0.5-1份、水145-150份。本发明采用氮掺杂石墨烯和改性聚酰亚胺树脂制备了锂离子电池负极片,氮掺杂石墨烯和改性聚酰亚胺树脂具有协同作用,可在嵌脱锂过程中有效地抑制负极材料的体积膨胀,稳定循环,从而提高锂离子电池的综合性能。同时,本发明制备得到的锂离子电池负极片比表面积大,比电容量高,而且柔性较高,并且采用特殊工艺进行涂布,涂布于负极片表面固化后,所得负极片表面较为平滑,粗糙感弱,因此能够有效防止隔膜被刺穿,延长电池使用寿命。(The present invention relates to field of lithium ion battery, more specifically, the present invention relates to a kind of anode plate for lithium ionic cell, by weight, including following raw material: 70-75 parts of aerosil, 70-75 parts of graphene, 1-2.5 parts of binder, 0.5-1 parts of conductive agent, 0-1 parts of dispersing agent, 0.5-1 parts of thickener, 145-150 parts of water.The present invention is prepared for anode plate for lithium ionic cell using nitrogen-doped graphene and modified polyimide resin, nitrogen-doped graphene and modified polyimide resin have synergistic effect, the volume expansion of negative electrode material can be effectively inhibited during embedding de- lithium, stablize circulation, to improve the comprehensive performance of lithium ion battery.Simultaneously, the anode plate for lithium ionic cell large specific surface area that the present invention is prepared, specific capacitance is high, and it is flexible higher, and be coated using special process, after being coated on negative electrode tab surface cure, gained negative electrode tab surface is more smooth, harsh feeling is weak, therefore diaphragm can be effectively prevent to be pierced, and extends battery.)

1. a kind of anode plate for lithium ionic cell, which is characterized in that by weight, including following raw material: aerosil 70-75 parts, 70-75 parts of graphene, 1-2.5 parts of binder, 0.5-1 parts of conductive agent, 0-1 parts of dispersing agent, 0.5-1 parts of thickener, 145-150 parts of water.

2. anode plate for lithium ionic cell according to claim 1, which is characterized in that the graphene is N doping graphite Alkene.

3. anode plate for lithium ionic cell according to claim 2, which is characterized in that the preparation side of the nitrogen-doped graphene Method is as follows:

A) graphene is carried out in water to ultrasound, obtain dispersion liquid；

B) nitrogen dopant is added into dispersion liquid obtained by step a), obtains mixture；

C) mixture obtained by step b) is placed in autoclave, reacts 2-3h at 85-90 DEG C, is then heated to 210-250 DEG C, 10-12h is reacted, nitrogen-doped graphene is finally made.

4. anode plate for lithium ionic cell according to claim 3, which is characterized in that the matter of the graphene and nitrogen dopant Amount is than being 1:(0.2-0.8).

5. anode plate for lithium ionic cell according to claim 3, which is characterized in that in step b), the nitrogen dopant is The mixture of triethanolamine and guanidine carbonate.

6. anode plate for lithium ionic cell according to claim 5, which is characterized in that the matter of the triethanolamine and guanidine carbonate Amount is than being 1:(0.5-2).

7. anode plate for lithium ionic cell according to claim 1, which is characterized in that the binder is modified polyimide Resin.

8. anode plate for lithium ionic cell according to claim 7, which is characterized in that the system of the modified polyimide resin Preparation Method is as follows:

1) carboxylic diamine derivative is dissolved in n,N-dimethylacetamide solvent, be added aromatic dicarboxylic anhydride monomer into Row reaction, obtains polyamic acid solution；

2) dehydrating agent and catalyst reaction 5-10h is added in gained polyamic acid solution in step 1), it is final to be made modified poly- Imide resin.

9. anode plate for lithium ionic cell according to claim 8, which is characterized in that in step 1), described carboxylic two Amine derivative is 3,4- diamino -2- naphthoic acid.

10. a kind of preparation method of basis such as described in any item anode plate for lithium ionic cell of claim 1-9, feature exist In, it is described the preparation method is as follows:

I) aerosil, graphene are added in water, then add binder, conductive agent, dispersing agent, thickener, so After be ground up, sieved, be made negative electrode slurry；

Ii) by step I in coater oven) gained negative electrode slurry be applied to negative current collector surface, then carry out cold pressing roll, Then it is toasted under vacuum-pumping conditions, negative electrode tab is made.

Technical field

The invention belongs to field of lithium ion battery, more particularly it relates to a kind of anode plate for lithium ionic cell and its Preparation method.

Background technique

In recent years, the high speed development of portable electronic device, electric tool and electric vehicle engineering is to lithium ion battery Performance more stringent requirements are proposed, thus excite height ratio capacity of new generation, long circulation life lithium ion battery research. Lithium ion battery is mainly made of electrolyte, diaphragm, positive and negative pole material, has high-energy-density density, high voltage, long-life, nothing The characteristics such as memory effect, self discharge be small are portable cells most widely used at present.

Compared with the carbons negative electrode material of current commercialization, silicium cathode material has higher specific capacity and energy density, because This is considered as potential next-generation lithium ion battery negative material.But in actual use, silicium cathode material is embedding de- Lithium process can generate violent volume change, cause material dusting, coating from collection liquid surface peel off and solid electrolyte phase boundary The rupture repeatedly and generation of facial mask, the cyclical stability of material is not high, and battery life is shorter.Solve the actual use of silicium cathode material In the process the problem of volume expansion, generally use three kinds of methods: the first is improved to silicon materials itself, by reducing silicon The partial size of material itself makes its nanosizing or by the way that silicon materials are compound with other materials；Second is to electrolyte and bonding Agent is modified；The third is improved to electrode current collecting body and electrode structure.

Improving to silicon materials itself is the very effective method of solution silicium cathode material volume expansion, but after improving Silicium cathode material cycle performance it is poor；Improving to electrolyte, binder, electrode current collecting body and electrode structure can make The volume expansion problem of silicium cathode material is improved, but does not still solve the expansion issues of silicon inherently.Cause This, the present invention specifically addresses above-mentioned silicium cathode materials can generate violent volume change in embedding de- lithium process, cause material powder Change, coating are peeled off from collection liquid surface and SEI film ruptures repeatedly and are generated, so as to cause the circulation of material Stability is not high, the short problem of battery life.

Summary of the invention

To solve the above-mentioned problems, first aspect of the present invention provides a kind of anode plate for lithium ionic cell, by weight Meter, including following raw material: 70-75 parts of aerosil, 70-75 parts of graphene, 1-2.5 parts of binder, conductive agent 0.5-1 Part, 0-1 parts of dispersing agent, 0.5-1 parts of thickener, 145-150 parts of water.

As a kind of perferred technical scheme, the graphene is nitrogen-doped graphene.

As a kind of perferred technical scheme, the nitrogen-doped graphene the preparation method is as follows:

A) graphene is carried out to ultrasonic disperse in deionized water, to obtain uniform dispersion liquid；

B) nitrogen dopant is added into dispersion liquid obtained by step a), and is uniformly mixed and obtains mixture；

C) mixture obtained by step b) is placed in the autoclave with teflon lined, it is anti-at 85-90 DEG C 2-3h is answered, is then heated to 210-250 DEG C, reacts 10-12h, nitrogen-doped graphene is finally made.

As a kind of perferred technical scheme, the mass ratio of the graphene and nitrogen dopant is 1:(0.2-0.8).

As a kind of perferred technical scheme, in step b), the nitrogen dopant is the mixing of triethanolamine and guanidine carbonate Object.

As a kind of perferred technical scheme, the mass ratio of the triethanolamine and guanidine carbonate is 1:(0.5-2).

As a kind of perferred technical scheme, the binder is modified polyimide resin.

As a kind of perferred technical scheme, the modified polyimide resin the preparation method is as follows:

1) carboxylic diamine derivative is dissolved in n,N-dimethylacetamide solvent, aromatic dicarboxylic acid anhydride list is added Body is reacted, and polyamic acid solution is obtained；

2) dehydrating agent and catalyst reaction 5-10h is added in gained polyamic acid solution in step 1), final be made changes Property polyimide resin.

As a kind of perferred technical scheme, in step 1), the carboxylic diamine derivative is 3,4- diamino -2- Naphthoic acid.

The second aspect of the present invention provides a kind of preparation method of anode plate for lithium ionic cell, and the preparation method is such as Under:

I) aerosil, graphene are added in water, after mixing evenly successively add binder, conductive agent, Dispersing agent, thickener are ground up, sieved after being uniformly dispersed, and negative electrode slurry is made；

Ii) by step I in coater oven) gained negative electrode slurry be applied to negative current collector surface, be then cold-pressed It rolls, is then toasted under vacuum-pumping conditions, negative electrode tab is made.

The utility model has the advantages that the present invention is prepared for negative electrode of lithium ion battery using nitrogen-doped graphene and modified polyimide resin Piece, nitrogen-doped graphene and modified polyimide resin have synergistic effect, can effectively inhibit cathode during embedding de- lithium The volume expansion of material stablizes circulation, to improve the comprehensive performance of lithium ion battery.Meanwhile the lithium that the present invention is prepared Ion battery negative electrode tab large specific surface area, specific capacitance is high, and flexible higher, and is coated using special process, applies After being distributed in negative electrode tab surface cure, gained negative electrode tab surface is more smooth, and harsh feeling is weak, therefore diaphragm can be effectively prevent to be pierced It wears, extends battery.

Specific embodiment

It is further clear, complete that the technical characteristic work in technical solution is provided to the present invention With reference to embodiment Description, not to the limitation of its protection scope.

Word " preferred ", " preferred " in the present invention etc. refer to, can provide in some cases certain beneficial to effect The embodiment of the present invention of fruit.However, other embodiments are also likely to be preferred under identical circumstances or in other situations 's.In addition, do not imply that other embodiments are unavailable to the expression of one or more preferred embodiments, be also not intended to by Other embodiments exclude except the scope of the present invention.

First aspect of the present invention provides a kind of anode plate for lithium ionic cell, by weight, including following raw material: two 70-75 parts of silica aerogel, 70-75 parts of graphene, 1-2.5 parts of binder, 0.5-1 parts of conductive agent, 0-1 parts of dispersing agent increase Thick dose 0.5-1 parts, 145-150 parts of water.

In a preferred embodiment, by weight, including following raw material: 73 parts of aerosil, stone 73 parts of black alkene, 2 parts of binder, 0.8 part of conductive agent, 0.5 part of dispersing agent, 0.6 part of thickener, 147 parts of water.

<aerosil>

Aerosil of the present invention is also referred to as " blue smoke ", " solid cigarette ", with nano-porous structure (2 ~100nm), low-density, low-k (1.1~2.5), low thermal conductivity (0.013~0.025w/mk), high porosity (65%~99%), high-specific surface area (300~1000m²/ g) the features such as, it is aobvious in aspects such as mechanics, acoustics, calorifics, optics Peculiar property is shown, space flight and aviation, petrochemical industry, electric power, ship, new-energy automobile and lithium battery, heating power are widely used in Pipeline, building keep warm or cold, the fields such as LNG cold chain.

The present invention is not particularly limited the aerosil, can be commonly used in the art various two Silica aerogel can be prepared, such as the aerosil that can be prepared includes but is not limited to pass through colloidal sol- Gel method is prepared；It can also be commercially available, such as the aerosil being available commercially includes but is not limited to It buys from Jiangxi An Deli high and new technology Co., Ltd.

<graphene>

Graphene (Graphene) of the present invention be one kind by carbon atom with sp²It is in honeycomb that hybridized orbit, which forms hexangle type, The two-dimentional carbon nanomaterial of lattice.

The present invention is not particularly limited the graphene, can be conventional use of various graphenes, can prepare It obtains, such as the graphene that can be prepared includes but unlimited is by mechanically pulling off method, oxidation-reduction method, epitaxy method, carbon SiClx epitaxy, He Mofa, chemical vapour deposition technique are prepared；It can also be commercially available, such as be available commercially Graphene includes but is not limited to buy from Nanjing Xian Feng Nono-material Science & Technology Ltd..

In one embodiment, the graphene is nitrogen-doped graphene, the preparation method is as follows:

A) graphene is carried out to ultrasonic disperse in deionized water, to obtain uniform dispersion liquid；

B) nitrogen dopant is added into dispersion liquid obtained by step a), and is uniformly mixed and obtains mixture；

C) mixture obtained by step b) is placed in the autoclave with teflon lined, it is anti-at 85-90 DEG C 2-3h is answered, is then heated to 210-250 DEG C, reacts 10-12h, nitrogen-doped graphene is finally made.

In a preferred embodiment, the nitrogen-doped graphene the preparation method is as follows:

A) graphene (model XF001W) is subjected to ultrasonic disperse in deionized water, to obtain uniform dispersion liquid；

B) nitrogen dopant is added into dispersion liquid obtained by step a), and is uniformly mixed and obtains mixture；

C) mixture obtained by step b) is placed in the autoclave with teflon lined, is reacted at 90 DEG C 2h is then heated to 220 DEG C, reacts 10h, and nitrogen-doped graphene is finally made.

In one embodiment, the mass ratio of the graphene and nitrogen dopant is 1:(0.2-0.8).

In a preferred embodiment, the mass ratio of the graphene and nitrogen dopant is 1:0.5.

In one embodiment, the graphene and the mass ratio of deionized water are 1:1.

(nitrogen dopant)

Nitrogen dopant of the present invention is the additive rich in nitrogen source, can introduce nitrogen atom structure in the material.

Nitrogen dopant of the present invention be selected from urea, melamine, ammonium hydroxide, triethanolamine, hydrazine hydrate, guanethidine, pyrroles, The combination of one or more of aniline, guanidine carbonate, phosphoguanidine, guanidine hydrochloride, urea phosphate.

In one embodiment, the nitrogen dopant be triethanolamine (CAS:102-71-6) and guanidine carbonate (CAS: Mixture 593-85-1).

In a preferred embodiment, the mass ratio of the triethanolamine and guanidine carbonate is 1:(0.5-2).

In a kind of preferred embodiment, the mass ratio of the triethanolamine and guanidine carbonate is 1:1.

The application introduces nitrogen heteroatom by the way that nitrogen dopant is added in graphene, improves the specific capacitance of negative electrode material Amount.Since the specific capacitance of negative electrode material is smaller, by introducing nitrogen heteroatom in negative electrode material, the ratio of negative electrode material is improved Capacitance.

The applicant has been surprisingly found that, when being modified with two kinds of nitrogen dopants of triethanolamine and guanidine carbonate to graphene, Further improve lithium ion battery cyclical stability, applicant speculate the possible reason is: on the one hand in hydro-thermal reaction plus After entering triethanolamine and guanidine carbonate, thermal decomposition can be made to react collective effect with group, the nitrogen of introducing is finally with pyridine nitrogen, pyrrole Nitrogen, quaternary nitrogen and four kinds of graphite nitrogen different forms are coughed up to exist；Another aspect triethanolamine and guanidine carbonate interaction, make graphene Surface produces more defect sites, to generate more uniform curlings and fold on the surface of graphene.Therefore, it introduces Bond strength of the nitrogen in negative electrode material it is more preferable, can promote insertion of lithium ion during embedding de- lithium (i.e. charge and discharge) and It is detached from.

<binder>

The guarantee of binder of the present invention adhesion strength between abrasive material and matrix.

Binder of the present invention is selected from butadiene-styrene rubber, styrene butadiene ribber, carboxymethyl cellulose, gathers inclined difluoro second The combination of one or more of alkene, polyimides, acrylic resin, butyral resin.

In one embodiment, the binder is modified polyimide resin, the preparation method is as follows:

1) carboxylic diamine derivative is dissolved in n,N-dimethylacetamide solvent, aromatic dicarboxylic acid anhydride list is added Body is reacted, and polyamic acid solution is obtained；

2) dehydrating agent and catalyst reaction 5-10h is added in gained polyamic acid solution in step 1), final be made changes Property polyimide resin.

In a preferred embodiment, the modified polyimide resin the preparation method is as follows:

1) carboxylic diamine derivative is dissolved in n,N-dimethylacetamide solvent, pyromellitic acid anhydride is added It is reacted, obtains polyamic acid solution；

2) dehydrating agent acetic anhydride is added in gained polyamic acid solution in step 1) and catalyst of triethylamine reacts 7h, most Obtained modified polyimide resin eventually.

In a kind of preferred embodiment, carboxylic diamine derivative, n,N-dimethylacetamide, equal benzene tetramethyl Acid dianhydride, acetic anhydride, triethylamine molar ratio be 1:5:1:2:2.

(carboxylic diamine derivative)

In one embodiment, the example of the carboxylic diamine derivative, including but not limited to: 4,6- diaminos Base -1,3- phthalic acid (CAS:13324-94-2), 2,5- diamino -4- methyl benzoic acid (CAS:13066-80-3), 2,3- Diaminobenzoic acid (CAS:603-81-6), 2,4- diaminobenzoic acid (CAS:611-03-0), 2,5- diaminobenzoic acid (CAS:610-74-2), 2,6- diaminobenzoic acid (CAS:102000-59-9), 3,4- diaminobenzoic acid (CAS:619-05- 6), 3,5- diaminobenzoic acid (CAS:535-87-5), 3,4- diamino -2- naphthoic acid (CAS:612806-13-0), 2,6- bis- Amino -1- naphthoic acid (CAS:46390-04-9), 3,4- diaminostilbene-naphthoic acid (CAS:675877-59-5).

In a preferred embodiment, the carboxylic diamine derivative is 3,4- diamino -2- naphthoic acid (CAS:612806-13-0)。

The application strengthens the connection between negative electrode material and collector by the way that polyimides is added.Due to the phase of polyimides Capacitive is poor, is modified by using carboxylic diamine derivative to polyimides, improves the compatibility of polyimides, Strengthen the connection between negative electrode material and collector.

The applicant has been surprisingly found that, when the carboxylic diamine derivative is 3,4- diamino -2- naphthoic acid, into one Step improves lithium ion battery cyclical stability, applicant speculate the possible reason is: one side modified polyimide resin can Composite conducting elasticity inhibition layer is formed by active force with graphene, aerosil；Another aspect modified polyimide Active group on resin alleviates the irregular stress to SEI film of each point volume caused by negative terminal surface lithium deposition, To improve lithium ion battery cyclical stability.

In one embodiment, the mass ratio of the binder and graphene is 1:(30-70).

In a preferred embodiment, the mass ratio of the binder and graphene is 1:(32-45).

In a kind of preferred embodiment, the mass ratio of the binder and graphene is 1:36.5.

Applicant has been surprisingly found that, when the mass ratio of binder and graphene is 1:(30-70) when, the circulation of lithium ion battery Stability is preferable, this may be since modified polyimide resin and nitrogen-doped graphene, the thickener etc. in system can be sent out Good synergistic effect is waved, one side modified polyimide resin can interact with nitrogen-doped graphene and generate composite conducting bullet Property inhibition layer, inhibits the volume expansion of negative electrode material；Pyridine nitrogen, pyrroles's nitrogen, quaternary nitrogen and stone in another aspect nitrogen-doped graphene Four kinds of black nitrogen different nitrogen can realize the uniform of negative terminal surface lithium metal simultaneously with different component in system and Interaction of substituents Deposition, to improve lithium ion battery cyclical stability.When the mass ratio of binder and graphene is 1:36.5, lithium ion The cyclical stability of battery is best.When the mass ratio of binder and graphene is less than 1:70, modified polyimide resin and body Nitrogen-doped graphene, thickener in system etc. can not play good synergistic effect, and the volume expansion of negative electrode material is violent, lithium Ion battery cyclical stability is poor；When the mass ratio of binder and graphene be greater than 1:30 when, modified polyimide resin with Nitrogen-doped graphene, thickener in system etc. can not play good synergistic effect, and negative terminal surface lithium metal deposition is irregular Uneven, lithium ion battery cyclical stability is poor.

<conductive agent>

Conductive agent of the present invention is usually to add to guarantee that electrode has good charge-discharge performance in pole piece production Enter a certain amount of conductive materials, plays the role of collecting micro-current between active material, between active material and collector, with The contact resistance for reducing electrode accelerates the rate travel of electronics, while can also effectively improve lithium ion moving in electrode material Rate is moved, to improve the efficiency for charge-discharge of electrode.

In one embodiment, the conductive agent is selected from artificial graphite, natural graphite, graphene, Ketjen black, carbon nanometer The combination of one or more of pipe, carbon fiber, acetylene black, carbon black, conducting polymer.

In a preferred embodiment, the conductive agent is carbon nanotube, acetylene black.

In a kind of preferred embodiment, the conductive agent is acetylene black (CAS:1333-86-4), is purchased from Shanghai promise Safe Chemical Co., Ltd..

<dispersing agent>

Dispersing agent (Dispersant) of the present invention is one kind in the molecule while having lipophilicity and two kinds of hydrophily The interfacial agent of opposite nature.

In one embodiment, it is (next to be selected from carboxymethyl cellulose, hydroxyethyl cellulose, KELCOGEL for the dispersing agent From CPKelco company), GELMATE (Lai Zi great SUMITOMO CHEMICAL pharmaceutical Co. Ltd), pectin, alginic acid, guar gum, locust tree It is bean gum, gum arabic, dextrin, aldose, D-sorbite, lactose, rice starch, the polysaccharide of sucrose and monosaccharide, sodium taurocholate, bright The combination of one or more of glue, polyvinyl alcohol, neopelex, NDZ201, KH550, KH570.

In a preferred embodiment, the dispersing agent is carboxymethyl cellulose, gelatin and water-soluble polysaccharide.

In a kind of preferred embodiment, the dispersing agent is carboxymethyl cellulose (CAS:9000-11-7), is purchased from Changzhou Luo Wan Biotechnology Co., Ltd.

<thickener>

Thickener of the present invention is a kind of auxiliary rheological agents, can not only coating be made to thicken, and prevents sagging occur in construction Phenomenon, and the excellent mechanical performance of coating and storage stability can be assigned.For water paint lower for viscosity, right and wrong An often important analog assistant.

In one embodiment, the thickener is selected from inorganic thickening agent, cellulose ether, natural polymer, synthesis height The combination of one or more of molecule, solvay-type organo-metallic compound.

As the example of inorganic thickening agent, including but not limited to: fume colloidal silica, sodium bentonite, organobentonite, Diatomite, attapulgite soil, molecular sieve, Silica hydrogel.

As the example of cellulose ether, including but not limited to: methylcellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyl Propyl methocel, carboxymethyl cellulose, sodium carboxymethylcellulose, hydroxyethyl cellulose.

As the example of natural polymer, including but not limited to: starch, gelatin, sodium alginate, casein, guar gum, first Shell amine, gum arabic, xanthan gum, soybean protein glue, natural rubber, lanolin, agar.

As high molecular example is synthesized, including but not limited to: polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, Polyethylene glycol oxide, modified paraffin resin, carbomer, polyacrylic acid, Sodium Polyacrylate, Polyacrylate Emulsion, suitable fourth Rubber, butadiene-styrene rubber, polyurethane, modified polyurea, low-molecular polyethylene wax, polycarboxylic acids, polyethylene oxide.

As the example of solvay-type organo-metallic compound, including but not limited to: amino alcohol solvay-type phthalate ester.

In a preferred embodiment, the thickener is gelatin (CAS:9000-70-8), is purchased from Shandong Feng Taisheng Object Science and Technology Ltd..

The second aspect of the invention provides a kind of preparation method of anode plate for lithium ionic cell, and the preparation method is such as Under:

I) aerosil, graphene are added in water, after mixing evenly successively add binder, conductive agent, Dispersing agent, thickener are ground up, sieved after being uniformly dispersed, and negative electrode slurry is made；

Ii) by step I in coater oven) gained negative electrode slurry be applied to negative current collector surface, be then cold-pressed It rolls, is then toasted under vacuum-pumping conditions, negative electrode tab is made.