阅读说明：本技术 一种抑制固态锂电池锂枝晶生长的电解质膜的制备方法 (A kind of preparation method for the dielectric film inhibiting solid state lithium battery lithium dendrite growth ) 是由 廖健淞 陈庆 于 2019-08-20 设计创作，主要内容包括：本发明涉及抑制固态锂电池锂枝晶生长技术领域,具体涉及一种抑制固态锂电池锂枝晶生长的电解质膜的制备方法。一种抑制固态锂电池锂枝晶生长的电解质膜的制备方法由如下步骤组成：使用聚丙烯腈PAN和聚甲基丙烯酸甲酯PMMA、线性聚合物分别配制纺丝液进行同轴纺丝,在纺丝过程中对形成的膜材进行热处理拉伸后迅速冷却固化,所述溶液纺丝过程中各溶液流速PMMA＞线性聚合物＞PAN；之后将膜材置于锂离子电池电解液中进行浸泡；最后将膜材置于80～90℃下处理14.5～15.5min,获得所需的固体电解质膜,所述固体电解质膜为PMMA/线性聚合物/PAN的多层核壳结构纤维复合成膜。本发明有效解决了PMMA力学性能差难以抑制锂枝晶生长和PAN对锂金属不稳定的缺点。(The present invention relates to inhibit solid state lithium battery lithium dendrite growth technical field, and in particular to a kind of preparation method for the dielectric film for inhibiting solid state lithium battery lithium dendrite growth.A kind of preparation method of dielectric film inhibiting solid state lithium battery lithium dendrite growth is made of following steps: being prepared spinning solution respectively using polyacrylonitrile (PAN) and polymetylmethacrylate, linear polymer and is carried out coaxial spinning, it is cooled and solidified rapidly after carrying out heat treatment stretching to the membrane material of formation during the spinning process, each solution flow velocity PMMA > linear polymer > PAN in the solution spinning process；Membrane material is placed in lithium-ion battery electrolytes later and is impregnated；Membrane material is finally placed in 14.5~15.5min of processing at 80~90 DEG C, obtains required solid electrolyte film, the solid electrolyte film is PMMA/ linear polymer/PAN multi-layer core-shell structure fiber composite film forming.The present invention efficiently solves PMMA poor mechanical property and is difficult to the disadvantage for inhibiting lithium dendrite growth and PAN unstable to lithium metal.)

1. a kind of preparation method for the dielectric film for inhibiting solid state lithium battery lithium dendrite growth, which is characterized in that specific steps are such as Under:

(a) using polyacrylonitrile (PAN) and polymetylmethacrylate, linear polymer prepare respectively spinning solution carry out it is wet The coaxial spinning of method cools and solidifies rapidly after carrying out heat treatment stretching to the membrane material of formation during the spinning process；The polyacrylonitrile The spinning solution of preparation is the spinning solution for being 15% as the mass concentration of solvent using dimethyl sulfoxide；The linear polymer spinning solution For the linear polyethylene spinning solution for being 17% as the mass concentration of solvent using dimethyl sulfoxide；The polymethyl methacrylate is matched The spinning solution of system is that the dispersion of polymethyl methacrylate micro mist is swollen the spinning that lysigenous mass concentration is 18% in acetone Liquid；Each spinning flow velocity PMMA > linear polymer > PAN in the spinning process；The coaxial spinning is from the outer to the inner It is followed successively by polymethyl methacrylate, linear polymer, polyacrylonitrile；

(b) membrane material that (a) step is prepared is placed in lithium-ion battery electrolytes after and is impregnated；

(c) membrane material after finally impregnates (b) step is placed in 14.5~15.5min of processing at 80~90 DEG C, obtains required consolidate Body dielectric film.

2. a kind of preparation method of dielectric film for inhibiting solid state lithium battery lithium dendrite growth according to claim 1, Be characterized in that, each solution flow velocity PMMA in solution spinning process described in (a) step: linear polymer: PAN is 1.3~1.6:1.1 ~1.2:0.8~1.0.

3. a kind of preparation method of dielectric film for inhibiting solid state lithium battery lithium dendrite growth according to claim 1, Be characterized in that, each solution flow velocity PMMA in solution spinning process described in (a) step: linear polymer: PAN is 1.4~1.5:1.1 ~1.2:0.9~1.0.

4. a kind of preparation method of dielectric film for inhibiting solid state lithium battery lithium dendrite growth according to claim 1, It is characterized in that, membrane material described in (a) step carries out heat treatment stretching, and the membrane material formed in receiver board is specifically warming up to 120 DEG C It stretches, stretching ratio is controlled at 3-5 times.

5. a kind of preparation method of dielectric film for inhibiting solid state lithium battery lithium dendrite growth according to claim 1, It is characterized in that, smooth pressed sizing is carried out to membrane material using acrylic board in heat treatment process described in (a) step.

6. a kind of preparation method of dielectric film for inhibiting solid state lithium battery lithium dendrite growth according to claim 1, It is characterized in that, (b) time of immersion described in step is 5-10min.

7. a kind of preparation method of dielectric film for inhibiting solid state lithium battery lithium dendrite growth according to claim 1, It is characterized in that, (b) electrolyte described in step is that lithium battery often uses liquid electrolyte, and the electrolyte is lithium hexafluoro phosphate in carbonic acid Saturated solution in based organic solvent.

8. a kind of dielectric film for inhibiting solid state lithium battery lithium dendrite growth, which is characterized in that a kind of inhibition solid-state lithium electricity The dielectric film of pond lithium dendrite growth is prepared by the described in any item preparation methods of claim 1~7.

Technical field

The present invention relates to inhibit solid state lithium battery lithium dendrite growth technical field, and in particular to a kind of inhibition solid state lithium battery The preparation method of the dielectric film of lithium dendrite growth.

Background technique

Lithium ion energy density is high, and stability is strong, and memory-less effect has extended cycle life, as a kind of commercialized efficient Energy storage device is widely applied.Electrolyte used in conventional lithium ion battery is the lithium hexafluoro phosphate of liquid, due to Its own is extremely unstable, and easy decomposition leads to battery flatulence, at the same in high temperature, short circuit, overcharge or whens physical impacts easily burns And explosion.Although protection mechanism is added by outer enclosure, still there is biggish security risk.Solid lithium ion battery makes Liquid electrolyte is substituted with solid electrolyte, can fundamentally solve the safety problem of liquid lithium ionic cell and uses warm area Problem.Many scientific research personnel are absorbed in research polymer gel electrolyte, and introducing liquid solvent by polymeric inner makes its tool There is higher ionic mobility.Typical polymer has PVDF, PVC, PAN, PVP, PMMA etc., and this kind of material price is cheap, comes Source is wide, while its lithium ion conductivity rather moderate, very tempting in the prospect of technology production.But polymer gel electricity The problem of for solution matter since inside is there are big quantity of fluid, mechanical property is poor, is easy to appear leakage and lithium dendrite growth.Patent 201710003124.9 proposing a kind of PEO base solid polymer electrolyte membrane and preparation method thereof, passes through PEO and PMMA and be copolymerized Back loading lithium salts prepares gelatinous solid electrolyte, solves the problems, such as conventional solid-state gel-form solid polymer electrolyte leakage, but It is difficult to the growth for effectively limiting Li dendrite.Therefore, the inhibition for solid gel polymer dielectric lithium dendrite growth has Highly important practical significance.

Disclosing one kind application No. is the patent application of CN201410715763.4 can be used as lithium ion battery with novel solid State membrane materials for electrolyte and its preparation method and application.The material is containing poly- fluorine sulfimide base lithium salts and polyethylene oxide structure Block copolymer, molecular structure such as formula (I).This method is by Han fluorine Dan Ti ﹑ polyethylene oxide mixed dissolution in dry acetonitrile In, and acid binding agent is added, 1d~10d is reacted under the conditions of being placed in 0~100 DEG C, obtains the polymer of metal ion salt form；It will be golden The polymer for belonging to ion salt form is dissolved in organic solvent, is added and is carried out lithium ion exchanged reaction, obtains the polymerization of lithium salt form Object.Material of the present invention can be used as cell solid electrolyte material and be applied in preparing lithium battery.Material of the present invention is as solid Body electrolyte inhibits lithium dendrite growth in lithium ion battery, improves lithium ion transference number, the high conductivity of room temperature and stable There is preferable application prospect on circulating battery.

Application No. is the patent applications of CN201810400093.5 to disclose a kind of organo-mineral complexing dielectric film, including The double-layer structure being made of layer one and layer two；Layer one and layer two are made of the slurry for including ingredient same as below: inorganic solid-state Electrolyte, lithium salts, film forming agent, conducting lithium ions polymer, plasticizer and solvent；Wherein, the inorganic solid electrolyte of layer one contains The inorganic solid electrolyte content of amount>layer two, conducting lithium ions polymer content<layer two conducting lithium ions polymer of layer one Content.The invention also discloses the batteries comprising above-mentioned Organic-inorganic composite dielectric film.Organic-inorganic composite electricity of the present invention The flexibility of solution plasma membrane is good, conductivity is high, and meets the difference requirement of lithium ion cell positive, cathode to film simultaneously, can The growth for inhibiting Li dendrite, improves the comprehensive performance of battery.

Application No. is the patent applications of CN201610214376.1 to disclose a kind of lithium battery solid electrolyte film and its system Preparation Method, this method include the patch negative side Coating Ions conductive particle in the polymer film with gap, patch side of the positive electrode coating Ionic conduction particle or ionic conductivity particle, are prepared Ranvier's membrane；Assemble lithium battery, Ranvier's membrane be used as lithium battery every Film；During charging and discharging lithium battery, the liquid electrolyte of negative side is converted into solid electrolyte in the gap of Ranvier's membrane, raw At solid electrolyte film.The preparation method is a kind of method of in-situ preparation solid electrolyte film, and this method step is simple, can be with Compatible existing battery manufacturing process, further reduced the production cost of solid metal lithium battery；The solid of this method preparation Dielectric film can effectively inhibit the growth of Li dendrite and inhibit puncture of the Li dendrite to diaphragm, reduce lithium metal with It is further chemically reacted between electrolyte, metal lithium electrode can be effectively protected.

Application No. is: a kind of inhibition lithium dendrite growth cobalt acid lithium electrolysis of the patent application publication of CN201810052577.5 The preparation method of matter, the method is simple to operation, at low cost, and time-consuming short, the method adulterates Nb ion in positive electrode, Same order elements are carried out to the Co ionic sites in positive electrode lattice, changes lattice parameter, obtains the nothing of excellent electrochemical performance Machine electrolyte；It using lightweight carbon nitrogen polymer as filler in the present invention, is uniformly mixed with electrolyte, forms solid electrolyte, It can be used for inhibiting the growth of dendrite in lithium metal battery.

Application No. is: the patent application of CN201810163648.9 discloses a kind of composite solid electrolyte, including first Solid electrolyte layer and the second solid electrolyte layer, wherein the first solid electrolyte layer is polymer solid electrolyte layer, second Solid electrolyte layer includes copolymer solid electrolyte and inorganic solid electrolyte, and the second solid electrolyte layer is in the composite solid Mass content in body electrolyte is 50~90%, and mass content of the inorganic solid electrolyte in the second solid electrolyte layer is 10~70%；The invention also discloses method for preparing composite solid electrolyte and its applications；Complex solid disclosed by the invention Electrolyte combines the advantages of inorganic solid electrolyte and copolymer solid electrolyte, and conductivity is high, and electrochemical window mouth width can have Effect inhibits lithium dendrite growth, prevents the dusting of metal negative electrode, preparation method is simple, easy to industrialized production.

Summary of the invention

For the serious problem of existing polymer dielectric lithium dendrite growth, the first purpose of this invention is to propose one kind Inhibit the preparation method of the dielectric film of solid state lithium battery lithium dendrite growth.

In order to achieve the above first purpose, a kind of system for the dielectric film for inhibiting solid state lithium battery lithium dendrite growth of the present invention Preparation Method, steps are as follows for specific method:

(a) using polyacrylonitrile (PAN) and polymetylmethacrylate, linear polymer prepare respectively spinning solution carry out it is wet The coaxial spinning of method cools and solidifies rapidly after carrying out heat treatment stretching to the membrane material of formation during the spinning process；The polyacrylonitrile The spinning solution of preparation is the spinning solution for being 15% as the mass concentration of solvent using dimethyl sulfoxide；The linear polymer spinning solution For the linear polyethylene spinning solution for being 17% as the mass concentration of solvent using dimethyl sulfoxide；The polymethyl methacrylate is matched The spinning solution of system is that the dispersion of polymethyl methacrylate micro mist is swollen the spinning that lysigenous mass concentration is 18% in acetone Liquid；Each spinning flow velocity PMMA > linear polymer > PAN in the spinning process；The coaxial spinning is from the outer to the inner It is followed successively by polymethyl methacrylate, linear polymer, polyacrylonitrile；

(b) membrane material that (a) step is prepared is placed in lithium-ion battery electrolytes after and is impregnated；

(c) membrane material after finally impregnates (b) step is placed in 14.5~15.5min of processing at 80~90 DEG C, obtains required consolidate Body dielectric film.

Preferably, each solution flow velocity PMMA in solution spinning process described in (a) step: linear polymer: PAN be 1.3~ 1.6:1.1~1.2:0.8~1.0.

It is further preferred that each solution flow velocity PMMA in solution spinning process described in (a) step: linear polymer: PAN is 1.4~1.5:1.1~1.2:0.9~1.0.

Preferably, membrane material described in (a) step carries out heat treatment stretching, is specifically warming up to the membrane material formed in receiver board 120 DEG C of stretchings, stretching ratio are controlled in 3-5.

Preferably, smooth pressed sizing is carried out to membrane material using acrylic board in heat treatment process described in (a) step.Pass through Membrane material is sandwiched among two plates by acrylic board, is applied certain pressure and is carried out smooth sizing.

Preferably, (b) time of immersion described in step is 5-10min.

Preferably, (b) electrolyte described in step is that lithium battery often uses liquid electrolyte, in order to adsorb more electrolyte, Further preferred electrolyte is saturated solution of the lithium hexafluoro phosphate in carbonate based organic solvent.

Polyacrylonitrile (PAN) and polymetylmethacrylate of the present invention can be using commercially available conventional poly- third Alkene nitrile PAN and polymetylmethacrylate；For the ease of the dissolution of polymethyl methacrylate, polymethylacrylic acid is selected Methyl esters micro mist, the state coexisted in spinning solution for swelling and dissolution.

Fiber internal layer of the present invention uses linear polymer, keeps linear polymer spontaneous by heat treatment after adsorbing electrolyte It shrinks, electrolyte is fixed on inside dielectric film.

The spinning is using conventional solution-polymerized SBR.(a) each solution flow velocity compares in step solution spinning process Key, shell solution flow velocity is greater than core solution flow velocity in coaxial spinning process, so that it is thicker to form the fiber of spinning Shell structure, the polymer film that spinning is formed are presented a large amount of holes after hot-stretch solidifies rapidly, pass through heat after adsorbing electrolyte Processing makes linear polymer Spontaneous Contraction, to make filament contraction, electrolyte is fixed on inside dielectric film, many experiments hair Each solution flow velocity in existing solution spinning process, polymetylmethacrylate: linear polymer: the flow velocity of polyacrylonitrile (PAN) Effect is more excellent when than for 1.3~1.6:1.1~1.2:0.8~1.0, and obtained dielectric film performance is good.

The present invention second purpose to be achieved is to provide a kind of dielectric film for inhibiting solid state lithium battery lithium dendrite growth, A kind of dielectric film inhibiting solid state lithium battery lithium dendrite growth is prepared by above-mentioned preparation method.

By the present invention in that being matched respectively with polyacrylonitrile (PAN) and polymethyl methacrylate (PMMA), linear polymer It is made as spinning solution, coaxial spinning is carried out as raw material, heat treatment drawing is carried out to the membrane material for being formed in receiver board during the spinning process It stretches, membrane material is placed in lithium-ion battery electrolytes impregnates later, finally by the membrane material after immersion by rear cooling and solidifying rapidly It is placed in and is heat-treated, obtain required solid electrolyte film.Fiber in the solid electrolyte film is PMMA/ linear polymerization Object/PAN multi-layer core-shell structure fiber, each solution flow velocity PMMA > linear polymer > PAN in the solution spinning process, institute Stating linear polymer is polyolefins, and the electrolyte is that lithium battery often uses liquid electrolyte, is needed in the heat treatment process Membrane material is carried out shaping using acrylic board.During the preparation process due in spinning process shell solution flow velocity be greater than core solution Flow velocity, so that the fiber of spinning be made to form thicker shell, the polymer film that spinning is formed is in after the rapid chilling solidification of hot-stretch Now a large amount of holes make linear polymer Spontaneous Contraction by heat treatment after adsorbing electrolyte, electrolyte are fixed on electrolyte Inside film.There is following significant advantage using the dielectric film that method of the invention is prepared:

The utility model has the advantages that

1, the present invention is by the fiber of design special construction, and the PMMA on surface layer and lithium metal compatibility are preferable after spinning forms a film, in The linear polymer of interbed mechanical strength with higher after shrinking, the PAN of internal layer can effectively improve lithium ion conduction energy Power, this multi-layer core-shell structure efficiently solve PMMA poor mechanical property be difficult to inhibit lithium dendrite growth and PAN to lithium metal not Stable disadvantage, while the more uniform densification in surface can be made by surface shrinkage, more effectively prevent the leakage of electrolyte.

2, electrolyte network absorption electrolyte prepared by the present invention is stablized, and lithium ion conduction ability is excellent.

Detailed description of the invention

Attached drawing 1: rear surface lithium dendrite arm shape appearance figure is recycled in the dielectric film that embodiment 1 obtains；Smooth surface, without bright Aobvious lithium dendrite arm.

Attached drawing 2: rear surface lithium dendrite arm shape appearance figure is recycled in the dielectric film that comparative example 2 obtains；Surface has coarse lithium brilliant Branch distributed point.

Specific embodiment

In the following, the present invention will be further described in detail by way of specific embodiments, but this should not be interpreted as to the present invention Range be only limitted to example below.Without departing from the idea of the above method of the present invention, according to ordinary skill The various replacements or change that knowledge and customary means are made, should be included in the scope of the present invention.