CN103999268A

CN103999268A - Lithium ion battery and method for manufacturing same

Info

Publication number: CN103999268A
Application number: CN201280062019.8A
Authority: CN
Inventors: 加贺祐介; 西龟正志; 高原洋一
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2011-12-16
Filing date: 2012-10-10
Publication date: 2014-08-20
Also published as: WO2013088824A1; JP2013127857A

Abstract

Provided are: a lithium ion battery which has achieved improved reliability by suppressing internal short circuit caused by metal foreign substances and which is excellent in terms of cost; and a production technique for the lithium ion battery. In embodiment (1) of the present invention, a separator (SP1) and a separator (SP2) are configured to respectively adhere to the surfaces of a positive electrode (PEL) so that a gap is not formed between the positive electrode (PEL) and the separator (SP1) or between the positive electrode (PEL) and the separator (SP2). Namely, the positive electrode (PEL), the separator (SP1) and the separator (SP2) are formed integrally. In this connection, each separator (SP1, SP2) is configured from, for example, a material that contains a ceramic and an organic material, which are insulating substances, and a binder (a binding agent).

Description

Lithium ion battery and manufacture method thereof

Technical field

The present invention relates to a kind of lithium ion battery and manufacturing technology thereof, particularly relate to be a kind ofly applicable to possess positive pole, negative pole and by the lithium ion battery of the positive pole barrier film separated with negative electricity and manufacturing technology thereof and effective technology.

Background technology

As the background technology of the art, there is JP 2006-139978 communique (patent documentation 1).In this patent documentation 1, record negative or positive electrode and the integrated example of barrier film.

Prior art document

Patent documentation

Patent documentation 1: JP 2006-139978 communique

Summary of the invention

Invent problem to be solved

Follow the development of mancarried electronic aid, as the electric power supply source of these mancarried electronic aids, the small-sized secondary batteries that use can recharge.Wherein, energy density high, have extended cycle life, simultaneously self discharge lithium ion battery low and that operating voltage is high receives much concern.Lithium ion battery is above-mentioned owing to having advantages of, therefore, is used for the mancarried electronic aids such as digital camera, subnotebook PC, mobile phone.And in recent years, as electric vehicle battery or electric power storage battery, the research and development that can realize the large-scale lithium ion battery of high power capacity, high output and high-energy-density make progress.Particularly in automobile industry, for corresponding to environmental problem, use motor as the electric motor car of power source and use engine (internal combustion engine) and motor makes progress as the exploitation of the hybrid electric vehicle of power source.As the power supply of this electric motor car and hybrid electric vehicle, lithium ion battery receives much concern.But lithium ion battery is because operating voltage is high, energy density is high, so be necessary for the sufficient countermeasure of the abnormal heating being caused by internal short-circuit and external short circuit etc.

Lithium ion battery for example possesses that having reels and is coated with positive plate, the negative plate that is coated with negative electrode active material and the electrode coiling body that prevents that barrier film that positive plate contacts with negative plate from forming of positive active material.And in lithium ion battery, this electrode coiling body is inserted in outer tinning, and in tinning outside, inject electrolyte.; in lithium ion battery; the negative plate that is coated with the positive plate of positive active material and is coated with negative electrode active material in metal forming in metal forming is formed band shape; in order to make to form banded positive plate, directly do not contact with negative plate; clip membrane coil and be coiled into cross section helical form, form electrode coiling body.

Like this, positive plate, negative plate and barrier film are reeled around axle core and form electrode coiling body, due in common lithium ion battery, positive plate, negative plate and barrier film form with individual components (separating component), therefore, for example between positive plate and barrier film, there is gap.And, in the manufacturing process of lithium ion battery, before forming above-mentioned coiling body, positive plate and negative plate are cut into the size of regulation, but also cut positive plate and negative plate, form the collector plate of positive pole and negative pole.And, after forming above-mentioned electrode coiling body, for example, exist the anodal collector plate supersonic welding being formed on positive plate is connected on anodal collector ring, and the negative pole collector plate supersonic welding being formed on negative plate is connected on to the operation on negative pole collector ring.And electrode coiling body is inserted in outer tinning (container), inject electrolyte in this outer tinning after, for the inside of outer tinning is airtight, exist and utilize welding to wait the operation that connects outer tinning and lid.

Particularly, so-called anodal collector plate and anodal collector ring, the aluminium strip that carried out reeling on anodal collector plate, utilize ultrasonic bonding that anodal collector plate is connected on this aluminium strip.The ultrasonic bonding of now using is connected the technique of aluminium strip and anodal collector plate for the atom phase counterdiffusion by aluminium strip is caused with anodal collector plate friction.Therefore,, in the situation that utilizing ultrasonic bonding to connect anodal collector plate and aluminium strip, the possibility that produces metallic foreign body (aluminium) because of the phase mutual friction of aluminium strip and anodal collector plate raises.Same phenomenon also can produce in being connected of negative pole collector plate and copper strips.That is, utilize ultrasonic bonding to connect in the situation of negative pole collector plate and copper strips, the possibility rising that produces metallic foreign body (copper) because of the phase mutual friction of copper strips and negative pole collector plate.And, in the welding (arc-welding) of using in the operation of tinning and lid, for example, easily produce welding bits outside connecting.

By above situation, due to the operation of implementing in the front and back that form electrode coiling body, the possibility that metallic foreign body is invaded the inside of electrode coiling body raises.Particularly, in common lithium ion battery, because positive plate, negative plate and barrier film consist of different parts, therefore, for example, between positive plate and barrier film, have gap, the metallic foreign body producing in above-mentioned manufacturing process easily invades in this gap.Like this, if metallic foreign body invades the inside of electrode coiling body, the metallic foreign body of invading pierces through barrier film, positive pole and negative pole are because of metallic foreign body short circuit, if or the metallic foreign body that for example invades the gap of anodal and barrier film is attached on positive pole, the metallic foreign body adhering to is dissolved in electrolyte, is created in thereafter the phenomenon that negative pole is separated out.And, if arrive positive pole because separate out the metal of growing up from negative pole, produce problem anodal and negative pole short circuit.

Above, the lithium ion battery that uses common lithium ion battery to form the type of electrode coiling body is illustrated, for example, so long as by the positive plate that is coated with positive active material, be coated with the negative plate and the lithium ion battery that prevents that positive plate forms with the barrier film contacting of negative plate of negative electrode active material, even do not form the lithium ion battery of the cascade type of electrode coiling body, if by invading positive plate for positive plate and negative plate being cut into the metallic foreign body that the cut-out operation of prescribed level produces, between negative plate and barrier film, metallic foreign body pierces through barrier film, positive pole and negative pole are because of metallic foreign body short circuit, if or the metallic foreign body that for example invades the gap of anodal and barrier film is attached on positive pole, the metallic foreign body adhering to is dissolved in electrolyte, be created in the phenomenon that negative pole is separated out thereafter.And, if arrive positive pole because separate out the metal of growing up from negative pole, produce problem anodal and negative pole short circuit.

Therefore, make anodal and negative pole short circuit in order to prevent metallic foreign body from invading the gap between positive plate and negative plate and barrier film, positive plate and negative plate is integrated and form with barrier film, and it is effective for example making the gap disappearance between positive pole and barrier film.For example, in above-mentioned patent documentation 1, record by directly form barrier film on positive plate and negative plate positive plate and negative plate and the integrated example of barrier film.

But, in the battery of recording in above-mentioned patent documentation 1, for example, after the battery lead plate that is coated with active material in metal forming being dried and implementing pressurized treatments, at the barrier film of electrode plate surface coating slurries shape and be dried, form thus the integrated structure of battery lead plate and barrier film.But there is the such problem of process number increases many, that cause manufacturing cost in this technology.

The object of the invention is to, a kind of lithium ion battery and manufacturing technology thereof that can suppress to realize because of the internal short-circuit that metallic foreign body causes reliability raising and cost aspect excellence is provided.

Above-mentioned and other object of the present invention and new feature are understood by the description of this specification and appended accompanying drawing.

For solving the means of problem

If the summary of the representational content in disclosed invention in the application is described simply, as described below.

The manufacture method of the lithium ion battery in the present invention possesses: the 1st slurries that (a) coating contains active material on battery lead plate, the operation of the 2nd slurries that coating contains organic filler and inorganic particulate on described the 1st slurries.And possess: (b) after described (a) operation, make described the 1st slurries and the 2nd slurry dried of coating, on described battery lead plate, form thus described active material, on described active material, form the operation of the barrier film that contains described organic filler and described inorganic particulate.Also possess: (c) after described (b) operation, the operation to the pressurized treatments under described active material and described barrier film enforcement heating.

In addition, the manufacture method of the lithium ion battery in the present invention comprises: the 1st slurries that (a) coating contains active material on the first surface of battery lead plate, the operation of the 2nd slurries that coating contains organic filler and inorganic particulate on described the 1st slurries; (b) after described (a) operation, make described the 1st slurries and described the 2nd slurry dried that on described first surface, apply, on the described first surface of described battery lead plate, form described active material thus, on described active material, form the operation of the 1st barrier film that contains described organic filler and described inorganic particulate.And possess: (c) after described (b) operation, on second of the described first surface opposition side with described battery lead plate, apply described the 1st slurries, on described the 1st slurries, apply the operation of described the 2nd slurries; (d) after described (c) operation, make described the 1st slurries and described the 2nd slurry dried of coating on described second, on described second of described battery lead plate, form described active material thus, on described active material, form the operation of the 2nd barrier film that contains described organic filler and described inorganic particulate.Also possess: (e) after described (d) operation, to being formed on described active material on described first surface and described the 1st barrier film and being formed on described active material on described second and operation that described the 2nd barrier film is implemented the pressurized treatments under heating.

In addition, the manufacture method of the lithium ion battery in the present invention comprises: the 1st slurries that (a) coating contains active material on battery lead plate, the 2nd slurries that coating contains the 1st material on described the 1st slurries, the operation of the 3rd slurries that coating contains 2nd material different from described the 1st material on described the 2nd slurries.Also possess: (b) after described (a) operation, make described the 1st slurries, the 2nd slurries and described the 3rd slurry dried of coating, on described battery lead plate, form thus described active material, on described active material, form the operation of the barrier film being formed by the 1st dielectric film that contains described the 1st material and the 2nd dielectric film that contains described the 2nd material.And possess: (c) after described (b) operation, the operation to the pressurized treatments under described active material and described barrier film enforcement heating.

And, the manufacture method of the lithium ion battery in the present invention comprises: the 1st slurries that (a) coating contains active material on the first surface of battery lead plate, the 2nd slurries that coating contains the 1st material on described the 1st slurries, the operation of the 3rd slurries that coating contains 2nd material different from described the 1st material on described the 2nd slurries.And possess: (b) after described (a) operation, make described the 1st slurries that apply, described the 2nd slurries and described the 3rd slurry dried on described first surface, on the described first surface of described battery lead plate, form described active material thus, on described active material, form the operation of the 1st barrier film being formed by the 1st dielectric film that contains described the 1st material and the 2nd dielectric film that contains described the 2nd material.And possess: (c) after described (b) operation, on second of the described first surface opposition side with described battery lead plate, apply described the 1st slurries, on described the 1st slurries, apply described the 2nd slurries, on described the 2nd slurries, apply the operation of described the 3rd slurries.Next possesses: (d) after described (c) operation, make described the 1st slurries, described the 2nd slurries and described the 3rd slurry dried of coating on described second, on described second of described battery lead plate, form described active material thus, on described active material, form the operation of the 2nd barrier film being formed by described the 1st dielectric film that contains described the 1st material and described the 2nd dielectric film that contains described the 2nd material.Then possess: (e) after described (d) operation, to being formed on described active material on described first surface and described the 1st barrier film and being formed on described active material on described second and operation that described the 2nd barrier film is implemented the pressurized treatments under heating.

Lithium ion battery in the present invention is characterised in that, comprise: (a) positive pole, (b) negative pole and the either party's (c) and in described positive pole and described negative pole the integrated barrier film of electrode, described barrier film contains organic filler and inorganic particulate, and the average grain diameter of described organic filler is less than the average grain diameter of described inorganic particulate.

In addition, lithium ion battery in the present invention is characterised in that, comprise: (a) anodal, (b) negative pole and the either party's (c) and in described positive pole and described negative pole the integrated barrier film of electrode, described barrier film has: (c1) be formed on the 1st dielectric film on described electrode and (c2) be formed on the 2nd dielectric film on described the 1st dielectric film.

Invention effect

If the effect obtaining by the representational content in disclosed invention in the application is described simply, as described below.

Can suppress the internal short-circuit causing because of metallic foreign body, realize reliability and improve.In addition, can obtain the lithium ion battery of cost aspect excellence.

Accompanying drawing explanation

Fig. 1 means the figure of the schematic formation of lithium ion battery.

Fig. 2 means the profile of the internal structure of columnar lithium ion battery.

Fig. 3 means in the technology of inventor's research, the figure of the inscape of the last stage of formation electrode coiling body.

Fig. 4 means in the technology of inventor's research, positive pole, the 1st barrier film, negative pole and the 2nd barrier film is formed to the schematic diagram of the situation of electrode coiling body around axle core coiling.

Fig. 5 means the profile of the formation of positive pole in execution mode 1 and negative pole.

Fig. 6 means the figure of the positive pole with barrier film in execution mode 1 and the overlapping state of negative pole.

Fig. 7 means around axle core and reels with the figure of the positive pole of barrier film and the situation of negative pole.

Fig. 8 means the profile of the formation of the 1st variation.

Fig. 9 means the profile of the formation of the 2nd variation.

Figure 10 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 11 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 12 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 13 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 14 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 15 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 16 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 17 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 18 means the figure of an example of the applying device using in execution mode 1.

Figure 19 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 20 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 21 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 22 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 23 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 24 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 25 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 26 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 27 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 28 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 29 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 30 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 31 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 32 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 33 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 34 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 35 means the figure of the manufacturing process of the lithium ion battery in execution mode 1.

Figure 36 means the figure of the anodal formation with barrier film in execution mode 2.

Figure 37 means the figure of the manufacturing process of the lithium ion battery in execution mode 2.

Figure 38 means the figure of the manufacturing process of the lithium ion battery in execution mode 2.

Figure 39 means the figure of the manufacturing process of the lithium ion battery in execution mode 2.

Figure 40 means the figure of the manufacturing process of the lithium ion battery in execution mode 2.

Figure 41 means the figure of the manufacturing process of the lithium ion battery in execution mode 2.

Figure 42 means the figure of the manufacturing process of the lithium ion battery in execution mode 2.

Figure 43 means the figure of the manufacturing process of the lithium ion battery in execution mode 2.

Figure 44 means the figure of the manufacturing process of the lithium ion battery in execution mode 2.

Figure 45 means the figure of the manufacturing process of the lithium ion battery in execution mode 2.

Figure 46 means the figure of the anodal formation with barrier film in execution mode 3.

Figure 47 means the figure of the manufacturing process of the lithium ion battery in execution mode 3.

Figure 48 means the figure of the manufacturing process of the lithium ion battery in execution mode 3.

Figure 49 means the figure of the manufacturing process of the lithium ion battery in execution mode 3.

Figure 50 means the figure of the manufacturing process of the lithium ion battery in execution mode 3.

Figure 51 means the figure of the manufacturing process of the lithium ion battery in execution mode 3.

Embodiment

In the following embodiments, for convenient, when it needs, be divided into a plurality of parts or execution mode and describe, but situation except expressing especially, they are not irrelevant each other, and having a side is the opposing party's part or all the relation of variation, details, supplementary notes etc.

In addition, in the following embodiments, in the situation that mention (the comprising number, numerical value, amount, scope etc.) such as numerals of key element, except situation about expressing especially and the situation that is defined in significantly specific numeral principle etc., be not limited to this specifically numeral, can for specific numeral is above or below.

And in the following embodiments, except situation about expressing especially and think significantly necessary situation etc. principle, its inscape (also comprising key element step etc.) is not necessarily necessary, this need not illustrate.

Equally, in the following embodiments, while mentioning the shape, position relationship etc. of inscape etc., except situation about expressing especially and think significantly really not so situation etc. principle, for comprising in fact or similarly situation etc. approximate with this shape etc.This is also same for above-mentioned numerical value and scope.

In addition, for all figure of execution mode are described, in principle same parts are accompanied by prosign, omit the explanation of its repetition.Be explained, in order to make accompanying drawing understandable, sometimes plane graph be also accompanied by hatching.

(execution mode 1)

The summary > of < lithium ion battery

The oxidation-reduction potential of lithium is-3.03V (vs.NHE), is the most inferior metal existing on the earth.The voltage of battery is determined with the potential difference of negative pole by anodal, therefore, if lithium is used for to negative electrode active material, can obtain the highest electromotive force.In addition, the atomic weight of lithium is 6.94, and density is also 0.534g/cm ³, all less, so the weight of per unit electric weight is little, energy density also uprises.Therefore,, if lithium is used for to negative electrode active material, can manufacture the battery of small-sized and light weight.

Like this, as the negative electrode active material of battery, lithium is attractive material, but in the situation that the secondary cell that is applied to discharge and recharge have problems.That is, if used the battery of lithium to repeat to discharge and recharge in anticathode, the charging reaction that exoelectrical reaction that the dissolving because of lithium causes occurs and cause because of separating out of lithium.Now, because recharge produces the evolution reaction of lithium, therefore, in the performance degradation of secondary cell and fail safe, have problems.For example, the lithium generating in charging process reacts with electrolyte solvent at active surface, and its part is consumed in the formation of the tunicle that is called as SEI (Solid Electrolyte Interface) (solid electrolyte interface).Therefore, the internal resistance of battery raises, and discharging efficiency also reduces.That is,, along with the circulation that repeats to discharge and recharge, battery capacity diminishes.And if charging hastily, lithium is separated out with needle-like, dendritic crystal habit (Li dendrite), becomes the root that causes the various faults in secondary cell.For example, the specific area of Li dendrite is large, accelerates the reduction of the current efficiency that causes because of side reaction, and owing to being needle-like, therefore, sometimes pierces through barrier film and causes the internal short-circuit between positive pole and negative pole.If become this state, self discharge is large sometimes, can not use, or the heating causing because of internal short-circuit causes gas ejection or on fire as battery.By above situation, learnt: in negative pole, use in the secondary cell of lithium, in performance degradation and fail safe, have problems.

Therefore, studying and the novel secondary battery that dissolves and separate out the principle that so existing principle is different.Particularly, studying at anodal and negative pole the secondary cell that uses embedding, discharges the active material of lithium ion.In the charge and discharge process of this secondary cell, do not produce the dissolving of lithium and separate out such phenomenon, lithium ion only embeds between electrode active material, de-embedding.The secondary cell of the type is called as " rocking chair (rocking chair) " type or " shuttlecock (shuttle cock) " type, and due to the repetition for discharging and recharging, lithium ion only embeds, de-embedding, therefore has stable feature.In this manual this battery is called to lithium ion battery.As above-mentioned, in lithium ion battery, because the structure discharging and recharging middle positive pole and negative pole does not all change, only carry out lithium ion embedding, de-embedding (wherein, for the embedding of lithium ion, de-embedding, the lattice dilatation of active material is shunk), so, there is especially long-life cycle characteristics, and in electrode, do not use lithium metal, therefore, there is the also feature of tremendous raising of fail safe.

At this, can embed, the material of removal lithium embedded ion is for the active material of electrode, the condition that this active material is required is as follows.That is,, due to the ion embedding of the so limited size of lithium ion, de-embedding, therefore, active material needs hold site (position) and the diffusible passage of lithium ion (path) of lithium ion.And, for active material, need to be accompanied by lithium ion embedding (occlusion) and by electronics transfer material.

As meeting the positive active material of condition as mentioned above, can enumerate lithium-containing transition metal oxide.For example, as representational positive active material, can enumerate cobalt acid lithium, lithium nickelate, LiMn2O4 etc., but be not limited to them.Particularly, as positive active material, as long as for can embed, the material of removal lithium embedded, embed in advance the lithium-containing transition metal oxide of the lithium that has abundant amount, as transition metal, it can be the monomers such as manganese (Mn), nickel (Ni), cobalt (Co), iron (Fe) or the transition metal of more than two kinds of the take material that is main component.In addition, for crystal structures such as spinel crystal structure or layered crystal structures, so long as can guarantee that above-mentioned site and passage are just not particularly limited.And, also can use the material of the element substitutions such as Fe, Co, Ni, Cr, Al, Mg for a part of the transition metal in crystal and/or lithium, or in crystal doped with the material of the elements such as Fe, Co, Ni, Cr, Al, Mg as positive active material.

And, as the negative electrode active material that meets above-mentioned condition, can use material with carbon element or amorphous material with carbon element of crystalline.But negative electrode active material is not limited to these materials, for example, can use material with carbon elements such as native graphite, artificial various graphite preparations, coke etc.And, aspect its shape of particle, the material of applicable flakey, the various shapes of particle such as spherical, fibrous, block.

The schematic formation > of < lithium ion battery

Below, with reference to accompanying drawing, the schematic formation of above-mentioned lithium ion battery is described.Fig. 1 means the figure of the schematic formation of lithium ion battery.In Fig. 1, lithium ion battery has outer tinning CS, in the inside of this outer tinning CS, is filled with electrolyte EL.In being filled with the outer tinning CS of this electrolyte EL, be relatively set with positive plate PEP and negative plate NEP, between the positive plate PEP being oppositely arranged and negative plate NEP, dispose barrier film SP.

And, on positive plate PEP, be coated with positive active material, on negative plate NEP, be coated with negative electrode active material.For example, positive active material by can embed, the lithium-containing transition metal oxide of removal lithium embedded ion forms.In Fig. 1, schematically show this lithium-containing transition metal oxide and be coated in the situation on positive plate PEP.That is,, in Fig. 1, as the lithium-containing transition metal oxide being coated on positive plate PEP, show the schematic crystal structure of configuration aerobic, metallic atom and lithium.By this positive plate PEP and positive active material, form positive pole.

On the other hand, negative electrode active material for example by can embed, the material with carbon element of removal lithium embedded ion forms.In Fig. 1, schematically show this material with carbon element and be coated in the situation on negative plate NEP.That is,, in Fig. 1, as the material with carbon element being coated on negative plate NEP, show the schematic crystal structure that disposes carbon.By this negative plate NEP and negative electrode active material, form negative pole.

Barrier film SP prevents electrically contacting of anodal and negative pole, and has the function as the spacer that lithium ion is seen through.As barrier film SP, for example in the prior art, by constituting of polyethylene (PE), polypropylene (PP) or these materials.

Electrolyte EL is used nonaqueous electrolytic solution.Lithium ion battery is the embedding that utilizes the lithium ion in active material, de-ly imbeds the battery that row discharges and recharges, and lithium ion moves in electrolyte EL.Lithium is strong reductant, with the water generation hydrogen that reacts intensely.Therefore, lithium ion mobile lithium ion battery in electrolyte EL cannot be used the aqueous solution as electrolyte EL as existing battery.Therefore,, in lithium ion battery, use nonaqueous electrolytic solution as electrolyte EL.Particularly, as the electrolyte of nonaqueous electrolytic solution, can use LiPF ₆, LiClO ₄, LiAsF ₆, LiBF ₄, LiB (C ₆h ₅) ₄, CH ₃sO ₃li, CF ₃sO ₃li etc. or their mixture.In addition, as organic solvent, can use ethylene carbonate, dimethyl carbonate, propylene carbonate, diethyl carbonate, 1,2-dimethoxy-ethane, 1,2-diethoxyethane, gamma-butyrolacton, oxolane, 1,3-dioxa penta ring, 4-methyl isophthalic acid, 3 dioxa penta rings, diethyl ether, sulfolane, methyl sulfolane, acetonitrile, propionitrile etc. or their mixed liquor.

The mechanism > that < discharges and recharges

Lithium ion battery forms as mentioned above, below the mechanism discharging and recharging is described.First, the mechanism of charging is described.As shown in Figure 1, during to lithium ion cell charging, connecting charger CU between positive pole and negative pole.In this situation, in lithium ion battery, embed the de-embedding of lithium ion in positive active material, be discharged in electrolyte EL.Now, by lithium ion de-embedding from positive active material, electronics flows to charger from positive pole.And the lithium ion being discharged in electrolyte EL moves in electrolyte EL, by the barrier film SP being formed by micro-porous film, arrive negative pole.The lithium ion of this arrival negative pole is embedded in the negative electrode active material that forms negative pole.Now, by embed lithium ion in negative electrode active material, electronics flows into negative pole.Like this, via charger, electronics moves to negative pole from positive pole, completes thus charging.

Then, the mechanism of electric discharge is described.As shown in Figure 1, between positive pole and negative pole, be connected external loading.So, embed the de-embedding of lithium ion in negative electrode active material, be released in electrolyte EL.Now, from negative pole, discharge electronics.And the lithium ion being discharged in electrolyte EL moves in electrolyte EL, by the barrier film SP being formed by micro-porous film, arrive anodal.This arrives anodal lithium ion and is embedded in the anodal positive active material of formation.Now, by embed lithium ion in positive active material, electronics flows into anodal.Like this, electronics moves to positive pole from negative pole, discharges thus.In other words, can make electric current flow to negative pole from positive pole, drive load.As mentioned above, in lithium ion battery, by embedding, removal lithium embedded ion between positive active material and negative electrode active material, can discharge and recharge.

The formation > of < lithium ion battery

Then, the configuration example of actual lithium ion battery LIB is described.Fig. 2 means the profile of the internal structure of columnar lithium ion battery LIB.As shown in Figure 2, in the inside with the columnar outer tinning CS of bottom, be formed with the electrode coiling body WRF being formed by anodal PEL, barrier film SP1, SP2 and negative pole NEL.Particularly, electrode coiling body WRF is stacked to clip the mode of barrier film SP1 (SP2) between anodal PEL and negative pole NEL, around the axle core CR that is positioned at the central part of outer tinning CS, reels.Then, negative pole NEL is electrically connected to the negative wire plate NT that is arranged at outer tinning CS bottom, positive pole is electrically connected to the positive wire plate PT that PEL is arranged at the top of outer tinning CS.In the inside of electrode coiling body that is formed at outer tinning CS inside, inject electrolyte.Then, by battery cover CAP, outer tinning CS is airtight.

The coating liquid of anodal PEL by containing positive active material PAS and binding agent (adhesive) in the upper coating of positive plate (positive electrode collector) PEP also forms its dry rear pressurization.In the upper end of this positive pole PEL, be formed with the anodal collector plate PTAB of a plurality of rectangles, the plurality of anodal collector plate PTAB is connected with anodal collector ring PR.Then, this positive pole collector ring PR is electrically connected to positive wire plate PT.Therefore, anodal PEL is electrically connected to positive wire plate PT via anodal collector plate PTAB and anodal collector ring PR.For the low resistance of anodal PEL and derived current and a plurality of anodal collector plate PTAB are set promptly.

Such as using, to take cobalt acid lithium, lithium nickelate, LiMn2O4 etc. be the above-mentioned material of representative to the positive active material PAS that forms anodal PEL.In addition, binding agent is such as using polyvinyl fluoride, Kynoar, polytetrafluoroethylene etc.And, in positive plate, can use such as the metal forming being formed by conductive metal such as aluminium or net metal etc.

The coating liquid of negative pole NEL by containing negative electrode active material NAS and binding agent (adhesive) in the upper coating of negative plate (negative electrode collector) NEP and make it dry after pressurization form.In the bottom of this negative pole NEL, be formed with the negative pole collector plate NTAB of a plurality of rectangles, the plurality of negative pole collector plate NTAB is connected with negative pole collector ring NR.Then, this negative pole collector ring NR is electrically connected to negative wire plate NT.Therefore, negative pole NEL is electrically connected to negative wire plate NT via negative pole collector plate NTAB and negative pole collector ring NR.

The negative electrode active material NAS that forms negative pole NEL take such as using the above-mentioned material that material with carbon element etc. is representative.In addition, binding agent can be used such as Kynoar, polytetrafluoroethylene etc.And, on negative plate, can use such as the metal forming being formed by conductive metal such as copper or net metal etc.

The problem > that the < inventor finds

First, the detailed formation of existing electrode coiling body is described.Fig. 3 means the figure of the inscape of the last stage that forms electrode coiling body.In Fig. 3, the inscape that forms electrode coiling body is anodal PEL, barrier film SP1, negative pole NEL and barrier film SP2.Now, anodal PEL is for be coated with the structure of positive active material PAS on the two sides of positive plate PEP, and negative pole NEL is for being coated with the structure of negative electrode active material NAS on the two sides of negative plate NEP.And, at the upper avris of anodal PEL, be formed with the anodal collector plate PTAB of a plurality of rectangles.Similarly, at the lower avris of negative pole NEL, be formed with the negative pole collector plate NTAB of a plurality of rectangles.That is, in the prior art, anodal PEL, negative pole NEL and barrier film SP1, barrier film SP2 form as individual components (separating component).

Particularly, the formation of electrode coiling body WRF of the prior art is described.Fig. 4 means the schematic diagram that anodal PEL, barrier film SP1, negative pole NEL and barrier film SP2 is formed to the situation of electrode coiling body WRF around axle core CR reels.As shown in Figure 4, between anodal PEL and negative pole NEL, clip the barrier film SP1 as individual components, and, using and by the barrier film SP1 as individual components and barrier film SP2, clipped the mode of negative pole NEL, the anodal PEL that reels, barrier film SP1, negative pole NEL and barrier film SP2.Now, the anodal collector plate PTAB forming on anodal PEL is configured in the upper side of electrode coiling body WRF, and on the other hand, the negative pole collector plate (not shown) forming on negative pole NEL is configured in the lower side of electrode coiling body WRF.In above mode, formed electrode coiling body WRF of the prior art.

In common lithium ion battery, because positive plate, negative plate and barrier film form with individual components (separating component), therefore, after forming electrode coiling body WRF, for example, between positive plate and barrier film, there is gap.And, in the manufacturing process of lithium ion battery, before forming above-mentioned coiling body, positive plate and negative plate are cut into the size of regulation, and cut off positive plate and negative plate, form the collector plate of positive pole and negative pole.And, after forming electrode coiling body, for example, exist the anodal collector plate supersonic welding being formed on positive plate is connected on anodal collector ring, the negative pole collector plate supersonic welding being formed on negative plate is connected on to the operation on negative pole collector ring.Further, exist electrode coiling body is inserted in outer tinning (container), in this outer tinning, inject after electrolyte, for the inside of airtight outer tinning, utilize welding to wait the operation that connects outer tinning and lid.

Particularly, for anodal collector plate and anodal collector ring, the aluminium strip that carries out reeling on anodal collector plate, utilize ultrasonic bonding that anodal collector plate is connected on this aluminium strip.The ultrasonic bonding of now using is connected aluminium strip by the atom phase counterdiffusion causing with anodal collector plate because of friction aluminium strip with anodal collector plate.Therefore, utilize ultrasonic bonding to connect in the situation of anodal collector plate and aluminium strip, the possibility that produces metallic foreign body (aluminium) because of the friction of aluminium strip and anodal collector plate raises.Same phenomenon also produces in being connected of negative pole collector plate and copper strips.That is, utilize ultrasonic bonding to connect in the situation of negative pole collector plate and copper strips, the possibility rising that produces metallic foreign body (copper) because of the friction of copper strips and negative pole collector plate.And, in the welding (arc-welding) of using in the operation of tinning and lid, for example, easily produce welding bits outside connecting.

By above situation, due to the operation of implementing in the front and back that form electrode coiling body, the possibility that metallic foreign body invades the inside of electrode coiling body raises.Particularly there are the following problems: in common lithium ion battery, because positive plate, negative plate and barrier film consist of individual components, therefore, for example, between positive plate and barrier film, have gap, the metallic foreign body producing in above-mentioned manufacturing process easily invades in this gap.

Like this, if the metallic foreign body producing is invaded the inside of electrode coiling body WRF, likely between positive pole and negative pole, cause internal short-circuit.Particularly, the state that metallic foreign body is invaded the inside of electrode coiling body means that metallic foreign body invades the state in the gap forming between positive plate and barrier film or the gap that forms between negative plate and barrier film.For example, in the situation that metallic foreign body is copper, if invade the copper in gap, be attached to positive pole above, because of anodal high potential, copper oxidized (losing electronics), becomes metal ion and is dissolved in electrolyte.And if this metal ion arrives negative pole, metal ion is reduced (supply electronics), separates out at negative pole as metal (copper).If the mechanism that because of metal is such and continue to separate out at negative pole, the hole of the metal of growing up from negative pole by barrier film arrives anodal, the metal that anodal and negative pole are separated out via this and internal short-circuit occurs.On the other hand, in the situation that metallic foreign body is aluminium, although there is not the dissolving being caused by redox reaction, the phenomenon of separating out, large if the size of the metallic foreign body of invading becomes, piercing through barrier film, there is internal short-circuit because of metallic foreign body (aluminium) in anodal and negative pole.If anodal and negative pole generation internal short-circuit, cannot play a role as lithium ion battery.Like this, known in the manufacturing process of lithium ion battery, exist to produce the possibility of metallic foreign body, if the metallic foreign body producing invades in the gap forming between positive plate and barrier film or the gap that forms between negative plate and barrier film, likely anodal and negative pole generation internal short-circuit.

Therefore,, in present embodiment 1, execution can suppress because of the internal short-circuit that metallic foreign body causes, realize the improvement of the raising of lithium ion battery reliability.Below, the technological thought of implementing in this improved present embodiment 1 is described.

The feature > of < present embodiment 1

The technological thought of present embodiment 1 is conceived to: for example, in the situation that positive pole and barrier film are with the state formation electrode coiling body of individual components, between positive pole and barrier film, produce gap, because metallic foreign body is invaded the possibility rising that produces internal short-circuit in this gap in lithium ion battery.And, consider this starting point, present embodiment 1 completes based on following thought: if for example eliminate the gap forming between positive pole and barrier film when forming electrode coiling body, can suppress the inside that metallic foreign body invades lithium ion battery, therefore, can improve the reliability of lithium ion battery.And the basic thought based on present embodiment 1 has been expected the feature of present embodiment shown below 1.Feature to this present embodiment 1 describes.

Feature in present embodiment 1 completes based on following cognition: for example, if form positive pole and barrier film, between positive pole and barrier film, not can produce gap, therefore, can prevent between metallic foreign body intrusion positive pole and barrier film.So, in present embodiment 1, by this cognition being specialized to realize the feature of present embodiment 1.That is, present embodiment 1 is characterised in that, for example, to form positive pole and barrier film, not exist the mode in gap to form between positive pole and barrier film.In other words, integrated for positive pole and barrier film, also can bonding positive pole and barrier film.Particularly, on one side with reference to accompanying drawing, to forming integratedly the formation of anodal and barrier film, describe on one side.

Fig. 5 means the profile of the anodal PEL of present embodiment 1 and the formation of negative pole NEL.As shown in Figure 5, first, anodal PEL has the positive plate PEP for example consisting of aluminium, is formed with such as the positive active material PAS consisting of cobalt acid lithium etc. on the two sides of this positive plate PEP.And the bonding mode of positive active material PAS forming with the two sides with at positive plate PEP forms barrier film SP1 and barrier film SP2.; in present embodiment 1; the mode bonding with the positive active material PAS with for example forming at the first surface of anodal PEL forms barrier film SP1, and forms the bonding barrier film SP2 of positive active material PAS of formation on second with first surface opposition side at anodal PEL.Like this, in present embodiment 1, anodal PEL, the barrier film SP1 and the barrier film SP2 that by positive plate PEP and positive active material PAS, are formed have been formed.Therefore, according to present embodiment 1, between anodal PEL and barrier film SP1 or between anodal PEL and barrier film SP2, there is not gap, so, can prevent from being attached to the intrusion of the metallic foreign body on anodal PEL.Its result, the internal short-circuit in the lithium ion battery that can prevent from causing because of metallic foreign body, thus, can improve the reliability of lithium ion battery.

On the other hand, as shown in Figure 5, negative pole NEL is for being formed with the structure of the negative electrode active material NAS for example consisting of material with carbon element on the two sides of the negative plate NEP for example consisting of copper.Like this, anodal PEL and the negative pole NEL of the band barrier film SP1 (SP2) of present embodiment 1 have been formed.

For example, in the prior art shown in Fig. 3, because anodal PEL, barrier film SP1, barrier film SP2 and negative pole NEL form with individual components (separating component), therefore, as shown in Figure 4, when forming electrode coiling body WRF, must between anodal PEL and barrier film SP1 (barrier film SP2), produce gap.Its result, in the prior art, the possibility that the metallic foreign body producing in the ultrasonic bonding of implementing in assembling procedure thereafter or arc-welding invades in above-mentioned gap raises.And if metallic foreign body invades in the gap forming between anodal PEL and barrier film SP1 (barrier film SP2),, owing to producing the internal short-circuit of the lithium ion battery causing because of metallic foreign body, the reliability of lithium ion battery reduces.

On the other hand, in present embodiment 1, as shown in Figure 5, anodal PEL, barrier film SP1 and barrier film SP2 form.In other words, anodal PEL is mutually bonding with barrier film SP2 with barrier film SP1 or anodal PEL.Therefore, between anodal PEL and barrier film SP1 and do not produce the leeway in gap between anodal PEL and barrier film SP2.Therefore, according to present embodiment 1, owing to not having gap between anodal PEL and barrier film SP1 or between anodal PEL and barrier film SP2, so, can prevent from being attached to the intrusion of the metallic foreign body on anodal PEL.Its result, the internal short-circuit in the lithium ion battery that can prevent from causing because of metallic foreign body, thus, can improve the reliability of lithium ion battery.

To the anodal PEL of the coiling band barrier film SP1 (SP2) in present embodiment 1 and negative pole NEL and the state that forms electrode coiling body WRF specifically describe.Fig. 6 represents anodal PEL and the overlapping state of negative pole NEL of the band barrier film SP1 (SP2) of present embodiment 1.And, under the anodal PEL of this belt transect barrier film SP1 (SP2) and the overlapping state of negative pole NEL, as shown in Figure 7, around axle core CR reel anodal PEL and the negative pole NEL of band barrier film SP1 (SP2).Now, as shown in Figure 7, because the two sides at anodal PEL is bonded with barrier film SP1 and barrier film SP2, therefore known, after forming electrode coiling body WRF, between anodal PEL and barrier film SP1 or between anodal PEL and barrier film SP2, do not forming gap.

At this, in present embodiment 1, important aspect is to form anodal PEL, barrier film SP1 and barrier film SP2.That is, in present embodiment 1, by the two sides with at anodal PEL, barrier film SP1 and the bonding mode of barrier film SP2 are formed, between anodal PEL and barrier film SP1 or anodal PEL and barrier film SP2, do not produce gap.Form so anodal PEL, barrier film SP1 and the reason of barrier film SP2 based on shown below.; as illustrated in the hurdle of newfound problem in the inventor; if adhered to such as metallic foreign bodies such as copper on anodal PEL, the metallic foreign body being attached on anodal PEL is dissolved in electrolyte, and the metallic foreign body being dissolved in electrolyte is separated out on negative pole NEL.If this phenomenon continues, the metallic foreign body of separating out on negative pole NEL arrives anodal PEL, can cause the internal short-circuit of anodal PEL and negative pole NEL.Therefore, because of the dissolving of metallic foreign body, separate out the internal short-circuit of the lithium ion battery that such mechanism causes, reason is adhesion metal foreign matter on anodal PEL.Hence one can see that, and in order effectively to suppress dissolving because of metallic foreign body, separate out the internal short-circuit of the lithium ion battery that such mechanism causes, it is important making non-cohesive metallic foreign body on anodal PEL.Thus, in present embodiment 1, form anodal PEL, barrier film SP1 and barrier film SP2.According to this, form, due between anodal PEL and barrier film SP1 or very close to each other between anodal PEL and barrier film SP2, therefore, can prevent that metallic foreign body from invading and being attached to anodal PEL from gap.; present embodiment 1 completes from preventing from thinking producing the dissolving, the viewpoint of separating out of metallic foreign body of a reason of the internal short-circuit of lithium ion battery; by forming anodal PEL, barrier film SP1 and barrier film SP2, can effectively prevent dissolving because of metallic foreign body, separate out the internal short-circuit of the lithium ion battery causing.

But, according to the feature of present embodiment 1, form, can make gap disappear, therefore, not only can prevent dissolving because of metallic foreign body, separate out the internal short-circuit of the lithium ion battery causing, but also can prevent the intrusion of large metallic foreign body itself, thus, also can prevent from itself piercing through anodal PEL that barrier film SP1 (SP2) causes and the short circuit of negative pole NEL because of large metallic foreign body.; the feature that forms the present embodiment 1 of anodal PEL, barrier film SP1 and barrier film SP2 forms the dissolving can prevent because of metallic foreign body, separate out the internal short-circuit of the lithium ion battery that such mechanism causes; and, can also prevent from directly piercing through because of large metallic foreign body the internal short-circuit of the lithium ion battery that barrier film SP1 (SP2) causes.In other words, according to the feature of present embodiment 1, form, can effectively prevent from mainly because of the dissolving of the little metallic foreign body of size, separate out internal short-circuit that phenomenon causes to mainly because the large metallic foreign body of size directly pierces through the internal short-circuit that the different like this mechanism of internal short-circuit that barrier film SP1 (SP2) causes causes.; according to the feature of present embodiment 1; can prevent widely that internal short-circuit from causing because of the little metallic foreign body of size is to the internal short-circuit of the lithium ion battery of the internal short-circuit causing because of the large metallic foreign body of size, its result, can realize the raising of the sufficient reliability of lithium ion battery.

As mentioned above, according to the formation of present embodiment 1, form anodal PEL, barrier film SP1 and barrier film SP2.Thus, can suppress the internal short-circuit of lithium ion battery, and, in present embodiment 1, even if embodiment as produced internal short-circuit in lithium ion battery, also makes the countermeasure in safety that thermal runaway stops.That is, in present embodiment 1, suppressed fully the generation of the internal short-circuit of lithium ion battery, even and prepared for example to produce internal short-circuit, the means of thermal runaway also suppressed.Below, to for guaranteeing that this safe improvement describes.

Present embodiment 1 is further characterized in that the material that barrier film SP1 and barrier film SP2 are used.That is the barrier film SP1, using in present embodiment 1 and the material of barrier film SP2 are different from material of the prior art.Reason is, in present embodiment 1, as described later, the manufacturing process of barrier film SP1 and barrier film SP2 unlike the prior art, and need to make barrier film SP1, barrier film SP2 and anodal PEL bonding.; this be because; the barrier film of prior art with anodal PEL mutually independently parts (separating component) form and make the formation not bonding with anodal PEL, on the other hand, the barrier film SP1 (SP2) of present embodiment 1 is bonding and form with anodal PEL.Particularly, the barrier film SP1 (SP2) of present embodiment 1 for example can be by containing adhesive (binding agent), forming as the pottery of megohmite insulant and the material of organic material.As pottery now, can enumerate for example aluminium oxide (Al ₂o ₃) or silicon dioxide (SiO ₂).Thus, can improve the thermal endurance of barrier film SP1 (SP2).In addition, as organic material, can enumerate and take the polyolefin-based resins that high density polyethylene (HDPE) (fusing point: 130 ℃～137 ℃) and straight chain shape low density polyethylene (LDPE) (fusing point: 122 ℃～124 ℃) etc. are representative.

Particularly, present embodiment 1 has and in the constituent material of the barrier film SP1 (SP2) forming with anodal PEL, contains fusing point lower than the feature aspect the organic material of inorganic material (pottery).That is,, in present embodiment 1, as barrier film SP1 (SP2), contain and take the organic material that polyolefin-based resins is representative.This organic material also has simultaneously and prevents because of the abnormal current that battery short circuit causes, interior pressure and the rising of temperature and the function of catching fire sharply.That is, the barrier film SP1 (SP2) of present embodiment 1, except preventing the electrically contacting and make the function that lithium ion passes through of anodal and negative pole, also has the function as the thermo-fuse for preventing short circuit and overcharging.The shutoff having by this organic material (shut down) function, the fail safe that can keep lithium ion battery.For example, in the situation that lithium ion battery causes external short circuit because of some reason, although be to have large electric current to flow through moment, likely because of Joule heat temperature anomaly rise.Now, in the situation that contain fusing point lower than ceramic organic material in barrier film SP1 (SP2), even rise because short circuit produces temperature anomaly, fusing point also can melting lower than ceramic organic material, thus, near hole fusing point (minute aperture) obturation, therefore, can stop passing through of lithium ion between positive pole and negative pole.In other words, by contain fusing point lower than ceramic organic material in barrier film SP1 (SP2), externally cut off electric current during short circuit, make the temperature of the inside of lithium ion battery increase and stop.; according to present embodiment 1, to contain pottery (inorganic material) and fusing point, lower than the mode of ceramic organic material, form barrier film SP1 (SP2), therefore; excellent heat resistance, and the turn-off function of the abnormal current can there is the cutting-off of short-circuit time.Its result, according to present embodiment 1, the lithium ion battery of can provide safe, reliability is excellent.

Now, in present embodiment 1, the average grain diameter of the organic filler of formation organic material is preferably little than the average grain diameter of the inorganic particulate of formation inorganic material (pottery).Its reason is to diminish because form the average grain diameter of the organic filler of organic material, correspondingly mean that organic filler fills densely, thus, during organic filler melting, hole (minute aperture) is easily inaccessible, can bring into play fully the turn-off function that organic filler produces.Particularly, for example, the average grain diameter of organic filler is 1 μ m, and the average grain diameter of inorganic particulate is 4 μ m.

At this, the particle diameter of organic filler and inorganic particulate for example can be by measuring by laser diffraction and scattering method.This laser diffraction and scattering method is while having utilized particle-irradiation laser beam, is produced the determination method of diffraction scattering light by particle.Now, the light intensity distributions of diffraction scattering light is different because of each particle size, therefore, by detecting, analyze the light intensity distributions of diffraction scattering light, can measure particle size distribution.And average grain diameter refers to: take certain particle diameter is divided into the particle size distribution of powder (particle) in the situation in 2 regions as boundary, as the large region of particle diameter and the little equal particle diameter in region of particle diameter and be defined.Usually, this average grain diameter is called as " d50 ".

As mentioned above, according to present embodiment 1, with the bonding barrier film SP1 in the two sides at anodal PEL and barrier film SP2 and integrated mode forms, therefore, can eliminate between anodal PEL and barrier film SP1 or the gap producing between anodal PEL and barrier film SP2.Its result, the internal short-circuit in the lithium ion battery that can prevent from causing because of metallic foreign body, thus, can improve the reliability of lithium ion battery.

And, according to the lithium ion battery of present embodiment 1, can suppress the internal short-circuit that the metallic foreign body because producing in manufacturing process's (assembling procedure) causes, so, the fabrication yield of lithium ion battery can be improved.Its result, according to present embodiment 1, can also realize the cost cutting of lithium ion battery.Especially, in present embodiment 1, the effect of the cost cutting bringing except the raising by fabrication yield, never need the viewpoint of preparing barrier film as individual components to set out, also can realize the cost cutting of lithium ion battery.For example, in existing lithium ion battery, because the cost of the barrier film as individual components is high, therefore, be difficult to realize the cost cutting of lithium ion battery, but in present embodiment 1, do not need to prepare the barrier film as individual components, and do not need to manufacture the equipment as the barrier film of individual components yet, therefore, can expect the significantly cost cutting effect of lithium ion battery.; as described later; in present embodiment 1; owing to forming anodal PEL and barrier film SP1 (SP2); therefore, only change some operations of manufacturing anodal PEL just passable, do not need to arrange the equipment of manufacturing barrier film SP1 (SP2) itself; therefore, can realize the cost cutting of lithium ion battery.

And, in present embodiment 1, to contain fusing point, lower than the organic material of inorganic material and the mode of inorganic material, form barrier film SP1 (SP2).Thus, according to present embodiment 1, the barrier film SP1 (SP2) of the turn-off function of the abnormal current when excellent heat resistance can be provided and there is the cutting-off of short-circuit.Its result, according to present embodiment 1, the lithium ion battery of can provide safe, reliability is excellent.

In present embodiment 1, especially from preventing dissolving because of metallic foreign body, separate out the lithium ion battery that such mechanism causes internal short-circuit viewpoint and also prevent from directly piercing through because of large metallic foreign body the viewpoint of the internal short-circuit of the lithium ion battery that barrier film SP1 (SP2) causes, take to form the formation of anodal PEL, barrier film SP1 and barrier film SP2, but the technological thought of present embodiment 1 is not limited to this formation.That is, the technological thought of present embodiment 1 is to make gap to disappear, and is to disappear by this gap, prevents that metallic foreign body from invading the inside of lithium ion battery.Therefore, present embodiment 1 described above is such, may not be made as the formation that forms anodal PEL, barrier film SP1 and barrier film SP2, also can consider other configuration example very close to each other.Below, this distortion example is described.

The variation > of < execution mode 1

Fig. 8 means the profile of the formation of the 1st variation.In Fig. 8, the aspect different from above-mentioned execution mode 1 is in this 1st variation, to take to form the formation of negative pole NEL, barrier film SP1 and barrier film SP2.Particularly, negative pole NEL has the negative plate NEP for example consisting of copper, is formed with by the negative electrode active material NAS forming such as material with carbon element etc. on the two sides of this negative plate NEP.And the bonding mode of negative electrode active material NAS forming with the two sides with at negative plate NEP is formed with barrier film SP1 and barrier film SP2.That is, in this 1st variation, for example on the first surface of negative pole NEL to form barrier film SP1 with the bonding mode of negative electrode active material NAS, and, on second of the first surface opposition side with negative pole NEL, form the barrier film SP2 bonding with negative electrode active material NAS.Like this, in this 1st variation, the negative pole NEL consisting of negative plate NEP and negative electrode active material NAS, barrier film SP1 and barrier film SP2 form.Therefore,, according to this 1st variation, owing to not having gap between negative pole NEL and barrier film SP1 or between negative pole NEL and barrier film SP2, therefore, can prevent from being attached to the intrusion of the metallic foreign body on negative pole NEL.Its result, the internal short-circuit in the lithium ion battery that can prevent from causing because of metallic foreign body, thus, can improve the reliability of lithium ion battery.And, with above-mentioned execution mode 1 similarly, to contain fusing point, lower than the organic material of inorganic material and the mode of inorganic material, form barrier film SP1 (SP2), therefore, can provide brought by turn-off function safe, lithium ion battery that reliability is excellent.

On the other hand, as shown in Figure 8, anodal PEL is for forming the structure of the positive active material PAS for example consisting of cobalt acid lithium on the two sides of the positive plate PEP for example consisting of aluminium.Like this, negative pole NEL and the anodal PEL of the band barrier film SP1 (SP2) of this 1st variation have been formed.

Then, Fig. 9 means the profile of the formation of the 2nd variation.In Fig. 9, the aspect different from above-mentioned execution mode 1 is to be bonded on a face of anodal PEL and integrated and barrier film SP2 is bonded on a face of negative pole NEL and integrated at this 2nd variation septation SP1.Particularly, as shown in Figure 9, anodal PEL is formed with positive active material PAS on the two sides of positive plate PEP, with one of them face on the bonding mode of the positive active material PAS that forms be formed with barrier film SP1.On the other hand, negative pole NEL is formed with negative electrode active material NAS on the two sides of negative plate NEP, with one of them face on the bonding mode of the negative electrode active material NAS that forms form barrier film SP2.In basis the 2nd variation forming like this, between anodal PEL and barrier film SP1 or can be very close to each other between negative pole NEL and barrier film SP2, therefore, can prevent that metallic foreign body is to the intrusion of inside lithium ion cell.Its result, the internal short-circuit in the lithium ion battery that can prevent from causing because of metallic foreign body, thus, can improve the reliability of lithium ion battery.And, with above-mentioned execution mode 1 similarly, to contain fusing point, lower than the organic material of inorganic material and the mode of inorganic material, form barrier film SP1 (SP2), therefore, can provide brought by turn-off function safe, lithium ion battery that reliability is excellent.

The manufacture method > of the lithium ion battery of < execution mode 1

The lithium ion battery of present embodiment 1 forms as described above, below, with reference to accompanying drawing on one side its manufacture method described on one side.

First, to formation, the operation as the anodal PEL of the band barrier film SP1 (SP2) of the feature of present embodiment 1 describes.As shown in figure 10, mix the positive active material PAS that for example formed by cobalt acid lithium and as the carbon of conductive auxiliary agent.And, as shown in figure 11, forming and make the binding agent (adhesive) for example being formed by Kynoar be dissolved in the solution forming in 1-METHYLPYRROLIDONE (NMP), mixing positive active material PAS and conductive auxiliary agent in this solution, make slurries SL1.

Similarly, as shown in figure 12, mix for example aluminium oxide (Al ₂o ₃) and/or silicon dioxide (SiO ₂) etc. the organic material OM (particle diameter is for example 1 μ m) of ceramic powders CRS (particle diameter is such as being 4 μ m) and polyolefin-based resins formation by take such as high density polyethylene (HDPE) (fusing point: 130～137 ℃) and/or straight chain shape low density polyethylene (LDPE) (fusing point: 122～124 ℃) etc. be representative.And, as shown in figure 13, forming and make the binding agent (adhesive) for example being formed by Kynoar be dissolved in the solution forming in 1-METHYLPYRROLIDONE (NMP), mixing ceramic powders CRS and organic material OM in this solution, make slurries SL2.

As shown in figure 14, the slurries SL1 that contain positive active material PAS and binding agent (adhesive) be coated in positive plate (positive electrode collector) PEP on thereafter.Particularly, as shown in figure 15, for example, use chill coating machine (die coater) DC, on the positive plate PEP consisting of aluminium, coating contains the positive active material PAS slurries SL1 of (also comprising conductive auxiliary agent).

Then, as shown in figure 16, on the slurries SL1 that contains positive active material PAS being coated on positive plate PEP, apply the mixing slurries SL2 that has ceramic powders CRS and organic material OM.Particularly, as shown in figure 17, use chill coating machine DC, on the slurries SL1 that contains positive active material PAS being coated on positive plate PEP, apply the mixing slurries SL2 that has ceramic powders CRS and organic material OM.At this, first to using after chill coating machine DC applies the mixing slurries SL1 that has a positive active material PAS on positive plate PEP, on these slurries SL1, applying mixingly has the successively coating process of the slurries SL2 of ceramic powders CRS and organic material OM to describe, for example, also can use following while coating process: use chill coating machine DC on positive plate PEP, to apply mixing slurries SL1 and the mixing slurries SL2 that has ceramic powders CRS and organic material OM that has positive active material PAS simultaneously.

Particularly, the working procedure of coating in the lump of slurries SL1 and slurries SL2 for example carries out with the applying device shown in Figure 18.Figure 18 means the schematic diagram of an example of the applying device using in present embodiment 1.In Figure 18, applying device for example has and rotates cylinder RL1 freely, at the surface configuration positive plate PEP of this cylinder RL1.And, with respect to the positive plate PEP that is configured in cylinder RL1 surface, configuration chill coating machine DC1 and chill coating machine DC2.This chill coating machine DC1 for example forms as follows: via supply pump PMP1, be connected with the groove that stores slurries SL1, the slurries SL1 being accumulated in groove flows into chill coating machine DC1 by supply pump PMP1, and from this chill coating machine, DC1 is coated in slurries SL1 positive plate PEP.Similarly, chill coating machine DC2 for example forms as follows: via supply pump PMP2, be connected with the groove that stores slurries SL2, the slurries SL2 being accumulated in groove flows into chill coating machine DC2 by supply pump PMP2, and from this chill coating machine, DC2 is coated in slurries SL2 positive plate PEP.By using applying device as constructed as above, can first on positive plate PEP, apply slurries SL1, on these slurries SL1, apply slurries SL2.

Then, as shown in figure 19, make to be coated in the slurries that contain positive active material PAS on positive plate PEP and contain ceramic powders CRS and the slurry dried of organic material OM.Particularly, by for example positive plate PEP being heated below 120 ℃, the slurries SL1 and the slurries SL2 that make to be coated on positive plate PEP are dry.Heat treated herein need to be set as the temperature of not melting of organic material OM contained in slurries SL2.By making slurries SL1 and slurries SL2 dry, can on positive plate PEP, form positive active material PAS as described above, on this positive active material PAS, form the mixture of ceramic powders CRS and organic material OM.

And, make to be coated in positive plate PEP a face (first surface) positive active material PAS and contain ceramic powders CRS and the mixture of organic material OM dry after, as shown in figure 20, the another side (the second face) at positive plate PEP above applies mixing slurries SL1 and the mixing slurries SL2 that has ceramic powders CRS and organic material OM that has positive active material PAS.

Thereafter, as shown in figure 21, by for example below 120 ℃, positive plate PEP being heated, the slurries SL1 and the slurries SL2 that are coated on the another side of positive plate PEP is dry, on the two sides of positive plate PEP, form the mixture of positive active material PAS and ceramic powders CRS and organic material OM.

Then, as shown in figure 22, positive plate PEP is implemented to use to heating, the pressurized treatments of cylinder RL.This heating, pressurized treatments are for example 120 ℃ of following enforcements.Thus, can realize the densification of the positive active material PAS being coated on positive plate PEP.Like this, according to present embodiment 1, as shown in figure 23, can on positive plate PEP, form positive active material PAS, on this positive active material PAS, form barrier film SP1 and the barrier film SP2 that contains ceramic powders CRS and organic material OM.

According to present embodiment 1, barrier film SP1 (SP2) and positive pole can be dried to processing and pressurized treatments integrated formation in the lump, therefore, the advantage that can obtain cutting down process number, can cut down manufacturing cost.In addition, according to present embodiment 1, in the mode that contains ceramic powders CRS and organic material OM, form barrier film SP1 (SP2), therefore, excellent heat resistance, and there is turn-off function.Therefore,, according to present embodiment 1, can manufacture safe lithium ion battery.And according to present embodiment 1, barrier film SP1 (SP2) forms with positive pole, therefore, can make barrier film SP1 (SP2) and the gap of positive interpolar disappear, so, can prevent the intrusion of metallic foreign body.Therefore, can prevent internal short-circuit, can the high lithium ion battery of fabrication reliability.

Then, to forming the operation of negative pole NEL, describe.As shown in figure 24, production example is as the negative electrode active material NAS consisting of material with carbon element.And, as shown in figure 25, forming and make the binding agent (adhesive) for example being formed by Kynoar be dissolved in the solution in 1-METHYLPYRROLIDONE (NMP), mixing negative electrode active material NAS in this solution, makes slurries SL3.

As shown in figure 26, the slurries SL3 that contain negative electrode active material NAS and binding agent (adhesive) be coated in negative plate (negative electrode collector) NEP on thereafter.Particularly, as shown in figure 26, for example, use chill coating machine, on the negative plate NEP being formed by copper, apply negative electrode active material NAS.And the negative electrode active material NAS that makes to be coated on negative plate NEP is dry.Particularly, by for example heating at the NEP of anticathode plate below 120 ℃, the negative electrode active material NAS that makes to be coated on negative plate NEP is dry.

And, make to be coated in negative electrode active material NAS on a face of negative plate NEP dry after, on the another side of negative plate NEP, apply the mixing slurries SL3 that has negative electrode active material NAS.Thereafter, by for example heating at the NEP of anticathode plate below 120 ℃, the negative electrode active material NAS that makes to be coated on the another side of negative plate NEP is dry.

Like this, as shown in figure 27, form negative electrode active material NAS on the two sides of negative plate NEP after, anticathode plate NEP implements heating, pressurized treatments.This heating, pressurized treatments are for example 120 ℃ of following enforcements.Thus, can realize the densification of the negative electrode active material NAS being coated on negative plate NEP.As described above, can form negative plate NEP.

Then, as shown in figure 28, the positive plate PEP that is coated with barrier film SP1 (SP2) and positive active material PAS is cut off, processed.Thus, can form on one side (top) of positive plate PEP a plurality of anodal collector plate PTAB of rectangular shaped.Like this, can form anodal PEL integrated with barrier film SP1 (SP2) and after processing.

Similarly, to being coated with the negative plate NEP of negative electrode active material NAS, cutting off, process.Thus, can form on one side (below) of negative plate NEP a plurality of negative pole collector plate NTAB of rectangular shaped.Like this, as shown in figure 29, can on negative plate NEP, form coating negative electrode active material NAS the negative pole NEL after processing.

Then, as shown in figure 30, will (anodal PEL and negative pole NEL integrated and that form be overlapping for SP2 (not shown) with barrier film SP1.Now, the upper anodal collector plate PTAB forming of anodal PEL and the upper negative pole collector plate NTAB forming of negative pole NEL are configured in rightabout.

, as shown in figure 31, anodal PEL with barrier film SP1 (SP2) and negative pole NEL under overlapping state be wound on axle core CR on, form electrode coiling body WRF thereafter.Like this, can form electrode coiling body WRF.

Then, shown in figure 32, the anodal collector plate PTAB that the upper end from electrode coiling body WRF is outstanding is connected to anodal collector ring PR.Similarly, the outstanding negative pole collector plate NTAB in the bottom from electrode coiling body WRF is connected to negative pole collector ring NR.At this, anodal collector plate PTAB and anodal collector ring PR be connected and negative pole collector plate NTAB for example utilizes supersonic welding to fetch with being connected of negative pole collector ring NR to carry out.Therefore, in the situation that anodal PEL and barrier film SP1 (SP2) form discretely with individual components, owing to having gap between anodal PEL and barrier film SP1 (SP2), therefore, existence metallic foreign body when above-mentioned ultrasonic bonding disperses, and metallic foreign body invades the possibility in the gap forming between anodal PEL and barrier film SP1 (SP2).On the other hand, in present embodiment 1, because anodal PEL and barrier film SP1 (SP2) form and do not have gap, therefore, can prevent that the metallic foreign body producing from invading the inside of electrode coiling body WRF and being attached on anodal PEL when ultrasonic bonding.

Then, as shown in figure 33, electrode coiling body WRF is inserted into the inside of outer tinning CS.And, as shown in figure 34, process outer tinning CS and form ditch DT.This ditch DT makes it at above-below direction, not move and arrange in order to be fixedly inserted into the electrode coiling body WRF of outer tinning CS inside.

And, as shown in figure 35, to the inside of having inserted the outer tinning CS of electrode coiling body WRF, inject electrolyte EL.By top with sealing of lid outer tinning CS, can manufacture lithium ion battery in present embodiment 1 thereafter.

The advantage > of the manufacture method of the lithium ion battery of < execution mode 1

For example, as the manufacturing technology that forms anodal and barrier film, think to make positive active material to be dried and to implement after pressurized treatments, on the positive active material of having implemented this dry processing and pressurized treatments, apply the technology of diaphragm material (slurries).The in the situation that of this technology, having can be than being easier to realize integrated advantage anodal and barrier film.Such manufacturing technology, owing to applying the diaphragm material of slurries shape on dried positive active material, is therefore called as dry (the wet on dry) mode of wet cover sometimes.

In the dry mode of above-mentioned wet cover, the operation of slurries that for example contains electrode material due to coating and the operation of the slurries that coating contains diaphragm material be for independently, so have a plurality of working procedure of coating.That is, in the dry mode of wet cover, after the slurries that coating contains electrode material, make this slurry dried, dried electrode material is implemented to pressurized treatments.So far operation can be carried out to manufacture anodal existing manufacturing equipment., there is the operation that on the electrode material that form apply diaphragm material, therefore, except manufacturing anodal existing manufacturing equipment, need to apply diaphragm material and make its dry new manufacturing equipment thereafter.Thus, exist the manufacturing process of lithium ion battery elongated and cannot realize the problem points of sufficient cost.That is, the dry mode of wet cover, for emphasis being placed in to the technology of property easy to manufacture aspect, from the viewpoint of further propelling cost, is the technology that there is room for improvement.

On the other hand, according to the manufacture method of the lithium ion battery of present embodiment 1, coated electrode material (positive active material) and diaphragm material (pottery and organic material) in the lump on positive plate.Thus, compare with the dry mode of wet cover of coated electrode material and diaphragm material respectively, can realize further cost.; in the manufacture method of the lithium ion battery of present embodiment 1; after applying in the lump the electrode material of slurry condition and the diaphragm material of slurry condition; the diaphragm material of the electrode material of slurry condition and slurry condition is dry in the lump; dried electrode material and diaphragm material in the lump carried out to pressurized treatments thereafter.Thus, according to the manufacture method of the lithium ion battery of present embodiment 1, can directly apply the anodal manufacturing equipment of current existence, diaphragm material also forms on electrode material.Thus, do not need newly to arrange only for applying the other manufacturing equipment of diaphragm material, therefore, can realize fully cost.; by directly using the manufacture line of electrode in the manufacture method of the lithium ion battery in present embodiment 1; can obtain realizing the coating in the lump of electrode material and diaphragm material, dry, pressurized treatments in the lump in the lump, therefore can obtain the advantage of sufficient cost.Be explained, this manufacture method of lithium ion battery of present embodiment 1 that is conceived to cost, owing to applying the diaphragm material of slurry condition on the electrode material of slurry condition, therefore, being called as wet (the wet on wet) mode of wet cover sometimes.

(execution mode 2)

The feature > of < execution mode 2

In above-mentioned execution mode 1, to the barrier film that contains organic material and inorganic material and the anodal integrated lithium ion battery forming are illustrated, in present embodiment 2, to by anodal integrated and described by the example that the stacked film of the 1st dielectric film (inorganic insulating membrane) containing organic and/or inorganic materials and the 2nd dielectric film (organic insulating film) that contains organic material forms barrier film with barrier film.

Figure 36 means the barrier film of present embodiment 2 and the profile of anodal integrative-structure.As shown in figure 36, in the barrier film of present embodiment 2 and anodal integrative-structure, on the two sides of positive plate PEP, be formed with positive active material PAS, in the mode directly contacting with this positive active material PAS, form the dielectric film IF1 containing such as inorganic material such as ceramic powders CRS (aluminium oxide or silicon dioxide).And, in the mode directly contacting with this dielectric film IF1, form the dielectric film IF2 that contains the organic material OM such as polyolefin-based resins.That is,, in present embodiment 2, by the stacked film of dielectric film IF1 and dielectric film IF2, form barrier film SP1 (SP2).Below, the advantage of this formation is described.

For example, as above-mentioned execution mode 1, consider to form barrier film SP1 (SP2) to contain the mode of organic and/or inorganic materials and organic material simultaneously.In this situation, in the situation that contain fusing point lower than ceramic organic material in barrier film SP1 (SP2), even because short circuit produces the abnormal ascending of temperature, fusing point is lower than ceramic organic material melting, thus, near hole fusing point (minute aperture) obturation, therefore, can stop seeing through of lithium ion between positive pole and negative pole.In other words, by contain fusing point lower than ceramic organic material in barrier film SP1 (SP2), externally cut off electric current during short circuit, make the temperature of the inside of lithium ion battery increase and stop.; as above-mentioned execution mode 1; by forming barrier film SP1 (SP2) to contain pottery (inorganic material) and fusing point lower than the mode of ceramic organic material, excellent heat resistance, and the turn-off function of the abnormal current can there is the cutting-off of short-circuit time.Its result, according to above-mentioned execution mode 1, the lithium ion battery of can provide safe, reliability is excellent.

But, form practically in the situation of the barrier film SP1 (SP2) that contains inorganic material and organic material, there is the not possibility of homogenizing of the middle organic material of barrier film SP1 (SP2).Like this, if in barrier film SP1 (SP2) organic material homogenizing not, when the abnormal heating of lithium ion battery, the obturation that likely produces the hole (minute aperture) that the not homogenizing because of the organic material in barrier film SP1 (SP2) causes is bad.That is, organic material not homogenizing mean the region that exists region that organic material more exists and organic material less to exist in barrier film SP1 (SP2).So in the few region of organic material, even organic material melting, absolute magnitude is also few, therefore, can not fill up most holes.Its result, causes that when abnormal heating the cut-out of electrode reaction is bad, and the possibility that can not bring into play fully the turn-off function that the melting of organic material brings raises.

On the other hand, in present embodiment 2, by the dielectric film IF1 containing organic and/or inorganic materials, form barrier film SP1 (SP2) with the stacked film of the dielectric film IF2 that contains organic material.Therefore, in the barrier film SP1 of present embodiment 2 (SP2), due to inorganic material and organic material separated, therefore, can not be created in the problem of the not homogenizing of the organic material producing while mixing inorganic material and organic material.Thus, according to present embodiment 2, can suppress the reduction of the turn-off function that the not homogenizing because of organic material causes.That is,, according to present embodiment 2, the obturation that can suppress the hole (minute aperture) that the not homogenizing because of the organic material in barrier film SP1 (SP2) causes when the abnormal heating of lithium ion battery is bad.Its result, according to present embodiment 2, can not cause that the cut-out of electrode reaction is incomplete, can manifest reliably turn-off function, thus, can effectively cut off the electrode reaction of lithium ion battery.

Be explained, in present embodiment 2, with the bonding barrier film SP1 in the two sides anodal and barrier film SP2 integrated mode, form, so, can eliminate between anodal and barrier film SP1 or the gap producing between positive pole and barrier film SP2.Its result, the internal short-circuit in the lithium ion battery that can prevent from causing because of metallic foreign body, thus, can improve the reliability of lithium ion battery.

The manufacture method > of the lithium ion battery of < execution mode 2

The lithium ion battery of present embodiment 2 forms as mentioned above, below, with reference to accompanying drawing on one side its manufacture method described on one side.In present embodiment 2, also example integrated with stratiform to positive pole, ceramic powders CRS and organic material OM and that form describes.

First, as shown in Figures 10 and 11, utilize the method same with above-mentioned execution mode 1 to make the slurries SL1 that contains positive active material PAS.Further, in present embodiment 2, for example, as shown in figure 37, prepare aluminium oxide (Al ₂o ₃) or silicon dioxide (SiO ₂) etc. ceramic powders CRS (particle diameter is for example 4 μ m).And, as shown in figure 38, forming and make the binding agent (adhesive) for example being formed by Kynoar be dissolved in the solution in 1-METHYLPYRROLIDONE (NMP), mixing ceramic powders CRS in this solution, makes slurries SL4.Similarly, in present embodiment 2, for example, as shown in figure 39, Preparation Example is as by take the organic material OM (particle diameter is for example 1 μ m) that polyolefin-based resins that high density polyethylene (HDPE) (fusing point: 130～137 ℃) and straight chain shape low density polyethylene (LDPE) (fusing point: 122～124 ℃) etc. are representative forms.And, as shown in figure 40, forming and make the binding agent (adhesive) for example being formed by Kynoar be dissolved in the solution in 1-METHYLPYRROLIDONE (NMP), mixing organic material OM in this solution, makes slurries SL5.

As shown in figure 41, the slurries SL1 that contain positive active material PAS and binding agent (adhesive) be coated in positive plate (positive electrode collector) PEP on thereafter.Particularly, as shown in figure 41, for example, use chill coating machine DC, on the positive plate PEP being formed by aluminium, apply positive active material PAS (also comprising conductive auxiliary agent).Then, use chill coating machine DC, on the slurries SL1 being coated on positive plate PEP, apply the mixing slurries SL4 that has ceramic powders CRS.Then, use chill coating machine DC, on slurries SL4, apply the mixing slurries SL5 that has organic material OM.At this, first to using after chill coating machine DC applies the mixing slurries SL1 that has a positive active material PAS on positive plate PEP, on these slurries SL1, apply the mixing slurries SL4 that has ceramic powders CRS, further coating is mixing has the successively coating process of the slurries SL5 of organic material OM to describe, but also can use coating process following time: for example, on positive plate PEP, use chill coating machine DC to apply mixing have the slurries SL1 of positive active material PAS, mixing slurries SL4 and the mixing slurries SL5 that has organic filler that has ceramic powders CRS simultaneously.

Then, as shown in figure 42, make to be coated in slurries SL1 on positive plate PEP and slurries SL4 and slurries SL5 dry.Particularly, by for example positive plate PEP being heated below 120 ℃, make to be coated in slurries SL1 on positive plate PEP and slurries SL4 and slurries SL5 dry.Heat treated herein need to be set as forming the temperature of the not melting of organic filler of organic material OM.Thus, can on positive plate PEP, form positive active material PAS, on this positive active material PAS, form the dielectric film IF1 that contains ceramic powders CRS.Then, can on this dielectric film IF1, form the dielectric film IF2 that contains organic material OM.

And, after a face (first surface) the upper formation positive active material PAS and the dielectric film IF1 that contains ceramic powders CRS and the dielectric film IF2 that contains organic material OM of positive plate PEP, as shown in figure 43, the another side (the second face) at positive plate PEP above applies mixing have the slurries SL1 of positive active material PAS, mixing slurries SL4 and the mixing slurries SL5 that has organic material OM that has ceramic powders CRS.By for example 120 ℃ below positive plate PEP heated, make be coated in the slurries SL1 another side of positive plate PEP on and slurries SL4 and slurries SL5 dry thereafter.Thus, as shown in figure 44, can on the another side of positive plate PEP, also on positive plate PEP, form positive active material PAS, on this positive active material PAS, form the dielectric film IF1 that contains ceramic powders CRS.And, can on this dielectric film IF1, form the dielectric film IF2 that contains organic material OM.

Like this, form positive active material PAS and dielectric film IF1 and dielectric film IF2 on the two sides of positive plate PEP after, as shown in figure 45, positive plate PEP is implemented to use to heating, the pressurized treatments of cylinder RL.This heating, pressurized treatments are for example 120 ℃ of following enforcements.Thus, can realize the densification of the positive active material PAS being coated on positive plate PEP.Operation as described above, as shown in figure 36, can on the two sides of positive plate PEP, form positive active material PAS, in the mode directly contacting with this positive active material PAS, form the dielectric film IF1 containing such as inorganic material such as potteries (aluminium oxide or silicon dioxide).Then, can form the dielectric film IF2 that contains the organic materials such as polyolefin-based resins in the mode directly contacting with this dielectric film IF1.That is,, in present embodiment 2, can be formed by the stacked film of dielectric film IF1 and dielectric film IF2 barrier film SP1 (SP2).

According to present embodiment 2, due to the barrier film SP1 (SP2) that comprises the dielectric film IF1 consisting of ceramic powders CRS and the dielectric film IF2 consisting of organic material OM is dried in the lump, is pressurizeed and forming so that stratiform is integrated with positive pole, the advantage that therefore can obtain cutting down process number, can cut down manufacturing cost.In addition, when battery abnormal heating, do not cause that the cut-out of the bad electrode reaction causing of obturation that the not homogenizing because of the organic filler in barrier film SP1 (SP2) causes is incomplete, can manifest reliably turn-off function, cut off electrode reaction.

Be explained, later operation and above-mentioned execution mode 1 are roughly the same, therefore, omit explanation again.As mentioned above, can manufacture the lithium ion battery of present embodiment 2.

(execution mode 3)

Feature > in < execution mode 3

The formation of the lithium ion battery of the formation of the lithium ion battery of present embodiment 3 and above-mentioned execution mode 2 is almost same.That is, in above-mentioned execution mode 2, to by anodal integrated and be illustrated by the example that the stacked film of the 1st dielectric film containing organic and/or inorganic materials and the 2nd dielectric film that contains organic material forms barrier film with barrier film.In present embodiment 3, to by anodal integrated and describe by the 1st dielectric film (organic insulating film) that contains organic material with containing the example that the stacked film of the 2nd dielectric film (inorganic insulating membrane) of organic and/or inorganic materials forms barrier film with barrier film.

Figure 46 means the barrier film of present embodiment 3 and the profile of anodal integrative-structure.As shown in figure 46, in the barrier film of present embodiment 3 and anodal integrative-structure, on the two sides of positive plate PEP, be formed with positive active material PAS, in the mode directly contacting with this positive active material PAS, form the dielectric film IF1 containing such as organic material OM such as polyolefin-based resins.And, in the mode directly contacting with this dielectric film IF1, form the dielectric film IF2 that contains the inorganic material such as ceramic powders CRS (aluminium oxide or silicon dioxide).That is,, in present embodiment 3, by the stacked film of dielectric film IF1 and dielectric film IF2, form barrier film SP1 (SP2).

Like this, in present embodiment 3, by the dielectric film IF1 that contains organic material with containing the stacked film of the dielectric film IF2 of organic and/or inorganic materials, form barrier film SP1 (SP2).Therefore, in the barrier film SP1 of present embodiment 3 (SP2), due to inorganic material and organic material separated, therefore, can not be created in the problem of the not homogenizing of the organic material producing while mixing inorganic material and organic material.Thus, according to present embodiment 3, with above-mentioned execution mode 2 similarly, can suppress the reduction of the turn-off function that the not homogenizing because of organic material causes.That is,, according to present embodiment 3, the obturation that can suppress the hole (minute aperture) that the not homogenizing because of the organic material in barrier film SP1 (SP2) causes when the abnormal heating of lithium ion battery is bad.Its result, according to present embodiment 3, does not cause that the cut-out of electrode reaction is incomplete, can manifest reliably turn-off function, thus, can effectively cut off the electrode reaction of lithium ion battery.

Be explained, in present embodiment 3, with bonding barrier film SP1 and barrier film SP2 on anodal two sides integrated mode, form, so, can eliminate between anodal and barrier film SP1 or the gap producing between anodal and barrier film SP2.Its result, the internal short-circuit in the lithium ion battery that can prevent from causing because of metallic foreign body, thus, can improve the reliability of lithium ion battery.

The manufacture method > of the lithium ion battery of < execution mode 3

The lithium ion battery of present embodiment 3 forms as mentioned above, below, with reference to accompanying drawing on one side its manufacture method described on one side.In present embodiment 3, also anodal and ceramic powders CRS and organic material OM example integrated with stratiform and formation are described.

As shown in figure 47, for example, use chill coating machine DC, on the positive plate PEP consisting of aluminium, coating contains the positive active material PAS slurries SL1 of (also comprising conductive auxiliary agent).Then, use chill coating machine DC, on the slurries SL1 being coated on positive plate PEP, apply the mixing slurries SL5 that has organic material OM., use chill coating machine DC, on the slurries SL5 that contains organic material OM, apply the mixing slurries SL4 that has ceramic powders CRS thereafter.At this, first to using after chill coating machine DC applies the mixing slurries SL1 that has a positive active material PAS on positive plate PEP, on this positive active material PAS, apply the mixing slurries SL5 that has organic material OM, further coating is mixing has the successively coating process of the slurries SL4 of ceramic powders CRS to describe, but also can use coating process following time: for example, use chill coating machine DC on positive plate PEP, to apply the mixing slurries SL1 that has positive active material PAS simultaneously, mixing slurries SL5 and the mixing slurries SL4 that has ceramic powders CRS that has organic material OM.

Then, as shown in figure 48, make to be coated in slurries SL1 on positive plate PEP and slurries SL5 and slurries SL4 dry.Particularly, by for example positive plate PEP being heated below 120 ℃, make to be coated in slurries SL1 on positive plate PEP and slurries SL5 and slurries SL4 dry.Heat treated herein need to be set as forming the temperature of the not melting of organic filler of organic material OM.Thus, can on positive plate PEP, form positive active material PAS, on this positive active material PAS, form the dielectric film IF1 that contains organic material OM.And, can on this dielectric film IF1, form the dielectric film IF2 that contains ceramic powders CRS.

And, after a face (first surface) the upper formation positive active material PAS and the dielectric film IF2 that contains ceramic powders CRS and the dielectric film IF1 that contains organic material OM of positive plate PEP, as shown in figure 49, the another side (the second face) at positive plate PEP above applies mixing have the slurries SL1 of positive active material PAS, mixing slurries SL5 and the mixing slurries SL4 that has ceramic powders CRS that has organic material OM.By for example 120 ℃ below positive plate PEP heated, make be coated in the slurries SL1 another side of positive plate PEP on and slurries SL5 and slurries SL4 dry thereafter.Thus, as shown in figure 50, can also on positive plate PEP, form positive active material PAS at the another side of positive plate PEP, on this positive active material PAS, form the dielectric film IF1 that contains organic material OM.And, can on this dielectric film IF1, form the dielectric film IF2 that contains ceramic powders CRS.

Like this, form positive active material PAS and dielectric film IF1 and dielectric film IF2 on the two sides of positive plate PEP after, as shown in Figure 51, positive plate PEP is implemented to use to heating, the pressurized treatments of cylinder RL.This heating, pressurized treatments are for example 120 ℃ of following enforcements.Thus, can realize the densification of the positive active material PAS being coated on positive plate PEP.As described above, as shown in figure 46, can on the two sides of positive plate PEP, form positive active material PAS, in the mode directly contacting with this positive active material PAS, form the dielectric film IF1 containing such as organic materials such as polyolefin-based resins.And, can form in the mode directly contacting with this dielectric film IF1 the dielectric film IF2 that contains the inorganic material such as pottery (aluminium oxide or silicon dioxide).That is,, in present embodiment 3, can be formed by the stacked film of dielectric film IF1 and dielectric film IF2 barrier film SP1 (SP2).

According to present embodiment 3, due to by the barrier film SP1 (SP2) that comprises the dielectric film IF1 being formed by organic material OM and the dielectric film IF2 being formed by ceramic powders CRS with positive pole is dried in the lump, pressurizes and form so that stratiform is integrated, therefore the advantage that, can obtain cutting down process number, can cut down manufacturing cost.In addition, when battery abnormal heating, do not cause that the cut-out of the bad electrode reaction causing of obturation that the not homogenizing because of the organic filler in barrier film SP1 (SP2) causes is bad, can manifest reliably turn-off function, cut off electrode reaction.

Be explained, later operation and above-mentioned execution mode 1 are almost same, therefore, omit explanation again.As mentioned above, can manufacture the lithium ion battery of present embodiment 3.

Above inventor's proposed invention is illustrated based on its execution mode, but the present invention is not limited to above-mentioned execution mode, in the scope that does not depart from its purport, can carries out various changes and without explicit word.

Be explained, in execution mode 1～3, to form the example of barrier film on anodal two sides, be illustrated, but the technological thought of the present application be not limited to this.For example, also can on a face of positive pole, form barrier film, and form another barrier film on a face of negative pole, further, the technological thought of the present application also goes for forming the situation of barrier film on the two sides of negative pole.

At this, illustrated in above-mentioned execution mode 1, because of the dissolving of metallic foreign body, separate out the internal short-circuit of the lithium ion battery that such mechanism causes, reason is adhesion metal foreign matter on positive pole.Therefore, in order effectively to suppress dissolving because of metallic foreign body, separate out the internal short-circuit of the lithium ion battery that such mechanism causes, it is important making non-cohesive metallic foreign body on positive pole.Thus, in the technological thought of the present application, the electrode forming with barrier film can be the either party of anodal and negative pole, but especially from effectively suppressing dissolving because of metallic foreign body, separate out the viewpoint of the internal short-circuit of the lithium ion battery that such mechanism causes, illustrated in above-mentioned execution mode 1～3, preferably on anodal two sides, form the formation of barrier film.

In addition, in above-mentioned execution mode 1～3, the lithium ion battery of take is illustrated technological thought of the present invention as example, but technological thought of the present invention is not limited to lithium ion battery, can be widely used in possessing have positive pole, the electrical storage device (such as battery or capacitor etc.) of negative pole and the separated anodal barrier film with negative pole of electricity.

Industrial utilizability

The inventive example is manufactured as being widely used in and be take the manufacturing industry of the battery that lithium ion battery is representative.

Symbol description

CAP battery cover

CR axle core

CRS ceramic powders

The outer tinning of CS

CU charger

DC chill coating machine

DC1 chill coating machine

DC2 chill coating machine

EL electrolyte

IF1 dielectric film

IF2 dielectric film

LIB lithium ion battery

NAS negative electrode active material

NEL negative pole

NEP negative plate

NR negative pole collector ring

NT negative wire plate

NTAB negative pole collector plate

OM organic material

PAS positive active material

PEL is anodal

PEP positive plate

PMP1 supply pump

PMP2 supply pump

The anodal collector ring of PR

PT positive wire plate

The anodal collector plate of PTAB

RL cylinder

RL1 cylinder

SL1 slurries

SL2 slurries

SL3 slurries

SL4 slurries

SL5 slurries

SP barrier film

SP1 barrier film

SP2 barrier film

WRF electrode coiling body

Claims

1. a manufacture method for lithium ion battery, is characterized in that, comprising:

(a) the 1st slurries that coating contains active material on battery lead plate, the operation of the 2nd slurries that coating contains organic filler and inorganic particulate on described the 1st slurries;

(b) after described (a) operation, make described the 1st slurries and the 2nd slurry dried of coating, on described battery lead plate, form thus described active material, on described active material, form the operation of the barrier film that contains described organic filler and described inorganic particulate;

(c) after described (b) operation, the operation to the pressurized treatments under described active material and described barrier film enforcement heating.

2. the manufacture method of lithium ion battery claimed in claim 1, is characterized in that, in the stage of described (a) operation, the average grain diameter of described organic filler is less than the average grain diameter of described inorganic particulate.

3. the manufacture method of lithium ion battery claimed in claim 1, is characterized in that, described organic filler consists of polyolefin-based resins.

4. the manufacture method of lithium ion battery claimed in claim 1, is characterized in that, described inorganic particulate consists of pottery.

5. the manufacture method of lithium ion battery claimed in claim 4, is characterized in that, described inorganic particulate consists of aluminium oxide or silicon dioxide.

6. a manufacture method for lithium ion battery, is characterized in that, comprising:

(a) the 1st slurries that coating contains active material on the first surface of battery lead plate, the operation of the 2nd slurries that coating contains organic filler and inorganic particulate on described the 1st slurries;

(b) after described (a) operation, make to be coated in described the 1st slurries and described the 2nd slurry dried on described first surface, on the described first surface of described battery lead plate, form described active material thus, on described active material, form the operation of the 1st barrier film that contains described organic filler and described inorganic particulate;

(c) after described (b) operation, on second of the described first surface opposition side with described battery lead plate, apply described the 1st slurries, on described the 1st slurries, apply the operation of described the 2nd slurries;

(d) after described (c) operation, make to be coated in described the 1st slurries and described the 2nd slurry dried on described second, on described second of described battery lead plate, form described active material thus, on described active material, form the operation of the 2nd barrier film that contains described organic filler and described inorganic particulate;

(e) after described (d) operation, to being formed on described active material and described the 1st barrier film of described first surface and being formed on the described active material of described second and the operation of the pressurized treatments under described the 2nd barrier film enforcement heating.

7. a manufacture method for lithium ion battery, is characterized in that, comprising:

(a) the 1st slurries that coating contains active material on battery lead plate, the 2nd slurries that coating contains the 1st material on described the 1st slurries, the operation of the 3rd slurries that coating contains 2nd material different from described the 1st material on described the 2nd slurries;

(b) after described (a) operation, make described the 1st slurries, the 2nd slurries and described the 3rd slurry dried of coating, on described battery lead plate, form thus described active material, on described active material, form the operation of the barrier film being formed by the 1st dielectric film that contains described the 1st material and the 2nd dielectric film that contains described the 2nd material;

8. the manufacture method of lithium ion battery claimed in claim 7, it is characterized in that, described the 1st material is inorganic particulate, described the 2nd material is organic filler, described the 1st dielectric film is the inorganic insulating membrane that contains described inorganic particulate, and described the 2nd dielectric film is the organic insulating film that contains described organic filler.

9. the manufacture method of lithium ion battery claimed in claim 8, is characterized in that, described the 1st material is pottery, and described the 2nd material is polyolefin-based resins.

10. the manufacture method of lithium ion battery claimed in claim 9, is characterized in that, described the 1st material is aluminium oxide or silicon dioxide.

The manufacture method of 11. lithium ion batteries claimed in claim 7, it is characterized in that, described the 1st material is organic filler, described the 2nd material is inorganic particulate, described the 1st dielectric film is the organic insulating film that contains described organic filler, and described the 2nd dielectric film is the inorganic insulating membrane that contains described inorganic particulate.

The manufacture method of the lithium ion battery described in 12. claims 11, is characterized in that, described the 1st material is polyolefin-based resins, and described the 2nd material is pottery.

The manufacture method of the lithium ion battery described in 13. claims 12, is characterized in that, described the 2nd material is aluminium oxide or silicon dioxide.

The manufacture method of 14. 1 kinds of lithium ion batteries, is characterized in that, comprising:

(a) the 1st slurries that coating contains active material on the first surface of battery lead plate, the 2nd slurries that coating contains the 1st material on described the 1st slurries, the operation of the 3rd slurries that coating contains 2nd material different from described the 1st material on described the 2nd slurries;

(b) after described (a) operation, make described the 1st slurries that apply, described the 2nd slurries and described the 3rd slurry dried on described first surface, on the described first surface of described battery lead plate, form described active material thus, on described active material, form the operation of the 1st barrier film being formed by the 1st dielectric film that contains described the 1st material and the 2nd dielectric film that contains described the 2nd material;

(c) after described (b) operation, on second of the described first surface opposition side with described battery lead plate, apply described the 1st slurries, on described the 1st slurries, apply described the 2nd slurries, on described the 2nd slurries, apply the operation of described the 3rd slurries;

(d) after described (c) operation, make described the 1st slurries, described the 2nd slurries and described the 3rd slurry dried of coating on described second, on described second of described battery lead plate, form described active material thus, on described active material, form the operation of the 2nd barrier film being formed by described the 1st dielectric film that contains described the 1st material and described the 2nd dielectric film that contains described the 2nd material;

15. 1 kinds of lithium ion batteries, is characterized in that, comprising:

(a) anodal,

(b) negative pole and

(c) the integrated barrier film of any electrode and in described positive pole and described negative pole,

Described barrier film contains organic filler and inorganic particulate,

The average grain diameter of described organic filler is less than the average grain diameter of described inorganic particulate.

Lithium ion battery described in 16. claims 15, is characterized in that, described organic filler consists of polyolefin-based resins, and described inorganic particulate consists of pottery.

Lithium ion battery described in 17. claims 16, is characterized in that, described inorganic particulate consists of aluminium oxide or pottery.

18. 1 kinds of lithium ion batteries, is characterized in that, comprising:

(a) anodal,

(b) negative pole and

(c) the integrated barrier film of electrode of the either party and in described positive pole and described negative pole,

Described barrier film has:

(c1) be formed on the 1st dielectric film on described electrode and

(c2) be formed on the 2nd dielectric film on described the 1st dielectric film.

Lithium ion battery described in 19. claims 18, is characterized in that, described the 1st dielectric film is the inorganic insulating membrane that contains inorganic particulate, and described the 2nd dielectric film is the organic insulating film that contains organic filler.

Lithium ion battery described in 20. claims 19, is characterized in that, described the 1st dielectric film is the described inorganic insulating membrane that contains pottery, and described the 2nd dielectric film is the described organic insulating film that contains polyolefin-based resins.

Lithium ion battery described in 21. claims 20, is characterized in that, described the 1st dielectric film is the described inorganic insulating membrane that contains aluminium oxide or silicon dioxide.

Lithium ion battery described in 22. claims 18, is characterized in that, described the 1st dielectric film is the organic insulating film that contains organic filler, and described the 2nd dielectric film is the inorganic insulating membrane that contains inorganic particulate.

Lithium ion battery described in 23. claims 22, is characterized in that, described the 1st dielectric film is the described organic insulating film that contains polyolefin-based resins, and described the 2nd dielectric film is the described inorganic insulating membrane that contains pottery.

Lithium ion battery described in 24. claims 23, is characterized in that, described the 2nd dielectric film is the described inorganic insulating membrane that contains aluminium oxide or silicon dioxide.