JP6571406B2 - Lithium ion battery and manufacturing method thereof - Google Patents

Description

  The present invention relates to a lithium ion battery and a manufacturing method thereof.

  Lithium ion (secondary) batteries have been widely used in various applications in recent years as high-capacity, small and lightweight secondary batteries. As an example of a method for producing such a lithium ion battery, a method for producing a battery using an electrode prepared by applying a paste-like positive electrode active material and a negative electrode active material to a sheet-like positive electrode and negative electrode current collector is known. (For example, refer to Patent Document 1).

JP 2009-252385 A

  When a battery is produced by the method described in Patent Document 1 using a conventional electrode obtained by applying a paste-like positive electrode active material and a negative electrode active material, the electrode is efficiently attached to the battery outer container to ensure battery performance. Therefore, there is a problem that the shape and manufacturing method of the battery are restricted.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a method for manufacturing a lithium ion battery that can achieve excellent battery performance without being restricted by the shape of the battery.

  The method for producing a lithium ion battery according to the present invention comprises a slurry containing active material particles and a liquid in a container containing a container for containing an electrode composition comprising active material particles and an electrolyte. An injection step of injecting a substance; and at least a part of the liquid contained in the slurry substance injected into the storage part through the separation membrane provided in the storage part and capable of separating the active material particles and the liquid. And a discharging step of discharging from the housing portion.

  Here, the liquid is preferably an electrolytic solution or a non-aqueous solvent. Further, in the injection step, the slurry substance is injected from a first opening provided in the storage portion, and in the discharge step, at least a part of the liquid injected into the storage portion is supplied to the storage portion. It is preferable to discharge from a second opening provided at a position different from the first opening.

  In addition, the container has a positive electrode chamber and a negative electrode chamber separated by a separator, and in the injection step, the slurry-like substance is injected into at least one of the positive electrode chamber and the negative electrode chamber, In the discharging step, it is preferable to discharge the liquid from the one electrode chamber.

  Further, one surface of the separator has a region constituting the inner wall of the positive electrode chamber, the other surface has a region constituting the inner wall of the negative electrode chamber, and in the discharging step, the region of the separator has At least a portion may be used as the separation membrane.

  Furthermore, one of the region constituting the inner wall of the positive electrode chamber and the region constituting the inner wall of the negative electrode chamber of the separator has a region that does not overlap the other region, and in the discharging step, At least a part of the non-overlapping region may be used as the separation membrane.

  Moreover, in the said injection | pouring process, it is preferable to inject | pour a slurry-like substance into both the said positive electrode chamber and the said negative electrode chamber at the same time. Moreover, it is preferable that at least a part of the active material particles is covered with a layer containing a conductive additive and a polymer.

  Further, the lithium ion battery according to the present invention includes a positive electrode chamber filled with a positive electrode composition containing a positive electrode active material and an electrolytic solution, and a negative electrode filled with a negative electrode composition containing a negative electrode active material and an electrolytic solution. An active material particle and a liquid disposed on an inner surface of at least one of the positive electrode chamber and the negative electrode chamber, and a separator that separates the positive electrode chamber and the negative electrode chamber. It is characterized by including the separation membrane which can isolate | separate.

  ADVANTAGE OF THE INVENTION According to this invention, the lithium ion battery excellent in battery performance can be simply manufactured by accommodating an electrode efficiently, without receiving restrictions with the shape of a battery, etc. Moreover, more excellent battery performance can be ensured by controlling the ratio of the active material particles and the electrolytic solution in the active material to a preferable value while injecting the active material into the container in a low viscosity state.

It is a partially broken perspective view for demonstrating the manufacturing method of the lithium ion battery which concerns on the 1st Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the lithium ion battery which concerns on the 1st Embodiment of this invention. It is a perspective view for demonstrating the manufacturing method of the lithium ion battery which concerns on the 2nd Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the lithium ion battery which concerns on the 2nd Embodiment of this invention. It is explanatory drawing for demonstrating the discharge process at the time of manufacturing the lithium ion battery which concerns on the 2nd Embodiment of this invention.

[First Embodiment]
First, a lithium ion battery according to a first embodiment of the present invention and a manufacturing method thereof will be described with reference to FIGS. 1 and 2. 1 and 2 schematically show a state in the middle of manufacturing the lithium ion battery according to the present embodiment. FIG. 1 is a partially broken perspective view, and FIG. 2 is a cross-sectional view.

  Prior to describing the manufacturing method of the lithium ion battery of the present embodiment, the structure of the lithium ion battery manufactured by the manufacturing method of the present embodiment will be described.

  As shown in FIG. 1 and FIG. 2, the lithium ion battery of this embodiment is disposed in a container 1 that contains an electrode composition including active material particles and an electrolytic solution, and a container that the container 1 has. The separator 4 that divides the container into a positive electrode chamber 2 and a negative electrode chamber 3, a positive electrode composition 5 filled in the positive electrode chamber 2, a negative electrode composition 6 filled in the negative electrode chamber 3, and a positive electrode chamber 2 and a negative electrode current collector 8 disposed on the inner surface of the negative electrode chamber 3. The container 1 also functions as an outer can of the lithium ion battery.

  As illustrated in FIG. 1, the container 1 is formed in a substantially rectangular parallelepiped shape as an example, and a hollow portion inside the container 1 is used as a storage portion. In the container 1, a flat separator 4, which is an example of dividing the container into a positive electrode chamber 2 and a negative electrode chamber 3, is disposed. That is, one surface of the separator 4 is a part of the inner wall of the positive electrode chamber 2, and the opposite surface is a part of the inner wall of the negative electrode chamber 3. A positive electrode current collector 7 is disposed on the inner surface of the positive electrode chamber 2 facing the separator 4, and similarly, a negative electrode current collector 8 is disposed on the inner surface of the negative electrode chamber 3 facing the separator 4.

  Further, the positive electrode chamber 2 is filled with the positive electrode composition 5, and the negative electrode chamber 3 is filled with the negative electrode composition 6. The positive electrode composition 5 is composed of at least positive electrode active material particles and an electrolytic solution, and the negative electrode composition 6 is composed of at least negative electrode active material particles and an electrolytic solution.

  Here, in this specification, “filled” means that the positive electrode composition 5 containing the positive electrode active material particles and the electrolytic solution is accommodated in the positive electrode chamber 2, and the negative electrode active material particles and the electrolytic solution are mixed. It means a state in which the contained negative electrode composition 6 is housed in the negative electrode chamber 3. Preferably, each of the positive electrode active material particles or the negative electrode active material particles is mixed with the electrolyte in the positive electrode chamber 2 or the negative electrode chamber 3. It means the state.

The positive electrode active material particles constituting the positive electrode composition 5 include lithium and transition metal composite oxides (for example, LiCoO ₂ , LiNiO ₂ , LiMnO ₂ and LiMn ₂ O ₄ ), transition metal oxides (for example, MnO ₂ and V ₂ O ₅ ), transition metal sulfides (eg, MoS ₂ and TiS ₂ ), and conductive polymers (eg, polyaniline, polypyrrole, polythiophene, polyacetylene, poly-p-phenylene, and polycarbazole).

The negative electrode active material particles constituting the negative electrode composition 6 include graphite, non-graphitizable carbon, amorphous carbon, and polymer compound fired bodies (for example, those obtained by firing and carbonizing a phenol resin, a furan resin, or the like). Cokes (such as pitch coke, needle coke and petroleum coke), carbon fibers, conductive polymers (such as polyacetylene and polyquinoline), tin, silicon, and metal alloys (such as lithium-tin alloys, lithium-silicon alloys, Lithium-aluminum alloy and lithium-aluminum-manganese alloy) and composite oxides of lithium and transition metal (for example, Li ₄ Ti ₅ O ₁₂ ).

  In the battery of the present invention, the positive electrode active material particles and / or the negative electrode active material particles are coated active material particles in which at least a part of the surface thereof is coated with a coating agent containing a coating resin and a conductive additive. Is preferred.

  The coating agent contains a coating resin. When the surfaces of the positive electrode active material particles and the negative electrode active material particles are coated with the coating agent, the volume change of the electrode is alleviated and the expansion of the electrode can be suppressed. . Examples of the coating resin include vinyl resin, urethane resin, polyester resin, polyamide resin, epoxy resin, polyimide resin, silicone resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, and polycarbonate. Of these, vinyl resins, urethane resins, polyester resins and polyamide resins are preferred.

  As a conductive support agent, it selects from the material which has electroconductivity.

  Conductive agents include metals [aluminum, stainless steel (SUS), silver, gold, copper, titanium, etc.], carbon [graphite and carbon black (acetylene black, ketjen black, furnace black, channel black, thermal lamp black, single layer) Carbon nanotubes and multi-walled carbon nanotubes, etc.)], and mixtures thereof, but are not limited thereto.

  These conductive assistants may be used alone or in combination of two or more. Moreover, these alloys or metal oxides may be used. From the viewpoint of electrical stability, aluminum, stainless steel, carbon, silver, gold, copper, titanium and mixtures thereof are preferred, silver, gold, aluminum, stainless steel and carbon are more preferred, and carbon is more preferred. is there. These conductive aids may be those obtained by coating a conductive material (a metal material among the conductive aid materials described above) around the particle ceramic material or resin material with plating or the like.

  It is also possible to use conductive fibers as the conductive auxiliary. Examples of conductive fibers include carbon fibers such as PAN-based carbon fibers and pitch-based carbon fibers, conductive fibers obtained by uniformly dispersing highly conductive metal and graphite in synthetic fibers, and metals such as stainless steel. Examples thereof include fiberized metal fibers, conductive fibers obtained by coating the surfaces of organic fibers with metal, and conductive fibers obtained by coating the surfaces of organic fibers with a resin containing a conductive substance. Among these conductive fibers, carbon fibers are preferable.

  The coated active material particles are prepared by, for example, dropping and mixing a resin solution containing a coating resin over 1 to 90 minutes in a state where positive electrode active material particles or negative electrode active material particles are put in a universal mixer and stirred at 30 to 500 rpm. Furthermore, it can be obtained by further mixing a conductive assistant, raising the temperature to 50 to 200 ° C. with stirring, reducing the pressure to 0.007 to 0.04 MPa, and holding for 10 to 150 minutes.

  In the present embodiment, as will be described later, a slurry-like substance containing active material particles and a liquid is injected into the positive electrode chamber 2 and the negative electrode chamber 3, and finally the positive electrode composition 5 and the negative electrode composition 6 are respectively obtained. The positive electrode chamber 2 and the negative electrode chamber 3 are filled. The liquid contained in the slurry substance is preferably an electrolytic solution or a non-aqueous solvent. In the present invention, when the liquid is an electrolytic solution, the slurry-like material containing an active material is called an electrolyte solution slurry, and when the liquid is a non-aqueous solvent, the slurry-like material containing an active material is called a solvent slurry.

  As an electrolytic solution contained in the electrolytic solution slurry, an electrolytic solution used for manufacturing a lithium ion battery can be used.

As the electrolyte contained in the electrolytic solution, those used in an electrolytic solution of a normal lithium ion battery can be used. For example, inorganic acids such as LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ and LiClO ₄ can be used. And lithium salts of organic acids such as LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ and LiC (CF ₃ SO ₂ ) ₃ . Among these, LiPF ₆ is preferable from the viewpoint of battery output and charge / discharge cycle characteristics.

  As the non-aqueous solvent contained in the electrolyte solution and the non-aqueous solvent contained in the solvent slurry, those used in the electrolyte solution of a normal lithium ion battery can be used, for example, lactone compound, cyclic or chain-like Carbonic acid esters, chain carboxylic acid esters, cyclic or chain ethers, phosphate esters, nitrile compounds, amide compounds, sulfones, sulfolanes, and the like, and mixtures thereof can be used.

  The said non-aqueous solvent may be used individually by 1 type, and may use 2 or more types together.

  Among nonaqueous solvents, lactone compounds, cyclic carbonates, chain carbonates and phosphates are preferable from the viewpoint of battery output and charge / discharge cycle characteristics, and more preferable are lactone compounds, cyclic carbonates and A chain carbonate ester is more preferable, and a mixed solution of a cyclic carbonate ester and a chain carbonate ester is more preferable. Particularly preferred is propylene carbonate (PC) or a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC).

  Examples of the separator 4 include polyethylene, polypropylene and the like, microporous membrane films made of polyolefin, multilayer films of porous polyethylene film and polypropylene, non-woven fabric made of polyester fiber, aramid fiber, glass fiber, etc., and silica on the surface thereof, Examples include those having ceramic fine particles such as alumina and titania attached thereto.

  As the current collectors 7 and 8, a metal current collector or a resin current collector can be used. As the metal current collector, a known metal current collector can be used. For example, the metal current collector is selected from the group consisting of copper, aluminum, titanium, nickel, tantalum, niobium, hafnium, zirconium, zinc, tungsten, bismuth, antimony, and alloys containing one or more of these, and stainless steel alloys. It is preferable that it consists of 1 or more types. The metal current collector may be formed of a thin plate or a metal foil, or a metal layer may be formed on the surface of the substrate by a technique such as sputtering, electrodeposition, and coating.

  The polymer material constituting the resin current collector may be a conductive polymer or a polymer having no conductivity.

  Polymer materials include polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polycycloolefin (PCO), polyethylene terephthalate (PET), polyether nitrile (PEN), polytetrafluoroethylene (PTFE) Styrene butadiene rubber (SBR), polyacrylonitrile (PAN), polymethyl acrylate (PMA), polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVdF), epoxy resin, silicone resin, and mixtures thereof.

  From the viewpoint of electrical stability, polyethylene (PE), polypropylene (PP), polymethylpentene (PMP) and polycycloolefin (PCO) are preferable, and polyethylene (PE), polypropylene (PP) and polymethylpentene are more preferable. (PMP).

  In addition, the resin current collector is intended to improve the conductivity of the resin current collector containing the conductive polymer material, or to impart conductivity to the resin current collector containing the polymer material having no conductivity. Therefore, it is preferable that a conductive filler is included. The conductive filler is selected from materials having conductivity, and from the viewpoint of suppressing ion permeation in the current collector, it is preferable to use a material that does not have conductivity with respect to ions used as the charge transfer medium. Specific examples include, but are not limited to, carbon materials, aluminum, gold, silver, copper, iron, platinum, chromium, tin, indium, antimony, titanium, nickel, and the like. These conductive fillers may be used alone or in combination of two or more. Moreover, these alloy materials, such as stainless steel (SUS), may be used. From the viewpoint of corrosion resistance, aluminum, stainless steel, carbon material, nickel, and more preferably carbon material are preferred. In addition, these conductive fillers may be those obtained by coating the metal shown above with a plating or the like around a particulate ceramic material or resin material.

  Specific examples of the resin current collector include those obtained by dispersing 5 to 20 parts of acetylene black as a conductive filler in polypropylene and then rolling with a hot press. Moreover, the thickness is not particularly limited, and can be applied in the same manner as known ones or with appropriate changes.

  Next, with reference to FIG. 1 and FIG. 2, the manufacturing method of the lithium ion battery of this embodiment is demonstrated.

  Specifically, first, current collectors 7 and 8 are arranged in an electrode composition accommodating portion of container 1, and further separator 4 is arranged to divide the accommodating portion into positive electrode chamber 2 and negative electrode chamber 3. Thereafter, the positive electrode chamber 2 is filled with the positive electrode composition 5 and the negative electrode chamber 3 is filled with the negative electrode composition 6. In particular, in the present embodiment, the filling step of filling each of the positive electrode chamber 2 and the negative electrode chamber 3 with the electrode composition is a slurry-like substance containing at least active material particles and a liquid in each of the positive electrode chamber 2 and / or the negative electrode chamber 3. And a discharge step of discharging at least a part of the liquid contained in the slurry-like substance injected in the injection step from the positive electrode chamber 2 and / or the negative electrode chamber 3 through the separation membrane 9.

  In order to make this injection step and discharge step feasible, a first opening (injection port 2a) is provided above the positive electrode chamber 2, and a position different from the injection port 2a of the positive electrode chamber 2 [for example, A second opening (exhaust port 2b) is provided at an opposite site, that is, on the opposite side (downward) from the first opening (injection port 2a). Similarly, the negative electrode chamber 3 is also provided with an inlet 3a and an outlet 3b. These inlets 2 a, 3 a and outlets 2 b, 3 b are all holes that connect the inside and outside of the container 1 through the outer wall of the container 1.

  Hereinafter, the step of filling the positive electrode chamber 2 with the positive electrode composition 5 in this embodiment will be described in detail. The step of filling the negative electrode chamber 3 with the negative electrode composition 6 may also be realized by the same steps as described below.

  First, a slurry-like substance containing positive electrode active material particles and an electrolytic solution is injected from an injection port 2 a provided above the positive electrode chamber 2. The method of injecting the slurry-like substance into the positive electrode chamber 2 is not limited, and a known method such as a method of injecting the slurry-like substance into the positive electrode chamber 2 from the tank storing the slurry-like substance through the nozzle 20 is applied. Can do. Here, the slurry-like substance injected into the positive electrode chamber 2 is a positive electrode composition in which the proportion of the positive electrode active material particles contained therein is discharged into the positive electrode chamber 2 after discharging a part of the electrolyte solution after injection. It is prepared so that it may become lower than the ratio of the positive electrode active material particle contained in the thing 5. For this reason, the viscosity of the slurry-like substance at the time of injection becomes lower than the final viscosity of the positive electrode composition 5 at the time of completion of the lithium ion battery, and the slurry-like substance is prepared or injected into the positive electrode chamber 2. It becomes easy to handle during work.

  Thereafter, a part of the electrolytic solution contained in the slurry-like substance injected into the positive electrode chamber 2 is discharged from the discharge port 2b by pressurization or decompression. In FIG. 1 and FIG. 2, a discharge pipe 21 is inserted into the discharge port 2 b, and the electrolytic solution is discharged through this discharge pipe 21. At this time, it is not preferable that the active material particles are discharged from the positive electrode chamber 2 together with the electrolytic solution. Therefore, a separation membrane 9 capable of separating the active material particles and the liquid is disposed at the discharge port 2b. Specifically, in FIGS. 1 and 2, the separation membrane 9 is disposed in the tube of the discharge pipe 21, and always passes through the separation membrane 9 when exiting from the inside of the positive electrode chamber 2 through the discharge port 2 b. It is supposed to be.

  The separation membrane 9 is a filter formed of the same material as that of the separator 4, for example. By passing through the separation membrane 9, only the electrolytic solution contained in the slurry-like substance can be discharged from the cathode chamber 2 while leaving the active material particles contained in the slurry-like substance in the cathode chamber 2. As a part of the electrolytic solution is discharged from the positive electrode chamber 2, the ratio of the active material particles to the slurry-like material in the positive electrode chamber 2 increases. Thereby, the positive electrode active material 5 containing the active material particles in a preferable ratio from the viewpoint of battery performance can be filled in the positive electrode chamber 2.

  As a specific example, the slurry-like material initially injected into the positive electrode chamber 2 is a dispersion of active material particles and a conductive additive at a concentration of 1 to 50% by weight (preferably 5 to 30% by weight) based on the weight of the electrolytic solution. It is preferable to prepare by slurrying. Thereafter, the positive electrode composition 5 filled in the positive electrode chamber 2 after being adjusted through the discharging step is coated with 30 coated active material particles coated with a coating agent containing a conductive auxiliary agent based on the weight of the electrolytic solution. It is preferable to contain in a concentration of ˜80 wt% (preferably 30 to 60 wt%).

  In addition, after discharging a part of electrolyte solution from the positive electrode chamber 2 in the discharge | emission process mentioned above, you may inject | pour the slurry-like substance containing active material particle and electrolyte solution from the injection port 2a as needed. In this case, the ratio of the active material particles contained in the slurry material to be newly injected may be different from the ratio of the active material particles contained in the slurry material to be injected first.

  After the positive electrode composition 5 is filled in the positive electrode chamber 2 by the injection process and the discharge process, the active material particles and the electrolytic solution in the positive electrode chamber 2 are uniformly distributed by, for example, applying vibration and impact to the container 1. A mixed state is preferable. Thereafter, the discharge pipe 21 is removed, the inside of the positive electrode chamber 2 is deaerated under reduced pressure, and the inlet 2a and the outlet 2b are sealed using a seal member or the like.

  The material constituting the seal member is not particularly limited as long as it is a material that is durable to the electrolytic solution, but a polymer material, particularly a thermosetting resin is preferable. Specific examples include epoxy resins, polyolefin resins, polyurethane resins, and polyvinylidene fluoride resins. Epoxy resins are preferable because they are highly durable and easy to handle.

  As described above, filling of the negative electrode composition 6 into the negative electrode chamber 3 is also realized by a process similar to the process of filling the positive electrode composition 5 into the positive electrode chamber 2 described above. That is, first, a slurry-like material containing negative electrode active material particles and an electrolytic solution is injected into the negative electrode chamber 3 from the injection port 3a, and then the electrolyte contained in the injected slurry-like material is discharged through the separation membrane 9 into the discharge port. Drain from 3b. Thereafter, the inside of the negative electrode chamber 3 is degassed under reduced pressure, and the inlet 3a and the outlet 3b are sealed.

  The step of filling the positive electrode chamber 2 with the positive electrode composition 5 and the step of filling the negative electrode chamber 3 with the negative electrode composition 6 may be performed in parallel. In particular, by performing the injection of the slurry-like substance into the positive electrode chamber 2 and the injection of the slurry-like substance into the negative electrode chamber 3 at the same time, the separator 4 is strong from one side to the other side. It is preferable that no pressure is applied.

  The lithium ion battery by the manufacturing method of this invention is manufactured through the above process. The positive electrode composition 5 filled in the positive electrode chamber 2 of the lithium ion battery and the negative electrode composition 6 filled in the negative electrode chamber 3 are respectively compared with the slurry-like substances injected into the positive electrode chamber 2 or the negative electrode chamber 3. Thus, the viscosity is high and the concentration of the active material particles is high. According to the present embodiment, since the slurry-like substance is injected in a state where the viscosity is low (the ratio of the liquid is large), the slurry-like substance can be easily handled during production, and the shapes of the positive electrode chamber 2 and the negative electrode chamber 3 are improved. Regardless of this, the slurry-like substance can be easily injected. Thereafter, by discharging the liquid contained in the slurry-like substance from the positive electrode chamber 2 and the negative electrode chamber 3, the ratio of the active material particles contained in the slurry-like substance can be adjusted to a preferable value, and the battery performance can be improved.

  The embodiments of the present invention are not limited to those described above. For example, in the above description, the electrolytic solution slurry containing the electrolytic solution is first injected into the positive electrode chamber 2 and the negative electrode chamber 3. It may be a solvent slurry containing a water solvent and no electrolyte. In this case, a slurry-like substance containing positive electrode active material particles and a non-aqueous solvent is injected into the positive electrode chamber 2, and then most of the injected non-aqueous solvent is discharged from the discharge port 2b. Thereafter, an electrolytic solution containing a nonaqueous solvent and an electrolyte is injected from the injection port 2a. Even by such a procedure, the slurry and the positive electrode active material particles are injected into the positive electrode chamber 2 in a state of relatively low viscosity and are contained in the positive electrode composition 5 filled in the positive electrode chamber 2. The ratio can be adjusted to a preferred value. Similarly, when filling the negative electrode chamber 6 with the negative electrode composition 6, similarly, the solvent slurry is injected in the first injection step, the nonaqueous solvent is discharged in the discharge step, and the electrolytic solution is again injected from the injection port 3 a. The negative electrode composition 6 may be filled.

  In the above description, the separation membrane 9 is fixed to the discharge pipe 21 and is removed together with the discharge pipe 21 after the discharge process is completed. However, the separation membrane 9 may be directly fixed to the discharge ports 2b and 3b of the container 1, and may remain in the battery while being fixed to the container 1 even after completion of the lithium ion battery.

  In the above description, the container 1 has a substantially rectangular parallelepiped shape. However, the present invention is not limited to this, and the container 1 and the accommodating portion inside the container 1 may have various shapes. The separator 4 is not limited to a flat plate shape as shown in FIGS. 1 and 2 and can take various shapes.

[Second Embodiment]
Next, with reference to FIGS. 3-5, the lithium ion battery which is 2nd Embodiment of this invention, and its manufacturing method are demonstrated. FIG. 3 and FIG. 4 are views schematically showing a state in the process of manufacturing a lithium ion battery according to the second embodiment of the present invention, where FIG. 3 is a perspective view and FIG. 4 is a cross-sectional view. FIG. 5 is an explanatory diagram for explaining the discharging process. In the following description, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is simplified.

  Unlike the first embodiment, this embodiment is characterized in that a partial region of the separator 4 is used as the separation membrane 9. Accordingly, the flow path of the liquid when discharging the liquid contained in the slurry substance injected into the positive electrode chamber 2 and the negative electrode chamber 3 is different from that of the first embodiment. Hereinafter, the structure of the lithium ion battery in this embodiment will be described.

  In this embodiment, the container 1 is formed of a laminate pack and is supported by the clamper 22 at the time of manufacture. A separator 4 is disposed in the accommodating portion of the container 1, and the accommodating portion is divided into a positive electrode chamber 2 and a negative electrode chamber 3. Here, the positive electrode chamber 2 and the negative electrode chamber 3 are partially asymmetric with respect to the separator 4. Specifically, as shown in FIG. 3, a protruding portion 2 c is formed below the positive electrode chamber 2, and the depth of the positive electrode chamber 2 is deeper than the depth of the opposing negative electrode chamber 3 at this position. . FIG. 4 shows a cross-sectional shape of the lithium ion battery at this position. Note that, in another position, the negative electrode chamber 3 is provided with a protruding portion, and the depth of the negative electrode chamber 3 is deeper than that of the positive electrode chamber 2 at this position.

  The separator 4 has a region in which one surface forms the inner wall of the positive electrode chamber 2 and the other surface has a region in which the inner wall of the negative electrode chamber 3 is formed. Most of the region constituting the inner wall of the positive electrode chamber 2 of the separator 4 and the region constituting the inner wall of the negative electrode chamber 3 overlap each other. However, since the positive electrode chamber 2 and the negative electrode chamber 3 have asymmetric shapes, a part of the region constituting the inner wall of the positive electrode chamber 2 (a portion corresponding to the protruding portion 2c of the positive electrode chamber 2 described above) is formed. It does not overlap with the area constituting the inner wall of the negative electrode chamber 3. Similarly, the region constituting the inner wall of the negative electrode chamber 3 does not overlap with the region constituting the inner wall of the positive electrode chamber 2 in a part of the region (the region corresponding to the protruding portion of the negative electrode chamber 3). Of the regions constituting the inner wall of each electrode chamber of the separator 4, at least a part of the region that does not overlap the region constituting the other electrode chamber functions as a separation membrane 9 that can separate the active material particles and the liquid. .

  As described above, the negative electrode chamber 3 does not exist on the opposite side of the protruding portion 2c of the positive electrode chamber 2 with the separator 4 interposed therebetween, and instead, a terminal portion 8a protruding from the negative electrode current collector 8 as shown in FIG. Are arranged opposite to each other. The terminal portion 8a extends to the outside of the container 1 to constitute an electrode terminal. Further, a discharge pipe 21 is inserted between the container 1 and the terminal portion 8a. Also in the positive electrode current collector 7, a terminal portion 7 a is formed so as to protrude at a position facing the protruding portion of the negative electrode chamber 3 with the separator 4 interposed therebetween.

  FIG. 5 is a partially enlarged exploded view schematically showing each member in the vicinity of the protruding portion 2 c of the positive electrode chamber 2. As shown in the figure, a plurality of holes are provided at positions facing the protruding portion 2 c of the negative electrode current collector 8, and these holes function as discharge ports 2 b when discharging liquid from the positive electrode chamber 2. To do. A region overlapping the discharge port 2 b of the separator 4 functions as the separation membrane 9.

  Hereinafter, the manufacturing method of the lithium ion battery in this embodiment is demonstrated. First, the current collectors 7 and 8 and the separator 4 are bonded to the laminate exterior material forming the container 1 and supported by the clamper 22. At this time, the nozzle 20 and the discharge pipe 21 are supported by the clamper 22 together with the laminate exterior material forming the container 1. Thereby, the positive electrode chamber 2 and the negative electrode chamber 3 are formed in the accommodating part which the container 1 has.

  Thereafter, the positive electrode composition 5 is filled in the positive electrode chamber 2 and the negative electrode composition 6 is filled in the negative electrode chamber 3. Below, the process of filling the positive electrode composition 5 into the positive electrode chamber 2 will be specifically described.

  First, a slurry-like substance containing positive electrode active material particles and a liquid (electrolytic solution, nonaqueous solvent or the like) is injected into the positive electrode chamber 2 from the injection port 2 a using the nozzle 20. This injection step may be realized by the same method as the slurry-like material injection step in the first embodiment.

  Next, the liquid contained in the slurry-like substance injected into the positive electrode chamber 2 is discharged from the discharge port 2 b provided in the negative electrode current collector 8 by pressurization or decompression. In this discharging step, the liquid contained in the slurry-like substance is discharged along the path indicated by the block arrow in FIG. Specifically, the liquid injected into the positive electrode chamber 2 passes through the separation membrane 9 that is a part of the separator 4, passes through the discharge port 2 b provided in the negative electrode current collector 8, and the discharge pipe 21. It is discharged outside the container 1. In addition, since the positive electrode active material particles contained in the slurry-like material do not permeate the separation membrane 9, they are not discharged in the discharge process.

  Thereafter, a slurry-like substance or an electrolytic solution may be further injected from the injection port 2a as necessary. Next, the nozzle 20 and the discharge pipe 21 are removed, the inside of the positive electrode chamber 2 is deaerated under reduced pressure, and the inlet 2a and the outlet 2b are sealed using a seal member or the like.

  In addition, the process of filling the negative electrode composition 6 into the negative electrode chamber 3 may also be realized by the same procedure as the process of filling the positive electrode composition 5 described above into the positive electrode chamber 2. The step of filling the positive electrode composition 5 into the positive electrode chamber 2 and the step of filling the negative electrode composition 6 into the negative electrode chamber 3 may be performed in parallel.

  As described above, in the second embodiment, a partial region of the separator 4 is used as a separation membrane when liquid is discharged from the positive electrode chamber 2 and the negative electrode chamber 3. Thereby, it is not necessary to prepare a separation membrane separately from the separator 4.

  Also in this embodiment, the shape of the container 1 shown in FIG. 4 is only an example, and the container 1 may have various shapes. Further, the container 1 is not limited to the laminate exterior material, and may be formed of various materials. The shapes of the separator 4 and the current collectors 7 and 8 may be various shapes other than those illustrated.

DESCRIPTION OF SYMBOLS 1 Container 2 Positive electrode chamber 3 Negative electrode chamber 2a, 3a Inlet 2b, 3b Outlet 4 Separator 5 Positive electrode composition 6 Negative electrode composition 7 Positive electrode collector 8 Negative electrode collector 9 Separation membrane 20 Nozzle 21 Exhaust tube 22 Clamper

Claims (9)

Have a housing portion for housing the electrode composition comprising the active material particles and the electrolyte, the housing portion of the container is a member constituting a lithium ion battery, a slurry-like material containing the active material particles and liquid Injecting step of injecting,
A discharge step of discharging at least a part of the liquid contained in the slurry-like substance injected into the storage unit through the separation membrane provided in the storage unit and capable of separating the active material particles and the liquid from the storage unit; ,
A method for producing a lithium ion battery, comprising: In the manufacturing method of the lithium ion battery of Claim 1,
The method for producing a lithium ion battery, wherein the liquid is an electrolytic solution or a non-aqueous solvent. In the manufacturing method of the lithium ion battery according to claim 1 or 2,
In the injection step, the slurry-like substance is injected from a first opening provided in the housing portion,
In the discharging step, at least a part of the liquid injected into the container is discharged from a second opening provided at a position different from the first opening of the container. Battery manufacturing method. In the manufacturing method of the lithium ion battery as described in any one of Claim 1 to 3,
The accommodating portion has a positive electrode chamber and a negative electrode chamber separated by a separator,
In the injection step, the slurry substance is injected into at least one of the positive electrode chamber and the negative electrode chamber,
In the discharging step, the liquid is discharged from the one electrode chamber. In the manufacturing method of the lithium ion battery according to claim 4,
One surface of the separator has a region constituting the inner wall of the positive electrode chamber, and the other surface has a region constituting the inner wall of the negative electrode chamber,
In the discharging step, at least a part of a region of the separator is used as the separation membrane. In the manufacturing method of the lithium ion battery according to claim 5,
One of the region constituting the inner wall of the positive electrode chamber and the region constituting the inner wall of the negative electrode chamber of the separator has a region that does not overlap with the other region,
In the discharging step, at least a part of the non-overlapping region is used as the separation membrane. In the manufacturing method of the lithium ion battery as described in any one of Claim 4 to 6,
In the injecting step, a slurry material is injected into both the positive electrode chamber and the negative electrode chamber at the same time. In the manufacturing method of the lithium ion battery as described in any one of Claim 1 to 7,
A method for producing a lithium ion battery, wherein at least a part of the active material particles is coated with a layer comprising a conductive additive and a polymer. A positive electrode chamber filled with a positive electrode composition comprising a positive electrode active material and an electrolyte;
A negative electrode chamber filled with a negative electrode composition comprising a negative electrode active material and an electrolyte;
A separator that separates the positive electrode chamber and the negative electrode chamber;
Have
The lithium ion battery further includes a separation membrane disposed on an inner surface of at least one of the positive electrode chamber and the negative electrode chamber and capable of separating the active material particles and the liquid.

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