JP6587838B2 - Lithium ion batteries and wearable electronic devices - Google Patents

Description

  The present invention relates to a lithium ion battery provided in a wearable electronic device and a wearable electronic device including the lithium ion battery.

  A watch-type wearable electronic device having information processing ability, represented by a so-called smart watch, is well known. In such a wearable optical device, it is necessary to supply power from the outside or a built-in battery or the like in order to perform various kinds of information processing. In a wearable electronic device that requires such a power supply, it is preferable to incorporate the power supply in the wearable electronic device from the viewpoint of wearability and portability (see, for example, Patent Document 1).

JP-A-2015-55623

  However, in the above-described conventional wearable electronic device, the battery as a power source is formed in a rectangular shape that is a predetermined shape, etc., and thus a space of such a predetermined shape for storing the battery is secured in the wearable electronic device. There was a need to do. On the other hand, the outer shape of the housing of the wearable electronic device is preferably determined in consideration of ease of wearing and comfort when worn. Therefore, the housing of the wearable electronic device is often formed in a free shape, but if a battery of a predetermined shape is housed in such a free shape housing, there is a possibility that the space inside the housing cannot be used effectively. It was happening.

  The present invention has been made in view of the above-described problems, and one of its purposes is to provide a lithium ion battery and a wearable electronic device that can effectively use an internal space provided in the wearable electronic device. It is said.

The present invention includes an internal space and a structure that forms at least a part of a housing of a wearable electronic device, and both ends are fixed to the structure to be disposed in the internal space included in the structure. A separator that divides a space into a positive electrode chamber and a negative electrode chamber, a positive electrode composition comprising a positive electrode active material and an electrolyte filled in each of the positive electrode chamber and the negative electrode chamber, and a negative electrode comprising a negative electrode active material and an electrolyte A lithium ion battery comprising the composition solves at least one of the above problems.

  Since each of the positive electrode chamber and the negative electrode chamber is filled with the positive electrode composition and the negative electrode composition, the degree of freedom of the shape of the inner surface of the inner space of the casing is increased, and the inner space between the inner surface and the positive electrode and the negative electrode composition is increased. The gap can be made sufficiently small.

Here, it is preferable that the both ends of the separator are fixed in the internal space by being fixed in the structure. The wearable electronic device preferably has a clock function. Further, when the wearable electronic device is provided with a device main body and a band portion that is provided in the device main body and forms a ring shape when mounted, an internal space is provided in at least one of the device main body and the band portion of the wearable optical device. It is preferable. In addition, it is preferable that the lithium ion battery has flexibility and can supply power in a bent state.

  Here, it is preferable that at least a part of the inner surface of at least one of the positive electrode chamber and the negative electrode chamber is formed as a curved surface. Moreover, it is preferable to form a separator in flat form. In addition, a current collector is preferably provided in each of the positive electrode chamber and the negative electrode chamber. At this time, the current collector preferably has a portion that is not equidistant from the separator, and more preferably, the current collector is provided along the inner surface of the internal space.

  Moreover, it is preferable to coat at least a part of at least one of the positive electrode composition and the negative electrode composition with a layer mainly comprising a conductive additive and a polymer. Furthermore, at least one of the positive electrode composition and the negative electrode composition preferably contains a fibrous material. In this case, the fibrous material is preferably carbon fiber.

In addition, the present invention is applied to a wearable electronic device having a structure including an internal space and having a lithium ion battery provided in the internal space by fixing both ends to the structure. And a lithium ion battery is disposed in the internal space of the structure and separates the internal space into a positive electrode chamber and a negative electrode chamber, and a positive electrode composition and a negative electrode composition filled in each of the positive electrode chamber and the negative electrode chamber By providing the object, at least one of the above problems is solved.

  According to the present invention, it is possible to provide a lithium ion battery and a wearable electronic device that can effectively use an internal space provided in the wearable electronic device.

It is a perspective view which shows an example of the smart watch to which the lithium ion battery which is 1st Embodiment of this invention was applied. It is a BB and CC arrow sectional drawing of FIG. It is a perspective view which shows the other example of the smart watch to which the lithium ion battery which is 2nd Embodiment of this invention was applied. It is the cross-sectional view which cut | disconnected the smart watch shown in FIG. 3 in the longitudinal direction center.

(First embodiment)
With reference to FIG.1 and FIG.2, the lithium ion battery which is 1st Embodiment of this invention is demonstrated. FIG. 1 is a perspective view showing an example of a smart watch to which a lithium ion battery according to a first embodiment of the present invention is applied, and FIG. 2 is a cross-sectional view taken along arrows BB and CC in FIG.

  As shown in FIG. 1, the lithium ion battery L of the present embodiment is housed in a structure 1 that forms a band portion of a smart watch W that is a wearable electronic device having information processing capability. As shown in detail in FIG. 2, a substantially trapezoidal cavity is formed in the structure 1 in both a longitudinal section and a transverse section, and this cavity is defined as an internal space 1 a.

  More specifically, a hollow is formed in the structure 1 substantially throughout, and this hollow is defined as an internal space 1a. As shown in FIG. 2A, in the internal space 1a, The flat separator 4 is fixed in the internal space 1 a by fixing both ends thereof in the structure 1, whereby the internal space 1 a is divided into a positive electrode chamber 2 and a negative electrode chamber 3. As shown in FIG. 2B, the separator 4 extends along the longitudinal direction of the structure 1 that is a band (the direction from the lower left to the upper right in FIG. 2B).

  In the positive electrode chamber 2, as shown in FIG. 2 (a), a positive electrode current collector 7 having an end portion bent downward in FIG. 2 (a) along the curved surface of the internal space 1a is arranged. Similarly, as shown in FIG. 2A, the negative electrode chamber 3 is provided with a plate-like negative electrode current collector 8 extending along the inner surface of the internal space 1a. In addition, the positive electrode active material 5 and the negative electrode active material 6 are filled in the positive electrode chamber 2 and the negative electrode chamber 3 in a state where the negative electrode current collector 8 is disposed in the internal space 1a. Is formed.

  In filling the positive electrode active material 5 and the negative electrode active material 6, for example, the structure 1 is vertically divided into two at the position of the separator 4, and the positive electrode active material 5 and the negative electrode active material 6 are filled in the upper and lower spaces, respectively. Thereafter, the separator 4 may be sandwiched between the positive electrode active material 5 and the negative electrode active material 6 and both ends of the structure 1 divided into two under reduced pressure may be fixed by welding or the like.

  Here, as shown in FIG. 2B, the positive electrode current collector 7 is periodically folded downward along the curved surface of the internal space 1a even in the longitudinal direction of the structure 1 as a band. It is formed in a bent shape.

  Here, in this specification, “filled” means a state in which the positive electrode active material particles and the negative electrode active material particles are accommodated in the positive electrode chamber 2 and the negative electrode chamber 3, respectively. This means that the material particles, the negative electrode active material particles, and the electrolyte are accommodated in the positive electrode chamber 2 and the negative electrode chamber 3, respectively. More preferably, it means a state in which positive electrode active material particles and negative electrode active material particles are mixed with an electrolyte.

  In the present invention, the positive electrode chamber 2 and the negative electrode chamber 3 are filled with a positive electrode composition containing a positive electrode active material and an electrolyte and a negative electrode composition containing a negative electrode active material and an electrolyte. The positive electrode active material particles and the negative electrode active material particles may be directly put into the positive electrode chamber 2 and the negative electrode chamber 3, respectively. The slurry containing the positive electrode active material or the negative electrode active material particles and the nonaqueous solvent is used as the positive electrode chamber 2 and the negative electrode The positive electrode composition slurry containing the positive electrode active material or the negative electrode active material particles and the electrolytic solution and the negative electrode composition slurry may be put in the positive electrode chamber 2 and the negative electrode chamber 3, respectively. May be. When the powdered positive electrode active material and the negative electrode active material particles are directly put into the positive electrode chamber 2 and the negative electrode chamber 3, the positive electrode composition and the negative electrode are respectively added to the positive electrode chamber 2 and the negative electrode chamber 3 by adding an electrolytic solution thereafter. The composition is filled.

  When a slurry-like material containing a positive electrode active material or negative electrode active material particles and a non-aqueous solvent is put in the positive electrode chamber 2 and the negative electrode chamber 3, respectively, the active material particles and the non-aqueous solvent can be separated by pressurization or decompression thereafter. The positive electrode composition and the negative electrode composition are filled in each of the positive electrode chamber 2 and the negative electrode chamber 3 by allowing the non-aqueous solvent to pass through the membrane and further adding an electrolyte. When the positive electrode active material or negative electrode active material particles and the slurry-like positive electrode composition and negative electrode composition containing the electrolytic solution are put in the positive electrode chamber 2 and the negative electrode chamber 3, respectively, the active material particles are further pressurized or reduced in pressure. And a step of increasing the content of the positive electrode active material and the negative electrode active material contained in each of the positive electrode composition and the negative electrode composition by passing through a membrane capable of separating the electrolyte and the electrolyte and removing a part of the electrolyte Also good.

  The membrane capable of separating the active material particles and the non-aqueous solvent or the electrolytic solution is not limited as long as it is a membrane capable of separating the active material particles and the non-aqueous solvent solvent or the electrolytic solution, but the current collector and / or A film provided as a separator is preferred.

  When the positive electrode and negative electrode active material particles are filled in the positive electrode chamber 2 and the negative electrode chamber 3, the positive electrode and negative electrode active material particles are uniformly distributed in the positive electrode chamber 2 and the negative electrode chamber 3 by applying vibration and impact to the structure 1. Filling is preferred.

  In addition, the substance obtained by mixing the positive electrode and negative electrode active material particles with the electrolytic solution or the non-aqueous solvent is usually in the form of a slurry, but depending on the weight ratio of the positive electrode and negative electrode active material particles to the electrolytic solution, It may become a substance close to.

  And after depressurizing the inside of the structure 1, the opening part of this structure 1 is sealed using a sealing member etc., and an example of the lithium ion battery L of this invention can be manufactured.

The positive electrode active material particles constituting the positive electrode active material 5 include composite oxides of lithium and transition metals (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).

In addition, as the negative electrode active material particles constituting the negative electrode active material 6, graphite, non-graphitizable carbon, amorphous carbon, polymer compound fired body (for example, those obtained by firing and carbonizing a phenol resin, a furan resin, etc.), Coke (for example, pitch coke, needle coke and petroleum coke), carbon fiber, conductive polymer (for example, polyacetylene and polyquinoline), tin, silicon, and metal alloy (for example, lithium-tin alloy, lithium-silicon alloy, lithium) -Aluminum alloy and lithium-aluminum-manganese alloy), composite oxides of lithium and transition metal (for example, Li ₄ Ti ₅ O ₁₂ ) and the like.

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

  The coating agent includes a coating resin. When the periphery of the positive electrode active material particles is 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, polycarbonate, and the like. Among these, vinyl resin, urethane resin, polyester resin or polyamide resin is preferable.

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

  Specifically, metal [aluminum, stainless steel (SUS), silver, gold, copper, titanium, etc.], carbon [graphite, carbon black (acetylene black, ketjen black, furnace black, channel black, thermal lamp black, etc.), Single-walled 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 assistants may be those obtained by coating a particulate ceramic material or resin material with a conductive material (metal among the conductive auxiliary materials described above) by 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 in which the surface of organic fiber is coated with metal, and conductive fibers in which the surface of organic fiber is coated with a resin containing a conductive substance. Among these conductive fibers, carbon fibers are preferable.

  The coated active material particles are, for example, dropped into and mixed with a resin solution containing a coating resin over a period of 1 to 90 minutes in a state where the active material particles are put in a universal mixer and stirred at 30 to 500 rpm. It can be obtained by mixing, 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 step of filling the positive electrode chamber 2 and the negative electrode chamber 3 with the positive electrode composition and the negative electrode composition, the slurry-like substances each including the positive electrode active material and the negative electrode active material particles are electrolyte slurry containing an electrolyte solution. It is preferably a solvent slurry containing a non-aqueous solvent.

  As the electrolytic solution, an electrolytic solution containing an electrolyte and a non-aqueous solvent used for manufacturing a lithium ion battery can be used.

As the electrolyte, those used in ordinary electrolytic solutions can be used. For example, lithium salts of inorganic acids such as LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ and LiClO ₄ , LiN (CF ₃ SO ₂ ) ₂ and lithium salts of organic acids such as 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, those used in ordinary electrolytic solutions can be used, for example, lactone compounds, cyclic or chain carbonates, chain carboxylates, cyclic or chain ethers, phosphates, nitriles. Compounds, amide compounds, sulfones, sulfolanes and the like and mixtures thereof can be used.

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

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

  The slurry-like substance is preferably prepared by dispersing and slurrying the active material particles and the conductive additive at a concentration of 10 to 60% by weight based on the weight of the electrolytic solution or the non-aqueous solvent.

  As the separator 4, polyethylene, polypropylene, etc., microporous membrane film made of polyolefin, multilayer film 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 from 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, or 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, or a mixture 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. Preferably, 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.

  The material constituting the seal member is not particularly limited as long as it is a material that has adhesiveness to the current collectors 7 and 8 and is durable to the electrolytic solution. However, the material is a polymer material, particularly a thermosetting resin. Is preferred. 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.

  The structure 1 constituting the band portion is formed of metal, plastic, hard rubber, or the like, and has flexibility that allows at least bending along the longitudinal direction thereof.

  As an example, the lithium ion battery L according to the present embodiment drives a main body M that is a device main body of a wearable electronic device with a display of the smart watch W through a conductive portion (not shown) as illustrated in FIG. Used as a power battery. Thereby, the wearable electronic device of this embodiment is constructed.

  Therefore, according to the lithium ion battery L of this embodiment, the lithium ion battery L that can effectively use the internal space provided in the smart watch W that is a wearable electronic device can be realized.

  Moreover, the lithium ion battery L of this embodiment is applied to the smart watch W, and is not a mechanical or electronic movement, but is similar to a smartphone by touching a display surface on which time is displayed. Functions can be operated with the same feeling.

  Here, although the smart watch W has the shape of a conventional mechanical or electric watch, the battery that drives the smart watch W has only a few days, and therefore more There is a strong demand for a battery structure that can be used for a long time.

  Furthermore, in the lithium ion battery L of the present embodiment, the band part (structure 1), which is a functional component, can be used as a battery, so that the smart watch W can be used for a longer time. It becomes possible.

  Further, in the lithium ion battery L of the present embodiment, even if the structure 1 that is the band part of the smart watch W bends when the smart watch W is worn, there is a possibility that a problem occurs in the characteristics as the lithium ion battery L. Is very small. That is, in the lithium ion battery L of the present embodiment, since the positive electrode active material and the negative electrode active material are not heat-treated and dried as in the conventional lithium ion battery, the entire battery is bent. In this case, the possibility that the positive electrode or the negative electrode active material is peeled off from the current collector to cause a problem in characteristics as the lithium ion battery L is extremely small. In addition, even if the structure 1 is bent in the longitudinal direction by attaching the smart watch W, the lithium ion battery L can continue to supply the power supply voltage.

(Second Embodiment)
Next, with reference to FIG.3 and FIG.4, the lithium ion battery which is 2nd Embodiment of this invention is demonstrated. FIG. 3 is a perspective view showing an example of a state in which a lithium ion battery according to a second embodiment of the present invention is housed, and FIG. 4 is a cross-sectional view of the smart watch shown in FIG.

  As shown in FIGS. 3 and 4, the lithium ion battery L of the present embodiment is also housed in a structure 1 that is a device body (bezel) of a smart watch W of an example different from the first embodiment. . As shown in detail in FIG. 4, a recess 1g is formed on the upper surface of the structure 1 in the figure, and a main body M with a display of the smart watch W is disposed in the recess 1g. A cavity is formed in the inner space 1a.

  More specifically, a cavity is formed inside the structure 1, and the cavity is sealed from below by the lid 10 to form an internal space 1a. As shown in FIG. 4, the internal space 1a Inside, the flat separator 4 is fixed in the internal space 1a by fixing the peripheral portion thereof in the structure 1 via a ring-shaped or cylindrical sealing member 9, and thereby the internal space. 1 a is divided into a positive electrode chamber 2 and a negative electrode chamber 3.

  As shown in FIG. 4, the positive electrode chamber 2 has a shape in which the central portion is bent along the concave portion 1g along the curved surface of the internal space 1a, and the end portion is bent downward in FIG. As shown in FIG. 4, the positive electrode current collector 7 is disposed in the negative electrode chamber 3, and the surface of the negative electrode chamber 3 that contacts the arm of the user of the wearable electronic device (see FIG. 4). A negative electrode current collector 8 having a bent central portion is disposed along a convex portion 1h having a substantially circular shape in plan view formed on the lower surface), and further, the positive electrode current collector 7 and the negative electrode current collector 8 are arranged. Is filled in the positive electrode chamber 2 and the negative electrode chamber 3 with the positive electrode active material 5 and the negative electrode active material 6 being filled in the internal space 1a, thereby forming the lithium ion battery L of the present embodiment.

  In filling the positive electrode active material 5 and the negative electrode active material 6, the structure 1 is placed upside down in FIG. 4, and a predetermined amount of the positive electrode active material 5 is filled in the internal space 1a. In this state, the separator 4 is disposed on the positive electrode active material 5 after being leveled and the end of the separator 4 is fixed by the seal member 9, and then the negative electrode active material 6 is filled so that the center is slightly raised. Then, the lid 10 may be fitted and sealed.

  The specific configurations of the separator 4, the positive and negative electrode active materials 5 and 6, the positive and negative electrode current collectors 7 and 8, and the seal member 9 are the same as described in the first embodiment. The description is simplified.

  As an example, the lithium ion battery L of the present embodiment is used as a power supply battery for driving the display-equipped main body M of the smart watch W through a conductive portion (not shown) as shown in FIG. Thereby, the wearable electronic device of this embodiment is constructed.

  Therefore, the lithium ion battery L of the present embodiment can also realize the lithium ion battery L that can effectively use the storage space provided in the smart watch W that is a wearable electronic device.

  Further, the lithium ion battery L of the present embodiment is applied to the smart watch W as in the first embodiment, and is not a mechanical or electronic movement, but touches the display surface on which the time is displayed. By doing so, the same function as a smartphone can be operated with the same feeling.

  Furthermore, since the lithium ion battery L of this embodiment formed the lithium ion battery L to the maximum extent using the inner surface of the bezel that is the structure 1 of the device body of the smart watch W, the smart watch W can be used for a longer time. Is possible. That is, according to the present embodiment, by providing a battery on the inner surface of a functional component such as a frame or a structure, it is possible to provide a function as a battery.

(Modification)
The details of the lithium ion battery and the wearable electronic device of the present invention are not limited to the above-described embodiments, and various modifications are possible. As an example, in each of the above-described embodiments, the lithium ion battery L is provided in any one of the structures 1 constituting the band portion and the device main body of the smart watch W. You may provide the lithium ion battery L in any. The outer shape of the lithium ion battery according to the present invention is not particularly limited as long as it is appropriately selected from arbitrary shapes.

  The wearable electronic device provided with the lithium ion battery L of the present invention is not limited to the smart watch W as in the above-described embodiment, and various modifications are possible.

  On the other hand, the shape of the separator 4 is not particularly limited, but the manufacturing process and the like of the separator 4 can be simplified by forming the separator 4 in a flat plate shape as in the above-described embodiments. Further, the shape of the positive electrode current collector 7 and the negative electrode current collector 8 is not particularly limited, but the positive electrode and negative electrode current collectors are arranged along the inner surface of the structure 1 constituting the lithium ion battery as in the above-described embodiment. The provision of the electric conductors 7 and 8 is preferable because the capacity of the positive electrode composition and the negative electrode composition filled in the positive electrode chamber 2 and the negative electrode chamber 3 can be increased. Furthermore, at least the positive and negative electrode current collectors 7 and 8 and the separator 4 have portions that are not equally spaced, so that the storage space inside the structure 1 can be used more effectively.

  EXAMPLES Next, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the examples without departing from the gist of the present invention. Unless otherwise specified, “part” means “part by weight” and “%” means “% by weight”.

(Preparation of resin solution for coating)
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel and nitrogen gas inlet tube was charged with 83 parts of ethyl acetate and 17 parts of methanol, and the temperature was raised to 68 ° C. Next, a monomer compounded liquid in which 242.8 parts of methacrylic acid, 97.1 parts of methyl methacrylate, 242.8 parts of 2-ethylhexyl methacrylate, 52.1 parts of ethyl acetate and 10.7 parts of methanol were blended, and 2,2′- An initiator solution prepared by dissolving 0.263 parts of azobis (2,4-dimethylvaleronitrile) in 34.2 parts of ethyl acetate and stirring with a dropping funnel over 4 hours while blowing nitrogen into a four-necked flask. The radical polymerization was carried out by dropping continuously. After the completion of dropping, an initiator solution prepared by dissolving 0.583 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) in 26 parts of ethyl acetate was continuously added using a dropping funnel over 2 hours. Furthermore, the polymerization was continued for 4 hours at the boiling point. After removing the solvent to obtain 582 parts of resin, 1,360 parts of isopropanol was added to obtain a coating resin solution comprising a vinyl resin having a resin concentration of 30% by weight.

(Preparation of coated positive electrode active material particles)
96 parts by weight of LiCoO ₂ powder [Nippon Chemical Industry Co., Ltd. Cellseed C-8G] was put in a universal mixer and stirred at room temperature and 150 rpm, and the resin solution for coating (resin solid content concentration 30% by weight) was resin. The mixture was added dropwise over 60 minutes so that the solid content was 2 parts by weight, and the mixture was further stirred for 30 minutes.

  Next, 2 parts by weight of acetylene black [Denka Black (registered trademark) manufactured by Denki Kagaku Kogyo Co., Ltd.] was mixed in three portions with stirring, and the temperature was raised to 70 ° C. while stirring for 30 minutes, until 100 mmHg. The pressure was reduced and held for 30 minutes. The coated positive electrode active material particles were obtained by the above operation.

(Preparation of coated negative electrode active material particles)
Resin for coating in a state where 90 parts by weight of non-graphitizable carbon [Carbotron (registered trademark) PS (F) manufactured by Kureha Battery Materials Japan Co., Ltd.] is put in a universal mixer and stirred at room temperature and 150 rpm. The solution (resin solid content concentration of 30% by weight) was added dropwise and mixed over 60 minutes so that the resin solid content was 5 parts by weight, and the mixture was further stirred for 30 minutes.

  Next, 5 parts by weight of acetylene black [Denka Black (registered trademark) manufactured by Denki Kagaku Kogyo Co., Ltd.] was mixed in three portions with stirring, and the mixture was heated to 70 ° C. with stirring for 30 minutes. The pressure was reduced to 01 MPa and held for 30 minutes. The coated negative electrode active material particles were obtained by the above operation.

(Preparation of electrolyte)
LiPF ₆ was dissolved at a rate of 1 mol / L in a mixed solvent of ethylene carbonate (EC) and diethyl carbonate (DEC) (volume ratio 1: 1) to prepare an electrolytic solution for a lithium ion battery.

(Production of positive electrode-coated active material slurry)
67 parts by weight of the coated positive electrode active material, carbon fiber [Osaka Gas Chemical Co., Ltd. Donacarbo Mild S-243: average fiber length 500 μm, average fiber diameter 13 μm] 1 part by weight, and 32 parts by weight of the above electrolyte were mixed. A positive electrode-coated active material slurry was prepared.

(Manufacture of negative electrode-coated active material slurry)
A negative electrode-coated active material slurry was prepared by mixing 52 parts by weight of coated negative electrode active material particles, 1 part by weight of the same carbon fiber used in the production of the positive electrode-coated active material slurry, and 47 parts by weight of the electrolytic solution.

(Manufacture of lithium ion batteries 1)
A positive electrode active material slurry was poured and a positive electrode active material slurry was injected to form a positive electrode active material layer. Subsequently, a negative electrode active material slurry was formed by spreading a separator and forming a negative electrode active material layer. Subsequently, after covering the negative electrode current collector, the structure (case) was sealed with an adhesive.

  In order to confirm the operation as a battery, a charge / discharge tester was connected to the lead portion from the current collector, and a charge / discharge test was performed. It was confirmed that charging / discharging was possible and functioned as a lithium ion secondary battery.

(Manufacture of lithium ion batteries 2)
The inside of a substantially frustoconical structure (case) sealed at the bottom was separated by a separator to form a positive electrode chamber and a negative electrode chamber, and a positive electrode current collector and a negative electrode current collector were provided on the respective inner walls. Subsequently, the positive electrode chamber and the negative electrode chamber were filled with a positive electrode active material slurry and a negative electrode active material slurry composed of a powdered positive electrode active material and a negative electrode active material and an electrolyte, respectively, and then the upper portion of the structure was sealed. .

  In order to confirm the operation as a battery, a charge / discharge tester was connected to the lead portion from the current collector, and a charge / discharge test was performed. Also in this case, it was confirmed that charging / discharging was possible and functioned as a lithium ion secondary battery.

W smart watch L lithium ion battery 1 structure 1a internal space 2 positive electrode chamber 3 negative electrode chamber 4 separator 5 positive electrode active material 6 negative electrode active material 7 positive electrode current collector 8 negative electrode current collector 9 seal member 10 lid

Claims (13)

A structure including an internal space and constituting at least a part of a housing of the wearable electronic device;
A separator that is disposed in the internal space by fixing both ends to the structure, and divides the internal space into a positive electrode chamber and a negative electrode chamber,
A lithium ion comprising: a positive electrode composition comprising a positive electrode active material and an electrolyte filled in each of the positive electrode chamber and the negative electrode chamber; and a negative electrode composition comprising a negative electrode active material and an electrolyte. battery. The lithium ion battery according to claim 1,
The lithium ion battery, wherein both ends of the separator are fixed in the internal space by being fixed in the structure. The lithium ion battery according to claim 1 or 2 ,
The wearable electronic device has a clock function. The lithium ion battery according to any one of claims 1 to 3 ,
The wearable electronic device includes a device main body and a band portion that is provided in the device main body and forms a ring shape when mounted,
The lithium ion battery, wherein the internal space is provided in at least one of the device main body and the band portion of the wearable electronic device. In the lithium ion battery according to any one of claims 1 to 4 ,
The lithium ion battery has flexibility and can supply power in a bent state. In the lithium ion battery according to any one of claims 1 to 5 ,
At least a part of the inner surface of at least one of the positive electrode chamber and the negative electrode chamber is formed as a curved surface. In the lithium ion battery according to any one of claims 1 to 6 ,
A lithium ion battery, wherein a current collector is provided in each of the positive electrode chamber and the negative electrode chamber. The lithium ion battery according to claim 7 ,
The current collector has a portion that is not equidistant from the separator. The lithium ion battery according to claim 7 ,
The current collector is provided along the inner surface of the internal space. The lithium ion battery according to any one of claims 1 to 9 ,
Lithium characterized in that at least a part of at least one of the positive electrode composition and the negative electrode composition is covered with a layer mainly comprising a conductive additive and a polymer. Ion battery. The lithium ion battery according to claim 10 ,
At least one of the positive electrode composition and the negative electrode composition contains a fibrous material. In the lithium ion battery of claim 1 1, wherein,
The lithium ion battery, wherein the fibrous substance is carbon fiber. A wearable electronic device having a structure including an internal space and including a lithium ion battery provided in the internal space,
The lithium ion battery is
A separator that is disposed in the internal space by fixing both ends to the structure, and divides the internal space into a positive electrode chamber and a negative electrode chamber,
A mounting type comprising: a positive electrode composition containing a positive electrode active material and an electrolyte solution filled in each of the positive electrode chamber and the negative electrode chamber; and a negative electrode composition containing a negative electrode active material and an electrolyte solution. Electronics.

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