JP2006202680A - Polymer battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer battery capable of preventing degradation of battery performance due to generation of gas at initial charging, even in the case of use of a polymer electrolyte. <P>SOLUTION: Of the polymer battery 10 constituted of a polymer electrolyte layer 50 pinched by an electrode 41 with a cathode active material layer 43 electrically connected to a collector 42 and an electrode 46 with an anode active material layer 48 electrically connected to another collector 47 between the cathode active material layer 43 and the anode active material layer 48, at least either the anode active material layer or the polymer electrolyte layer 50 has a micro groove 51 formed communicating even outside on a contact face where the anode active material layer 48 and the polymer electrolyte layer 50 contact each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polymer battery having a polymer electrolyte and a method for producing the polymer battery.

  In recent years, hybrid vehicles, electric vehicles, and fuel cell vehicles have been manufactured and sold from the viewpoints of environment and fuel efficiency, and new developments are continuing. In these so-called electric vehicles, it is indispensable to use a power supply device capable of discharging and charging. As the power supply device, a secondary battery such as a lithium ion battery or a nickel hydride battery, an electric double layer capacitor, or the like is used.

  In particular, lithium ion secondary batteries are considered suitable for electric vehicles because of their high energy density and high durability against repeated charging and discharging, and various developments have been intensively advanced.

  However, in lithium ion batteries, especially lithium ion secondary batteries using a carbon-based material as the negative electrode active material, when charging is performed for the first time after assembly, a reaction occurs inside the battery, resulting in a large amount of hydrogen, hydrocarbons. Gases such as carbon oxides are generated. If such a gas is left inside the battery, the battery swells or the internal pressure of the battery increases, which may affect the laminated structure and cause a decrease in battery characteristics.

In order to solve this problem, a method for suppressing the decomposition of the electrolyte (for example, see Patent Documents 1 and 2) or a method for controlling the pressure and thickness of the entire battery to control gas generation (for example, Patent Documents) 3 and 4) are known.
JP-A-8-339824 JP 2002-373645 A JP-A-11-111339 JP 2003-123845 A

  However, the above method is based on a lithium ion secondary battery using a liquid organic solvent such as ethylene carbonate, propylene carbonate or dimethyl carbonate as a liquid electrolyte. No consideration is given to a lithium ion secondary battery including a gel electrolyte obtained by impregnating a polymer film such as polyvinylidene fluoride with a liquid organic solvent or an intrinsic solid polymer electrolyte such as polyethylene oxide as a so-called polymer electrolyte.

  Since the polymer electrolyte is different in component and gas permeability as compared with the liquid electrolyte, the above conventional technique cannot be applied as it is.

  The present invention has been made in view of the above circumstances, and even when a polymer electrolyte is used, a polymer battery capable of preventing a decrease in battery performance due to gas generation at the time of initial charge and a method for producing the polymer battery The purpose is to provide.

  The polymer battery of the present invention includes the positive electrode active material layer electrically connected to a current collector and the positive electrode active material layer electrically connected to another current collector. A polymer battery comprising a polymer electrolyte layer sandwiched between an active material layer and the negative electrode active material layer, wherein at least one of the negative electrode active material layer and the polymer electrolyte layer includes the negative electrode active material layer and Fine grooves communicating to the outside are formed on contact surfaces where the polymer electrolyte layers are in contact with each other.

  In the method for producing a polymer battery of the present invention, a positive electrode active material layer is formed on one current collector to form an electrode, and a negative electrode active material layer is formed on another current collector. A step of forming an electrode, a step of preparing a polymer electrolyte layer, and at least one of the negative electrode active material layer and the polymer electrolyte layer is provided with a fine groove that communicates to the outside of the contact surface when contacted later And a step of laminating the electrode and the polymer electrolyte so that the polymer electrolyte layer is sandwiched between the positive electrode active material layer and the negative electrode active material layer.

  According to the polymer battery of the present invention, since the fine groove communicating to the outside is formed on the contact surface where the negative electrode active material layer and the polymer electrolyte layer are in contact with each other, in the battery element during the first charge The generated gas is discharged from the fine groove to the outside. Accordingly, it is possible to prevent a decrease in battery performance due to the generated gas.

  According to the polymer battery manufacturing method of the present invention, since the negative electrode active material layer and the polymer electrolyte layer are formed with fine grooves communicating to the outside on the contact surface, the battery element is not subjected to the internal charging in the first charge. The gas generated in the gas is discharged from the fine groove to the outside. Accordingly, it is possible to prevent a decrease in battery performance due to the generated gas.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a view showing a polymer battery of the present invention.

  The polymer battery 10 of the present invention includes an electrode tab, an exterior 30, and a battery element 40.

  The electrode tab includes a positive electrode tab 21 and a negative electrode tab 22, each connected to the battery element 40 and drawn out of the exterior 30. Thereby, current is drawn from the battery element 40.

  The exterior 30 is formed of two laminate sheets. The laminate sheet has a three-layer structure in which both surfaces of an aluminum layer are covered with a resin layer. At least one of the laminate sheets is processed into a medium-high shape in order to provide a space that encloses the battery element 40. The edges of the laminate sheet are bonded by heat fusion or the like. Thereby, the battery element 40 is sealed inside the exterior 30.

  The battery element 40 includes an electrolyte layer 50 sandwiched between a positive electrode (electrode) 41 and a negative electrode (electrode) 46. The electrolyte layer 50 is a polymer solid electrolyte layer and is made of a polymer gel electrolyte having a polymer component or an all solid (intrinsic) polymer electrolyte.

  The positive electrode 41 includes a positive electrode current collector 42 and a positive electrode active material layer 43. A positive electrode active material layer 43 is formed on the positive electrode current collector 42 and is electrically connected to each other. The positive electrode current collector 42 is formed of, for example, an aluminum foil.

  The negative electrode 46 includes a negative electrode current collector 47 and a negative electrode active material layer 48. A negative electrode active material layer 48 is formed on the negative electrode current collector 47 and is electrically connected to each other. The negative electrode current collector 47 is formed of a copper foil.

  At least one of the negative electrode active material layer 48 and the electrolyte layer 50 is formed with a fine groove communicating to the outside on a contact surface where the negative electrode active material layer 48 and the electrolyte layer 50 are in contact with each other.

  The fine groove will be described in detail.

(Fine groove)
2 is a cross-sectional view of the battery element, and FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. In FIG. 3, the fine grooves are exaggerated for easy understanding.

  As shown in an enlarged view in FIG. 2, a plurality of fine grooves 51 are formed on the surface of the electrolyte layer 50 on the negative electrode active material layer 48 side. As shown in FIG. 3, the fine groove 51 communicates with the outside of the battery element 40. Therefore, the gas generated in the battery element 40 when it is charged for the first time is guided to the outside of the battery element 40 through the fine groove 51. The fine groove 51 is formed, for example, by roll pressing the electrolyte layer 50 in advance. The fine grooves 51 are formed, for example, in a triangular cross section having a depth of 10 μm at intervals of 200 μm.

  The fine groove 51 may be formed not on the surface of the electrolyte layer 50 but on the surface of the negative electrode active material layer 48 on the electrolyte layer 50 side. Further, the fine groove 51 may be provided on both surfaces of the negative electrode active material layer 48 and the electrolyte layer 50. Thereby, the escape route of gas can be widened.

(Production method)
Next, the manufacturing method of the polymer battery 10 of this invention is demonstrated.

  FIG. 4 is a diagram illustrating a state in which battery elements are stacked, FIG. 5 is a perspective view of a polymer battery, and FIG. 6 is a diagram illustrating a state in which the polymer battery is initially charged.

  First, the positive electrode 41 is formed. The positive electrode 41 is formed by forming a positive electrode active material layer 43 on a positive electrode current collector 42.

  Next, the negative electrode 46 is formed. The negative electrode 46 is formed by forming a negative electrode active material layer 48 on a negative electrode current collector 47.

  An electrolyte layer 50 is prepared. Then, micro grooves 51 having a predetermined depth are formed at a predetermined interval on one surface of the electrolyte layer 50 by a roll press.

  Then, as shown in FIG. 4, the electrolyte layer 50 is overlaid on the positive electrode 41 so that the surface of the electrolyte layer 50 on which the fine groove 51 is not formed contacts the positive electrode 41. A negative electrode 46 is further stacked on the electrolyte layer 50. As a result, the electrolyte layer 50 is sandwiched between the positive electrode active material layer 43 of the positive electrode 41 and the negative electrode active material layer 48 of the negative electrode 46 to form the battery element 40 as shown in FIGS. A fine groove 51 is provided on the contact surface between the layer 48 and the electrolyte layer 50.

  The positive electrode tab 21 is connected to the positive electrode 41 of the battery element 40, the negative electrode tab 22 is connected to the negative electrode 46, and the battery element 40 is hermetically sealed by the outer packaging 30 so that the electrode tabs 21 and 22 are pulled out. As described above, the polymer battery 10 as shown in FIGS. 1 and 4 is once manufactured.

(Function)
Next, the operation of the polymer battery 10 of the present invention will be described.

  As described above, in the polymer battery 10 of the present invention, the fine groove 51 is provided on the contact surface between the negative electrode active material layer 48 and the electrolyte layer 50. After the polymer battery 10 is once manufactured as a battery, it is charged for the first time.

  Gases such as hydrogen, hydrocarbons, and carbon oxides are generated by the initial charge. The generated gas passes through the fine groove 51 and is discharged from the inside of the electrode to the outside of the battery element 40. The gas is accumulated in the exterior 30 outside the battery element 40. Therefore, the exterior is opened by, for example, opening a hole in the exterior 30 once by an operator, and gas is removed from the interior of the exterior 30. After degassing, the unsealed portion of the exterior 30 is closed with resin or the like in a reduced pressure state.

  In addition, at the time of first charge or degassing, as shown in FIG. 5, the polymer battery 10 is disposed on the vibration table 60 and may be vibrated by ultrasonic vibration. Moreover, the polymer battery 10 may be heated at the time of degassing.

  As described above, a complete polymer battery is manufactured after degassing of the gas generated by the initial charge.

(effect)
According to the polymer battery 10 manufactured as described above, the following effects can be obtained.

  In the polymer battery 10 of the present invention, the gas generated during the initial charge is discharged to the outside of the battery element 40 through the fine groove 51. Therefore, it is possible to prevent the generated gas from spreading the interface between the electrode and the electrolyte layer 50 and deteriorating the battery performance. That is, the battery performance can be maintained even after the first charge.

  Further, since ultrasonic vibration is applied at the time of initial charge or degassing, the generated gas bubbles are easily carried to the fine groove and discharged to the outside of the battery element 40. As a result, degassing can be achieved more reliably, and the battery performance can be prevented from being lowered.

  Moreover, since the movement of the bubbles in the electrolyte layer 50 becomes more active by heating at the time of degassing, the bubbles can be more reliably conveyed to the fine groove, and the gas discharge can be promoted. As a result, degassing can be achieved more reliably, and the battery performance can be prevented from being lowered.

(Modification)
In the above embodiment, the polymer battery 10 is configured by preparing the positive electrode 41 and the negative electrode 46 as electrodes and providing the polymer electrolyte layer 50 between the positive electrode 41 and the negative electrode 46. However, the electrolyte layer 50 in which the fine groove 51 is formed as in the present invention can be applied to a battery other than the battery as described above. For example, it can be applied to a bipolar battery including a bipolar electrode.

  FIG. 7 is a diagram showing how the battery elements of the bipolar battery are assembled, and FIG. 8 is a diagram showing the battery elements of the bipolar battery.

  When configuring a bipolar battery, first, as shown in FIG. 7, a bipolar electrode 70 is formed. In forming the bipolar electrode 70, the positive electrode active material layer 43 is provided on one surface of the current collector 71, and the negative electrode active material layer 48 is provided on the other surface.

  An electrolyte layer 50 is prepared. On one surface of the electrolyte layer 50, fine grooves 51 having a predetermined depth are formed at predetermined intervals by a roll press.

  Then, the electrolyte layer 50 is sandwiched between the bipolar electrodes 70. At this time, the negative electrode active material layer 48 of the bipolar electrode 70 is brought into contact with one surface of the electrolyte layer 50 in which the fine groove 51 is formed.

  In this way, the battery element 40 shown in FIG. 8 is formed. As in the case of the positive electrode 41 and the negative electrode 46 described above, the positive electrode active material layer 43 or the negative electrode active material layer 48 is formed on one surface of the electrode disposed at the end of the stack.

  A bipolar battery can be constructed by connecting an electrode tab to the formed battery element and sealing it with an exterior.

  By applying the present invention to a bipolar battery, a battery having a high energy density per volume and a high power density can be obtained.

  In addition, the structure of the polymer battery of this invention should just use the well-known material used for the general lithium ion secondary battery except what was demonstrated especially, and is not specifically limited. The current collectors 42 and 47, the positive electrode active material layer 43, the negative electrode active material layer 48, the electrolyte, and the like that can be used in the polymer battery will be described below for reference.

[Current collector]
The current collector includes a positive electrode current collector used for the positive electrode and a negative electrode current collector used for the negative electrode, and is not particularly limited. However, a metal foil is usually used for both. The positive electrode current collector is often made of stainless steel, aluminum or the like, and the negative electrode current collector is often made of copper, stainless steel or the like.

Although the thickness of a collector is not specifically limited, Usually, it is about 1-100 micrometers.
[Positive electrode active material layer]
The positive electrode active material layer includes a positive electrode active material, a binder, and a conductive additive.

As the positive electrode active material, a composite oxide of lithium and a transition metal, which is also used in a solution-type lithium ion battery, can be used. Specifically, Li · Co-based composite oxide such as LiCoO _2, Li · Ni-based composite oxide such as LiNiO _2, Li · Mn-based composite oxide such as spinel LiMn ₂ O _4, Li · such LiFeO ₂ Examples thereof include Fe-based composite oxides. In addition, transition metal and lithium phosphate compounds and sulfate compounds such as LiFePO ₄ ; transition metal oxides and sulfides such as V ₂ O ₅ , MnO ₂ , TiS ₂ , MoS ₂ , and MoO ₃ ; PbO ₂ , AgO, NiOOH etc. are mentioned. By using a lithium-transition metal composite oxide as the positive electrode active material layer active material, the reactivity and cycle durability of the stacked battery can be improved and the cost can be reduced.

  In order to reduce the electrode resistance of the polymer battery, the positive electrode active material may have a particle size smaller than that generally used in a solution type lithium ion battery in which the electrolyte is not solid. Specifically, the average particle diameter of the positive electrode active material is preferably 0.1 to 5 μm.

  Examples of the conductive assistant include acetylene black, ketjen black, carbon black, graphite and the like, copper powder, silver powder and the like, and metal powder made of a mixture thereof. However, it is not necessarily limited to these.

  The blending amount of the positive electrode active material, the binder, and the conductive auxiliary in the positive electrode active material layer should be determined in consideration of the intended use of the battery (output importance, energy importance, etc.) and ion conductivity.

  The thickness of the positive electrode active material layer is not particularly limited, and should be determined in consideration of the intended use of the battery (such as emphasis on output and energy) and ion conductivity, as described for the blending amount. The thickness of a general positive electrode active material layer is about 5 to 500 μm.

[Negative electrode active material layer]
The negative electrode active material layer includes a negative electrode active material and a binder. Except for the type of the negative electrode active material, the contents are basically the same as those described in the section “Positive electrode active material”, and thus the description thereof is omitted here.

  As the negative electrode active material, a negative electrode active material that is also used in a solution-type lithium ion battery can be used. However, since the polymer battery of the present invention uses a solid polymer electrolyte, in consideration of the reactivity with the solid polymer electrolyte, a composite oxide of carbon or lithium and a metal oxide or metal is preferable. More preferably, the negative electrode active material is a composite oxide of carbon or lithium and a transition metal. More preferably, the transition metal is titanium. That is, the negative electrode active material is more preferably titanium oxide or a composite oxide of titanium and lithium.

  By using a composite oxide of carbon or lithium and a transition metal as the negative electrode active material layer active material, the reactivity and cycle durability of the stacked battery can be improved and the cost can be reduced.

[Electrolyte layer]
The material is not limited as long as it is a layer composed of a polymer having ion conductivity and exhibits ion conductivity. In the present invention, an intrinsic polymer electrolyte or a polymer gel electrolyte is used.

Examples of the intrinsic polymer electrolyte include known solid polymer electrolytes such as polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof. The solid polymer electrolyte layer contains a supporting salt (lithium salt) in order to ensure ionic conductivity. As the supporting salt, LiBF ₄ , LiPF ₆ , LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , or a mixture thereof can be used. However, it is not necessarily limited to these. A polyalkylene oxide polymer such as PEO and PPO can dissolve lithium salts such as LiBF ₄ , LiPF ₆ , LiN (SO ₂ CF ₃ ) ₂ , and LiN (SO ₂ C ₂ F ₅ ) ₂ well. Moreover, excellent mechanical strength is exhibited by forming a crosslinked structure.

The polymer gel electrolyte generally refers to an electrolyte solution held in an all-solid polymer electrolyte having ion conductivity. When the electrolyte layer is formed from the polymer gel electrolyte, the electrolytic solution is held in an amount of more than 0% by weight and 98% by weight or less. The electrolytic solution (electrolyte salt and plasticizer) is not particularly limited, and various conventionally known electrolytic solutions can be appropriately used. For example, inorganic acid anion salts such as LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiTaF ₆ , LiAlCl ₄ , Li ₂ B ₁₀ Cl ₁₀ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N or an organic acid anion salt selected from at least one lithium salt (electrolyte salt), cyclic carbonates such as propylene carbonate and ethylene carbonate; dimethyl carbonate; Chain carbonates such as methyl ethyl carbonate and diethyl carbonate; ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-dibutoxyethane; γ-butyrolactone, etc. Lactones; Nitriles such as acetonitrile Esters such as methyl propionate; amides such as dimethylformamide; plasticizers such as aprotic solvents (organic solvents) mixed with at least one selected from methyl acetate and methyl formate ) Can be used. However, it is not necessarily limited to these.

  In the present application, a polymer electrolyte having a similar electrolyte solution held in a polymer skeleton having no lithium ion conductivity is also included in the polymer gel electrolyte. The type of electrolyte solution (electrolyte salt and plasticizer) used is not particularly limited.

  Examples of the solid polymer electrolyte having ion conductivity include known solid polymer electrolytes such as polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof.

  For example, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), etc. are used as the polymer having no lithium ion conductivity used in the polymer gel electrolyte. it can. However, it is not necessarily limited to these.

  When the electrolyte layer is made of a polymer gel electrolyte, the electrolyte layer is formed by impregnating a separator such as a nonwoven fabric with a polymer gel raw material solution and then polymerizing using the above-described various methods. It may be. By using the separator, the filling amount of the electrolytic solution can be increased, and the thermal conductivity inside the battery is ensured.

[Laminate sheet]
The laminate sheet is used as a battery exterior 30 material. In general, a polymer metal composite film in which a heat-fusible resin film, a metal foil, and a resin film having rigidity are laminated in this order is used.

  As the heat-fusible resin, for example, polyethylene (PE), polypropylene (PP), modified polyethylene, modified polypropylene, ionomer, ethylene vinyl acetate (EVA) and the like can be used. As the metal foil, for example, Al foil or Ni foil can be used. As the resin having rigidity, polyamide synthetic fibers such as polyester such as polyethylene terephthalate (PET) and polyamide (nylon (registered trademark)) can be used. Specifically, PE / Al foil / PET laminated film laminated from the sealing surface side toward the outer surface; PE / Al foil / nylon (registered trademark) laminated film; Ionomer / Ni foil / PET laminated film; EVA / Al foil / PET laminated film; ionomer / Al foil / PET laminated film and the like can be used. The heat-fusible resin film acts as a seal layer when the battery element 40 is housed inside. The metal foil or the resin film having rigidity imparts moisture, breath resistance, and chemical resistance to the exterior 30 material. The laminate sheet can be easily and reliably bonded using heat sealing such as heat sealing, impulse sealing, ultrasonic welding, and high-frequency welding.

(Example)
Next, an example in which the polymer battery 10 to which the present invention is actually applied was manufactured and evaluated will be described.

<Sample preparation>
As examples, polymer batteries of Examples 1 to 4 having different specifications were prepared.

  The common structure of the produced polymer battery is as follows.

(Electrolyte layer)
A solution composed of a polyethylene oxide / polypropylene oxide copolymer oligomer and a 1000 ppm polymerization initiator as a precursor is sandwiched between quartz glass substrates, irradiated with ultraviolet rays for 15 minutes to crosslink the precursor, and a 50 μm solid electrolyte layer 50 is formed. Form. Thereafter, fine grooves having a triangular cross section with a depth of 10 μm were formed on one surface of the formed electrolyte layer 50 by a roll press at intervals of 200 μm.

(Positive electrode)
In order to form the positive electrode, the following materials were mixed to prepare a positive electrode slurry. The materials to be mixed are LiMn ₂ O ₄ (22% by weight) as a positive electrode active material, acetylene black (6% by weight) as a conductive additive, and an oligomer (18% by weight) of a copolymer of polyethylene oxide and polypropylene oxide as a precursor of an electrolyte. %), Li (C ₂ F ₅ SO ₂ ) ₂ N (9 wt%) as the supporting salt, N-methylpyrrolidone (45 wt%) as the solvent for adjusting the slurry viscosity, azobisisobutyronitrile (45 wt%) as the polymerization initiator Trace amount).

  A positive electrode slurry was applied to one side of the positive electrode current collector 42 and cured by thermal polymerization at 110 ° C. for 4 hours to form a positive electrode. For the positive electrode current collector 42, a stainless steel foil having a thickness of 20 μm was used.

(Negative electrode)
In order to form the negative electrode, the following materials were mixed to prepare a negative electrode slurry. The materials to be mixed are Li ₄ Ti ₅ O ₁₂ (14 wt%) as a negative electrode active material, acetylene black (4 wt%) as a conductive assistant, and an oligomer of a copolymer of polyethylene oxide and polypropylene oxide as a precursor of an electrolyte. (20% by weight), Li (C ₂ F ₅ SO ₂ ) ₂ N (11% by weight) as a supporting salt, N-methylpyrrolidone (51% by weight) as a solvent for adjusting slurry viscosity, and azobisisobuty as a polymerization initiator Ronitrile (trace amount).

  A negative electrode slurry was applied to one side of the negative electrode current collector 47 and cured by thermal polymerization at 110 ° C. for 4 hours to form a negative electrode. For the negative electrode current collector 47, a stainless steel foil having a thickness of 20 μm was used.

(Manufacturing)
The produced positive electrode 41 and negative electrode 46 were bonded together so as to sandwich the solid electrolyte layer 50 therebetween. At this time, the surface of the electrolyte layer 50 on which the fine grooves 51 were formed was bonded to the negative electrode 46 side to form the battery element 40. The battery element was sandwiched between laminate sheets and accommodated in the exterior 30, and the opening of the exterior 30 was sealed in a reduced pressure state to produce a polymer battery 10.

  In the following Examples 1 to 4, the process for charging the produced polymer battery 10 for the first time and degassing is different.

Example 1
In Example 1, the produced polymer battery was charged with a constant current (CC) to 2.7 V, and then charged with a constant voltage (CV) for a total of 15 hours. Next, the exterior laminate sheet was opened and degassed at room temperature. The degassing was performed by placing the polymer battery on a flat plate in a decompression container and placing a weight on the upper surface to decompress the interior of the container.

(Example 2)
In Example 2, the produced polymer battery was charged with a constant current (CC) to 2.7 V, and then charged with a constant voltage (CV) for a total of 15 hours. Next, the laminate sheet as the exterior was opened, and a weight was placed in the same manner as in Example 1, and degassing was performed at room temperature. Immediately before the end of charging, that is, immediately before degassing, the polymer battery was subjected to ultrasonic vibration for about 10 minutes.

(Example 3)
In Example 3, the produced polymer battery was charged with a constant current (CC) to 2.7 V, and then charged with a constant voltage (CV) for a total of 15 hours. Next, the laminate sheet as the exterior was opened, and a weight was placed in the same manner as in Example 1, and degassing was performed at room temperature. At the time of degassing, ultrasonic vibration was performed for about 10 minutes together with the decompression vessel.

Example 4
In Example 4, the produced polymer battery was charged with a constant current (CC) to 2.7 V, and then charged with a constant voltage (CV) for a total of 15 hours. Next, the laminate sheet as the exterior was opened, and a weight was placed in the same manner as in Example 1, and degassing was performed at 50 ° C. At the time of degassing, ultrasonic vibration was performed for about 10 minutes together with the decompression vessel.

(Comparative example)
As a comparative example, a polymer battery similar to that of Example 1 was produced except that fine grooves were not formed in the electrolyte layer. The produced polymer battery was charged with a constant current (CC) to 2.7 V, and then charged with a constant voltage (CV) for a total of 15 hours. Next, the exterior laminate sheet was opened and degassed at room temperature. The degassing was performed by placing the polymer battery on a flat plate in a decompression container and placing a weight on the upper surface to decompress the interior of the container.

<Charge / discharge test>
A charge / discharge test was performed on each of the polymer batteries of Examples 1 to 4 and the comparative example manufactured as described above.

  The polymer battery was discharged at 0.2 C to 1.5 V, the respective battery capacities were measured, and constant current (CC) -constant voltage (CV) charging was performed again at 2.7 V at 0.2 C. Next, the battery was discharged again at 2C to 1.5 V, and the battery capacity was measured.

<Evaluation>
9 and 10 are diagrams showing the ratio of the discharge capacities of Examples 1 to 4 with respect to the comparative example.

  When the discharge capacity of the comparative example at 0.2 C is 1, the discharge capacity of Examples 1 to 4 is shown in FIG. Moreover, when the discharge capacity of the comparative example at 0.2 C is 1, FIG. 10 shows the discharge capacity at 2 C of Examples 1 to 4.

  As shown in FIG. 9, it can be seen that each of the polymer batteries of Examples 1 to 4 has an improved discharge capacity ratio as compared with the comparative example. Further, as shown in FIG. 10, it can be seen that the polymer batteries of Examples 1 to 4 have both improved discharge capacities at 2C as compared with the comparative examples.

  When Examples 1 to 4 are compared with each other, the discharge capacity ratio of Examples 2 to 4 to which ultrasonic vibration is applied is higher than that of Example 1. In particular, Example 4 in which ultrasonic vibration was performed while heating at a high temperature showed the highest discharge capacity ratio.

  From these results, it can be seen that the gas generated by the ultrasonic vibration is easily carried to the fine groove and released. It can be seen that the movement of the gas in the electrolyte is easier particularly at high temperatures.

  In addition, when comparing Examples 2 and 3, it is found that applying ultrasonic vibration when degassing increases gas discharge and the discharge capacity ratio is higher than applying ultrasonic vibration before degassing. I understand.

  From the above, it can be seen that by oscillating and heating the polymer battery at the time of degassing, the battery characteristics can be improved most than before. Next, it is preferable to vibrate at the time of degassing, and it is preferable to vibrate immediately before degassing. However, it can be seen that the battery characteristics can be significantly improved as compared with the prior art because the fine grooves are formed without applying vibration and heating.

  In the above embodiment, at least one of the negative electrode active material layer 48 and the electrolyte layer 50 is formed with a fine groove that communicates with the outside on the contact surface where the negative electrode active material layer 48 and the electrolyte layer 50 are in contact with each other. Shows the case. However, it is not limited to this. A fine groove communicating to the outside may also be provided on the contact surface of the positive electrode active material layer 43 and the electrolyte layer 50. In this case, the gas generated on the positive electrode side can also be guided to the outside of the battery element. It is possible to more surely prevent a decrease in battery performance due to gas generation.

(Second Embodiment)
In 2nd Embodiment, the polymer battery 10 of the said 1st Embodiment is connected in parallel and / or in series, and an assembled battery is comprised.

  FIG. 11 is a perspective view of an assembled battery according to the second embodiment.

  As shown in FIG. 11, the assembled battery 100 is formed by connecting a plurality of polymer batteries 10 according to the first embodiment described above. Between the batteries, the electrodes 21 and 22 of each battery are connected by a conductive bar. In this assembled battery 100, electrode terminals 101 and 102 are provided on one side as electrodes.

  In this assembled battery 100, ultrasonic welding, heat welding, laser welding, rivets, caulking, electron beam, or the like can be used as a connection method when a plurality of batteries 10 are connected. By adopting such a connection method, the assembled battery 100 having long-term reliability can be manufactured.

  According to the assembled battery 100, it is possible to obtain high capacity and high output by using the polymer battery 10 according to the first to fourth embodiments described above, and to obtain the reliability of each battery. Therefore, long-term reliability as an assembled battery can be improved.

  In addition, the connection of the polymer battery 10 as an assembled battery may be all connected in parallel, or all the polymer batteries 10 may be connected in series. May be combined.

(Third embodiment)
In the third embodiment, the vehicle is configured by mounting the polymer battery 10 of the first embodiment or the assembled battery 100 of the second embodiment as a driving power source. A vehicle using the polymer battery 10 or the assembled battery as a power source for a motor is an automobile in which wheels are driven by a motor, such as an electric vehicle and a hybrid vehicle.

  For reference, FIG. 12 shows a schematic diagram of an automobile 110 on which the assembled battery 100 is mounted. The assembled battery 100 mounted on the automobile has the characteristics described above. For this reason, an automobile equipped with the assembled battery 100 has high durability and can provide sufficient output even after being used for a long period of time.

It is a figure which shows the polymer battery of this invention. FIG. 3 is a sectional view taken along line 3-3 in FIG. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. It is a figure which shows a mode that a battery element is laminated | stacked. It is a perspective view of a polymer battery. It is a figure which shows a mode that a polymer battery is charged for the first time. It is a figure which shows a mode that the battery element of a bipolar battery is assembled. It is a figure which shows the battery element of a bipolar battery. It is a figure which shows the ratio of the discharge capacity of Examples 1-4 with respect to a comparative example. It is a figure which shows the ratio of the discharge capacity of Examples 1-4 with respect to a comparative example. It is a perspective view of the assembled battery which concerns on 2nd Embodiment. It is the schematic of the motor vehicle carrying an assembled battery.

Explanation of symbols

10 ... polymer battery,
21 ... Positive electrode tab,
22 ... negative electrode tab,
30 ... Exterior,
40 ... Battery element,
41 ... positive electrode,
42 ... positive electrode current collector,
43 ... positive electrode active material layer,
46 ... negative electrode,
47. Negative electrode current collector,
48 ... negative electrode active material layer,
50 ... polymer electrolyte layer,
51 ... Fine groove,
60 ... Excitation table,
70: Bipolar electrode,
71 ... current collector,
100 ... assembled battery,
101, 102 ... electrode terminals,
110: Car.

Claims (8)

The positive electrode active material layer and the negative electrode active material layer are composed of an electrode in which a positive electrode active material layer is electrically connected to a current collector and an electrode in which a negative electrode active material layer is electrically connected to another current collector. A polymer battery comprising a polymer electrolyte layer sandwiched between material layers,
A polymer battery in which at least one of the negative electrode active material layer and the polymer electrolyte layer is formed with a fine groove communicating with the outside on a contact surface where the negative electrode active material layer and the polymer electrolyte layer are in contact with each other. The positive electrode active material layer includes a composite oxide of lithium and a transition metal,
The polymer battery according to claim 1, wherein the negative electrode active material layer contains a composite oxide of carbon or lithium and a transition metal. The electrode is a bipolar electrode in which the positive electrode active material layer is provided on one surface of a current collector and the negative electrode active material layer is provided on the other surface,
The polymer battery according to claim 1 or 2, wherein the solid electrolyte layer is sandwiched between the bipolar electrodes.   At least one of the positive electrode active material layer and the polymer electrolyte layer is formed with a fine groove communicating to the outside on a contact surface where the positive electrode active material layer and the polymer electrolyte layer are in contact with each other. 4. The polymer battery according to any one of 3. Forming a positive electrode active material layer on one current collector to constitute an electrode; and
Forming a negative electrode active material layer on another current collector to form an electrode;
Preparing a polymer electrolyte layer;
Forming a fine groove in at least one of the negative electrode active material layer and the polymer electrolyte layer, which is communicated to the outside of the contact surface when contacted later;
Laminating the electrode and the polymer electrolyte so as to sandwich the polymer electrolyte layer between the positive electrode active material layer and the negative electrode active material layer;
The manufacturing method of the polymer battery which has this.   6. The method for producing a polymer battery according to claim 5, further comprising a step of ultrasonically exciting the laminate after the step of laminating the electrode and the polymer electrolyte, at the time of initial charge or immediately after the initial charge.   The method for producing a polymer battery according to claim 6, wherein the laminate is heated at the same time in the ultrasonic vibration step.   8. The method according to claim 5, further comprising a step of forming a fine groove in at least one of the positive electrode active material layer and the polymer electrolyte layer, which is communicated to the outside of the contact surface when contacted later. The manufacturing method of the polymer battery of description.

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