JP2000106154A - Whole solid battery and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To do away with swellings, etc., of a battery case when sealing the battery, and to prevent battery characteristics from spoiling, by impressing pressure on a battery elements within a outer package body, and by closely adhering the battery element with the outer package body. SOLUTION: A whole solid battery element 6 is loaded in a resin sealing mold 7 previously set at the resin curing temperature, and a thermosetting resin 9 softened in a resin-melting part 8 heated at the resin-softening temperature is injected from a cavity 10, then it is pressurized by a pressurizing punch 11 of an upper mold of the resin-sealing mold 7, thus the thermosetting resin is cured with the pressure being kept. The impressed pressure in this time is set at 50-10,000 kgf/cm2. When the whole solid battery element 6 is sealed with the thermosetting resin, it is once sealed at low-pressure, then the temperature is raised to the resin-softening temperature, thereafter the pressure of 50-10,000 kgf/cm2 is again impressed at the temperature, to cool and cure. Thus, joining of the interface between the electrodes and the solid electrolyte can be maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an all-solid-state battery and a method for manufacturing the same.

[0002]

2. Description of the Related Art In a conventional all-solid-state battery, a battery element composed of three layers of a positive electrode, a solid electrolyte, and a negative electrode formed in accordance with the height inside a battery case is arranged in a metal battery case. In some cases, coin-type batteries have been reported.

[0003] However, the sealing by "caulking" is performed when the periphery of the battery case is caulked because the sealing plate or the battery case is made of metal, and the caulking is performed by press working and has a "bent" portion. Stress concentrates on the "bent" portion, and swelling is likely to occur at the center of the battery case or the sealing plate. In particular, in the case of an all-solid battery, the materials constituting the battery element are all solid, and there is no cushioning material to relieve the pressure applied to the element such as a resin separator used in a conventional liquid battery. The battery case is likely to swell. This swelling of the battery creates a gap between the battery element and the battery case or sealing plate which also serves as a current collector plate, which lowers the current collection performance and increases the internal resistance, resulting in lower battery characteristics. Many electrode materials used in lithium secondary batteries such as lithium cobaltate, lithium nickelate, iron disulfide, titanium disulfide, graphite, indium, aluminum, and lithium-aluminum alloy repeat expansion and contraction during charge and discharge. It is known. All-solid-state batteries using these electrode materials, due to the change in volume, the junction of the electrode-solid electrolyte interface in the battery element is damaged,
Due to poor contact, battery characteristics, particularly charge / discharge cycle characteristics, are significantly reduced.

[0004] An all-solid-state battery sealed with a high-temperature curing type resin is described in Japanese Patent Application Laid-Open No. 6-275247. However, when the resin is simply sealed with a resin, the resin shrinks in volume when cured, regardless of whether the resin used is a thermosetting resin or a thermoplastic resin. Therefore, a gap is generated between the battery element and the resin, the electrodes expand and contract when the battery is charged and discharged, and a bonding failure occurs at the interface between the particles,
This leads to deterioration of cycle characteristics.

[0005]

SUMMARY OF THE INVENTION From the above prior art,
There is a need to develop a manufacturing method that does not impair the battery characteristics even if the battery case swells when closing the battery or the electrodes expand and contract during charging and discharging.

According to the present invention, when the battery is sealed, the battery case does not swell, the junction between the electrode and the solid electrolyte in the all-solid-state battery element, and the adhesion between the all-solid-state battery element and the outer package are maintained. It is an object to provide an intact battery.

[0007]

Means for Solving the Problems In order to solve the above problems, an all solid state battery of the present invention comprises an all solid state battery element in which a solid electrolyte is interposed between a positive electrode and a negative electrode, which is covered with an outer package. Pressure is applied to the all-solid-state battery element inside the outer body, and the all-solid-state battery element and the outer body are in close contact with each other. Further, the all-solid-state battery element is thermoset resin or thermoplastic. When sealing with a resin, the resin is cured in a pressurized state so that no gap is formed between the all-solid-state battery element and the current collector plate during assembly. Further, when the all-solid-state battery element attempts to expand and contract due to charge and discharge, the force can be suppressed by the resin, and thus the all-solid-state battery element can be put in a pressurized state.

As a result, an all-solid-state battery having excellent battery characteristics without lowering the current collecting property can be obtained.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The all-solid-state battery of the present invention is an all-solid-state battery in which an all-solid-state battery element having a solid electrolyte interposed between a positive electrode and a negative electrode is covered with an outer package. Pressure is applied to the solid-state battery element, and the solid-state battery element is characterized by being in intimate contact with the exterior body.There is no swelling when sealing the battery, and the electrode is not charged or discharged during charging and discharging. Pressing the all-solid-state battery element with the force generated by expansion,
Battery characteristics are not impaired by maintaining the bonding between the electrode and the solid electrolyte interface and the adhesion between the all-solid battery element and the package in the all-solid battery element.

[0010] The pressure applied to the all solid state battery element is 50k.
When the pressure is less than gf / cm ² , the effect of pressurization is not observed.
In the case of 000 kgf / cm ² or more, cracks occur in the all solid state battery element and the battery performance is reduced.
Pressurization of gf / cm ² is preferred.

It is preferable to use either a thermosetting resin or a thermoplastic resin for the outer package. Since a metal battery case and a sealing plate are not used, there is no swelling at the time of closing the battery and all solids are used. Adhesion between the battery element and the package is maintained, and the battery characteristics are not impaired. Further, since the all-solid-state battery element is pressurized again in the fluid of the molten resin, the bonding interface is further strengthened. This pressurization is different from the uniaxial press, which is usually used when forming a battery element, and is a so-called hydrostatic pressure press. By reshaping the entire battery element with a uniform pressure, the packing density inside the battery element is further increased. Also, there is a preferable effect that the bonding between particles and the bonding interface between the electrode and the electrolyte layer can be made stronger.

When a resin is used as the outer package, the current collecting performance of the battery is improved by providing a metal current collector plate on at least one of the positive electrode and the negative electrode, the surface not facing the solid electrolyte layer.

As the thermosetting resin, any one of epoxy resin, phenol resin, urea resin, melamine resin, unsaturated polyester resin and polyimide resin can be used. Table 1 shows the physical properties of these resins.

[0014]

[Table 1]

From the above thermosetting resins, those having more preferable physical properties can be selected depending on the use of the all solid state battery. For example, when mounting an all-solid-state battery on a printed wiring board, heat resistance is required because the battery passes through a solder reflow bath like an IC or a capacitor. From the physical properties of various resins shown in Table 1, in applications where heat resistance is required,
As the thermosetting resin, an epoxy resin, a phenol resin, or a polyimide resin is preferable. Also, epoxy resin,
Since phenolic resin is also excellent in terms of compressive strength, the effect of pressurizing the battery element with the force generated by the expansion of the electrode accompanying the charging and discharging of the battery is large, and it can be said that it is a more preferable resin.

Further, in the case where a water-phobic material is used for a battery element, such as an all solid battery using a Li ₃ PO ₄ —Li ₂ S—SiS ₂ based lithium ion conductive solid electrolyte, The moisture permeating through the case may greatly impair the reliability of the battery, such as its storability. Therefore, a resin having a low water absorption is preferable, and an epoxy resin is preferably used.

When a mixture of these thermosetting resins and a filler is used, the mechanical strength is further increased, and more preferable results are obtained. Examples of the filler include carbon fiber, metal fiber, and glass fiber. In the case where the filler is used as an outer package of a battery, glass fiber is particularly preferably used since short-circuiting between the positive electrode and the negative electrode occurs when the battery has electrical conductivity.

As the thermoplastic resin, any of polyphenylene sulfide resin, liquid crystal polyester resin, polyethylene resin, polypropylene resin, polyamide resin, polyacetal resin and polyethylene terephthalate resin can be used. Table 2 shows the physical properties of these resins.

[0019]

[Table 2]

From the above-mentioned thermoplastic resins, those having more preferable physical properties can be selected depending on the use of the all-solid-state battery. For example, when mounting an all-solid-state battery on a printed wiring board, heat resistance is required because the battery passes through a solder reflow bath like an IC or a capacitor. From the physical properties of the various resins shown in Table 2, in applications where heat resistance is required,
As the thermoplastic resin, a polyphenylene sulfide resin, a liquid crystal polyester resin, or a polyethylene terephthalate resin is preferable. In addition, since polyphenylene sulfide resin and liquid crystal polyester resin are also excellent in terms of compressive strength, the effect of pressing the battery element with the force generated by the expansion of the electrode accompanying the charging and discharging of the battery is large, and it is a more preferable resin. I can say.

Further, in the case where a water-phobic material is used for a battery element, such as an all-solid battery using a Li ₃ PO ₄ —Li ₂ S—SiS ₂ -based lithium ion conductive solid electrolyte, The moisture permeating through the case may greatly impair the reliability of the battery, such as its storability. Therefore, a resin having a low water absorption is preferable, and a polyphenylene sulfide resin and a liquid crystal polyester resin are used.

The use of a mixture of these thermoplastic resins with a filler further increases the mechanical strength, and provides more favorable results. Examples of the filler include carbon fiber, metal fiber, and glass fiber. In the case where the filler is used as an outer package of a battery, glass fiber is particularly preferably used since short-circuiting between the positive electrode and the negative electrode occurs when the battery has electrical conductivity.

Further, as a method of manufacturing an all solid state battery of the present invention, an all solid state battery element having a solid electrolyte interposed between a positive electrode and a negative electrode is sandwiched between two metal plates as electrode terminals.
This is a method of sealing the periphery with a thermosetting resin or a thermoplastic resin while applying a pressure of 50 to 10000 kgf / cm ^{2 to} the metal plate. According to this manufacturing method, unlike a sealing plate or a battery case used for a conventional coin-type battery, since a metal plate is not pressed, there is no “bent” portion of the metal, and the stress is reduced. Concentration is less likely to occur. Therefore, the case is unlikely to swell due to the elasticity of the metal at the time of sealing. In addition, the battery element is pressurized by a force generated by the expansion of the electrode, the junction at the electrode-solid electrolyte interface in the battery element is maintained, and the battery characteristics are not impaired. Furthermore, since the all-solid-state battery element is pressurized again in the fluid of the molten resin, the bonding interface becomes strong. This pressurization is different from the uniaxial press, which is usually used when forming a battery element, and is a so-called hydrostatic pressure press. By reshaping the entire battery element with a uniform pressure, the packing density inside the battery element is further increased. Also, there is a preferable effect that the bonding between particles and the bonding interface between the electrode and the electrolyte layer can be made stronger.

Further, as another method of manufacturing the all solid state battery of the present invention, an all solid state battery element having a solid electrolyte interposed between a positive electrode and a negative electrode is embedded in a thermosetting resin in a molten state in an amount of 50 to 50%. A method in which thermosetting is performed while applying a pressure of 10,000 kgf / cm ² , a method in which an all solid state battery element is sealed with a thermoplastic resin in a molten state, then cooled and cured, and then heated again to a resin softening temperature. 50 ~ 10000kgf again
There is a method of cooling and curing while applying a pressure of / cm ² .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view of an all-solid-state battery element according to the present embodiment. As shown in FIG. 1, a pre-formed positive electrode mixture layer 2 is attached to one surface of a solid electrolyte layer 1 obtained by pre-forming a solid electrolyte powder, and a pre-formed negative electrode mixture layer 3 is attached to the opposite surface. It is configured by pressing.
Further, the current collector plates 4 and 5 with leads are attached to the positive electrode side and the negative electrode side, and the all-solid-state battery element 6 is obtained.

The all-solid-state battery element 6 manufactured as described above
Is resin-encapsulated using a resin-sealing mold shown in FIG.
The all-solid-state battery element 6 is loaded into a resin sealing mold 7 set at a resin curing temperature in advance, and a thermosetting resin 9 heated to a resin softening temperature and softened at a resin melting portion 8 is injected from a cavity 10. Then, pressure is applied by the upper pressing punch 11 of the resin sealing mold, and the thermosetting resin is cured while maintaining this pressure. The applied pressure at this time is 50 to 10000k
gf / cm ² . FIG. 3 shows a cross-sectional view of the all-solid-state battery manufactured in this manner. The all-solid-state battery element 6 is sealed with a sealing resin 12.

When all solid-state battery elements are sealed with a thermoplastic resin, they are once sealed at a low pressure, then heated to a resin softening temperature, and then heated again at a temperature of 50 to 10,000 kgf.
Cooling / curing while applying a pressure of / cm ² .

(Embodiment 2) An all-solid-state battery element is manufactured in the same manner as in Embodiment 1.

The all-solid-state battery element manufactured as described above is loaded into a resin sealing mold set at a resin melting temperature in advance, and the thermoplastic resin is heated to the resin softening temperature and softened at the resin melting portion. Is injected from the cavity and pressurized by a pressurizing punch of the upper die of the sealing die, and while maintaining this pressure, the die temperature is lowered to room temperature to cure the thermoplastic resin. The applied pressure at this time is 50 to 10000 kgf
/ Cm ² . In the all-solid-state battery manufactured as described above, the all-solid-state battery element is sealed with a sealing resin.

As another method for sealing the all-solid-state battery element with a thermoplastic resin, the element is once sealed at a low pressure, then heated to a resin softening temperature, and then heated again at a temperature of 50 to 10,000.
It is also possible to cool and harden while applying a pressure of kgf / cm ² .

(Embodiment 3) The all-solid-state battery element 13 includes:
On one side of the solid electrolyte layer preformed from the solid electrolyte powder,
The pre-formed positive electrode mixture layer is combined with the pre-formed negative electrode mixture layer on the opposite surface, and pressed against each other. Further, the positive electrode mixture layer side and the negative electrode mixture layer side are sandwiched between two metal plates, and are sealed with a resin using a resin sealing mold shown in FIG. The all-solid-state battery element 13 is loaded into a resin-sealing mold 14 set at a resin curing temperature in advance, and the metal plate is pressed with the upper pressing die 18 of the resin-sealing mold to 50 to 100.
While applying a pressure of 00 kgf / cm ^2, a thermosetting resin 16 heated to a resin softening temperature and softened in a resin melting portion 15 is injected from a cavity 17, and the periphery is sealed with the thermosetting resin. FIG. 5 shows a cross-sectional view of the all-solid-state battery manufactured in this manner. All-solid-state battery element 13 is sealing resin 1
9 is sealed.

As the solid electrolyte, Li ₂ S—SiS ₂ , Li ₂ S—B ₂ S ₃ , L _{2
i 2 PO 4 -Li 2 S-} SiS 2, LiI-Li 2 S-Si
S ₂ , LiI-Li ₂ SP ₂ S ₅ , Li _3.6 Si _0.6 P _{0.4
O 4, Li 3.4 V 0.6 Si} 0.4 O 4, LiI-Li 3 PO 4 -
Silver ion conductors such as P ₂ S ₆ and Li _3.3 PO _3.8 N _0.22 such as Ag ₆ I ₄ WO ₄ and RbAg ₄ I ₆ , and copper ion conductors such as RbCu ₄ I _1.6 Cl _3.6 and RbCu ₁₆ I ₇ Cl ₁₃
And the like can be used. In the present invention, the solid electrolyte is not particularly limited, and it is clear that a similar effect can be obtained with any solid electrolyte.

As an electrode material, for a lithium battery, iron disulfide (Li _x FeS ₂ ), titanium disulfide (Li _x TiS ₂ ), and molybdenum disulfide (Li _x ) are used as metal sulfides.
MoS ₂ ), metal oxides include tungsten oxide (Li _x WO ₃ ), molybdenum dioxide (Li _x MoO ₂ ),
Molybdenum trioxide (Li _x MoO ₃ ), vanadium pentoxide (Li _x V ₂ O ₅ ), vanadium oxide (Li _x V ₆ O ₁₃ ),
Lithium cobaltate (Li _x CoO ₂ ), lithium nickelate (Li _x NiO ₂ ), lithium manganate (LixM
n ₂ O 4), lithium titanate (Li _x Ti ₂ O 4), a low melting point metal such as indium, aluminum, tin, antimony or the like or an alloy containing them as a metal electrode, and graphite as a carbon-based material Can be
Two of these can be arbitrarily selected, and a compound having a noble equilibrium potential can be used as a positive electrode and a noble compound can be used as a negative electrode. For silver batteries, Ag, Ag _x V ₂ O ₅
Cu, Cu ₂ S, Cu _x TiS ₂ , Cu _x
Mo ₆ S ₈ or the like can be used.

In the present invention, the electrode material is not particularly limited, and it is clear that the same effect can be obtained with any of the electrode materials. In particular, as in the case where an intermetallic compound or an interlayer compound is used, the same effect can be obtained. When a material whose volume changes significantly due to expansion and contraction during charging and discharging of the battery is used as the electrode, the effect is extremely large.

[0036]

Next, a specific example of the present invention will be described with reference to the drawings.

Example 1 Li ₃ PO ₄ as a solid electrolyte
Using -Li ₂ S-SiS ₂ type glass-like solid electrolyte was produced all-solid-state battery of the present invention. The positive electrode mixture, lithium cobaltate (LiC _{O O 2)} and the solid electrolyte at a weight ratio of 3:
2 and prepared by mixing. The negative electrode mixture was prepared by mixing an indium-lithium alloy (In-Li) powder and the solid electrolyte at a weight ratio of 7: 3. Using a powder molding die of these electrode mixtures, three layers of a positive electrode layer, a solid electrolyte layer, and a negative electrode layer were integrally formed to produce an all-solid-state battery element having a diameter of 10 mm. A current collector with a lead was attached to the positive electrode side and the negative electrode side.

The all-solid-state battery element thus manufactured is previously loaded into a resin sealing mold at a mold temperature of 170 ° C., and a thermosetting epoxy resin softened at 180 ° C. in a resin melting portion. Is injected from the cavity, and the upper pressurizing punch of the sealing mold is pressurized at 500 kgf / cm ² ,
While maintaining the pressure, the mold temperature was raised to 185 ° C., and the thermosetting epoxy resin was cured and sealed to form an all-solid battery.

The configured all-solid-state battery was charged and discharged with a current of 150 μm.
A, A charge / discharge cycle test was performed in a voltage range of 2.0 to 3.6 V.

The pressure during molding is 0 to 12000 kgf / c.
An all-solid-state battery was manufactured in the same manner as described above except that the range was changed within the range of m ² , and the same charge / discharge cycle test was performed.
The results are shown in FIG. 6 as a ratio of the actual discharge capacity to the design capacity. From this figure, it can be seen that the pressure range during molding is 50 to
It was found that good cycle characteristics were obtained when the pressure was 10,000 kgf / cm ² .

When the all-solid-state battery was disassembled for 12,000 kgf / cm ² , cracks occurred in the all-solid-state battery element inside, and it is considered that the battery performance deteriorated due to the cracks. This crack is due to the all-solid-state battery element being crushed due to too high pressure during resin molding.

An all solid state battery was manufactured in the same manner as described above except that 40 wt% of glass fiber was mixed as a filler with a thermosetting epoxy resin.
A similar charge / discharge cycle test was performed. As a result, as shown in the figure, characteristics superior to those containing no filler were obtained.

Example 2 Li ₃ PO ₄ as a solid electrolyte
Using -Li ₂ S-SiS ₂ type glass-like solid electrolyte was produced all-solid-state battery of the present invention. The positive electrode mixture was prepared by mixing lithium nickelate (LiNiO ₂ ) and the solid electrolyte at a weight ratio of 3: 2. The negative electrode mixture was prepared by mixing iron disulfide (FeS ₂ ) and the solid electrolyte at a weight ratio of 5: 5. Using a powder molding die of these electrode mixtures, a positive electrode layer, a solid electrolyte layer, and a three-layered negative electrode layer were integrally molded to produce an all-solid-state battery element having a diameter of 10 mm.
A current collector with leads was attached to the positive electrode side and the negative electrode side of the all solid state battery element.

The all-solid-state battery element thus manufactured is previously loaded into a resin sealing mold at a mold temperature of 260 ° C., and the thermoplastic polyphenylene sulfide resin softened at 300 ° C. in the resin melting portion. Is injected from the cavity, and the pressurizing punch of the upper die of the sealing die is set to 500 kgf /
pressurized with cm ^2, a mold temperature while maintaining the pressure is lowered to room temperature, sealed to cure the thermoplastic polyphenylene sulfide resin, and constitute an all-solid battery.

A charge / discharge current of 150 .mu.
A, A charge / discharge cycle test was performed in a voltage range of 0.5 to 3.2 V.

The pressure during molding is 0 to 12000 kgf / c
An all-solid-state battery was manufactured in the same manner as described above except that the range was changed within the range of m ² , and the same charge / discharge cycle test was performed.
The results are shown in FIG. 7 as the ratio of the actual discharge capacity to the design capacity. From this figure, it can be seen that the pressure range during molding is 50 to
It was found that good cycle characteristics were obtained when the pressure was 10,000 kgf / cm ² .

When the all-solid-state battery was disassembled for 12000 kgf / cm ² , cracks occurred in the all-solid-state battery element inside, and it is considered that the battery performance deteriorated due to the cracks. This crack is considered to be caused by the all-solid-state battery element being crushed because the pressure during resin molding was too high.

An all-solid-state battery was manufactured in the same manner as described above, except that a mixture obtained by mixing 40 wt% of glass fiber as a filler with a thermoplastic polyphenylene sulfide resin was used, and a similar charge / discharge cycle test was performed. . As a result, as shown in the figure, characteristics superior to those containing no filler were obtained.

Example 3 Li ₃ PO ₄ as a solid electrolyte
Using -Li ₂ S-SiS ₂ type glass-like solid electrolyte was produced all-solid-state battery of the present invention. The positive electrode mixture, lithium cobaltate (LiC _{O O 2)} and the solid electrolyte at a weight ratio of 3:
2 and prepared by mixing. The negative electrode mixture was prepared by mixing titanium disulfide (TiS ₂ ) and the solid electrolyte at a weight ratio of 7: 3. Using a powder molding die of these electrode mixtures, three layers of a positive electrode layer, a solid electrolyte layer, and a negative electrode layer were integrally formed to produce an all-solid-state battery element having a diameter of 10 mm. A current collector with a lead was attached to the positive electrode side and the negative electrode side.

The all-solid-state battery element manufactured in this manner was used as a thermosetting resin such as epoxy resin, filler-containing (40 wt%) epoxy resin, phenol resin, urea resin, melamine resin, unsaturated polyester resin, and polyimide resin. A thermosetting resin was used, using a polyphenylene sulfide resin as a thermoplastic resin, a polyphenylene sulfide resin containing filler (40 wt%), a liquid crystal polyester, a polyamide resin, a polyacetal resin, a polyethylene terephthalate resin, a polyethylene resin, a polypropylene resin, and a polycarbonate resin. The molding pressure was 500 kgf by the same method as in Example 1 and the method using thermoplastic resin by the same method as in Example 2.
/ Cm ² and the resin was cured and sealed to form an all-solid battery.

A charge / discharge current of 150 .mu.
A. The battery was discharged to 0.5 V, the discharge capacity before storage was measured, then charged to 1.7 V, and stored for 3 months in a high-temperature, high-humidity environment of 85 ° C. and 90% RH. After the end of the storage period, the all solid state battery was discharged to a discharge current of 150 μA and 0.5 V, and the capacity retention ratio with respect to the discharge capacity before storage was examined.
It was shown to.

As a result, it was found that a resin having a lower water absorption exhibited a higher capacity retention rate after storage at high temperature and high humidity, and that a highly reliable all solid state battery was obtained according to the present invention.

[0053]

[Table 3]

Example 4 Li ₃ PO ₄ as a solid electrolyte
Using -Li ₂ S-SiS ₂ type glass-like solid electrolyte was produced all-solid-state battery of the present invention. The positive electrode mixture, lithium cobaltate (LiC _{O O 2)} and the solid electrolyte at a weight ratio of 3:
2 and prepared by mixing. The negative electrode mixture was prepared by mixing lithium titanate (LiTi ₂ O ₄ ) and the solid electrolyte at a weight ratio of 7: 3. Using a powder molding die of these electrode mixtures, three layers of a positive electrode layer, a solid electrolyte layer, and a negative electrode layer were integrally formed to produce an all-solid-state battery element having a diameter of 10 mm. A current collector with a lead was attached to the positive electrode side and the negative electrode side.

The all-solid-state battery element thus prepared was used as a thermosetting resin such as epoxy resin, filler-containing (40 wt%) epoxy resin, phenol resin, urea resin, melamine resin, unsaturated polyester resin, and polyimide resin. A thermosetting resin was used, using a polyphenylene sulfide resin as a thermoplastic resin, a polyphenylene sulfide resin containing filler (40 wt%), a liquid crystal polyester, a polyamide resin, a polyacetal resin, a polyethylene terephthalate resin, a polyethylene resin, a polypropylene resin, and a polycarbonate resin. The molding pressure was 500 kgf by the same method as in Example 1 and the method using thermoplastic resin by the same method as in Example 2.
/ Cm ² and the resin was cured and sealed to form an all-solid battery.

A charge / discharge current of 150 .mu.
A. Discharge was performed to 0.5 V, and the discharge capacity before reflow was measured. Then, the battery was charged to 3.0 V and passed through a solder reflow bath at 260 ° C. for 3 minutes. After solder reflow, the all solid state battery was discharged to 0.5 V at a discharge current of 150 μA,
The capacity retention ratio with respect to the discharge capacity before solder reflow was examined, and the results are shown in Table 4.

As a result, it was found that a resin having a higher heat distortion temperature shows a higher capacity retention ratio, and that the present invention provides a highly reliable all-solid-state battery capable of solder reflow.

[0058]

[Table 4]

Example 5 Li ₃ PO ₄ as a solid electrolyte
Using -Li ₂ S-SiS ₂ type glass-like solid electrolyte was produced all-solid-state battery of the present invention. The positive electrode mixture, lithium cobaltate (LiC _{O O 2)} and the solid electrolyte at a weight ratio of 3:
2 and prepared by mixing. The negative electrode mixture was prepared by mixing lithium titanate (LiTi ₂ O ₄ ) and the solid electrolyte at a weight ratio of 7: 3. The three layers of the positive electrode layer, the solid electrolyte layer, and the negative electrode layer were integrally molded using the electrode mixture by using a powder molding die, thereby producing an all-solid-state battery element having a diameter of 10 mm.

The positive electrode layer and the negative electrode layer of the all-solid-state battery element thus manufactured were 0.15 mm thick and 13 mm in diameter.
500kgf / c between stainless steel discs
While pressurizing at m ² , the surroundings were sealed with a thermosetting epoxy resin to produce an all-solid battery. Further, the all-solid-state battery was manufactured by sealing the periphery with a thermoplastic polyphenylene sulfide resin instead of a thermosetting epoxy resin.

The thus obtained all solid state battery was subjected to a charge / discharge cycle test at a charge / discharge current of 100 μA and a voltage range of 0.5 to 3.0 V.

The pressure during molding is 0 to 12000 kgf / c
An all-solid-state battery was manufactured in the same manner as described above except that the range was changed within the range of m ² , and the same charge / discharge cycle test was performed.
The results are shown in FIG. 8 as the ratio of the actual discharge capacity to the design capacity. From this figure, it can be seen that the pressure range during molding is 50 to
It was found that good cycle characteristics were obtained when the pressure was 10,000 kgf / cm ² .

When the all-solid-state battery was disassembled for 12000 kgf / cm ² , it was considered that cracks occurred in the all-solid-state battery element inside, and that the battery performance was lowered. This crack is due to the all-solid-state battery element being crushed due to too high pressure during resin molding.

Further, with respect to the all-solid-state battery molded at 500 kgf / cm ² , a high-temperature high-humidity storage test and a test of solder reflow characteristics were performed in the same manner as in Examples 3 and 4.

As a result, no deterioration in battery characteristics was observed even after storage at high temperature and high humidity and after solder reflow, and it was found that an all-solid battery having high reliability was obtained according to the present invention.

[0066]

[Table 5]

[0067]

As described above, according to the present invention, since the metal battery case and the sealing plate are not used, there is no swelling or deformation at the time of closing the battery, and the force generated by the expansion of the electrode is not. The battery element is pressurized and the electrodes of the battery element
An advantageous effect is obtained in that the bonding at the solid electrolyte interface is maintained and the battery characteristics are not impaired.

[Brief description of the drawings]

FIG. 1 is a structural sectional view of an all-solid-state battery element according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a resin sealing mold according to an embodiment of the present invention.

FIG. 3 is a structural sectional view of an all-solid-state battery according to an embodiment of the present invention.

FIG. 4 is a schematic sectional view of a resin sealing mold according to an embodiment of the present invention.

FIG. 5 is a structural sectional view of an all solid state battery according to one embodiment of the present invention.

FIG. 6 is a diagram showing charge / discharge cycle characteristics of an all-solid-state battery according to one embodiment of the present invention.

FIG. 7 is a diagram showing charge / discharge cycle characteristics of an all-solid-state battery according to one embodiment of the present invention.

FIG. 8 is a diagram showing charge / discharge cycle characteristics of an all-solid-state battery according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solid electrolyte layer 2 Positive electrode mixture layer 3 Negative electrode mixture layer 4 Current collecting plate with lead 5 Current collecting plate with lead 6 All solid-state battery element 7 Resin sealing mold 8 Resin fusion part 9 Resin 10 Cavity 11 Punch for pressurization REFERENCE SIGNS LIST 12 sealing resin 13 all solid-state battery element 14 resin sealing mold 15 resin melting portion 16 thermosetting resin 17 cavity 18 pressurizing punch 19 sealing resin

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shigeo Kondo 1006 Kazuma Kadoma, Kazuma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. 5H011 AA01 AA04 CC02 CC05 CC09 CC12 DD02 DD12 KK04 5H029 AJ01 AJ11 AK02 AK03 AK05 AK11 AL02 AL03 AL04 AL11 AM11 AM12 AM13 CJ02 CJ03 CJ06 CJ08 CJ28 DJ02 DJ05 EJ06 EJ12 HJ14 HJ15

Claims (11)

[Claims] An all-solid-state battery in which an all-solid-state battery element having a solid electrolyte interposed between a positive electrode and a negative electrode is covered with an exterior body, wherein pressure is applied to the all-solid-state battery element inside the exterior body. An all-solid-state battery in which the all-solid-state battery element and the outer package are in close contact. 2. An applied pressure of 50 to 10,000 kgf
² / cm ² . 3. The all-solid-state battery according to claim 1, wherein the exterior body is made of one of a thermosetting resin and a thermoplastic resin. 4. The thermosetting resin according to claim 3, wherein the thermosetting resin is any one of an epoxy resin, a phenol resin, a urea resin, a melamine resin, an unsaturated polyester resin and a polyimide resin, or a resin obtained by mixing a filler with these resins. All solid state battery. 5. The thermoplastic resin is any one of a polyphenylene sulfide resin, a liquid crystal polyester resin, a polyethylene resin or a polypropylene resin, a polyamide resin, a polyacetal resin, and a polyethylene terephthalate resin.
4. The all-solid-state battery according to claim 3, which is a resin obtained by mixing a filler with these resins. 6. The all-solid-state battery according to claim 3, wherein a metal current collector is provided on at least one of the positive electrode and the negative electrode of the all-solid-state battery element, the surface not facing the solid electrolyte layer. 7. An all-solid-state battery element having a solid electrolyte interposed between a positive electrode and a negative electrode is sandwiched between two metal plates as electrode terminals, and a pressure of 50 to 10,000 kgf / cm ² is applied to the metal plate. A method for manufacturing an all-solid battery, wherein the periphery is sealed with a thermosetting resin or a thermoplastic resin. 8. A thermosetting resin in a molten state in which an all-solid-state battery element having a solid electrolyte interposed between a positive electrode and a negative electrode is thermally cured while applying a pressure of 50 to 10,000 kgf / cm ^2. A method for producing an all-solid-state battery, comprising: 9. An all-solid-state battery element having a solid electrolyte interposed between a positive electrode and a negative electrode is sealed with a molten thermoplastic resin, cooled and hardened, and heated again to a resin softening temperature. A method for producing an all-solid-state battery, wherein the battery is cooled and cured while applying a pressure of 50 to 10,000 kgf / cm ² again at the temperature. 10. The thermosetting resin is an epoxy resin, a phenol resin, a urea resin, a melamine resin, an unsaturated polyester resin or a polyimide resin, or a resin obtained by mixing a filler with these resins. 3. The method for producing an all-solid-state battery according to item 1. 11. The thermoplastic resin is any one of a polyphenylene sulfide resin, a liquid crystal polyester resin, a polyethylene resin, a polypropylene resin, a polyamide resin, a polyacetal resin, and a polyethylene terephthalate resin, or a resin obtained by mixing a filler with these resins. 10. The method for producing an all-solid-state battery according to 7 or 9.