JP4192486B2 - Battery pack - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery pack in which a battery and / or an electric circuit is housed and sealed in a case.
[0002]
[Prior art]
As an electronic device, for example, a battery pack (also referred to as a battery package) for supplying power and a device for supplying power for operating the device from the battery pack, for example, a portable so-called notebook Type personal computers (hereinafter referred to as notebook personal computers for short), information terminals, video tape recorders, recorders, mobile phones and the like.
[0003]
Many of the battery packs used in these electronic devices are equipped with a secondary battery that can be repeatedly charged and discharged, and as the secondary battery, a so-called lithium ion secondary battery having a high volumetric energy density is used. Is often used.
[0004]
However, a lithium ion secondary battery has a narrow tolerance for overcharge and overdischarge. Therefore, a battery pack usually includes a battery such as a control circuit for preventing overdischarge and overcharge of the lithium ion secondary battery. A circuit is attached.
[0005]
[Problems to be solved by the invention]
However, in such a battery pack, if a leakage of the electrolyte from the secondary battery occurs, the electrolyte immerses the battery circuit or leaks outside the pack, and the battery circuit or the external There is a problem of adversely affecting electronic devices.
[0006]
On the other hand, a method of separating the secondary battery and the electric circuit part with a partition made of resin has been proposed (Patent No. 30141493), but a gap is generated in the electrode part, and the electrolytic solution is immersed by a capillary phenomenon. It cannot be prevented. Moreover, in the wall which only isolate | separates a secondary battery and an electric circuit part, there exists a possibility that the electrolyte solution which leaked from the secondary battery may leak out of a case, and may damage an electric equipment. Further, if the partition wall has a double structure, the battery pack will be enlarged.
[0007]
On the other hand, a structure has been proposed in which a resin such as silicon rubber is applied to the surface of a printed wiring board constituting an electric circuit to protect the printed wiring board from an electrolyte leaked from a secondary battery (Japanese Patent No. 3014093). In this structure, the coating film resin on the substrate surface is dissolved by the electrolytic solution, and the protection is destroyed.
[0008]
In addition, there is a method of absorbing the electrolyte solution using a material such as water absorbent paper so that the leaked electrolyte solution is not discharged outside the case, but the electrolyte solution may penetrate the entire water absorbent paper. When an electric circuit including an electrode and a control circuit comes into contact with the surface of the water absorbent paper, the water absorbent paper becomes a substance having electrical performance and cannot be insulated. If it does not have a function of safely holding the leaked electrolyte, the electrolyte may be decomposed by moisture to generate harmful substances. Although it is necessary to waterproof all the electric circuit parts, the apparatus and cost for processing will be required.
[0009]
The present invention has been proposed in view of such a conventional situation, and even if leakage of the electrolyte from the secondary battery occurs, it prevents leaching to the outside of the battery circuit or the pack, and is reliable. An object of the present invention is to provide an excellent battery pack.
[0010]
[Means for Solving the Problems]
The battery pack of the present invention is a battery pack in which one or more batteries and an electric circuit connected to the batteries are surrounded and accommodated by a box-shaped first case and a second case. In one of the first and second cases, a separation wall is formed from the inner bottom surface toward the opening, and the other case has an inner bottom surface at a position corresponding to the separation wall. A separation groove is formed in the portion, and when the first case and the second case are combined with the opening sides facing each other, the separation wall and the separation groove are combined, whereby the battery The battery storage portion for storing the battery and the electric circuit storage portion for storing the electric circuit are separated, the separation groove is filled with resin, and the space between the separation groove and the separation wall is filled with the resin. It is characterized by that.
[0011]
In the battery pack according to the present invention as described above, since the separation wall and the separation groove are combined and the separation groove is filled with resin, the battery storage portion and the electric circuit storage portion are completely separated. In the unlikely event that the electrolyte leaks from the battery, leaching to the outside of the battery circuit or the pack is prevented.
[0012]
In the battery pack of the present invention, one or more batteries are enclosed and accommodated by a box-shaped first case and a second case, and an electric circuit connected to the batteries is provided as a case. A battery pack provided outside, wherein one of the first and second cases has an opening end portion folded outward to form a folded portion, and the other case has an opening end portion. It is bent into a staircase shape to form a stepped portion, and when the first case and the second case are combined with the opening sides facing each other, the folded portion and the stepped portion are combined, The step portion is filled with resin, and the space between the folded portion and the step portion is filled with the resin.
[0013]
In the battery pack according to the present invention as described above, when the first case and the second case are combined, the folded portion and the stepped portion are combined, and the folded portion and the stepped portion are Since the gap is filled with the resin, the battery and the electric circuit are completely separated, and even if the electrolyte leaks from the battery, leaching to the outside of the battery circuit or the pack is prevented.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
<First Embodiment>
One structural example of the battery pack 1 according to the present embodiment is shown in FIGS. 1 is a developed perspective view of the battery pack 1, FIG. 2 is a cross-sectional view taken along the line AA ′ in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line BB ′ in FIG. is there. FIG. 4 is a cross-sectional view showing a state where the battery is housed and sealed in the case.
[0016]
As shown in FIG. 1, the battery pack 1 includes flat batteries 2 a to 2 c and an electric circuit 3 that are housed and sealed in a first case 4 and a second case 5.
[0017]
The batteries 2a to 2c are power generation sources such as lithium ion batteries. In the batteries 2a to 2c, for example, a wound layer body in which a film-like positive electrode and a negative electrode are wound in close contact via a separator is sealed together with a non-aqueous electrolyte in, for example, a rectangular battery can. Become.
[0018]
The electric circuit 3 is composed of a control circuit or the like that receives power generated from the batteries 2a to 2c and controls its output. The electric circuit 3 is formed by mounting an active component such as a semiconductor and a passive component such as a capacitor on a mounting substrate on which a wiring pattern is formed. The batteries 2 a to 2 c and the electric circuit 3 are connected by the connection electrode 6.
[0019]
As shown in FIG. 2, the first case 4 includes a bottom surface portion 4 a that covers the bottom surfaces of the batteries 2 a to 2 c and side wall portions 4 b and 4 c that cover the side surfaces of the batteries 2 a to 2 c, and has a hollow box shape. It is configured. The batteries 2a to 2c and the electric circuit 3 are accommodated in the hollow portion.
[0020]
As shown in FIG. 3, the second case 5 includes a top surface portion 5 a that covers the top surfaces of the batteries 2 a to 2 c and side wall portions 5 b and 5 c that cover the side surfaces of the batteries 2 a to 2 c and has a hollow box shape. It is configured. The batteries 2a to 2c and the electric circuit 3 are accommodated in the hollow portion.
[0021]
The first and second cases 4 and 5 are made of an insulating material, and the size and shape are determined according to the number and form of the batteries.
[0022]
As an insulating material, engineering plastics, such as a polycarbonate, are mentioned suitably, for example. However, since only the engineering plastic has poor thermal conductivity, when the battery generates heat, the temperature of the battery rises inside the sealed case. Therefore, it is preferable to add materials such as aluminum powder, carbon, and carbon fiber having high thermal conductivity to an insulating material such as polycarbonate (hereinafter abbreviated as PC).
[0023]
Thermally conductive materials such as aluminum powder, carbon and carbon fiber have conductivity at the same time. In order to improve the thermal conductivity while ensuring the insulation of the case, as shown in FIG. 5, the molecules of the PC material are arranged around the molecules 20 such as aluminum powder, carbon, carbon fiber and the like in a molecular arrangement. 21 is preferably arranged. The blending of the heat conductive material into the PC material is 20% or less of the total amount.
[0024]
As shown in FIG. 2, the side wall end portions 4 b ′ and 4 c ′ of the first case 4 are formed in a concave shape, and as shown in FIG. 3, the side wall end portions 5 b ′ of the second case 5. , 5c ′ are formed in a convex shape, and by engaging the concave shape with the convex shape, the first case 4 and the second case 5 are engaged with each other as shown in FIG. The batteries 2a to 2c and the electric circuit 3 are housed and sealed therein.
[0025]
The battery pack 1 of the present invention includes an electrolyte leakage prevention structure formed integrally with the first case 4 and the second case 5. With this electrolyte leakage prevention structure, the battery housing part in which the batteries 2a to 2c are housed in the case and the electric circuit housing part in which the electric circuit 3 is housed can be separated almost completely. Even if the electrolyte solution leaks from ~ 2c, the electrolyte solution can be prevented from entering the electric circuit portion.
[0026]
The electrolyte leakage prevention structure includes separation grooves 7a and 7b formed integrally with the first case 4, separation walls 8a and 8b formed integrally with the second case 5, and the separation grooves 7a and 7b. And the resin 9 filled in.
[0027]
As shown in FIG. 2, the separation groove 7a is surrounded by convex portions 7a ₁ and 7a ₂ that are formed substantially vertically inward from the bottom surface portion 4a of the first case 4 and the bottom surface portion 4a therebetween. It is comprised from the recessed part which becomes. Further, the separation groove 7b is composed of convex portions 7b ₁ and 7b ₂ formed substantially vertically inward from the bottom surface portion 4a of the first case 4 and a concave portion surrounded by the bottom surface portion 4a therebetween. ing.
[0028]
As described above, the first case 4 is formed with the two separation grooves 7a and 7b, and the space between the separation groove 7a and the separation groove 7b is a battery housing portion in which the batteries 2a to 2c are housed. A space between the groove 7a and the side wall portion 4b becomes an electric circuit storage portion in which the electric circuit 3 is stored. The separation grooves 7a and 7b are filled with resin 9.
[0029]
On the other hand, as shown in FIG. 3, the separation walls 8 a and 8 b are walls formed so as to extend substantially vertically from the upper surface portion 5 a of the second case 5 toward the inside. The separation walls 8a and 8b are formed at positions corresponding to the separation grooves 7a and 7b formed in the first case 4, respectively.
[0030]
Then, as shown in FIG. 4, when the first case 4 and the second case 5 are combined, the separation walls 8a and 8b mesh with the separation grooves 7a and 7b. Thereby, the battery housing part and the electric circuit housing part are separated by the separation walls 8a and 8b and the separation grooves 7a and 7b. The connection electrode 6 that connects the batteries 2a to 2c and the electric circuit 3 is led out through the bottom of the separation groove 7a, as shown in FIGS.
[0031]
As shown in FIG. 1, the separation grooves 7a and 7b and the separation walls 8a and 8b that constitute the electrolyte leakage prevention structure actually have a closed curve shape around the battery housing portion formed inside the case. Be placed.
[0032]
However, since the gap is generated only by separating the battery storage part and the electric circuit storage part by the separation walls 8a and 8b and the separation grooves 7a and 7b, the electrolyte leaked from the batteries 2a to 2c immerses the electric circuit due to the capillary phenomenon. In addition, there is a possibility that the electrolytic solution leaks to the outside of the case and damages the electrical equipment, which is insufficient.
[0033]
Therefore, in the battery pack 1 of the present invention, the separation grooves 7a and 7b are filled with the resin 9. By filling the separation grooves 7a and 7b with the resin 9, the gap between the separation grooves 7a and 7b and the separation walls 8a and 8b is filled with the resin 9, so that the battery housing portion and the electronic circuit housing portion are completely formed. Can be isolated. In addition, by filling the separation grooves 7a and 7b with the resin 9, in the unlikely event that the electrolyte leaks from the batteries 2a to 2c, the electrolyte prevents the electrolyte from entering the electric circuit housing portion by capillary action. be able to.
[0034]
As the resin 9 filled in the separation grooves 7a and 7b, many curable resins such as a thermoplastic resin such as polyamide and polyolefin, a moisture curable resin such as a silicon resin and a silyl group-containing special polymer can be selected. .
[0035]
In order to prevent the electrolyte solution leaking from the batteries 2a to 2c from entering the battery circuit side, methods such as blocking of the electrolyte solution, replacement / absorption of the electrolyte solution, and neutralization of the electrolyte solution can be considered. The resin 9 is a waterproof resin that does not dissolve in the electrolytic solution such as an acrylic resin from the viewpoint of blocking the electrolytic solution, and a silyl group-containing special polymer from the viewpoint of replacement or absorption of the electrolytic solution. Resin that causes a chemical reaction to swell the electrolyte, and from the viewpoint of neutralization of the electrolyte, there are many resins such as a resin that causes a chemical reaction to the electrolyte and neutralizes the performance of the electrolyte. A resin can be selected.
[0036]
As described above, the battery pack 1 of the present invention includes an electrolyte leakage prevention structure including the separation grooves 7a and 7b and the separation walls 8a and 8b and the resin 9 filled in the separation grooves 7a and 7b. Therefore, the battery storage part and the electric circuit storage part can be completely separated, and even if the electrolyte solution leaks from the batteries 2a to 2c, the electrolyte solution enters the electric circuit side, It is possible to prevent leakage. As a result, the battery pack 1 of the present invention is a highly reliable battery pack that has almost no influence on external electrical equipment and the like even if the electrolyte leaks from the battery stored inside.
[0037]
In the above-described embodiment, the description has been given by taking as an example a battery pack that accommodates three rectangular lithium ion secondary batteries. However, the present invention is not limited to this, and a lithium ion secondary battery is described. Other batteries may be used, and the number and arrangement of the batteries are not limited. Further, the shape of the battery is not limited to a rectangular shape, and may be a laminated flat shape or a cylindrical shape, for example.
[0038]
In the above-described embodiment, the case where the first case and the second case are separated has been described as an example. However, the present invention is not limited to this, and the first case The case and the second case may be formed integrally at the end portion of the side wall and combined by a hinge structure. In addition, it can change suitably in the range which does not deviate from the meaning of this invention.
[0039]
<Second Embodiment>
One structural example of the battery pack 30 according to the present embodiment is shown in FIGS. 6 is a plan view of the battery pack 30, and FIG. 7 is a cross-sectional view taken along the line CC 'in FIG. 8 is a perspective view showing a state where the battery is housed and sealed in the case, and FIG. 9 is a cross-sectional view taken along the line EE ′ in FIG.
[0040]
As shown in FIG. 8, the battery pack 30 includes batteries 31 a to 31 c housed in a first case 32 and a second case 33 and sealed. An electric circuit 34 is arranged outside the case.
[0041]
The batteries 31a to 31c are power generation sources, and examples thereof include lithium ion batteries as in the case of the batteries 2a to 2c described above.
[0042]
As shown in FIG. 7, the first case 32 includes a bottom surface portion 32 a that covers the bottom surface of the battery and a side wall portion 32 b that covers the side surface of the battery, and is configured in a hollow box shape. The batteries 31a to 31c are accommodated in the hollow portion. In the first case 32, the end portions of the side wall portions 32b are bent stepwise to form step portions 35a and 35b. Resin 36 is supplied to the step portions 35a and 35b.
[0043]
As shown in FIG. 9, the second case 33 includes an upper surface portion 33 a that covers the upper surface of the battery and a side wall portion 33 b that covers the side surface of the battery, and is configured in a hollow box shape. The batteries 31a to 31c are accommodated in the hollow portion. In the second case 33, the end portion of the side wall portion 33b is folded to form folded portions 37a and 37b.
[0044]
The first and second cases 32 and 33 are made of an insulating material like the first and second cases 4 and 5 described above, and the size and shape are determined according to the number and form of the batteries. It is done.
[0045]
As shown in FIGS. 6 and 7, the first case 32 and the second case 33 are integrally connected by a hinge structure that can be bent at one of the long sides. Then, the first case 32 and the second case 33 are combined to face each other by being bent along the line DD ′ in FIG. 6, and the batteries 31a to 31c are housed and sealed therein. At this time, as shown in FIG. 7, the step portions 35 a and 35 b of the first case 32 and the folded portions 37 a and 37 b of the second case 33 are combined.
[0046]
Further, since the resin 36 is supplied to the step portions 35a and 35b, the resin 36 is filled between the step portions 35a and 35b and the folded portions 37a and 37b. The resin 36 also has a function as a bonding agent for bonding the step portions 35 a and 35 b and the folded portions 37 a and 37 b, that is, the first case 32 and the second case 33.
[0047]
As the resin 36 supplied to the step portions 35a and 35b, in the same manner as the resin 9 described above, many curings such as a thermoplastic resin such as polyamide and polyolefin, a moisture curable resin such as a silicon resin and a silyl group-containing special polymer, etc. Can be used.
[0048]
As described above, since the joint portion between the first case 32 and the second case 33 has a stepped shape, and the portion is filled with the resin 36, the first case 32 and the second case 33 Even if the electrolyte solution leaks from the batteries 31a to 31c, it is possible to prevent the electrolyte solution from leaking due to capillary action.
[0049]
Connection between the batteries 31a to 31c and the electric circuit 34 is performed by connection electrodes 38a to 38d led to the outside on the case sealing side. The connection electrodes 38 a to 38 d are sandwiched between joint portions of the first case 32 and the second case 33.
[0050]
As described above, the battery pack 30 of the present invention includes an electrolyte leakage prevention structure including the step portions 35a and 35b, the folded portions 37a and 37b, and the resin 36 supplied to the step portions 35a and 35b. Therefore, the batteries 31a to 31c can be almost completely sealed in the case, and even if the electrolyte solution leaks from the batteries 31 to 31c, it can be prevented from leaking outside the case. As a result, the battery pack 30 of the present invention has a highly reliable battery pack that has almost no influence on an external electronic circuit, electrical equipment, etc. even if the electrolyte leaks from the battery stored inside. Become.
[0051]
In the above-described embodiment, the description has been given by taking as an example a battery pack that accommodates three rectangular lithium ion secondary batteries. However, the present invention is not limited to this, and a lithium ion secondary battery is described. Other batteries may be used, and the number and arrangement of the batteries are not limited. Further, the shape of the battery is not limited to a rectangular shape, and may be a laminated flat shape or a cylindrical shape, for example.
[0052]
In the above-described embodiment, the first case and the second case are integrally formed at the end portion of the side wall portion, and the case where the structure is combined by a hinge structure has been described as an example. The present invention is not limited to this, and may have a structure in which the first case and the second case are separated. In addition, it can change suitably in the range which does not deviate from the meaning of this invention.
[0053]
【The invention's effect】
Since the battery pack of the present invention has an electrolyte leakage prevention structure in which a resin is filled in the gap, the battery can be completely isolated and sealed in the case, and the electrolyte leaks from the battery by any chance. Even so, it is possible to prevent the electronic circuit from being immersed or leaked outside the case. As a result, the battery pack according to the present invention is a highly reliable battery pack that has almost no influence on an electronic circuit, an electric device, or the like even if the electrolyte solution leaks from the battery stored inside.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a configuration example of a battery pack according to the present invention.
FIG. 2 is a diagram showing a configuration example of the battery pack of the present invention, and is a cross-sectional view taken along the line AA ′ in FIG.
FIG. 3 is a diagram showing a configuration example of a battery pack according to the present invention, and is a cross-sectional view taken along line BB ′ in FIG. 1;
FIG. 4 is a diagram showing a configuration example of a battery pack according to the present invention, and is a cross-sectional view showing a state where a battery is housed and sealed in a case.
FIG. 5 is a cross-sectional view schematically showing a molecular configuration of a case material used in the battery pack of the present invention.
FIG. 6 is a plan view showing a configuration example of a battery pack according to the present invention.
7 is a diagram showing a configuration example of the battery pack of the present invention, and is a cross-sectional view taken along the line CC ′ in FIG. 6. FIG.
FIG. 8 is a view showing a configuration example of the battery pack of the present invention, and is a perspective view showing a state where the battery is housed and sealed in a case;
9 is a diagram showing a configuration example of the battery pack of the present invention, and is a cross-sectional view taken along the line EE ′ in FIG. 8. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Battery pack, 2a-2c battery, 3 Electric circuit, 4 1st case, 5 2nd case, 6 Connection electrode, 7a, 7b Separation groove, 8a, 8b Separation wall, 9 Resin

Claims (7)

A battery pack in which one or more batteries and an electric circuit connected to the batteries are enclosed and accommodated by a box-shaped first case and a second case,
In one of the first and second cases, a separation wall is formed from the inner bottom surface toward the opening, and the other case is separated into an inner bottom surface at a position corresponding to the separation wall. A groove is formed,
When the first case and the second case are combined with the opening sides facing each other, the separation wall and the separation groove are combined to thereby store the battery and the electric circuit. Is separated from the electrical circuit storage section for storing
A battery pack, wherein the separation groove is filled with resin, and a space between the separation groove and the separation wall is filled with the resin. The first and second cases are made of a thermoplastic resin and further contain a material having high thermal conductivity selected from carbon, carbon fiber, and aluminum powder. Battery pack. The battery pack according to claim 1, wherein the resin is a thermoplastic resin selected from a polyamide resin and a polyolefin resin, or a moisture curable resin selected from a silicon resin and a silyl group-containing resin. A battery pack in which one or more batteries are enclosed and housed by a box-shaped first case and a second case, and an electric circuit connected to the battery is provided outside the case. ,
One of the first and second cases has an opening end portion folded outward to form a folded portion, and the other case has an opening end portion folded in a staircase shape to form a stepped portion. And
When the first case and the second case are combined with the opening sides facing each other, the folded portion and the stepped portion are combined,
A battery pack, wherein the step portion is filled with resin, and a space between the folded portion and the step portion is filled with the resin. The battery pack according to claim 4, wherein the first case and the second case are integrally formed and are combined by a hinge structure. 5. The first and second cases are made of a thermoplastic resin, and further contain a material having high thermal conductivity selected from carbon, carbon fiber, and aluminum powder. Battery pack. 5. The battery pack according to claim 4, wherein the resin comprises a thermoplastic resin selected from a polyamide resin and a polyolefin resin, or a moisture curable resin selected from a silicon resin and a silyl group-containing resin.

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