Flexible envelope type battery and electrically conductible sealing structure thereof and assembling method thereof

A flexible-envelope type battery and an electrically conductible sealing structure thereof and an assembling method thereof are provided. The battery includes an electrode pair, a flexible envelope and a pair of electrically conductible sealing structures. Each sealing structure includes a conductive terminal and a fixed member. The conductive terminal includes a bottom board and a protruding block, for conducting an electric current from the electrode pair to the outside. The bottom board is disposed within the flexible envelope and combined with the electrode pair. The protruding block is disposed on the bottom board for passing through and protruding from an upper surface of the flexible envelope. The fixed member is for tightly fixing the flexible envelope and the conductive terminal.

This application claims the benefit of Taiwan application Serial No. 96150632, filed Dec. 27, 2007, the subject matter of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates in general to a battery and an assembling method thereof, and more particularly to a flexible-envelope type battery and an electrically conductible sealing structure thereof and an assembling method of the flexible-envelope type battery.

2. Description of the Related Art

No matter whether the commodity is a popular small portable electronic product or a big vehicle, such as the motorcycle or car, a battery is indispensable. For most portable electronic products, the main electric power source is from the battery. So, how to reduce the manufacturing cost and provide a safe and useful battery to the consumers simultaneously is an important goal for the industry.

Referring toFIG. 1andFIG. 2,FIG. 1is a schematic diagram of a conventional flexible-envelope type battery, andFIG. 2is a cross-sectional view at2-2′ line inFIG. 1. The conventional flexible-envelope battery100includes an electrode pair110, a flexible envelope120, a pair of internal conductive leads130aand130b, a pair of external conductive leads140aand140b, a pair of conductive rivets150aand150band two pair of sealing parts160a,160b,170aand170b. The internal lead130a, the external lead140a, the conductive rivet150aand the sealing parts160aand170aare disposed correspondingly to an anodic collecting electrode111of the electrode pair110. Similarly, the internal lead130b, the external lead140b, the conductive rivet150band the sealing parts160band170bare disposed correspondingly to an anodic collecting electrode111′ of the electrode pair110.

InFIG. 2, the anodic collecting electrode111and cathodic collecting electrode111′ are combined with the internal lead130aand130bby welding or fusing. And, the conductive rivets150aand150bpass through the two holes120hand120h′ of flexible envelope120for conducting electric currents from the anodic and the cathodic collecting electrodes111and111′ to the external leads140aand140b. The conductive rivets150aand150bare also used to fix the sealing parts160a,160b,170aand170bfor sealing the two holes120hand120h′ so as to prevent the electrolyte-leak occurred via the two holes120hand120h′.

In the conventional way of conducting the electric current to the outside, the conductive rivet is used for connecting the internal lead and the external lead, allowing the electric current to pass through. Thus, the passing of the electric current is limited by the cross-section area of the conductive rivet. In the conventional way of sealing the openings, the conductive rivet is subject to a constant pressure over a long period of time, so as to result in the stress corrosion. The conductive rivet accompanied a jointed seam is inevitable, and therefore a risk of the electrolyte-leak exists. Furthermore, the conventional flexible-envelope type battery100consisted of a lot of elements described above makes an assembling method thereof complicated, laborious and time-consuming. For example, solders and equipments for welding must be prepared for performing the conventional assembling method. Thus, the quality is difficult to be raised and the production cost is difficult to be reduced in the conventional way of producing the battery.

SUMMARY OF THE INVENTION

The invention is directed to a flexible-envelope type battery and an electrically conductible sealing structure thereof and an assembling method thereof. The electrically conductible sealing structure is for conducting an electric current from inside to outside, or vice versa, of the battery, and furthermore the electrically conductible sealing structure conducts the electric current in direct contact with the electrode pair. Therefore, a larger cross-section area for conducting the electric current over the conventional techniques can be provided. Moreover, the electrically conductible sealing structure is free of the rivets described above in the case of conducting the electric current. So, the stress corrosion and the jointed seam of a rivet close to the electrolyte and the electrode pair are inexistent, and the electrolyte-leak will be prevented.

According to a first aspect of the present invention, an electrically conductible sealing structure of a flexible-envelope type battery is provided. The battery comprises a flexible envelope and an electrode pair enveloped in the flexible envelope. The sealing structure comprises a conductive terminal and a fixed member. The conductive terminal comprises a bottom board and a protruding block. The bottom board is disposed within the flexible envelope and combined with the electrode pair. The protruding block is disposed on the bottom board for passing through and protruding from an upper surface of the flexible envelope. The fixed member is for tightly fixing the flexible envelope and the conductive terminal, and furthermore the fixed member comprises a clamp component. The clamp component has a first clamping portion, a second clamping portion and a bending portion. The bending portion connects the first clamping portion and the second clamping portion so that the first clamping portion is disposed around the protruding block and attached on the upper surface of the flexible envelope, and the second clamping portion is attached onto a lower surface of the flexible envelope.

According to a second aspect of the present invention, a flexible-envelope type battery is provided. The flexible-envelope type battery comprises an electrode pair, a flexible envelope and a pair of electrically conductible sealing structures. The electrode pair is enveloped in the flexible envelope and has an anodic collecting electrode and a cathodic collecting electrode. The electrically conductible sealing structures are for acting as an anodic conductive lead and a cathodic conductive lead of the battery respectively. Each sealing structure comprises a conductive terminal and a fixed member. The conductive terminal is for conducting an electric current from the anodic or the cathodic collecting electrode to the outside, and furthermore the conductive terminal comprises a bottom board and a protruding block. The bottom board is disposed within the flexible envelope and combined with the electrode pair. The protruding block is disposed on the bottom board for passing through and protruding from an upper surface of the flexible envelope such that the electric current from the anodic or the cathodic collecting electrode is conducted to the outside via the bottom board and the protruding block. The fixed member is for tightly fixing the flexible envelope and the conductive terminal, and furthermore the fixed member comprises a clamp component. The clamp component has a first clamping portion, a second clamping portion and a bending portion. The bending portion connects the first clamping portion and the second clamping portion so that the first clamping portion is disposed around the protruding block and attached on the upper surface of the flexible envelope, and the second clamping portion is attached onto a lower surface of the flexible envelope.

According to a third aspect of the present invention, an assembling method of a flexible-envelope type battery is provided. The battery comprises an electrode pair and a flexible envelope. The assembling method comprises the following steps: First, the electrode pair is combined with a bottom board of a conductive terminal. The flexible envelope is hot-press sealed to form a flexible envelope having a reserved hole. Then, the electrode pair combined with the conductive terminal is disposed in the flexible envelope so that a protruding block of the conductive terminal passes through and protrudes from an upper surface of the flexible envelope. After that, the flexible envelope and the conductive terminal are fixedly clamped by a clamp component, wherein a first clamping portion of the clamp component is disposed around the protruding block and attached on the upper surface of the flexible envelope, and a second clamping portion of the clamp component is attached onto a lower surface of the flexible envelope. Subsequently, an electrolyte is injected into the flexible envelope via the reserved hole. The flexible envelope is vacuated via the reserved hole. Lastly, the reserved hole is hot-press sealed.

The invention will become apparent from the following detailed description of the preferred but non-limiting embodiment. The following description is made with reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION

In embodiments of the present invention, a new electrically conductible structure for conducting an electric current from inside to outside of a battery is provided. Referring toFIG. 3, a schematic diagram of a flexible-envelope type battery according to a preferred embodiment of the invention is shown. As indicated inFIG. 3, the flexible-envelope type battery200comprises an electrode pair210enveloped in a flexible envelope220and a pair of electrically conductible sealing structures230and230′. The electrode pair210includes an anodic collecting electrode211and a cathodic collecting electrode211′. And, the sealing structures230and230′ is disposed correspondingly to the anodic and the cathodic collecting electrode211and211′ respectively for acting as an anodic conductive lead and a cathodic conductive lead of the battery200so that the sealing structures230and230′ conduct an electric current from the collecting electrodes211and211′ to the outside.

The relation between the battery200and the sealing structures230and230′ will be described hereinafter with reference to the accompanying drawings,FIG. 4andFIGS. 5a-7c. Because the anode part is similar to the cathode part in the battery200, the following description will be directed to the anode part, and the description related to the cathode part will be omitted.

Please refer to bothFIG. 4andFIGS. 5a-7c.FIG. 4is an exploded view of the collecting electrode at4′ region inFIG. 3.FIGS. 5a-7care schematic diagrams of each element in the electrically conductible sealing structure respectively. As indicated inFIG. 4, the sealing structure230includes a conductive terminal231, a fixed member, an internal sealing gasket232, an external sealing gasket233and an insulation gasket234. The fixed member includes a clamp component235and a fastening component, such as a screw236aand a screw cap236b.

InFIG. 4andFIGS. 5a-5b, the conductive terminal231includes a bottom board231aand a protruding block231b. The bottom board231ais disposed within the flexible envelope220and combined with the anodic collecting electrode211by clamping. The protruding block231bis disposed on the bottom board231afor passing through and protruding from an upper surface of the flexible envelope220. The bottom board231aindicated inFIG. 5acan be bent to be a U-shaped bottom board231aindicated inFIG. 5b. The U-shaped bottom board231ahas an electrodic clamping portion231c, which is the inner concave surface of the U-shaped bottom board231a, for clamping the anodic collecting electrode211of the electrode pair210. In the present embodiment, the conductive terminal231is preferably made of aluminum or copper depending on applying to an anode or a cathode, but is not limited to. In contrast to the conventional technique, the collecting electrodes are combined with the U-shaped bottom board of the conductive terminal by clamping, not by welding. Therefore, solders and equipments for welding and the process therefor can be omitted in the present embodiment.

But, it should be understood that some collecting electrodes having unusual shape couldn't be clamped into the clamp component231cindicated inFIG. 5b. In that situation, the conventional welding technique can be used according to one embodiment of the invention, those collecting electrodes also can be directly welded with the unbent bottom board231aindicated inFIG. 5a.

InFIG. 4andFIGS. 6a-6b, the clamp component235has a first clamping portion235a, a second clamping portion235band a bending portion235c. The bending portion235cconnects the first clamping portion235aand the second clamping portion235b. When the bending portion235cis bent as indicated inFIG. 6b, the clamp component235is a U-shaped clamp component235. The first clamping portion235awill be disposed around the protruding block231band attached on the upper surface of the flexible envelope220, and the second clamping portion235bwill be attached onto a lower surface of the flexible envelope220. In the present embodiment, the clamp component235is preferably made of aluminum or stainless steel, but is not limited thereto.

InFIG. 4andFIGS. 7a-7c, the internal sealing gasket232is disposed within the flexible envelope220and between the flexible envelope220and the conductive terminal231. The external sealing gasket233is disposed on the upper surface of the flexible envelope220and between the flexible envelope220and the clamp component235. The insulation gasket234is disposed on the upper surface of the flexible envelope220and between the flexible envelope220and the external sealing gasket233and wedged into the external sealing gasket233. In the present embodiment, the internal sealing gasket232is preferably made of polymer, but is no limited thereto. The external sealing gasket233is preferably made of rigid material such as aluminum or stainless steel, but is no limited to. The insulation gasket234is preferably made of electrically isolated material such as insulating polymer, but is no limited thereto.

Besides, the flexible envelope220has a penetrating hole220hdisposed correspondingly to the anodic collecting electrode211. The first clamping portion235ahas a first opening235h. The internal sealing gasket232has a second opening232h. The external sealing gasket233has a third opening233h. The insulation gasket234has a fourth opening234h. And, the protruding block231bof the conductive terminal231passes through the second opening232h, the penetrating hole220h, the fourth opening234h, the third opening233hand the first opening235hsequentially.

In generally, the flexible envelope220may include a metallic foil such as an aluminum foil. So, inFIG. 7c, the insulation gasket234has a flanged wall234pwfor being embedded into the penetrating hole220hof the flexible envelope220to electrically insulate the metallic foil of the flexible envelope220from the protruding block231bof the conductive terminal231.

After assembling the elements indicated inFIG. 4, the screw236aand the screw cap236bare used for fastening one end of the first clamping portion235aand one end of the second clamping portion235btightly to exert a pressure upon the first clamping portion235a, the external sealing gasket233, the insulation gasket234, the flexible envelope220, the internal sealing gasket232, the bottom board231aand the second clamping portion235bto form an airtight structure in correspondence with the penetrating hole220h. And, the electric current from the anodic collecting electrode211can be conducted to the outside via the bottom board231aand the protruding block231b. In other words, the conductive terminal231can be used to conduct the electric current from the anodic collecting electrode211to the outside.

Besides, the fixed member is for tightly fixing the flexible envelope220and the conductive terminal231. And, the fastening component of the fixed member, which is the screw236aand the screw cap236bindicated inFIG. 4, is merely a kind of fastener for fastening the first and the second clamping portion235aand235b. So, it should be understood that the fastening component also can be a rivet, a bolt or a spring clamp for fastening the first and the second clamping portion235aand235bin the embodiments of the invention. Additionally, in one embodiment of the invention, the bending portion235cof the clamp component235indicated inFIG. 6acan be cut off while the first clamping portion235aand the second clamping portion235bremain. Furthermore, two fastening components will be configured correspondingly to the ends of the clamping portions235aand235brespectively for fastening the first and the second clamping portion235aand235btightly, so as to exert a pressure to form an airtight structure in correspondence with the penetrating hole220h.

An assembling method of the flexible-envelope type battery200will be described hereinafter with reference to a flow chart. Referring toFIG. 8, the assembling method of the flexible-envelope type battery inFIG. 3is shown. As indicated inFIG. 8, the assembling method includes the following steps.

First, in step S81, the bottom board231aof the conductive terminal231is combined with the electrode pair210. As described above, the bottom board231ais the U-shaped bottom board231ahaving the electrodic clamping portion231c. In step S81, the conductive terminal231is combined with the electrode pair210by clamping the electrode pair210into the electrodic clamping portion231c.

Then, in step S82, the internal sealing gasket232is disposed on the bottom board231aof the conductive terminal231such that the protruding block231bpasses through the second opening232h.

Next, in step S83, the flexible envelope220is hot-press sealed to form a flexible envelope having a reserved hole. As indicated inFIG. 4, the flexible envelope220may be distributed into an upper flexible sheet and a lower flexible sheet, and the penetrating hole220his disposed at the upper flexible sheet. In step S83, the conductive terminal231is disposed between the upper flexible sheet and the low flexible sheet, and the protruding block231bof the conductive terminal231passes through and protrudes from the upper surface of the upper flexible sheet via the penetrating hole220h, and then the upper flexible sheet and the low flexible sheet are hot-press sealed to form a flexible envelope having a reserved hole (not shown in the drawings).

Afterwards, in step S84, the insulation gasket234is wedged into the external sealing gasket233, and then the external sealing gasket233wedged with the insulation gasket234is disposed on the upper surface of the flexible envelope220such that the protruding block231bpasses through the fourth opening234hof the insulation gasket234and the third opening233hof the external sealing gasket233.

Then, in step S85, the flexible envelope220and the conductive terminal231are clamped fixedly by the clamp component235. The first clamping portion235aof the clamp component235is disposed around the protruding block231band attached on the upper surface of the flexible envelope220, and a second clamping portion235bof the clamp component235is attached onto a lower surface of the flexible envelope220. The external sealing gasket233wedged with the insulation gasket234is disposed between the flexible envelope220and the first clamping portion235a.

Next, in step S86, an electrolyte is injected into the flexible envelope220via the reserved hole.

Then, in step S87, the flexible envelope220is vacuated via the reserved hole.

Afterwards, in step S88, the reserved hole is hot-press sealed, and the assembling method is finished.

According to the flexible-envelope type battery and the electric conductible sealing structure thereof and the assembling method disclosed in the above embodiment of the invention, a new electrically conductible structure is provided for conducting an electric current from inside to outside of a battery. In the case of conducting the electric current, the electrically conductible structure is a non-screwed and non-riveted structure, so as to effectively reduce the manufacturing processes and decrease the manufacturing equipments. Furthermore, the electrically conductible structure conducts the electric current in direct contact with the electrode pair. Therefore, a larger cross-section area for conducting the electric current over the conventional techniques can be provided. Moreover, the stress corrosion and the jointed seam of a rivet close to the electrolyte and the electrode pair are inexistent, and the electrolyte-leak will be prevented so as to decrease the product defect rate and enhance the market competitiveness.