CN1249836C

CN1249836C - Lithium ion secondary battery

Info

Publication number: CN1249836C
Application number: CNB028177444A
Authority: CN
Inventors: 金英德; 全太玄
Original assignee: KEREA POWER CELL Inc
Current assignee: KEREA POWER CELL Inc; Korea Power Cell Inc
Priority date: 2001-07-23
Filing date: 2002-03-11
Publication date: 2006-04-05
Anticipated expiration: 2022-03-11
Also published as: KR20020003107A; KR100389968B1; CN1554132A; JP2004537144A; WO2003010848A1

Abstract

Disclosed is a thin and wide lithium ion secondary battery capable of preventing leakage of an electrolyte and enhancing an energy storage density by securing the sealing between a cap and a can. The battery is characterized in that a flange is applied to the can, and an upper portion of the can including the flange is inserted into the cap, assembled, and welded. A welding area necessary for welding the can and the cap is secured to thereby prevent leakage of an electrolyte. A metal container having a wide opening and a thickness of 0.3mm or less can be used as the battery can, which remarkably increases the energy storage density. The can and the cap are assembled by an insertion method, there is no need to use a separate jig during welding of the can and the cap, which enhances productivity and thus decrease production costs.

Description

Lithium rechargeable battery

Technical field

The present invention relates to a kind of thin and wide lithium rechargeable battery, more particularly relate to a kind of so thin and wide lithium rechargeable battery, it is by guaranteeing to cover and having the closed state between the wide area jar of wide opening and the battery that can prevent solution leakage, improve energy storage density and prepare different shape.

Background technology

In order to satisfy the needs of portable type electronic product Market Growth and variation, demand for the rechargeable battery of supplying as portable energy also increases fast, and described portable type electronic product for example is mobile phone, field camera and notebook computer.Along with these portable type electronic products become more and more littler and more and more lighter, more performance and multiple function can be provided again simultaneously, make the requirement that improves the secondary cell energy storage density is also become more and more urgent.

In order to satisfy such demand, the research of process several years has produced popular lithium rechargeable battery at present, and it makes lithium ion reversibly to insert from the agent structure of material and to take out.With existing aqueous solution type secondary cell, for example nickel-cadmium cell is compared with Ni-MH battery, lithium rechargeable battery per unit volume and per unit weight have higher energy density, and have improved and discharge and recharge the life-span, and the very fast existing battery that is used for portable type electronic product that substituted.

Meanwhile, portable terminal and the present trend of personal mobile information terminal are: the size of its display has increased communication function owing to the raising of technology and display message amount increases, and the consumption of energy also increases fast thus.Therefore, using under the conventional situation of thickness, be difficult to obtain enough running times less than the thin lithium rechargeable battery of 6mm.So, need to connect two or more batteries or use very thick battery.From in appearance, these lithium rechargeable batteries are made of a jar and a lid, put into electrolyte in wherein jar, and described lid constitutes the container of sealing with jar.Then,, thereby improved interior pressure,, electrolyte has often taken place reveal therefore in the contact portion of jar and lid because abiogenous electrode expands and the gas generation during using secondary cell along with the bulk of lithium rechargeable battery and the growth of capacity.The leakage of electrolyte causes fatal influence to the performance of battery, is using under the situation of battery even, can the circuit of the electronic installation that uses this battery be polluted, thereby has shortened life-span of expensive electronic devices.

Fig. 1 a and 1b are the schematic diagrames that is used to illustrate conventional lithium rechargeable battery.

As previously mentioned, reveal the problem that is caused for fear of electrolyte, conventional rectangle lithium ion battery has focused on the sealing surface of jar and lid is minimized, and adopts the narrow and dark canister of opening.Then, if compare with the aperture area of container, the surface area of dark type inside has increased, and then metallic plate should be drawn into the same size with the degree of depth, thereby can cause the crack of container corner or the distortion of chamber wall, this manufacturing for wide slim battery is disadvantageous.In addition, because this container depth depression has just had making the restriction of different shape container.

Recently, a kind of wall thickness occurred and be the lithium ion rectangular battery about 0.2mm, but it is only limited to having the aluminium of very high draw ratio as surface mass.Metal with high draw ratio is easy to carry out the degree of depth and stretches, but the interior pressure of battery makes its distortion again easily, in the laser welding that is used for sealing, because the high-termal conductivity of this metal makes it have very high welding mortality.Because technology difficulty strengthens, improved the processing cost of metal surface material so the degree of depth stretches, and selected aspect metal material and the change thickness very big restriction is arranged.

Meanwhile, prepare lithium rechargeable battery by a kind of like this method, this method comprises firmly will covering to be inserted in the jar, and by the step of laser beam with its welding, to guarantee bonding area and to improve the productivity ratio of large-scale production.

With reference to Fig. 1 a, in the lithium rechargeable battery that uses the routine of exerting oneself the insertion method and preparing,,, will make the thickness increase of battery cover 21 like this so that firmly battery cover 21 is inserted in this jar with two step structures preparation jar.And under to jar 11 and lid 21 situations of welding and sealing, the opening that weld is not only wide but also thin, and the thickness increase of battery cover 21 is the keys that guarantee airtight quality.For above-mentioned reasons, if increased the thickness of battery cover 21, then the loss of the energy density of unit volume battery will become very big.Therefore, in order to prepare thin large space battery, it is inappropriate adopting the method for firmly inserting.As shown in Fig. 1 a (4), under the situation of jar 11 and lid 21 assemblings, protective circuit box 30 and positive temperature coefficient resistor (PTC) box 40 has been installed, the energy density loss of per unit volume is just very big.Therefore, a kind of like this examination of repaying has just been arranged, electrode body has been inserted in the not only wide but also dark metal can of opening, placed the plate shape metal lid of single stage structure, and should jar and lid welding and sealing.

With reference to accompanying drawing 1b, not firmly to insert, and be not under the situation of the battery lid that is shaped of two steps, adopting single stage and wide plate shape, the just essential thickness that improves battery can 12 and battery lid 22 is so that guarantee to be used to weld necessary enough bonding areas.Then, because the maximum weld length of the canister that is allowed and the consistency of thickness of this canister, then the thickness of canister just is difficult to guarantee suitable sealing less than 0.3mm, and the shortcoming that causes productivity ratio to reduce has just been arranged.

In addition, not firmly to insert, and be not under the situation of the battery lid 22 that is shaped of two steps, adopting single stage and wide plate shape, just the binding site of self-contained battery jar 12 and battery lid 22 accurately.This just needs highly precisely departure, thereby has improved production cost, also need use expensive automatic fixture in welding procedure, owing to spent process time in the fixed position, has reduced speed of production, has improved production cost thus.

Summary of the invention

Therefore, technical purpose of the present invention provides a kind of lithium rechargeable battery, wherein adopted flange on the battery can, make jar and its thickness of lid of preparation compare the thin of routine, thereby strengthened energy storage density, regulate the outstanding length of flange, thereby strengthened sealing effectively, and improved productivity ratio thus.

Another object of the present invention provides a kind of lithium rechargeable battery, and wherein the outer surface of this battery can be used for installing protective circuit box and positive temperature coefficient resistor box to greatest extent, and described outer surface is made of the shape of jar.

With other characteristic, provide a kind of lithium rechargeable battery to achieve these goals.This lithium rechargeable battery comprises: a jar, it comprises one first district and one second district, each zone all has a space independently, this space comprises a bottom, upper shed part and be connected bottom and upper shed sidewall partly, and the separate space in first district and second district communicates with each other, first district comprises the bottom of a sealing, so that insert battery lead plate downwards and introduce electrolyte, second district comprises a predetermined zone, it seals, and it is outwards outstanding by the sidewall in first district, and remaining presumptive area comprises opening portion, and this makes spatial communication and flange that forms by the space of first area formation and second area, it is outwards outstanding and form by second district's top edge, wherein aspect cross-sectional area second district greater than first district; A lid, it comprise the top of a sealing and form can around the sidewall of closure flange, this lid is with above-mentioned canned fitting over, and to form an independent closed container, so just makes the medial surface of cap side-wall to the outside of this flange; An electrode tip, the one end is connected with battery lead plate, and the other end is exposed to the outside of jar.

Here, the bottom in second district has a predetermined zone, and it is formed by the outstanding 2-10mm length of the sidewall in first district, and the length range of the flange of being given prominence to by the sidewall in second district is 0.2-2mm.If jar and lid be such location, promptly the internal face of sidewall is to the outside of flange, then the lid of Xing Chenging sidewall all around can have 1mm or littler gap between the outside of the inboard of cap side-wall and flange.The altitude range of second district's sidewall is 0.5mm to 3mm, and the altitude range of cap side-wall is 0.5mm to 5mm.

In addition, the bottom in second district of the sealing that other end of preferred electrode end passes jar is to be exposed to the outside of jar.And, be provided with a protective circuit box, wherein have circuit, be electrically connected installation protective circuit box in the space that the outside and the outside, second district by the sidewall in first district form with electrode tip.In addition, a positive temperature coefficient resistor box is set, wherein has the positive temperature coefficient resistor device, be electrically connected with electrode tip, the outside of the first district sidewall that this positive temperature coefficient resistor box is installed in jar, or the outside of the bottom, second district of jar make the positive temperature coefficient resistor box be positioned in the space that the outside by the outside of first district's sidewall and bottom, second district forms like this, or be installed in the sidewall in first district, make the positive temperature coefficient resistor box be positioned under the flange.

In addition, jar the flange and the sidewall or the upside of lid weld the container of formation sealing.

Description of drawings

What Fig. 1 a and 1b showed is the perspective view of the lithium rechargeable battery of routine; With

What Fig. 2 to Fig. 5 showed is the perspective view of lithium rechargeable battery of the present invention.

Embodiment

Following with reference to accompanying drawing, the preferred embodiments of the invention are described in detail.In the accompanying drawings, the same element with said function is given same Reference numeral, and the description of its repetition is had a mind to omit.

What Fig. 2 showed is the perspective view of jar of the present invention.In Fig. 2, mark " A " shows is the cutaway view of a-a ' line intercepting in Fig. 2.What Fig. 3 showed is the perspective view of lid of the present invention.In Fig. 3, mark " B " shows is the cutaway view of b-b ' line intercepting in Fig. 3.Fig. 4 shows is the perspective view of the container that assembles, and wherein the jar of Fig. 2 is assembled together with lid among Fig. 3.In Fig. 4, mark " C " shows is the cutaway view of c-c ' line intercepting in Fig. 4.The perspective view of a kind of structure that Fig. 5 shows, protective circuit box and positive temperature coefficient resistor box are installed in the assembly that is made of jar shown in Fig. 4 and lid in this structure.In Fig. 5, mark " D " shows is the cutaway view of d-d ' line intercepting in Fig. 5, is the cutaway view of e-e ' line intercepting in Fig. 5 and mark " E " shows.

With reference to Fig. 2, jars 100 are divided into the 1st district 110 and second district 120, and they all have a space independently, and communicate with each other.The cross-sectional area in second district 120 is greater than the area of first district's cross section.

First district 110 comprises the bottom 112 and the sidewall 113 that is connected top 111 and bottom 112 of upper shed part 111, sealing, to form a space.

Second district 120 comprises bottom 122, upper shed part 121, the sidewall 123 that is connected with bottom 122 with top 121, and forming a space, and flange 124 is protruding and form by the top edge of sidewall 123.At this moment, the predetermined portions 122 ' of the bottom 122 in second district 120 is partly closed, and is different with the bottom 112 in first district 110, and it is protruding, and the remainder 122 of 120 bottoms 122, second district " be opening, be connected with the top 111 in first district 110.Therefore, the space in first district 110 is communicated with by the top in first district 110 and the bottom 122 in second district 120 with the space in second district 120.Meanwhile, only by a sidewall, the sealing of bottom 122 in second district 120 and the zone of stretching out have just been formed.In this case, all the other sidewalls except that a sidewall 123 are positioned at another sidewall 113 in first district 110 in the sidewall in second district 120 " extended line on.

Though do not show in the drawings, battery lead plate and electrolyte are positioned in jars 100 first district 110, and an end of electrode tip is connected with battery lead plate, and its other end passes the bottom 122 ' of stretching out and sealing in second district 120 of jar 100, outside being exposed to.

The flange 124 of jar 100 and lid assembling described below, thus a container that seals formed.

Meanwhile, when measuring time-out by a sidewall 113 ' in first district, the ideal length in the sealing of the bottom 122 in second district 120 and the zone 122 ' of stretching out is 2-10mm.By protection box or the volume of positive temperature coefficient resistor box and the machinability of considering will be described below of installation; determine this length, described protection box or positive temperature coefficient resistor box are installed in the space that the outside by the sealing in the outside of a sidewall 113 ' in first district 110 of jar 100 and second district 120 and the bottom 122 ' of stretching out forms.Yet, if the length of stretching out has surpassed above-mentioned scope, the problem that can bring tank volume to increase.

By the length that control is stretched out, flange 124 can improve the validity of sealing.Preferred flange 124 is stretched out by the sidewall in second district 120, and its length of stretching out is 0.2-2mm.Determine this length by jar and the lid considering hereinafter will describe in conjunction with the machinability of work.

With reference to Fig. 3, lid 200 comprises the top 210 and the sidewall 230 of a sealing, and in order to can form flange 124 encapsulation all around to the jar 100 of Fig. 2, its shaping has such structure, and promptly the inner underside of this structure is an opening.At this moment, when jar 100 and lid 200 assemble each other, the mode of assembling is that the medial surface of sidewall 230 of lid 200 is to the outside of the flange 124 of jar 100, and the upside of the flange 123 of jar 100 contacts with the zone that the inside of the upside 210 of lid 200 is selected, then the sidewall 230 of preferred cap 200 should have such characteristics, between the inboard of the sidewall 230 around the lid 200 that promptly forms and the outside of flange 124 1mm or littler gap is arranged.If this gap is too big, although jars 100 and lid 200 be bonded to each other by welding procedure etc., sealing still may be lowered.

In addition, if the height of the sidewall 123 in second district 120 of jar 100 is 0.5mm to 3mm, the height of the sidewall 230 of preferred cap 200 is 0.5mm to 5mm.This is because under the situation with 200 assemblings of jar 100 and lid, and preferred sealing is such, i.e. first district 110 of closed container 100 and second district 120 at least are if but the height of lid 200 is too big, the then machinability of jar 100 and lid 200 combinations reduction.

With reference to Fig. 4, jars 100 and lid assembling so each other, make the medial surface of sidewall 230 of lid 200 to the outside of flange 124, and the upside of jars 100 flange 123 is selected regional the contact with the inside of the upside 210 of lid 200.By adopting laser welding or resistance welded, the sidewall 230 of lid and upside combine with the flange 124 of jar 100, form the container of sealing like this.

Therefore, jar upside comprise the flange that stretches into lid, and with the welding of this flange and lid, thereby can guarantee to be used for jar and lid welds necessary bonding area, do not need independently anchor clamps and weld.

Meanwhile, as a kind of safe device, this lithium rechargeable battery is used to cut off the positive temperature coefficient resistor device of electric current, or is used to prevent the protective circuit that excessively discharges and recharges.

With reference to Fig. 5, at a sidewall 113 by jars 100 first district " the outside and the space of the outside formation of the downside 122 ' that stretches out and seal in second district on a protective circuit box 410 is set, it is electrically connected with electrode tip.At this moment, this protective circuit box 410 is installed securely, the downside 122 ' in sidewall 113 ' in first district that its position is contiguous jar 100 or second district of jar 100.

In addition, at another sidewall 113 by jars 100 first district " the outside and the space that forms of the downside of flange 124 on installation one positive temperature coefficient resistor box 420, it is electrically connected with electrode tip.At this moment, this positive temperature coefficient resistor box 420 is fixedly mounted in jar 100 sidewalls 113 " the outside.By installation protective circuit box 410 in the space of the outside formation of the downside 122 ' that stretches out and seal in a sidewall 113 ' outside in first district of jar 100 and second district; and same positive temperature coefficient resistor box 420 is installed in another sidewall 113 in jars 100 first district " the outside and the space that forms of the downside of flange 124 in; adhere to protective circuit and the volume of the flexible-packed battery for preparing reduces, and simultaneously as the energy storage density enhancing of the unit volume of battery flexible package.

, be provided with an electrolyte injecting hole 600 therebetween, the downside 122 ' that stretches out so that inject the electrolyte into the sealing of second district.One end of electrode tip with penetrate jars 100 second district under stretch out with the battery lead plate of enclosed areas 122 ' and be connected, the other end 500 is installed in the outer wall of the downside 122 ' in second district.At this moment, in the next predetermined zone in second district, passing very firmly closely of electrode tip 50 make electrolyte to reveal, and after electrolyte injected, electrolyte injecting hole 600 sealed tightly.

[embodiment 1]

Used thickness is of the present invention jar and the lid that the 0.15mm metallic plate is made, and makes thickness and be 4.2mm, minor axis length and be 34mm and long axis length is the rectangle lithium rechargeable battery of 54mm.

At this moment, the length that the flange of jar stretches out is 0.5mm, and the space between the inboard of the sidewall of the outside of the flange of jar and lid is set to 0.1mm, so that the enough areas that are provided for welding.This jar and lid assemble as shown in Figure 4, and the upside of flange then jar and lid and sidewall are by the laser welding combination.In addition, protective circuit box and positive temperature coefficient resistor box are attached to the outside of jar securely with Fig. 4 shape.

Therefore, the unit volume energy storage density that has of the lithium rechargeable battery of the manufacturing of flexible package is 420Wh/l.

[according to the embodiment of the lithium rechargeable battery of Fig. 1 a]

Use the jar and the lid of shape shown in Fig. 1 a, preparation thickness is that 4.2mm, minor axis length are 34mm and long axis length is the rectangle lithium rechargeable battery of 50mm.At this moment, the plate thickness that is used for jar is 0.3mm, and the plate thickness that is used for lid is 0.8mm.The jar and the lid of preparation assemble in the mode of Fig. 1 a (3), and use laser welding.Then, shown in Fig. 1 a (4), protective circuit box and positive temperature coefficient resistor box are attached to securely the outside of this assembly.

Here, the unit volume energy storage density that has of the lithium rechargeable battery of the manufacturing of flexible package is 286Wh/l.

[according to the embodiment of the lithium rechargeable battery of Fig. 1 b]

Use the jar and the lid of shape shown in Fig. 1 b, preparation thickness is that 4.2mm, minor axis length are 34mm and long axis length is the rectangle lithium rechargeable battery of 50mm.At this moment, use the metallic plate of 0.3mm thickness with one deck structure preparation jar and lid.The jar and the lid of this preparation assemble in the mode of Fig. 1 b (3), and use laser welding.

[comparative example 1]

First embodiment of the present invention is compared with [according to the embodiment of the lithium rechargeable battery of Fig. 1 a], and the unit volume energy storage density of first embodiment of the present invention is greater than [according to the embodiment of the lithium rechargeable battery of Fig. 1 a] as can be known.Therefore, have the lithium rechargeable battery of the present invention of same energy storage density, can make thinner secondary cell than [according to the embodiment of the lithium rechargeable battery of Fig. 1 a] with [according to the embodiment of the lithium rechargeable battery of Fig. 1 a].Therefore, by the molded degree of depth of container being done, then can easily make the battery of different shape than conventional depth as shallow.

[comparative example 2]

Deposited 5 days with the charged state of 4.2V with the battery of the present invention of previous embodiments 1 with according to the lithium rechargeable battery of Fig. 1 a and 1b preparation.And the core at each battery punches respectively.Under the air pressure of 500pa, the hole of battery was kept 1 hour.

Under this condition, in the battery of [according to the embodiment of the lithium rechargeable battery of Fig. 1 b], there is a spot of electrolyte to ooze out, its voltage is reduced to 3.97V, and the battery and the battery of the present invention of [according to the embodiment of the lithium rechargeable battery of Fig. 1 a] all do not have electrolyte to ooze out, and voltage is respectively 4.12V and 4.13V.

In addition, the battery of [according to the embodiment of the lithium rechargeable battery of Fig. 1 b] needs carry out in 30 minutes altogether welding procedure, compares with a battery of the present invention that only needs carry out welding procedure in 10 minutes, and production efficiency has been lost 3 times or more.And, the battery of [according to the embodiment of the lithium rechargeable battery of Fig. 1 b] needs the independent welding equipment and the anchor clamps of complicated shape, and battery of the present invention only need insert jar the insertion process of lid downside, does not need independent anchor clamps, thereby has saved step.

Industrial applicibility

As mentioned above, lithium rechargeable battery of the present invention has wherein adopted flange on the battery can, and the upside of the jar by will comprising flange inserts lid and jar and lid are assembled up, can guarantee that like this jar and lid weld necessary bonding area, to prevent the leakage of electrolyte.The opening that is used as the canister of battery case is not only wide but also shallow, and its thickness with canister is reduced to below the 0.3mm, thereby has obviously improved energy storage density.

In addition,, then when welded tank and lid, do not need independently anchor clamps, thereby can boost productivity, reduce production costs because jar and lid are finished assembling with an insertion process.

Also have, protective circuit box and positive temperature coefficient resistor box can be installed on the space outerpace that forms by this jar structure, thereby obviously improve the energy storage density of flexible-packed battery unit volume.

With reference to embodiment preferred, the present invention is described in detail, those of ordinary skills can make various improvement in view of the above and substitute, and this does not break away from the essence and the scope of claims of the present invention.

Claims

1, a kind of lithium rechargeable battery comprises:

A jar, it comprises one first district and one second district, each zone all has a space independently, this space comprises a bottom, upper shed part and be connected bottom and upper shed sidewall partly, and the separate space in first district and second district communicates with each other, first district comprises the bottom of a sealing, so that insert battery lead plate downwards and introduce electrolyte, second district comprises a predetermined zone, described predetermined zone is sealed, and it is outwards outstanding by the sidewall in first district, and the remaining area of second district except that predetermined zone comprises opening portion, this makes the space that forms by the first area be communicated with by the upper shed part in described first district and the under shed part in second district with the space that second area forms, with a flange, it is outwards outstanding and form by second district's top edge, wherein aspect cross-sectional area second district greater than first district;

A lid, it comprise the top of a sealing and form can around the sidewall of closure flange, this lid is with above-mentioned canned fitting over, and to form an independent closed container, so just makes the medial surface of cap side-wall to the outside of this flange; With

An electrode tip, the one end is connected with battery lead plate, and the other end is exposed to the outside of jar.

2, according to the lithium rechargeable battery of claim 1, wherein the bottom in second district has a predetermined zone, and it is formed by the outstanding 2-10mm length of the sidewall in first district, and the length range of the flange of being given prominence to by the sidewall in second district is 0.2-2mm.

3, according to the lithium rechargeable battery of claim 1, if wherein jar and lid are to locate like this, be the outside of the medial surface of sidewall to flange, then the sidewall around the lid of Xing Chenging can have 1mm or littler gap between the outside of the inboard of cap side-wall and flange.

4, according to the lithium rechargeable battery of claim 1, wherein the altitude range of second district's sidewall is 0.5mm to 3mm, and the altitude range of cap side-wall is 0.5mm to 5mm.

5, according to the lithium rechargeable battery of claim 1, the bottom in second district of other end of electrode tip sealing of passing jar wherein is to be exposed to the outside of jar.

6, according to the lithium rechargeable battery of claim 1 or 5, also comprise being provided with a protective circuit box wherein have circuit, be electrically connected installation protective circuit box in the space that the outside and the outside, second district by the sidewall in first district form with electrode tip.

7, according to the lithium rechargeable battery of claim 1 or 5, also comprise and be provided with a positive temperature coefficient resistor box, wherein has the positive temperature coefficient resistor device, be electrically connected with electrode tip, this positive temperature coefficient resistor box is installed in the outside of first district's sidewall of jar, or the outside of the bottom, second district of jar, make the positive temperature coefficient resistor box be positioned in the space that the outside by the outside of first district's sidewall and bottom, second district forms like this, or be installed in the sidewall in first district, make the positive temperature coefficient resistor box be positioned under the flange.

8, according to the lithium rechargeable battery of claim 1, the wherein sidewall of Guan flange and lid or upside welding forms the container that seals.