WO2008047986A1

WO2008047986A1 - Battery pack

Info

Publication number: WO2008047986A1
Application number: PCT/KR2007/001965
Authority: WO
Inventors: Kil-Tack Woo
Original assignee: Elentec Co., Ltd.
Priority date: 2006-10-20
Filing date: 2007-04-23
Publication date: 2008-04-24
Also published as: KR100685115B1

Abstract

Battery pack according to present invention comprises, a battery cell comprising negative electrode and positive electrode, and supplying charged electric power; a protection circuit module(PCM) for preventing the battery cell from being over-charged or over-discharged; a negative electrode plate coupled to the negative electrode; a positive electrode plate coupled to the positive electrode; a holder coupled to the upper portion of the battery cell and having a first opening provided in a portion where the holder is coupled to the electrode of the battery cell; a cover case being formed in shape of '⊂' character approximately and coupled to the battery cell, receiving the PCM, negative electrode plate, positive electrode plate and the holder. By present invention a battery pack which has improved mechanical strength by cover case protecting the battery cell is provided, and a battery pack which is convenient for assemble or disassemble of cover case and battery cell by cover case in shape of '⊂' character approximately is provided, and a battery pack in which a PCM or an electrode can be easily replaced when a defect is found in the PCM or the electrode is provided. Therefore, it is possible to reduce a replacement cost.

Description

Description BATTERY PACK

Technical Field

[I] The present invention relates to a battery pack, and more specifically, to an inner- type battery pack of which the mechanical strength is enhanced, and which is easily replaced when defects occur, and overall weight and size of it is reduced.

[2] In general, an inner-type battery pack which is used as a power supply of a mobile communication terminal has a structure that a battery cell and a protection circuit module (PCM) are coupled to each other.

[3] In the battery cell, an electrode-stacked unit composed of a positive electrode sheet and a negative electrode sheet are housed in a metallic casing. On the outer surface of the casing, a positive electrode and a negative electrode are provided.

[4] Further, the PCM for preventing the battery cell from being exploded and overcharged is mounted on the outside of the battery cell.

[5] That is, the battery pack is constructed as one unit in which the battery cell and the

PCM are coupled to each other. As mobile communication terminals using such a battery pack are in trend of reduction in size and weight, there is a demand for the reduction in size, thickness, and weight of the battery pack. Background Art

[6] One example of the battery pack has been disclosed in Japanese Unexanined Patent

Application Publication No. 2002-334686 (hereinafter, referred to as the related art). The battery pack disclosed in the related art includes a battery cell, a protection circuit module (PCM) mounted on the side of the battery cell, and an electrode for electrically connecting the battery cell and the PCM.

[7] The PCM and the electrode are integrally fixed to the battery cell by a molding.

[8] In the battery pack according to the related art, however, since the PCM and the electrode are fixed to the battery cell through the molding portion formed by injection- molding resin, there are considerable difficulties in manufacturing the battery pack.

[9] Further, in such a manufacturing method, when defects occur in the flow of melt resin at a process of forming the molding portion, the strength of the molding portion decreases and cracks or pinholes are generated in the molding portion.

[10] Because of the above-described problems, the PCM can not be satisfactorily protected because the molding portion is easily broken by an external impact.

[I I] Further, in the related art where the PCM and the electrode are integrated with the molding portion, when a defect is found in any one of the PCM and the electrode, the entire integrated PCM and electrode should be replaced. Therefore, a replacement cost increases.

Disclosure of Invention

Technical Problem

[12] An advantage of the present invention is that it provides a battery pack which has improved mechanical strength by cover case protecting the battery cell.

[13] Also, another advantage of the invention is that it provides a battery pack which is convenient for assemble or disassemble of cover case and battery cell by cover case in shape of " τ= " character approximately.

[14] Another advantage of the invention is that it provides a battery pack in which a PCM or an electrode can be easily replaced when a defect is found in the PCM or the electrode. Therefore, it is possible to reduce a replacement cost.

[15] A further advantage of the invention is that it provides a battery pack in which a separate case for covering the circumferential surface of a battery cell is not used so that the overall weight and size of the battery pack can be reduced. Technical Solution

[16] The present invention is created to solve said problem, by provide a battery pack which has improved mechanical strength by case in shape of " τ= " character protecting the battery cell.

[17] Battery pack according to present invention comprises, a battery cell comprising negative electrode and positive electrode, and supplying charged electric power; a protection circuit nr)dule(PCM) for preventing the battery cell from being overcharged or over-discharged; a negative electrode plate coupled to the negative electrode; a positive electrode plate coupled to the positive electrode; a holder coupled to the upper portion of the battery cell and having a first opening provided in a portion where the holder is coupled to the electrode of the battery cell; a cover case being formed in shape of " τ= " character approximately and coupled to the battery cell, receiving the PCM, negative electrode palte, positive electrode plate and the holder.

[18] Here, the battery the cover case comprises upper cover and lower cover and connection part to connect the upper cover with the lower cover, and the connection part comprises neck part for smooth bending.

[19] And, the connection part is formed in two separated type and formed in one body with the upper cover and lower cover individually. [20] Preferably, the cover case includes an outer fitting section at the portion where it comes in contact with the battery cell, for fixing the battery cell.

[21] Here, one side of the negative electrode plate is coupled to the PCM, and the other side of it is received in the holder so it is coupled to the negative electrode of the battery cell through the first opening provided in the holder.

[22] And, the holder is coupled to the upper portion of the battery cell by a both- side tape or adhesives.

[23] Here, the holder has an insertion projection formed thereon and the cover case has an insertion groove formed therein such that the holder and the cover case can be coupled to each other by insertion.

[24] Preferably, the PCM has a second opening formed in a portion where it is coupled to the negative electrode plate, and the negative electrode plate is coupled to the negative electrode by spot welding.

[25] And, the positive electrode plate is connected by both- side tape to the positive electrode formed in bottom part of the battery cell and to one side of the battery cell's upper part by passing through side face of the battery cell.

[26] Hereinafter, the present invention is explained in detail with attached drawings.

[27] Referring to Fig.1, battery pack according to present invention comprises, a battery cell 10 comprising negative electrode 11 and positive electrode 13, and supplying charged electric power; a protection circuit nr)dule(PCM) 40 for preventing the battery cell 10 from being over-charged or over-discharged; a negative electrode plate 30 coupled to the negative electrode 11; a positive electrode plate 35 coupled to the positive electrode 13; a holder 20 coupled to the upper portion of the battery cell 10 and having a first opening 21 provided in a portion where the holder 20 is coupled to the electrode of the battery cell 10; a cover case 50 being formed in shape of " τ= " character approximately and coupled to the battery cell 10, receiving the PCM 40, negative electrode plate 30, positive electrode plate 35 and the holder 20.

[28] And, the battery pack can further comprise label sheet 80 attached to side surfaces of the battery cell 10 to prevent it from moving freely.

[29] And, the battery pack can further comprise submersion label(95) for detection whether the cell 10 is under water or not.

[30] Hereinafter, each component is explained in detail.

[31] Referring to Fig.l to Fig.3, the battery cell 10 comprises negative electrode 11 and positive electrode 13, by negative electrode plate30 coupled to negative electrode 11 and positive electrode plate 35 coupled to positive electrode 13 the battery cell is connected to PCM 40 electrically and can supply charged electrical power. [32] Here, the battery cell 10 is formed by an electrode- stacked unit composed of a positive electrode sheet and a negative electrode sheet which are housed in a metallic casing. [33] The battery cell 10 can be made in various type for example, nickel-cadnium battery or lithium ion battery. [34] Preferably, the battery cell 10 is provided as a lithium ion battery which can be charged with a high-capacity voltage for the size thereof, compared with other batteries. After being charged, the lithium ion battery can discharge for a long time.

Further, since the lithium ion battery is composed of one battery, it is convenient to manage. [35] The negative electrode 11 provided in the upper surface of the battery cell 10 is coupled to the negative electrode plate 30 connected to the PCM 40. And, the positive electrode plate 35 is coupled to positive electrode 13 in the battery cell 10. [36] Here, the positive electrode 13 can be formed in bottom part of the battery cell 10.

[37] In this case, the positive electrode plate(13) is coupled to positive electrode 13 formed in bottom part of the battery cell 10, and is coupled to one side of upper part of the battery cell 10 passing through the side surface of the cell 10. [38] And, the positive electrode plate 35 is coupled to the side surface of the battery cell

10 by both-side tape. [39] The holder 20 can be coupled to upper part of the battery cell 10, for example by both-side tape or by adhesives bonding. [40] In this case, the holder can comprise first opening 21 for receiving the negative electrode plate 30 in the position where it faces the electrode of battery cell 10. [41] As seen in Fig.1, after the battery cell 10 is coupled with the PCM 40, negative electrode plate 30, positive electrode plate 35 and the holder 20, it is coupled with cover case 50 formed in shape of " τ= " character approximately. That is, the cover case

50 formed in shape of " τ= " character receives the upper part, bottom part and side part of the battery cell 10. [42] By this, the battery pack can be protected from external force and it's mechanical strength can be improved. [43] The PCM 40 is provided for prevent the battery cell 10 from being over charged or over discharged, and from explosion and over flow of current and prevent short circuit of the electrodes in battery cell 10. [44] That is, the PCM 40 protect the battery cell from explosion and the like, so it is assembled in manufacturing process of battery cell 10, and it prolong the life time of the battery cell 10. [45] As seen Fig.l and Fig.3, the PCM 40 is coupled to the negative electrode plate 30, and by this negative electrode plate 30 the PCM is electrically connected with the negative electrode 11 in the battery cell 10. [46] Here, the negative electrode plate 30 can be coupled to the central portion of the

PCM 40 in various way, for example, by soldering. [47] And, PCM 40 comprises second opening 41 in the portion where it is coupled with negative electrode plate 30, the negative electrode plate 30 is coupled to the negative electrode 11 in battery cell by spot welding through the second opening 41. [48] As seen in Fig. 1 and Fig.3, the PCM is coupled to the positive electrode plate 35, and by this positive electrode plate 35 it is connected electrically to the positive electrode 13 in the battery cell 10. [49] Here, the positive electrode plate 35 is coupled to the PCM 40 in the condition that it is received in receiving portion 23 in the holder 20. [50] The PCM 40 is coupled to upper part of the holder 20 coupled to the battery cell 10.

In this case, the holder 20 comprises first opening 21 in the position where it faces the electrode of battery cell 10, and the negative electrode plate 30 is received in the first opening 21, and the negative electrode plate 30 is coupled to the negative electrode 11. [51] The PCM 40 is received in one side of the cover case 50 of " τ= " shape, and it is prevented from being moved freely and protected from external force. In this case, the cover case 50 further comprises outer fitting section 57, and the PCM is more prevented from being moved freely by it, and wrapping it by label sheet 80, strength of battery pack is improved. [52] One side of the negative electrode plate 30 is coupled to the negative electrode of the battery cell 10, and the other side of it is coupled to the PCM 40, so this PCM 40 is electrically connected with the battery cell 10. [53] The negative electrode plate 30 can be formed in various shape, for example as seen in Fig.l and Fig.3, it can be formed in shape of straight metal plate and can be bent to be coupled to the PCM 40 and the negative electrode 11. [54] The negative electrode plate 30 can be coupled to central portion of the PCM 40, both side part of the negative electrode plate 30 is coupled to the PCM 40. In this case, the both side part of the negative electrode plate 30 can be coupled to the central portion of the PCM 40 by soldering. [55] And, the negative electrode plate 30 can be coupled to the negative electrode 11 in various way. Preferably, for convenient process, it can be coupled by spot welding through the second opening 41 in the PCM 40. [56] The negative electrode plate 30 can be received in the first opening 21 of the holder

20 coupled to the battery cell 10. That is, the negative electrode plate 30 is coupled to the negative electrode 11 through the first opening 21. [57] One side of the positive electrode plate 35 is coupled to the positive electrode of the battery cell 10, and the other side of it is coupled to the PCM 40, this PCM 40 is electrically connected to the battery cell 10. [58] Here, the positive electrode plate 35 can be made from various materials, for example, from nickel plate. [59] The positive electrode plate 35 can be formed in various shape, for example, as seen in Fig.l and Fig.3, it can be formed in shape of straight metal plate and can be bent to be coupled to the PCM 40 and the positive electrode 13. [60] That is, the positive electrode plate 35 is coupled to the positive electrode 13 in bottom part of the battery cell, and is coupled to one side of upper part of the battery cell 10 passing through side surface of the cell 10. [61] In this case, the positive electrode plate 35 can be coupled in various way, for example, it can be coupled by both-side tape to side surface of the battery cell 10. [62] And, the positive electrode plate 35 is received in receiving portion 23 formed in one side of the holder 20 to be coupled to the PCM 40, and is supported and protected by being received in the cover case of " τ= " shape. [63] The holder 20 is coupled to upper part of the battery cell 10 and supports the negative electrode plate 30, the PCM 40 and the positive electrode plate 35 to prevent them from moving freely. [64] The holder 20 is coupled to the upper part of the battery cell 10 in various way, for example, is coupled by both-side tape 90a or adhesives. In this case, the holder 20 can comprise first opening 21 at the position where it faces the negative electrode 11 of the battery cell 10. [65] Here, the holder 20 receives the negative electrode plate 30 in the first opening 21, through this first opening 21 the negative electrode 11 and the negative electrode plate

30 is connected. [66] As seen in Fig.1, the holder 20 is coupled to the PCM 40 by connection parts 27 formed in them individually. [67] The holder 20 comprises receiving portion 23 to receive the positive electrode plate

35 in one side of it. That is, the positive electrode plate 35 which is coupled to the positive electrode 13 passes through the side surface of the battery cell to be received in the receiving portion 23 formed in one side of the holder 20 which is coupled to the battery cell 10. [68] And, as seen in Fig.5a, the holder can comprise inserting protrusion 51 for inserting connection with the inserting groove 25 formed in the cover case 50. That is, the holder 20 is supported by the cover case 50 and prevented from moving freely. [69] Here, the inserting groove 25 is formed to penetrate the cover case 50.

[70] In the meanwhile, as seen in Fig.5b, the holder 20 can comprise inserting groove 25, in this case, the cover case 50 can comprise inserting protrusion 51 for inserting connection. [71] Here, it is more convenient in manufacturing process to form inserting groove 25 in the cover case 50 than to form inserting protrusion 51 in it, and it can reduce error rate in manufacturing process of the cover case 50, as seen Fig.5a, it is preferable to form inserting groove 25 in the cover case 50 and inserting protrusion in the holder 20. [72] As seen in Fig.2a, the cover case 50 receives the PCM 40, negative electrode plate

30, and the positive electrode plate 35, and is formed in shape of " τ= " approximately and is coupled to the battery cell 10. By this, the cover case 50 protects the PCM 40, the negative electrode plate 30, and the positive electrode plate 35 and prevent them from moving freely. [73] In this case, said "approximately" means that it does not need to be formed in shape of exact " τ= ", but it can be formed in shape similar to " τ= " by necessity. [74] The cover case 50 can comprise upper cover 52, lower cover 53, and connection part

54 to connect the upper cover 52 and lower cover 53. [75] Here, the upper cover 52 and lower cover 52 and the connection part 54 can be formed in separate part or in one body. [76] That is, if the cover case 50 is formed in one body, as seen in Fig.4a, by the rotation of the upper cover 52 and the lower cover 53 forms " τ= " shape at last. [77] And, the connection part 54 can comprise neck part for smooth bending.

[78] The neck part 55 can be formed in various position, and in various shape. That is, the neck part 55 can be formed in shape of "V" character approximately or "U" character approximately. [79] In this case, said "approximately" means that it does not need to be formed in shape of exact "V" or "U", but it can be formed in shape similar to "V"or "U" by necessity. [80] In the meanwhile, as seen in Fig.4b, the connection part 54 can be formed in two parts and one body with the upper cover 52 and lower cover 53. In this case, by groove in connection part 54 insert connection can be made. [81] Here, if the connection part 54 of the cover case 50 is formed in two parts, it is more easy to make a mold for the cover case 50, productivity of the cover case 50 can be improved. [82] And, when the cover case 50 is coupled to the battery cell 10, the separated

parts of the connection part 54 is coupled to the battery cell 10 so it is more easy to coupling the cover case 50. [83] The cover case 50 can comprise outer fitting section 57 in the position where the cover case 50 contacts the battery cell 10 to fix the cell, in this case, height of the outer fitting section 57 can be 3 nillimeter(mm) approximately. [84] Here, said 3 millimeter is exemplary, not limited to this, the outer fitting section 57 can be formed in various height. [85] In the meanwhile, as seen in Fig.2a and Fig.2b, label sheet 80 can be wrapped around the battery cell 10 and the outer fitting section 57 to prevent the cell from moving freely. By this, mechanical strength of the battery cell can be improved. [86] As seen in Fig.5a, the cover case 50 can comprise inserting groove 25 for inserting connection with inserting protrusion 51 formed in the holder 20. By this, the cover case 50 support the holder 20 and prevent it from moving freely. [87] Here, the inserting groove 25 is formed to penetrate the cover case 50.

[88] The cover case 50 can comprise attaching part 59 for attachment of the submersion label 95. Here, the attaching part 59 can be formed in various position in the cover case

50, for example, as seen in Fig.l, in upper part of the cover case 50. [89] In the condition that the cover case 50 receives the PCM 40, the negative electrode plate 30, the positive electrode plate 35 and the holder and is coupled to the battery cell

10, label sheet 80 is wrapped around the battery cell 10 to prevent it from moving freely and improve the mechanical firmness of the battery pack. [90] Here, as seen in Fig.2b, the label sheet 80 wraps the outer fitting section 57 of the cover case 50. [91] The label sheet(80) can comprise at least one of character, image or graphics on it's surface. That is to say, trademark or name of products or manufacturing company can be displayed by the character, image or graphics. [92] Submersion label(95) is for identifying submersion under water, whether the battery pack is submersed under water or not by color change or run over of mark on submersion label(95). [93] The submersion label(95) can be attached in various position in the cover case(50), for example, as seen in Fig.l, can be attached in attaching part(59) in the cover case(50) for identifying submersion under water of the battery pack.

Advantageous Effects

[94] By present invention a battery pack which has improved mechanical strength by cover case protecting the battery cell is provided. [95] And, a battery pack which is convenient for assemble or disassemble of cover case and battery cell by cover case in shape of " τ= " character approximately is provided. [96] And, a battery pack in which a PCM or an electrode can be easily replaced when a defect is found in the PCM or the electrode is provided. Therefore, it is possible to reduce a replacement cost. [97] And a battery pack in which a separate case for covering the circumferential surface of a battery cell is not used so that the overall weight and size of the battery pack can be reduced is provided. [98] And, by automation the assembling process, mass production of the battery pack is possible.

Brief Description of the Drawings [99] Fig. 1 is an disassembled perspective view of a battery pack according to present invention; [100] Fig. 2 is an assembled perspective view of the battery pack before label sheet is attached; [101] Fig. 3 is an assembled perspective view of the battery pack after label sheet is attached; [102] Fig. 4 is an assembled sectional view of the batter pack according to the present invention;

[103] Fig. 5 is a perspective view of operating process of cover case formed in one body; [104] Fig. 6 is a perspective view of cover case formed in separated parts; [105] Fig. 7 is a perspective view showing first example of assembling process of cover case and PCM and holder; [106] Fig. 8 is a perspective view showing second example of assembling process of cover case and PCM and holder.

Mode for the Invention [107] Hereinafter, assembling process of said battery pack is explained in detail referring to

Fig.1 and Fig.2. [108] First, as seen in Fig.1, both-side tape 90a, 90b is attached to upper surface and side surface of the battery cell 10. [109] Next, the holder 20 is coupled to the upper part of the battery cell 10, that is on the both-side tape. In this case, the first opening 21 in the holder 20 faces the negative electrode 11 formed in upper part of the battery cell 10. [110] Next, by separate process, the negative electrode plate 30 is coupled to the central portion of the PCM 40, and the positive electrode plate 35 is coupled to one side of the

PCM 40 by soldering or spot welding. [I l l] Next, said separate process, the PCM which is coupled with the negative electrode plate 30 and the positive electrode plate 35 is coupled with the holder 20, in this case, the PCM 40 and the holder 20 are coupled to each other by the connection part 27 formed at edge of them. [112] Next, the negative electrode plate 30 is coupled to the negative electrode 11 through the first opening in the holder 20 coupled to the battery cell 10. [113] And the positive electrode plate 35 is received in the receiving portion 23 formed in the holder 20 and is coupled to the positive electrode 13 by passing through the side surface of the battery cell 10. [114] Next, the negative electrode plate 30 is coupled to the negative electrode 11 formed in the battery cell 10 through the second opening 41 formed in the PCM 40 by spot welding. [115] Next, the positive electrode plate 35 is coupled to the positive electrode 13 by spot welding. [116] Next, as seen in Fig.2a, the battery cell 10 which is coupled to the PCM 40, the holder 20, negative electrode plate 30 and the positive electrode plate 35 is coupled to the cover case 50. In this case, the outer fitting section 57 formed in the cover case 50 is coupled to the battery cell 10. [117] Next, as seen in Fig.2b, the battery cell 10 which is coupled to the cover case 50 is wrapped by label sheet 80, in this case, the outer fitting section is wrapped too. [118] Next, submersion label 95 is attached in the receiving portion 59 formed in upper part of the cover case 50. [119] Said assembling process of battery pack is an exemplary, the scope of present invention is not limited to said example, and part of the assembling process can be modified.

Claims

[ 1 ] A battery pack comprising : a battery cell comprising negative electrode and positive electrode, and supplying charged electric power; a protection circuit nr)dule(PCM) for preventing the battery cell from being over-charged or over-discharged; a negative electrode plate coupled to the negative electrode; a positive electrode plate coupled to the positive electrode; a holder coupled to the upper portion of the battery cell and having a first opening provided in a portion where the holder is coupled to the electrode of the battery cell; a cover case being formed in shape of " τ= " character approximately and coupled to the battery cell, receiving the PCM, negative electrode palte, positive electrode plate and the holder .

[2] The battery pack according to claim 1, wherein the battery the cover case comprises upper cover and lower cover and connection part to connect the upper cover with the lower cover, and the connection part comprises neck part for smooth bending.

[3] The battery pack according to claim 2, wherein the connection part is formed in two separated type and formed in one body with the upper cover and lower cover individually.

[4] The battery pack according to claim 3, wherein the cover case includes an outer fitting section at the portion where it comes in contact with the battery cell, for fixing the battery cell.

[5] The battery pack according to claim 4 one side of the negative electrode plate is coupled to the PCM, and the other side of it is received in the holder so it is coupled to the negative electrode of the battery cell through the first opening provided in the holder.

[6] The battery pack according to claim 5, wherein the holder is coupled to the upper portion of the battery cell by a both- side tape or adhesives.

[7] The battery pack according to claim 6, wherein the holder has an insertion projection formed thereon and the cover case has an insertion groove formed therein such that the holder and the cover case can be coupled to each other by insertion.

[8] The battery pack according to claim 7, wherein the PCM has a second opening formed in a portion where it is coupled to the negative electrode plate, and the negative electrode plate is coupled to the negative electrode by spot welding.

[9] The battery pack according to claim 8, wherein the positive electrode plate is connected by both- side tape to the positive electrode formed in bottom part of the battery cell and to one side of the battery cell's upper part by passing through side face of the battery cell.