CN2805102Y

CN2805102Y - Suare shaped lithium ion cell

Info

Publication number: CN2805102Y
Application number: CNU2004201028947U
Authority: CN
Inventors: 潘福中; 周耀华; 朱建华
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2004-12-15
Filing date: 2004-12-15
Publication date: 2006-08-09
Anticipated expiration: 2014-12-15

Abstract

The utility model relates to a square lithium ion battery which comprises an assembly of a battery pole core, which is composed of a positive pole, a negative pole and a diaphragm and electrolyte fluid, wherein the assembly of the battery pole core and the electrolyte fluid are contained together in a metal casing; the outer surface of the metal casing is provided with a groove-shaped safety valve near the corner position; the groove-shaped safety valve is arranged on the outer surface and the wide face of the metal casing; the residual thickness of the groove-shaped safety valve is 0.01 to 0.15 mm. The utility model has the advantages of convenient processing, low cost, high sensitivity, pressure relief in time and capability of effectively improving the safety performance of the battery.

Description

Rectangular lithium ion battery

[technical field]

The utility model relates to a kind of lithium ion battery with safety valve, especially square lithium rechargeable battery.

[background technology]

For lithium rechargeable battery, because improper use, when perhaps situation appears being short-circuited unusually etc. in battery self, inside battery may gather a large amount of heats and gas in moment, make cell internal pressure raise, cause battery to be blasted, on fire, thereby cause the destruction of battery, even jeopardize personal safety.

Traditional quadrate secondary lithium ion battery is not generally established safety valve and is depended on protective circuit, improves structure and mainly contains: and the pressure relief safety valve that setting is made of tinsel in the combination cover of battery (CN1200199, CN1138753); Delineating on the blank cover or at the bottom of the battery case or the compacting groove, formation can be opened the weak link (CN2133055Y) of decompression; At the sidewall ditch groove of battery case, be filled with the blast resistance construction (ZL99236454.X) of metal or synthetic resin encapsulant in this groove; Wide center at battery case is provided with the groove (CN2373901Y) that is " * " shape, and " ten " font or " Y " font groove (CN2529389Y) are to play the purpose of pressure-relief explosion-proof.

But in the said method, the safety valve structure complexity that has, cost height; The difficulty of processing that has is big, the precision requirement height, and homogeneity is poor; And the most fragile position when all the position being set not raising for inner pressure of battery because of safety valve, and make that the break reliability and the promptness of pressure release of safety valve is relatively poor.

[utility model content]

Technical problem to be solved in the utility model provide a kind of simple in structure, pressure release is highly sensitive, the rectangular lithium ion battery that fail safe is good.

For solving the problems of the technologies described above:

The Battery Pole Core assembly that rectangular lithium ion battery of the present utility model is made up of positive pole, negative pole and barrier film reaches electrolyte and is accommodated in jointly in the metal shell, is provided with the groove safety valve near corner positions on the described metal shell surface.

Technique scheme can further be improved to:

This fluted body safety is cut down on the outer surface that can be arranged at shell.And be preferably disposed on wide of shell.

The residual thickness that fluted body safety is cut down can be 0.01～0.15mm.Its front projection is straight line or curve.The angle of the center line of this straight line or curve and battery case side is 15～75 degree.

Positive progressive effect of the present utility model is:

1, highly sensitive, pressure release is timely, can effectively improve battery safety;

2, to process easyly, cost is low.

[description of drawings]

In conjunction with example the utility model is described in further detail with reference to the accompanying drawings:

Fig. 1 is the schematic perspective view of the utility model rectangular lithium ion battery;

Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7 are the front projection embodiment schematic diagram of the utility model rectangular lithium ion battery shell upper groove safety valve;

Fig. 8 (a) and (b) are respectively no safety valve battery and are out of shape forward and backward schematic diagram.

The reference numeral explanation:

The 1-battery case; 2-groove safety valve; The vertical side of 3-.

[embodiment]

The utility model rectangular lithium ion battery comprises the electrode cores assembly of being made up of positive pole, negative pole and barrier film, and said modules is encapsulated in the metal shell with non-hydrolysis electrolyte.As shown in Figure 1, this lithium ion battery has metal shell 1, installs fluted safety valve 2 at shell 1 exterior surface angle position, and this groove safety valve 2 is arranged on wide of shell 1, it spends angle for 3 one-tenth 15～75 with the side of shell 1, and angle is too high or too low all can not to play good explosion-proof effect.

Please refer to Fig. 2～Fig. 7, the front projection of groove safety valve 2 can be designed to straight line (Fig. 2) as required, perhaps is the curve (Fig. 3～Fig. 6), perhaps be the combined shaped (Fig. 7) of above-mentioned line style along this rectilinear direction.

The residual thickness of groove safety valve 2 can under the condition of the normal use that does not influence battery, be done different designs according to concrete needs.In secondary cell of the present invention, the residual thickness of described groove safety valve 2 is 0.01～0.15mm.When thickness is lower than 0.01mm, processing difficulties, and make the housing part too weak easily, and be difficult to guarantee the mechanical strength of battery, cause the outer casing rupture leakage; During greater than 0.15mm, can not play the effect of the pressure release of well breaking.

When cell expansion is out of shape, dotted line position such as Fig. 8 that housing is wide, bending amplitude maximum, wherein the distortion of corner positions is particularly serious.This kind deformation energy forms a kind of shearing at surface of shell, and the tension force when this shearing expands with normal housing is compared, and the easier housing that makes breaks when dilatancy.Therefore, the utility model is provided with groove in the bight of battery case, and is highly sensitive, and pressure release is timely, can prevent effectively that inner pressure of battery from increasing, heat accumulation causes danger such as battery explosion, improves battery safety.

The foregoing description just embodies the preferred version of technical solutions of the utility model, those skilled in the art to wherein some part some changes that may make all embodied principle of the present utility model, belong within the protection range of the present utility model.

Claims

1. rectangular lithium ion battery, comprise the electrode cores assembly of forming by positive pole, negative pole and barrier film, said modules is encapsulated in the metal shell with non-hydrolysis electrolyte, it is characterized in that: described metal shell is cutting down near being provided with fluted body safety on the position in bight.

2. rectangular lithium ion battery as claimed in claim 1 is characterized in that: described fluted body safety is cut down on the outer surface that is arranged at described shell.

3. rectangular lithium ion battery as claimed in claim 1 is characterized in that: described fluted body safety is cut down on wide that is arranged at described shell.

4. rectangular lithium ion battery as claimed in claim 1 or 2 is characterized in that: the residual thickness that described fluted body safety is cut down is 0.01～0.15mm.

5. rectangular lithium ion battery as claimed in claim 1 is characterized in that: the front projection that described fluted body safety is cut down is a straight line.

6. rectangular lithium ion battery as claimed in claim 5 is characterized in that: the angle of described straight line and battery case side is 15～75 degree.

7. rectangular lithium ion battery as claimed in claim 1 is characterized in that: the front projection that described fluted body safety is cut down is a curve.

8. rectangular lithium ion battery as claimed in claim 1 is characterized in that: described curve is curved line, " V " shape line or wave.

9. rectangular lithium ion battery as claimed in claim 7 is characterized in that: the angle of the center line of described curve and battery case side is 15～75 degree.