CN201397865Y

CN201397865Y - Center pin capable of improving safety performance of cylindrical lithium ion battery

Info

Publication number: CN201397865Y
Application number: CN2009200965466U
Authority: CN
Inventors: 金庚镐; 王晓丹; 步绍宁; 陈英龙; 高俊奎
Original assignee: Tianjin Lishen Battery JSCL
Current assignee: Tianjin Lishen Battery JSCL
Priority date: 2009-04-28
Filing date: 2009-04-28
Publication date: 2010-02-03
Anticipated expiration: 2019-04-28

Abstract

The utility model discloses a center pin capable of improving the safety performance of a cylindrical lithium ion battery, which comprises a center pin body (1) positioning in the battery core; necking-in parts (2) are respectively formed at the top and the bottom of the center pin body (1), and the included angles between the outer side surface of the necking-in parts (2) and the vertical direction are acute angles. Compared with the prior art, the utility model discloses a center pin with a function of improving the safety performance of a cylindrical lithium ion battery, which adopts the design of two necking-in ends, so that the short circuit in the battery caused by a burr and a pinpoint on the fringe can be effectively avoided so as to ensure the use security of the battery; the center pin can be easily inserted in the center of the battery core without damaging the battery core; the manufacturing cost is low; and the production practice is of great significance.

Description

A kind of center needle that improves the cylindrical lithium ion battery security performance

Technical field

The utility model relates to the battery technology field, particularly relates to a kind of center needle that improves the cylindrical lithium ion battery security performance.

Background technology

Along with the continuous development of IT industry, people are more and more higher to the demand of high energy battery.Cylindrical lithium ion battery has advantages such as volumetric specific energy height, long service life, memory-less effect, is widely used in fields such as notebook computer, mobile DVD, electric tool.Therefore, people also constantly increase for the requirement of this battery security, reliability.

At present, the cylindrical lithium ion battery of selling on the market mainly consists of the following components: the positive plate of being made up of positive active material and plus plate current-collecting body (aluminium foil); The negative plate of forming by negative electrode active material and negative current collector (Copper Foil); Be separated by barrier film between positive/negative plate, barrier film and positive/negative plate together are wound into cylindric volume core; Be used to load the metal shell of volume core and electrolyte; The insulating trip up and down that core top and bottom and other conductive materials separate will be rolled up; Be used for sealed cell and have the assembled battery lid of certain safety guard.

There are following three kinds of potential safety hazards in the battery of this composition: 1. battery is after charge and discharge cycles process repeatedly, and the center gap place is because the expansion of pole piece can be out of shape, even fracture causes internal short-circuit; 2. when battery is subjected to the external force extruding, roll up core center gap place the most yielding initiation battery internal short-circuit; 3. when volume core center gap place deformed, the gas that battery is subjected to high heat condition generation was difficult to get rid of from the center, can cause safety problem.

At present, the common method that addresses the above problem is to insert the center needle parts at volume core center gap place, prevents to roll up core distortion in these cases.Yet, too high or too low all can't the inhibition of the intensity of center needle rolled up core in the generation that is subjected to deformation under the external force effect, and under the effect of external force, very easily pierce through positive/negative plate and cause short circuit at the most advanced and sophisticated place of the profile of metal center pin, in addition, it is impaired that center needle shape unreasonable can cause in the battery pack process of assembling volume core center.Thereby the shaped design of center needle is most important to the fail safe of cylindrical lithium ion battery.

The utility model content

In view of this, the purpose of this utility model provides a kind of center needle that improves the cylindrical lithium ion battery security performance, it has the design of head and the tail closing in type, the battery internal short-circuit that can avoid burr and edge tip to be caused effectively, guarantee the safe in utilization of battery, this center needle also is convenient to be inserted into the battery roll core center, can not cause damage to battery roll core, and low production cost is of great practical significance.

For this reason, the utility model provides a kind of center needle that improves the cylindrical lithium ion battery security performance, include center needle needle body 1, the top of described center needle needle body 1 and bottom have closing in portion 2, described center needle needle body 1 is arranged in battery roll core, and the lateral surface of this closing in portion 2 and the angle of vertical direction are acute angle.

Preferably, the lateral surface of described closing in portion 2 and the angle of vertical direction are 10～18 °.

Preferably, the wall thickness of described center needle needle body 1 is 0.1～0.25mm, and the vertical height of described closing in portion 2 is for being not less than 0.5mm.

Preferably, described center needle needle body 1 adopts stainless steel material to make.

The technical scheme that is provided by above the utility model as seen, compared with prior art, the utility model provides a kind of center needle that improves the cylindrical lithium ion battery security performance, it has the design of head and the tail closing in type, and the battery internal short-circuit that can avoid burr and edge tip to be caused effectively guarantees the safe in utilization of battery, this center needle also is convenient to be inserted into the battery roll core center, can not cause damage to battery roll core, and low production cost, be of great practical significance.

Description of drawings

A kind of structural representation that improves the center needle of cylindrical lithium ion battery security performance that Fig. 1 provides for the utility model;

A kind of local enlarged diagram in top that improves the center needle of cylindrical lithium ion battery security performance that Fig. 2 provides for the utility model;

Among the figure, 1 is the center needle needle body, and 2 is center needle closing in portion.

Embodiment

In order to make those skilled in the art person understand the utility model scheme better, the utility model is described in further detail below in conjunction with drawings and embodiments.

A kind of structural representation that improves the center needle of cylindrical lithium ion battery security performance that Fig. 1 provides for the utility model.

Referring to Fig. 1, the utility model provides a kind of center needle that improves the cylindrical lithium ion battery security performance, includes center needle needle body 1, and the top of described center needle needle body 1 and bottom have closing in portion 2, and described center needle needle body 1 is arranged in battery roll core.

The lateral surface of this closing in portion 2 and the angle of vertical direction are acute angle, and in the utility model, the lateral surface of this closing in portion 2 and the angle of vertical direction are preferably 10～18 °.

In the utility model, the wall thickness of described center needle needle body 1 is 0.1～0.25mm, described center needle needle body 1 adopts stainless steel material to make, the length of described center needle needle body 1 is 95%～98% of battery roll core length overall, and the diameter of described center needle needle body 1 is 65%～75% of a battery roll core center gap diameter.

The vertical height of described closing in portion 2 is for being not less than 0.5mm.

For the center needle that the utility model provides, the process that specifically joins in the battery is as follows:

1, with battery roll core, bottom spacer is put into battery case;

2, resistance welded negative electrode lug and battery case make its connection;

3, vertically center needle is joined volume core center, and be pressed into the negative electrode lug contact position of least significant end and battery roll core bottom;

4, add and to prevent Upper gasket that center needle moves the core that makes the test, and carry out slot rolling to volume core top;

5, inject electrolyte to battery case;

6, welding anode ear and battery cover;

7, building battery cover at last carries out machinery and seals.

The utility model is a battery safety hidden danger of having stopped in the past to have the burr between seam center needle slit to cause by the center needle of seamless configuration design, and when battery was subjected to external force deformation, the tip that can avoid the distortion of place, original seam center needle slit to produce caused internal short-circuit.Simultaneously, the most advanced and sophisticated battery internal short-circuit that causes of oral area burr and edge can be effectively avoided in the closing in type design (as shown in Figure 2) located from beginning to end of center needle.This closing in design is also provided convenience for the operation of the contact pin in the production process simultaneously at the enhancing battery security, makes center needle be convenient to be inserted into volume core center, and is difficult for causing the damage to the volume core.The configuration design of this seamless center needle is easier to producer and makes, and helps reducing production costs.In addition, in design, use rational diameter, thickness and material to guarantee the intensity of center needle.

In sum, compare with the center needle of prior art, the utility model provides a kind of center needle that improves the cylindrical lithium ion battery security performance, it has the design of head and the tail closing in type, and the battery internal short-circuit that can avoid burr and edge tip to be caused effectively guarantees the safe in utilization of battery, this center needle also is convenient to be inserted into the battery roll core center, can not cause damage to battery roll core, and low production cost, be of great practical significance.

The above only is a preferred implementation of the present utility model; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the utility model principle; can also make some improvements and modifications, these improvements and modifications also should be considered as protection range of the present utility model.

Claims

1, a kind of center needle that improves the cylindrical lithium ion battery security performance, it is characterized in that, include center needle needle body (1), the top of described center needle needle body 1 and bottom have closing in portion (2), described center needle needle body (1) is arranged in battery roll core, and the lateral surface of this closing in portion (2) and the angle of vertical direction are acute angle.

2, center needle as claimed in claim 1 is characterized in that, the lateral surface of described closing in portion (2) and the angle of vertical direction are 10～18 °.

3, center needle as claimed in claim 1 is characterized in that, the wall thickness of described center needle needle body (1) is 0.1～0.25mm, and the vertical height of described closing in portion (2) is for being not less than 0.5mm.

As each described center needle in the claim 1 to 3, it is characterized in that 4, described center needle needle body (1) adopts stainless steel material to make.