CN207398186U - Secondary cell - Google Patents

Abstract

The utility model provides a secondary battery, which comprises an electrode assembly and a stretchable insulating sleeve. The stretchable insulating sleeve has an inner cavity opened at the upper end, the electrode assembly is accommodated in the inner cavity of the stretchable insulating sleeve, and the stretchable insulating sleeve is attached to the electrode assembly and tightly wraps the electrode assembly from the outside. When the electrode assembly enters the inner cavity through the upper opening of the stretchable insulating sleeve, the stretchable insulating sleeve will be stretched and deformed as the electrode assembly enters, and the stretched and deformed stretchable insulating sleeve will tightly wrap the electrode assembly from the outside. Therefore, When the electrode assembly needs to be put into the casing, the retractable insulating sleeve can protect the electrode assembly from the outside, prevent the electrode assembly from being scratched by the opening of the casing, reduce the risk of short circuit of the electrode assembly, and improve the safety performance of the secondary battery. The stretchable insulating sleeve has an integral structure and is fixed to the electrode assembly by its own stretchability, so the assembly process is simple. Due to the stretchability of the stretchable insulating sleeve, the group margin of the secondary battery will not be affected.

Description

secondary battery

technical field

The utility model relates to the field of batteries, in particular to a secondary battery.

Background technique

A hard case-shaped secondary battery generally includes an electrode assembly and a case, and the electrode assembly generally includes a positive electrode, a negative electrode, and a separator separating the positive electrode and the negative electrode. Because the height of the shell is usually large, when the electrode assembly is put into the shell, the electrode assembly is easy to contact with the opening of the shell within a long stroke, and the shell is sharp at the opening, so it is easy to put the electrode assembly into the shell. The outermost separator was scratched, exposing the negative electrode. However, if the exposed negative electrode comes into contact with the case, it poses a short circuit risk.

Utility model content

In view of the problems existing in the background technology, the purpose of the utility model is to provide a secondary battery, which can reduce the risk of short circuit of the electrode assembly and improve the safety performance of the secondary battery.

In order to achieve the above object, the utility model provides a secondary battery, which includes an electrode assembly and a stretchable insulating sleeve. The stretchable insulating sleeve has an inner cavity opened at the upper end, the electrode assembly is accommodated in the inner cavity of the stretchable insulating sleeve, and the stretchable insulating sleeve is attached to the electrode assembly and tightly wraps the electrode assembly from the outside.

The beneficial effects of the utility model are as follows: Initially, the depth of the inner cavity of the telescopic insulating sleeve can be less than the height of the electrode assembly; The surface of the electrode assembly will be stretched and deformed as the electrode assembly enters until the electrode assembly completely enters the stretchable insulating sleeve. The stretchable insulating sleeve after stretching and deformation tightly wraps the electrode assembly from the outside. Therefore, when the electrode assembly needs to be put into the casing, the stretchable insulating sleeve can protect the electrode assembly from the outside and prevent the electrode assembly from being scratched by the opening of the casing. , reduce the risk of short circuit of the electrode assembly, and improve the safety performance of the secondary battery. At the same time, the stretchable insulating sleeve has an integrated structure and is fixed to the electrode assembly by utilizing its own stretchability, so the assembly process is simple. In addition, due to the stretchability of the stretchable insulating sleeve, the expansion of the electrode assembly will not be restricted, and the group margin of the secondary battery will not be affected.

Description of drawings

FIG. 1 is a schematic diagram of a secondary battery according to the present invention.

FIG. 2 is an exploded view of a secondary battery according to the present invention.

FIG. 3 is another schematic diagram of the secondary battery according to the present invention, wherein the casing is omitted.

FIG. 4 is a schematic diagram of an embodiment of an electrode assembly of a secondary battery according to the present invention.

FIG. 5 is a schematic diagram of another embodiment of an electrode assembly of a secondary battery according to the present invention.

FIG. 6 is a schematic diagram of a stretchable insulating sleeve of a secondary battery according to the present invention.

FIG. 7 is another schematic diagram of the retractable insulating sleeve of the secondary battery according to the present invention.

Wherein, the reference signs are explained as follows:

1 electrode assembly 21 cavity

11 Positive electrode 22 Through hole

12 negative electrode 3 top cover assembly

13 Diaphragm 4 Housing

2 retractable insulating sleeves

Detailed ways

The secondary battery of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to FIGS. 1 to 7 , the secondary battery according to the present invention includes an electrode assembly 1 and a stretchable insulating sleeve 2 . The stretchable insulating sheath 2 has an inner cavity 21 open at the upper end. The electrode assembly 1 is housed in the inner cavity 21 of the stretchable insulating sheath 2 . The stretchable insulating sheath 2 is attached to the electrode assembly 1 and tightly wraps the electrode assembly 1 from the outside.

Usually, the secondary battery further includes a casing 4 for accommodating the electrode assembly 1 and the stretchable insulating sleeve 2 . The housing 4 has a receiving cavity opened at the upper end.

Initially, the depth of the inner cavity 21 of the stretchable insulating sleeve 2 may be smaller than the height of the electrode assembly 1; The surface of the electrode assembly 1 will stretch and deform as the electrode assembly 1 enters until the electrode assembly 1 completely enters the stretchable insulating sleeve 2 . The stretchable insulating sleeve 2 after stretching and deformation tightly wraps the electrode assembly 1 from the outside. Therefore, when the electrode assembly 1 needs to be put into the casing 4, the stretchable insulating sleeve 2 can protect the electrode assembly 1 from the outside and prevent the electrode assembly 1 from Scratched by the opening of the casing 4, the risk of short circuit of the electrode assembly 1 is reduced, and the safety performance of the secondary battery is improved. At the same time, the stretchable insulating sleeve 2 has an integrated structure and is fixed to the electrode assembly 1 by utilizing its own stretchability, so the assembly process is simple. In addition, since the stretchable insulating sleeve 2 has stretchability, it will not limit the expansion of the electrode assembly 1, and will not affect the group margin of the secondary battery (group margin refers to the thickness of the electrode assembly 1 and the thickness of the casing 4 The ratio of the thickness of the storage cavity; in a secondary battery, the casing 4 usually contains an electrolyte, and the electrode assembly 1 is soaked in the electrolyte, and the electrode assembly 1 will expand during charging and discharging. If the insulating sleeve cannot be stretched, it will limit the expansion of the electrode assembly 1).

Referring to FIGS. 4 and 5 , the electrode assembly 1 may include a positive electrode 11 , a negative electrode 12 , and a separator 13 separating the positive electrode 11 and the negative electrode 12 . The positive electrode 11 generally includes a positive electrode collector (such as aluminum foil) and a positive active material coated on the surface of the positive collector, and the negative electrode 12 usually includes a negative collector (such as copper foil) and a negative active material coated on the surface of the negative collector. , The diaphragm 13 can be polypropylene.

The electrode assembly 1 can have different structures. Specifically, in one embodiment, referring to FIG. 4 , the positive electrode 11 , the separator 13 and the negative electrode 12 are wound together to form a wound electrode assembly 1 . Alternatively, in another embodiment, referring to FIG. 5 , the positive electrode 11 , the separator 13 and the negative electrode 12 can also be stacked together to form a laminated electrode assembly 1 .

Usually, the outermost layer of the electrode assembly 1 is the diaphragm 13, and the inner side of the diaphragm 13 is the negative electrode 12. If the electrode assembly 1 is not protected by the stretchable insulating sleeve 2, then the electrode assembly 1 will be damaged when the electrode assembly 1 enters the casing 4. The outermost separator 13 is easily scratched by the opening of the case 4 , thus causing the negative electrode 12 to be in electrical contact with the case 4 , resulting in a short circuit. And by setting the retractable insulating sleeve 2, the risk of short circuit can be reduced.

The stretchable insulating sleeve 2 is integrally formed of elastic material with good shrinkage performance.

Referring to Fig. 6, the stretchable insulating sleeve 2 is a film structure. The film structure can reduce the space occupied by the stretchable insulating sleeve 2, increase the energy density of the secondary battery, and reduce the influence of the stretchable insulating sleeve 2 on the group margin of the secondary battery.

Referring to FIGS. 1 to 3 , the secondary battery further includes a top cover assembly 3 , and the electrode assembly 1 is fixedly connected to the top cover assembly 3 . The top cover assembly 3 includes a top cover plate and two electrode terminals disposed on the top cover plate, and the positive electrode 11 and the negative electrode 12 of the electrode assembly 1 are respectively electrically connected to the two electrode terminals.

The top cover assembly 3 is also fixedly connected with the casing 4 , thereby enclosing the electrode assembly 1 and the retractable insulating sleeve 2 in the casing 4 .

Referring to FIG. 3 , the upper end of the retractable insulating sleeve 2 can be fixed to the top cover assembly 3 . Specifically, in the process of preparing the secondary battery, firstly, the electrode assembly 1 is fixedly connected with the top cover assembly 3, and then the electrode assembly 1 is inserted into the inner cavity 21 of the stretchable insulating sleeve 2 and the stretchable insulating sleeve 2 is stretched; After the stretchable insulating sleeve 2 is stretched to the lower part of the top cover assembly 3, the upper end of the stretchable insulating sleeve 2 is fixedly connected with the top cover assembly 3, and the top cover assembly 3 closes the opening of the inner cavity 21, and the electrode assembly 1 is completely closed. between the top cover assembly 3 and the retractable insulating sleeve 2; finally, the electrode assembly 1 covered with the retractable insulating sleeve 2 is inserted into the casing 4, and the casing 4 is fixedly connected to the top cover assembly 3. Fixing the stretchable insulating sheath 2 to the top cover assembly 3 can prevent the stretchable insulating sheath 2 from returning to its original state under its own elastic force.

The casing 4 of the secondary battery also contains an electrolyte solution. In order to ensure that the electrode assembly 1 is soaked in the electrolyte, a plurality of through holes 22 can be provided on the surface of the stretchable insulating sleeve 2 .

Referring to FIG. 2 , there can be one or more electrode assemblies 1 , and the specific number depends on the capacity requirement of the secondary battery.

Claims (10)

1. A secondary battery, characterized in that it comprises an electrode assembly (1) and a stretchable insulating sleeve (2); The stretchable insulating sleeve (2) has an inner cavity (21) opened at the upper end, the electrode assembly (1) is accommodated in the inner cavity (21) of the stretchable insulating sleeve (2), and the stretchable insulating sleeve (2) is attached to the electrode The electrode assembly (1) is tightly wrapped on the assembly (1) and from the outside. 2. The secondary battery according to claim 1, characterized in that the secondary battery further comprises a casing (4) for accommodating the electrode assembly (1) and the stretchable insulating sleeve (2). 3. The secondary battery according to claim 1, characterized in that, the electrode assembly (1) comprises a positive electrode (11), a negative electrode (12) and an electrode separating the positive electrode (11) from the negative electrode (12). Diaphragm (13). 4. The secondary battery according to claim 3, wherein The positive electrode (11), the separator (13) and the negative electrode (12) are wound together to form a wound electrode assembly (1); or The positive electrode (11), separator (13) and negative electrode (12) are stacked together to form a laminated electrode assembly (1). 5. The secondary battery according to claim 1, characterized in that the stretchable insulating sleeve (2) is integrally formed of elastic material. 6. The secondary battery according to claim 1, characterized in that the stretchable insulating sleeve (2) is a film structure. 7. The secondary battery according to claim 1, characterized in that the secondary battery further comprises a top cover assembly (3), and the electrode assembly (1) is fixedly connected to the top cover assembly (3). 8. The secondary battery according to claim 7, characterized in that the upper end of the retractable insulating sleeve (2) is fixed to the top cover assembly (3). 9. The secondary battery according to claim 1, characterized in that, a plurality of through holes (22) are further provided on the surface of the stretchable insulating sleeve (2). 10. The secondary battery according to claim 1, characterized in that there are one or more electrode assemblies (1).