CN217589042U - Lithium ion secondary battery with high safety performance - Google Patents

Abstract

The utility model discloses a lithium ion secondary battery with high safety performance, which comprises a battery shell; the outer surface of the battery shell is wrapped with an insulating protective adhesive tape; a pole group protective sleeve is arranged in the battery shell; the pole group protective sleeve is internally provided with a pole group; the top of the pole group is provided with a positive pole lug and a negative pole lug; the top of the pole group is covered with an upper bracket; the left end and the right end of the upper bracket are provided with a positive pole through hole and a negative pole through hole; a battery cover and an outer gasket are arranged right above the upper bracket from bottom to top; the left end and the right end of the battery cover are provided with a positive pole column and a negative pole column; the positive lug of the pole group penetrates upwards through the positive through hole and then is connected with the lower end of the positive pole column; the negative pole lug of the pole group penetrates upwards through the negative pole through hole and then is connected with the lower end of the negative pole column; at least one outer side surface on the pole group protective sleeve is a frosted surface; and/or at least one inner side surface of the battery shell is a frosted surface. The utility model discloses can effectively promote the battery and fall in the reply, vibrate and collide with the external security performance when assaulting, promote the whole security performance of battery.

Description

Lithium ion secondary battery with high safety performance

Technical Field

The utility model relates to a battery technology field especially relates to a lithium ion secondary battery of high security performance.

Background

Lithium ion batteries have the advantages of high specific energy, high cycle times, long storage time and the like, are widely applied to portable electronic equipment (such as mobile phones, digital video cameras and portable computers), and are also widely applied to large and medium-sized electric equipment such as electric automobiles, electric bicycles, electric tools and the like.

The performance of the vehicle-mounted high-capacity power battery is good and bad, and the overall performance of the electric automobile is directly influenced. This puts higher demands on the vehicle-mounted power battery of the electric vehicle (such as higher safety, higher specific capacity and lighter weight). Therefore, the safety performance of the lithium ion battery is more and more required.

For lithium ion batteries, the safety performance is an important index for measuring the lithium ion batteries and is also an index for a battery manufacturer to pay attention to a client. Therefore, the safety performance of the battery is improved in the design and manufacturing process of the battery, and the method has important significance.

At present, when the existing lithium ion battery is subjected to external impacts such as vibration or falling, the problems of internal short circuit of the battery, safety valve opening, electrolyte overflow and the like can be caused, so that serious potential safety hazards are caused, and the safety of the battery in the using process is seriously influenced.

Therefore, there is a need to develop a technology that can reliably improve the safety of the lithium ion battery against external impacts.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a lithium ion secondary battery of high security performance to the technical defect that prior art exists.

Therefore, the utility model provides a lithium ion secondary battery with high safety performance, which comprises an outer gasket, a battery cover, an upper bracket, a pole group protective sleeve, a battery shell and an insulating protective adhesive tape;

the outer surface of the hollow battery shell with an opening at the top is wrapped with an insulating protective adhesive tape;

a hollow pole group protective sleeve with an opening at the top is arranged in the inner cavity of the battery shell;

the pole group is arranged in the inner cavity of the pole group protective sleeve;

the left end and the right end of the top of the pole group are respectively provided with a positive pole lug and a negative pole lug;

the top of the pole group is covered with an upper bracket;

the left end and the right end of the upper bracket are respectively provided with a positive pole through hole and a negative pole through hole;

a battery cover and an outer gasket are sequentially arranged right above the upper bracket from bottom to top;

the left end and the right end of the battery cover are respectively provided with a positive pole mounting hole and a negative pole mounting hole;

a safety valve is arranged at the transverse middle position of the battery cover and provided with an opening;

the outer gasket is provided with a safety valve exposure hole at the position corresponding to the safety valve;

the positive pole is vertically arranged on the positive pole mounting hole in a penetrating manner;

the negative pole is vertically arranged on the negative pole mounting hole in a penetrating manner;

the positive lug of the pole group upwards penetrates through the positive through hole on the upper bracket and then is connected with the lower end of the positive pole;

the negative pole ear of the pole group upwards penetrates through the negative pole through hole on the upper bracket and then is connected with the lower end of the negative pole column;

the top of the battery cover is provided with an outer gasket;

the left end and the right end of the outer gasket are respectively provided with a positive pole accommodating hole and a negative pole accommodating hole;

the upper end of the positive pole is embedded into the positive pole accommodating hole;

the upper end of the negative pole is embedded into the negative pole accommodating hole;

the electrode group protective sleeve is provided with a plurality of outer side faces which are used for contacting with the inner side face of the battery shell, wherein at least one outer side face is a frosted face;

and/or, for a plurality of inner sides that the battery case has, wherein at least one inner side is a frosted surface.

Preferably, the shapes of the pole group protective sleeve and the battery shell are cuboid.

Preferably, the shape of the insulating protective tape is U-shaped;

and the insulating protective tapes are adhered to the front side and the rear side of the battery shell.

Preferably, the frosted surface of the pole group protective sleeve and the frosted surface of the battery shell have roughness of 6.3 mu m and Ra and 100 mu m respectively, wherein Ra is the contour arithmetic mean deviation.

Preferably, when the outer side surface of the pole group protective sleeve and the inner side surface of the battery case are both provided with the frosted surfaces, the frosted surfaces on the pole group protective sleeve and the frosted surfaces on the battery case are arranged in a right-facing and corresponding mode and are in mutual contact.

Preferably, the pole group protective sleeve is made of PET, PP or PE;

the battery shell is a hard shell or a soft shell.

Preferably, the surface of the material of the pole group protective sleeve is clean and oil-free, and the edge of the material is free from burrs;

the pole group protective sleeve is an integrated protective sleeve or a split protective sleeve.

Preferably, a plurality of holes are arranged at equal intervals at the bottom of the pole group protective sleeve.

Preferably, the left and right outer side surfaces of the pole group protective sleeve are frosted surfaces;

the frosted area of the frosted surface is positioned at the lower end of the left and right outer side surfaces of the pole group protective sleeve.

By above the utility model provides a technical scheme is visible, compares with prior art, the utility model provides a lithium ion secondary battery of high security performance, its design science can effectively promote the battery and fall, vibrate and collide with the external security performance when assaulting such as collide with in the reply, and then promote lithium ion battery's whole security performance, promote lithium ion battery's batch production and use, be favorable to improving the market application prospect of battery manufacturing enterprise product, have great production practice meaning.

Drawings

Fig. 1 is a cross-sectional view of a lithium ion secondary battery with high safety performance according to the present invention;

fig. 2 is a schematic perspective view of a protective cover for a pole group in a high-safety lithium ion secondary battery provided by the present invention;

fig. 3 is a schematic diagram of a front structure of a lithium ion secondary battery with high safety performance according to the present invention (the front structure of the battery of the comparative example is the same), and a region a in fig. 3 is a region where the battery of the example and the battery of the comparative example perform X-Ray photography.

Fig. 4 is a schematic diagram obtained by taking a picture of an X-ray of the battery after the inverted drop test according to the embodiment of the present invention;

FIG. 5 is a schematic diagram obtained by taking a photograph of the battery of comparative example taken by X-ray after the inverted drop test;

in the figure, 1 is an outer gasket, 2 is a battery cover, 3 is an upper bracket, 4 is a pole group, 5 is a pole group protective sleeve, 6 is a battery shell, and 7 is an insulating protective adhesive tape;

10 is a safety valve exposure hole, 50 is a hole, and 51 is a frosted area;

21 is a positive pole, and 22 is a negative pole;

31 is a positive electrode through hole, and 32 is a negative electrode through hole;

the reference numeral 41 denotes a positive electrode tab, and 42 denotes a negative electrode tab.

Detailed Description

The technical solutions of the present invention will be described clearly and completely below with reference to embodiments of the present invention, and it should be understood that the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Referring to fig. 1 to 5, the present invention provides a lithium ion secondary battery with high safety performance, which comprises an outer gasket 1, a battery cover 2, an upper bracket 3, a pole group 4, a pole group protective sleeve 5, a battery case 6 and an insulating protective tape 7;

the hollow battery shell 6 with an opening at the top is wrapped with an insulating protective adhesive tape 7;

a hollow pole group protective sleeve 5 with an opening at the top is arranged in the inner cavity of the battery shell 6;

a pole group 4 is arranged in the inner cavity of the pole group protective sleeve 5;

the left end and the right end of the top of the pole group 4 are respectively provided with a positive pole lug 41 and a negative pole lug 42;

the top of the pole group 4 is covered with an upper bracket 3;

the upper holder 3 is provided at its left and right ends with a positive electrode passage hole 31 and a negative electrode passage hole 32, respectively;

a battery cover 2 and an outer gasket 1 are sequentially arranged right above the upper bracket 3 from bottom to top;

the left end and the right end of the battery cover 2 are respectively provided with a positive pole mounting hole and a negative pole mounting hole;

the positive pole mounting hole is vertically provided with a positive pole 21 in a penetrating way;

the negative pole 22 vertically penetrates through the negative pole mounting hole;

the positive lug 41 of the pole group 4 upwards penetrates through the positive through hole 31 on the upper bracket 3 and then is connected with the lower end of the positive pole 21;

the negative pole ear 42 of the pole group 4 penetrates through the negative pole through hole 32 on the upper bracket 3 upwards and is connected with the lower end of the negative pole post 22;

the top of the battery cover 2 is provided with an outer gasket 1;

the left end and the right end of the outer gasket 1 are respectively provided with a positive pole accommodating hole 11 and a negative pole accommodating hole 12;

the upper end of the positive pole 21 is embedded into the positive pole accommodating hole 11;

the upper end of the negative pole 22 is embedded in the negative pole accommodating hole 12;

a plurality of outer side surfaces (for example, a left outer side surface, a right outer side surface, a front outer side surface and a back outer side surface of the pole group protective sleeve shown in fig. 1) on the pole group protective sleeve 5 for contacting with the inner side surface of the battery case 6, wherein at least one outer side surface is a frosted surface;

and/or, for a plurality of inner side surfaces (e.g., the left inner side surface, the right inner side surface, the front inner side surface, and the rear inner side surface of the battery case 6 shown in fig. 1) that the battery case 6 has, at least one of the inner side surfaces is a frosted surface.

The utility model discloses in, on specifically realizing, the shape of utmost point group protective sheath 5 and battery case 6 is the cuboid shape.

In the utility model, the insulating protective tape 7 is shaped like U;

and insulating protective tapes 7 attached to the front and rear sides of the battery case 6.

The utility model discloses in, in the concrete realization, the roughness of the frosting of utmost point group protective sheath 5 and the frosting of battery case 6 is that Ra is not less than 6.3 mu m and is not more than 100 mu m. Where Ra is the arithmetic mean deviation of the profile.

The utility model discloses in, on specifically realizing, when utmost point protective sheath 5's lateral surface and battery case 6's medial surface all had the frosting, to the frosting on utmost point protective sheath 5 and the battery case 6 of organizing, both are preferred to be corresponding the setting just and contact each other to reinforcing frictional force improves the ability of resisting external impact.

In the utility model, in the concrete implementation, a safety valve (i.e. a pressure relief valve) is arranged at the transverse middle position of the battery cover 2;

the outer gasket 1 is provided with a safety valve exposure hole 10 at a position corresponding to the safety valve.

In the present invention, in particular, the position of the pole group protecting sleeve 5 is located between the pole group 4 made by winding or lamination and the battery case 6;

in particular, the pole group protection sleeve 5 is made of a material which is corrosion-resistant, high temperature-resistant, low temperature-resistant and does not deform and shrink after long-term use, and is particularly preferably made of PET (polyethylene terephthalate), PP (polypropylene) or PE (polyethylene). The material surface of the pole group protective sleeve 5 is clean and free of oil stains and burrs at the edges (i.e., edges).

The utility model discloses in, on specifically realizing, the shape of utmost point group protective sheath 5 follows the battery design demand, can the integral type protective sheath, also can be for split type protective sheath.

The utility model discloses in, on specifically realizing, utmost point group protective sheath 5 can increase in advance before the preparation and be provided with the indentation of buckling for utmost point group protective sheath adds man-hour, can carry out plastic processing through buckling the indentation, realizes processing fast.

In the present invention, in the specific implementation, referring to fig. 2, the bottom of the pole group protection sleeve 5 is provided with a plurality of (not limited to three shown in fig. 2) holes 50 at equal intervals.

It should be noted that, in the present invention, the electrode group protecting jacket 5 can be added with holes to ensure the infiltration of the electrolyte into the electrode group. The main purpose of the pole group protective sleeve opening is to ensure the absorption of the pole group to electrolyte, maintain the normal charge and discharge performance of the battery and prolong the service life of the battery core.

It should be noted that the design of the holes of the protective sleeve of the electrode assembly is different from one cell to another. Whether the pole group protective sleeve is provided with the hole depends on the absorption condition of the pole group to the electrolyte. If the holes are designed, the contact of the electrolyte and the inner wall of the battery case is a normal condition, because the corrosion or leakage of the battery case can not be caused under the condition of no abuse or abnormality.

It should be noted that, theoretically, after the protective sleeve of the electrode assembly is perforated, the breakdown voltage between the electrode assembly and the battery case is reduced. Therefore, the utility model discloses under the condition of utmost point group protective sheath trompil design, can increase an insulating pad piece in the battery case inboard to and increase an insulating material's at the bottom of the battery case gasket piece again. So as to ensure the insulation between the pole group and the battery shell.

In the practical implementation of the present invention, referring to fig. 2, the right and left outer side surfaces of the pole group protecting jacket 5 are frosted surfaces;

the frosted area 51 (i.e. the area where frosting exists) of the frosted surface is located at the lower end of the left and right outer side surfaces of the pole group protection sleeve 5.

In the present invention, it should be noted that the electrode set of the battery is designed as the conventional electrode set, and the electrode set includes a positive plate, a negative plate and a diaphragm, and the positive plate and the negative plate are respectively located at two sides of the diaphragm;

the positive plate comprises a positive current collector and a positive mixture mainly composed of an active substance, a conductive agent, a binder and the like; the components and the component proportion of the positive electrode mixture can be conventional technologies, and are not described in detail herein;

the negative plate comprises a negative current collector and a negative mixture mainly composed of a negative active substance, a negative conductive agent, a negative dispersing agent, a negative binder and the like; the components and the component ratios of the negative electrode mixture may be those conventionally used in the art and will not be described in detail herein.

In the utility model, the positive plate, the negative plate and the diaphragm can be made into the pole group of the battery through the winding process or the lamination process.

In the present invention, the battery case 6 may be a hard case, such as a hard plastic case, an aluminum case, a steel case, or the like. The battery case 6 may also be a soft bag, such as a pouch-type soft bag. The soft bag can be made of plastic, and polypropylene, polybutylene terephthalate, polybutylene succinate and the like can be used as the plastic.

The utility model discloses in, what need explain is, set up the frosting through the medial surface at the lateral surface of utmost point group protective sheath and/or battery case, can show the frictional force that increases between utmost point group and the battery case inner wall, reduce the acceleration of utmost point group when bearing external impact, reduce the relative slip between utmost point group and the battery case, promote the security performance of battery.

In order to understand the technical solution of the present invention more clearly, the working principle of the present invention is explained below.

It should be noted that, in the prior art, the protective sleeves of the pole groups are made of smooth materials. The friction force between the pole group protective sleeve and the inner wall of the battery shell is very small. Therefore, when the battery is subjected to external impacts such as vibration, inverted falling, bumping and the like, the pole group has a high probability of generating relative displacement in the battery case. This displacement may increase the pressure in the vicinity of the safety valve for a short time, which may cause the safety valve to open. After the safety valve is opened, the flammable electrolyte overflow risk is increased, and serious potential safety hazards are caused. Meanwhile, in the process that the electrode group generates relative displacement, the diaphragm in the battery is possibly extruded to cause deformation and bending of the diaphragm, so that the diaphragm loses the isolation effect on the positive electrode piece and the negative electrode piece, the internal short circuit of the battery is caused, and the thermal runaway accident of the battery is caused.

Compared with the prior art, the utility model provides a lithium ion secondary battery of high security performance can follow the security performance that promotes the battery in two aspects. Firstly, when the battery bears external impact, the utility model discloses can be through setting up the frosting on utmost point group protective sheath 5 and/or battery case 6, can increase the frictional force between utmost point group and the battery case, reduce the acceleration when the utmost point group slides in the battery, avoid the inside instantaneous high pressure to the relief valve production of battery, reduce the risk that the relief valve opened, electrolyte is excessive. Secondly, the utility model discloses can reduce the displacement in the battery case that the utmost point group caused when experiencing external shock to the bending of diaphragm or deformation have been avoided. Thus, the utility model discloses can show the probability that reduces the inside emergence positive pole piece of battery and negative pole piece contact, cause the short circuit, effectively avoid the battery to take place the thermal runaway accident.

In order to further clearly understand the technical solution of the present invention, the following description is made with reference to specific examples and comparative examples to illustrate the working principle and technical effects of the lithium ion battery prepared by the present invention.

Examples are given.

Referring to fig. 1, for the present invention, after the positive plate, the negative plate and the diaphragm are made into the pole group 4 by winding or lamination, the pole group 4 and the upper bracket 3 are isolated by the diaphragm surrounding the negative plate (the top of the negative plate has the exposed negative ear). When the battery is inverted, the pole group is supported between the pole group 4 and the upper bracket 3 only by the diaphragm, and the supporting force is extremely small. Fig. 2 is an outline diagram of a pole group protective sleeve of a lithium ion secondary battery during experimental tests, wherein the pole group protective sleeve 5 is located between a pole group 4 and a battery case 6 and plays a role in protecting a pole group structure, and it should be noted that the pole group protective sleeves in the prior art are all designed to have smooth surfaces.

In the embodiment of the present invention, a frosted protective sleeve with Ra =50 μm is used to make the battery. The batteries of examples were subjected to the same inverted drop test as the comparative example, i.e., the batteries of examples were subjected to the inverted drop test of batteries on an existing drop test apparatus, as the batteries of comparative example, setting the drop height of the batteries to 1.6m. After the test, the safety valve of the battery is not opened, and the phenomenon of electrode liquid overflow does not exist.

Comparative example.

The cell used as a comparative example was a cell made using a smooth-surfaced pole group protective sheath. For the battery of the comparative example, after the positive plate, the negative plate and the diaphragm are made into a pole group by winding or laminating, the pole group and the upper bracket are separated by the diaphragm surrounding the negative plate (the top of the negative plate is provided with an exposed negative lug). When the battery is inverted, the pole group is supported by the diaphragm only between the pole group and the upper support, and the supporting force is extremely small. The pole group protective sleeves in the prior art are all designed to be smooth surfaces.

The battery of the comparative example was placed on an existing drop test apparatus, and a drop test was performed with the drop height of the battery set to 1.6m in order to approximate the actual use condition, with the drop test being performed with the downward inversion in the vertical direction. When the battery of the comparative example was inverted, the top end of the electrode group was supported only by the separator, and the support strength was insufficient. When the battery of the comparative example was in contact with the ground, the electrode group was further slid in the direction of the ground (downward direction) within the battery case due to the failure of the separator to support the electrode group, resulting in relative displacement of the electrode group and the battery case. When the inversion falls the in-process, when the acceleration that drops downwards at the battery is great, this relative displacement can make the utmost point group exert a higher pressure to the inside electrolyte of battery to form great instantaneous pressure through hydraulic pressure transmission to the relief valve of battery (setting usually on the battery cover), and then probably lead to the relief valve to open, electrolyte is excessive, causes the potential safety hazard. After the examination, the safety valve was opened and there was a case where the electrolyte overflowed after the battery of the comparative example was subjected to the inverted drop test.

Fig. 3 is a schematic diagram of a front structure of a lithium ion secondary battery with high safety performance according to the present invention (the front structure of the battery of the comparative example is the same), and a region a in fig. 3 is a region photographed by the battery of the example and the battery X-Ray of the comparative example.

Fig. 4 is the utility model discloses battery X-ray after inverting drop test takes a picture the measuring result. Fig. 5 is an X-ray photograph measurement result of the battery of the comparative example after the inverted drop test.

In both the comparative examples and examples, the cells before and after dropping were subjected to an X-Ray test, and the distance between the electrode group and the cell cover was recorded and compared.

Referring to table 1 below, it can be seen that, for the batteries of examples and the batteries of comparative examples, the electrode group of the battery of examples was not significantly displaced before and after the inverted drop, as compared to the distance between the top end of the negative electrode sheet and the cover of the battery before and after the inverted drop, whereas the battery of comparative example was displaced by about 2.1 mm.

It should be noted that fig. 4 is a photograph of the battery after the battery of the embodiment has fallen. Due to the optimization effect in the embodiment, the internal structure of the battery is not significantly changed before the test. Can be understood to be substantially identical to a battery that has not been tested.

Referring to fig. 4, the X-Ray image is not clear and is light gray without stacking because the membrane 401 is relatively transparent to X-Ray.

The separator 401 is located between the negative electrode sheet 402 and the upper holder 3 without contacting the upper holder 3, as shown in fig. 4. The negative plate 402 is the bottom black portion of fig. 4. The battery cover 2, the negative plate 402 and the negative tab 42 can be clearly photographed. Therefore, the distance between the top end of the negative electrode sheet 402 and the cell cover 2 (shown in table 1) was selected as an indication of the displacement before and after the drop test in the description of this patent. As can be seen in fig. 4, the diaphragm 401 does not significantly stack or deform. The distance between the top end of the negative electrode sheet 402 and the battery cover 2 is preferably maintained.

In fig. 4, the negative electrode tab 42 and the negative electrode sheet 402 are welded together or integrally formed, and then welded to the battery cover by ultrasonic welding or laser welding. The positive tab is the same.

The battery cover 2 has an insulating film 404 on the bottom thereof.

Referring to fig. 5, with the battery of the comparative example, after dropping, it was seen that the negative electrode sheet 402 was likely to come into contact with the upper holder 3 because the separator 401 had been deformed and stacked as the entire electrode assembly was moved up. The distance between the upper edge of the negative electrode tab 402 and the cell cover 2 is shortened. There is a risk of pinching the explosion-proof valve position on the battery cover.

Regarding the battery of the comparative example, it can be seen from fig. 5 that after the inverted drop test, the top of the negative electrode plate inside the electrode group of the battery of the comparative example is already in contact with the upper bracket, and at this time, the separator is already bent, so that the separator may lose the capability of isolating and protecting the positive and negative electrode plates, and the risk of internal short circuit and thermal runaway is high. For the battery of the embodiment, as can be seen from fig. 4, after the inverted drop test, the top of the negative electrode piece inside the electrode group of the battery does not contact with the upper bracket, so that the risk can be effectively avoided.

TABLE 1 comparison of distance between the top of the negative plate and the cover of the cell before and after the inverted drop

It should be noted that the operations in the examples are only for further illustrating the implementation method of the present invention, and do not limit the application scope of the present invention. In normal manufacturing, use, storage, test process, can all pass through the technical scheme of the utility model, promote lithium ion secondary battery's security performance.

To sum up, compare with prior art, the utility model provides a pair of lithium ion secondary battery of high security performance, its design science can effectively promote the battery in the reply fall, the vibration with collide with the external security performance when assaulting such as, and then promote lithium ion battery's whole security performance, promote lithium ion battery's batch production and use, be favorable to improving the market perspective of battery manufacturing enterprise product, have great production practice meaning.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (9)

1. A lithium ion secondary battery with high safety performance is characterized by comprising an outer gasket (1), a battery cover (2), an upper bracket (3), a pole group (4), a pole group protective sleeve (5), a battery case (6) and an insulating protective adhesive tape (7);

the outer surface of the hollow battery case (6) with an opening at the top is wrapped with an insulating protective adhesive tape (7);

a hollow pole group protective sleeve (5) with an opening at the top is arranged in the inner cavity of the battery shell (6);

a pole group (4) is arranged in the inner cavity of the pole group protective sleeve (5);

the left end and the right end of the top of the pole group (4) are respectively provided with a positive pole lug (41) and a negative pole lug (42);

the top of the pole group (4) is covered with an upper bracket (3);

the left end and the right end of the upper bracket (3) are respectively provided with a positive pole through hole (31) and a negative pole through hole (32);

a battery cover (2) and an outer gasket (1) are sequentially arranged right above the upper bracket (3) from bottom to top;

the left end and the right end of the battery cover (2) are respectively provided with a positive pole mounting hole and a negative pole mounting hole;

a safety valve is arranged at the transverse middle position of the battery cover (2) and is provided with an opening;

the outer gasket (1) is provided with a safety valve exposure hole (10) at the position corresponding to the safety valve;

the positive pole mounting hole is vertically provided with a positive pole (21) in a penetrating way;

the negative pole column (22) is vertically arranged on the negative pole column mounting hole in a penetrating way;

the positive lug (41) of the pole group (4) upwards penetrates through the positive through hole (31) on the upper bracket (3) and then is connected with the lower end of the positive pole column (21);

the negative electrode lug (42) of the electrode group (4) upwards penetrates through the negative electrode through hole (32) on the upper bracket (3) and then is connected with the lower end of the negative electrode post (22);

the top of the battery cover (2) is provided with an outer gasket (1);

the left end and the right end of the outer gasket (1) are respectively provided with a positive pole accommodating hole (11) and a negative pole accommodating hole (12);

the upper end of the positive pole (21) is embedded into the positive pole accommodating hole (11);

the upper end of the negative pole (22) is embedded into the negative pole accommodating hole (12);

the electrode group protective sleeve (5) is provided with a plurality of outer side faces which are in contact with the inner side face of the battery shell (6), wherein at least one outer side face is a frosted face;

and/or, a plurality of inner side surfaces are arranged on the battery shell (6), wherein at least one inner side surface is a frosted surface.

2. The lithium ion secondary battery with high safety performance as claimed in claim 1, wherein the shape of the electrode group protective case (5) and the shape of the battery case (6) are both rectangular parallelepiped.

3. The lithium ion secondary battery of high safety according to claim 1, wherein the shape of the insulating protective tape (7) is "U" -shaped;

and insulating protective tapes (7) adhered to the front and rear sides of the battery case (6).

4. The lithium ion secondary battery with high safety performance as claimed in claim 1, wherein the roughness of the frosted surface of the electrode group protective case (5) and the roughness of the frosted surface of the battery case (6) are both 6.3 μm or less and Ra or less and 100 μm, wherein Ra is the contour arithmetic mean deviation.

5. The lithium ion secondary battery with high safety performance as claimed in claim 1, wherein when the outer side surface of the pole group protection sleeve (5) and the inner side surface of the battery case (6) are both frosted, the frosted surface on the pole group protection sleeve (5) and the frosted surface on the battery case (6) are arranged in opposite correspondence and are mutually contacted.

6. The lithium ion secondary battery of high safety according to claim 1, wherein the electrode group protective case (5) is a protective case made of PET, PP or PE;

the battery shell (6) is a hard shell or a soft shell.

7. The high-safety lithium ion secondary battery according to claim 1, wherein the material surface of the electrode group protective sleeve (5) is clean and free of oil stains and burrs at the edges;

the pole group protective sleeve (5) is an integrated protective sleeve or a split protective sleeve.

8. The lithium ion secondary battery with high safety performance as claimed in claim 1, wherein the bottom of the protective cover (5) of the electrode group is provided with a plurality of holes (50) at equal intervals.

9. The high-safety lithium ion secondary battery according to any one of claims 1 to 8, wherein the right and left outer side surfaces of the electrode group protective sheath (5) are frosted surfaces;

and the frosted area (51) of the frosted surface is positioned at the lower end of the left and right outer side surfaces of the pole group protective sleeve (5).

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