CN212991165U - Button type lithium ion battery and shell - Google Patents

Abstract

The utility model relates to a lithium ion battery field discloses a knot formula lithium ion battery and casing. The first shell wall of the shell comprises at least two cylindrical ring segments and convex ring segments formed by bending between every two adjacent cylindrical ring segments, the inner diameter and the outer diameter of each cylindrical ring segment are the same, the outer diameter of any two cylindrical ring segments is different, the outer diameter of the cylindrical ring segment close to the first top cover is narrower than the outer diameter of the cylindrical ring segment close to the opening of the first polar shell, the outer diameter of each convex ring segment is gradually narrowed from the opening of the first polar shell to the first top cover along the axial direction, and the inner diameter and the outer diameter of the sealing ring segment are narrowed from the opening of the first polar shell to the first top cover along the axial direction; the sealing ring is tightly sleeved on the first pole shell; the openings of the first polar shell and the second polar shell are oppositely sleeved; the first top cover and the second top cover are respectively positioned at the two axial ends of the first shell wall and the second shell wall which are sleeved with each other, and the first polar shell and the second polar shell form a sealed cavity. By adopting the scheme, the sealing performance of the button type lithium ion battery is improved.

Description

Button type lithium ion battery and shell

Technical Field

The utility model relates to a lithium ion battery makes the field, especially relates to a knot formula lithium ion battery and casing.

Background

With the wider application of intelligent wearable products, people have wider and wider requirements on small-size lithium ion button type secondary rechargeable batteries (button type lithium ion batteries for short). Button lithium ion battery is more and more applied to intelligent wearing products such as earphone etc.. Improving the sealing performance of the button cell is a major problem to be solved at present.

The inventor is carrying out the utility model discloses an in the research process discovery, present button cell adopts, adopts a segmentation compression to seal, has the leakproofness risk, especially when depositing and circulate to certain degree after, has the weeping risk easily.

Disclosure of Invention

An object of the embodiment of the utility model is to provide a knot formula lithium ion battery and casing adopts this technical scheme to be favorable to improving knot formula lithium ion battery's leakproofness.

In a first aspect, an embodiment of the present invention provides a button type lithium ion battery case, including:

the first pole shell comprises a first top cover and a first shell wall which are integrally formed, wherein the first shell wall is positioned on one surface of the first top cover and surrounds the edge of the first top cover, and the first shell wall comprises at least two cylindrical ring segments and convex ring segments formed by bending between every two adjacent cylindrical ring segments; the inner diameter and the outer diameter of each cylindrical ring section are the same; the outer diameters of any two cylindrical ring sections are different; the outer diameters of the cylindrical ring segments close to the first top cover are all narrower than the outer diameters of the cylindrical ring segments close to the opening of the first polar shell; the outer diameter of each convex ring segment is gradually narrowed from the opening of the first polar shell to the first top cover along the axial direction, and the inner diameter and the outer diameter of each sealing ring segment are narrowed from the width to the first top cover along the axial direction;

the sealing ring is tightly sleeved on the first pole shell;

a second diode housing including a second top cap and a second housing wall integrally formed with the second diode housing, the second housing wall surrounding an edge of the second top cap, being perpendicular to the second top cap, and being located on one side of the second top cap,

the openings of the first pole shell and the second pole shell are oppositely sleeved, the second shell wall is tightly sleeved outside the first shell wall, and the sealing ring is arranged between the first pole shell and the second pole shell at intervals;

the first top cover and the second top cover are respectively positioned at the two axial ends of the first shell wall and the second shell wall which are sleeved with each other, and the first polar shell and the second polar shell form a sealed cavity.

Optionally, the packing ring segment comprises: the cylindrical ring segments are at least three, and the two convex ring segments are respectively positioned between every two adjacent cylindrical ring segments and are formed by bending.

Optionally, the difference between the outer diameters of the two cylindrical ring segments located at the two axial ends of any convex ring segment is 0.1mm to 1 mm.

Optionally, the radially protruding width of any convex ring segment is 0.05mm to 0.5mm respectively.

Optionally, the inner wall of the sealing ring is closely attached to the outer wall of the first housing wall and the end surface of the opening.

Optionally, a raised annular boss and an inward recessed groove are further arranged on the outer wall of the sealing ring,

when the opening of the first top cover is downward, the groove is positioned below the annular boss and extends to the opening position of the first pole shell,

the annular boss is pressed between the first shell wall and the second shell wall to seal a gap between the first shell wall and the second shell wall, and the groove completely enters between the first shell wall and the second shell wall.

Optionally, at least two grooves are arranged on the outer wall of the sealing ring.

Optionally, each of the grooves is uniformly distributed around an outer wall of the seal ring.

Optionally, each groove is parallel to the axial direction of the seal ring.

Optionally, the axial width of the annular boss is greater than or equal to 0.1mm and less than or equal to 0.5 mm.

Optionally, the depth of the groove is 1/2 times the wall thickness of the first housing wall in which the groove is located.

Optionally, the wall thickness of the first cylindrical ring section of the second casing wall at the end of the open side is greater than the wall thickness of the ring section between the first cylindrical ring section and the second top cover;

the first cylindrical ring segment of the second casing wall is compressed: and the sealing ring is positioned outside the sealing ring outside the convex ring section close to the first top cover.

Optionally, the outer diameter of the second casing wall is uniform, and the inner diameter of the first cylindrical ring segment of the second casing wall is smaller than the inner diameter of the ring segment between the first cylindrical segment and the second top cover.

Optionally, the wall thickness of the first cylindrical ring segment of the second casing wall is greater than or equal to 0.15mm and less than or equal to 0.25 mm.

Optionally, the wall thickness on the second casing wall is greater than or equal to 0.05mm and less than or equal to 0.15mm, excluding the first cylindrical ring segment.

Optionally, the wall thickness of the outer convex ring segment of the first housing wall close to the first top cover is greater than the wall thickness of the ring segment between the outer convex ring segment and the opening of the first pole housing.

Optionally, the wall thickness of the outer convex ring segment of the first casing wall proximate the first head cover, and the first head cover to the outer convex ring segment are uniform.

Optionally, a wall thickness of the outer convex ring segment of the first casing wall proximate the first head cover is greater than or equal to 0.15mm and less than or equal to 0.25 mm.

Optionally, a wall thickness of a ring segment of the first casing wall from the outer convex ring segment proximate to the first head cover to an opening of the first casing wall is greater than or equal to 0.05mm and less than or equal to 0.15 mm.

Optionally, the first pole piece and the second pole piece are steel shells respectively.

In a second aspect, an embodiment of the present invention provides a button type lithium ion battery, including:

the button lithium ion battery case as described above,

the battery comprises a battery cell and a battery cover, wherein the battery cell comprises positive plates, negative plates and diaphragms, the diaphragms are arranged between any adjacent positive plates and negative plates at intervals, one of the positive and negative electrodes of the battery cell is electrically connected with a first pole shell, and the other of the positive and negative electrodes of the battery cell is electrically connected with a second pole shell;

and the electrolyte is soaked in the electric core.

Therefore, according to the technical scheme of the embodiment, because the outer diameter of the shell of the button lithium ion battery of the embodiment is changed in a multi-section step mode along the axial direction, the first shell wall positioned at the inner layer is provided with the multi-section cylindrical ring sections along the axial direction, and the outer convex ring sections protruding in the radial direction are arranged between every two cylindrical ring sections, when the second shell wall is sealed, besides the radial inward acting force on the second shell wall, when the second shell wall positioned at the periphery is pressed inwards, the second shell wall positioned at the first outer convex ring section is also provided with the pressure for pressing the first outer convex ring section, the second shell wall is pressed above the first outer convex ring section, and the first outer convex ring section provides a radial support for pressing the second shell wall, so that the sealing performance for pressing the second shell wall is improved. And because the first convex ring section adopts the reducing structure, radial deformation is not easy to occur, and the sealing performance of the button lithium ion battery after storage or circulation is easier to improve.

In addition, in the embodiment, the change direction of the outer diameter of the first shell wall is single from narrow to wide from the direction from the first top cover to the opening, the change direction can be realized by stamping, the processing technology is simple, the processing cost is low, and the first shell wall is not easy to deform after being processed.

This embodiment is through setting up a plurality of evagination ring segments, and the axial width of every section cylindricality ring segment shortens greatly, and intensity improves greatly and be difficult for warping, more is favorable to the attenuate design of casing, and this embodiment can be through setting up each evagination ring segment's radial evagination width narrower to ensure the volume that is used for holding electric core in the casing, be favorable to improving knot formula lithium ion battery's capacity.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, do not constitute an undue limitation on the invention.

Fig. 1 is a schematic structural diagram of a first pole piece provided in embodiment 1 of the present invention;

fig. 2 is a schematic structural diagram of a second pole piece provided in embodiment 1 of the present invention;

fig. 3 is a schematic view of an assembly structure of a button-type lithium ion battery case provided in embodiment 1 of the present invention;

fig. 4 is a schematic structural diagram of a button-type lithium ion battery case provided in embodiment 1 of the present invention;

fig. 5 is a schematic structural diagram of a first pole piece provided in embodiment 2 of the present invention;

fig. 6 is a schematic structural diagram of a second pole piece provided in embodiment 2 of the present invention;

fig. 7 is a schematic structural diagram of a button-type lithium ion battery case provided in embodiment 2 of the present invention;

fig. 8 is a schematic structural view of a seal ring provided in embodiment 3 of the present invention;

fig. 9 is a schematic cross-sectional structure view of a button lithium ion battery provided in embodiment 3 of the present invention during electrolyte injection;

FIG. 10 is an enlarged schematic view of the component C of FIG. 9;

fig. 11 is a schematic cross-sectional view of a button-type lithium ion battery case provided in embodiment 4 of the present invention;

fig. 12 is a schematic structural diagram of a button-type lithium ion battery provided by the comparative example 1 of the present invention.

Reference numerals:

1: a first pole piece; 11: a first top cover; 12: a first pole piece;

121: a first cylindrical ring segment of the first casing wall; 122: a second cylindrical ring section; 123: a third column exchanging section;

131: a first convex ring section;

2: a second pole piece; 21: a second top cover; 22: a second shell wall;

221: a first cylindrical ring segment of the second shell wall;

3: a seal ring; 31: an annular boss; 32: a groove; 14: an annular table.

Detailed Description

The invention will be described in detail with reference to the drawings and specific embodiments, wherein the exemplary embodiments and descriptions are provided to explain the invention, but not to limit the invention.

Example 1

As shown in reference to figures 1-4,

this embodiment provides a button lithium ion battery, and it mainly includes: the battery comprises a battery core, electrolyte soaked in the battery core and a shell for sealing the battery core. The battery cell can be a laminated battery cell or a winding battery cell, and comprises a positive plate, a negative plate and a diaphragm, wherein the diaphragm is arranged between the adjacent positive plate and the negative plate at intervals. The first electrode shell 1 of one of the anode and the cathode of the battery cell is electrically connected, and the other is electrically connected with the second electrode shell 2, so that the two electrode shells forming the shell are used as electrodes of the button lithium ion battery to provide power supply for the outside. The present embodiment may be, but is not limited to, illustrated with the first pole case 1 as the negative electrode and the second pole case 2 as the positive electrode, but is not limited thereto.

The polar shell of this embodiment mainly includes first polar shell 1, second polar shell 2, sealing washer 3, first polar shell 1, the opening of second polar shell 2 is just facing to cup jointing, form the cavity of holding electric core, first polar shell 1, second polar shell 2 respectively with the negative pole of electric core, anodal electric connection, first top cap 11, second top cap 21 is as button lithium ion battery's negative pole respectively, anodal, sealing washer 3 cup joints at the cover at first polar shell 1, between second polar shell 2, with sealed first polar shell 1, the clearance between the second polar shell 2, realize the sealing of electric core, and for button lithium ion battery's positive pole, the negative pole provides insulating isolation.

The utility model discloses use first polar shell 1 to be connected as first polar shell 1 with the negative pole of electric core and cup joint at the inlayer, second polar shell 2 cup joints as second polar shell 2 with the positive pole of electric core and is the indication at the skin, but actually is not limited to here.

The first pole piece shell 1 is of an integrated structure and comprises a first top cover 11 and a first shell wall 12, wherein the first shell wall 12 surrounds the edge of the first top cover 11, is positioned on one surface of the first top cover 11, is perpendicular to the first top cover 11, and forms a semi-closed shell with an opening at one axial end and the first top cover 11 at the other axial end;

the first pole shell 1 is prepared by the following process: the method comprises the steps of placing a first metal sheet (preferably, but not limited to, a steel sheet) in a stamping device, stamping the first metal sheet by using a stamping die head, stamping the first metal sheet to form a first polar shell 1 when the stamping die head is pressed downwards, wherein a first top cover 11 is located at the lowest part of the stamping die head, a first shell wall 12 is formed around the edge of the first top cover 11 and around the axial periphery of the stamping die head, and the outer diameter of the first shell wall 12 is in multi-stage step change along the axial direction of the first shell wall 12.

Namely, the direction of the opening from the first top cover 11 to the first pole housing 1 along the axial direction of the first housing wall 12 is divided into: the first cylindrical ring section 121 and the second cylindrical ring section 122, and a first outer convex ring section 131 formed by bending is arranged between the first cylindrical ring section 121 and the second cylindrical ring section 122.

The outer diameter of the first cylindrical ring section 121 is smaller than that of the second cylindrical ring section 122, and the difference value is about 0.1mm to 1mm, such as but not limited to 0.4 mm. The outer diameter of the first outer convex ring segment 131 gradually narrows and widens in the axial direction from the first top cover 11 to the opening of the first pole housing 1. The connection part with the first cylindrical ring segment 121 is the narrowest part of the outer diameter, and the outer diameter is equal to the outer diameter of the first cylindrical ring segment 121; the junction with second cylindrical ring section 122 is the widest point of the outer diameter, which is equal to the outer diameter of second cylindrical ring section 122. The first outer convex ring section 131 is bent in an R-shaped angle, and is a slightly flat saddle protruding outward between the first cylindrical ring section 121 and the second cylindrical ring section 122, and the width of the edge (radial width of the saddle) of the first outer convex ring section 131 protruding outward from the first cylindrical ring section 121 in the radial direction is about 0.05mm to 0.5mm, such as but not limited to 0.4 mm.

In the embodiment, when the second casing wall 22 is sealed, in addition to the radially inward acting force on the second casing wall 22, when the peripherally located second casing wall 22 is pressed inward, a pressing force for pressing the first outer convex ring segment 131 is also applied to the second casing wall 22 located at the first outer convex ring segment 131, so that the second casing wall 22 is pressed above the first outer convex ring segment 131, and the first outer convex ring segment 131 provides a radial support for pressing the second casing wall 22, thereby improving the sealing performance for pressing the second casing wall 22. In addition, the first outer convex ring segment 131 adopts a reducing structure, so that radial deformation is not easy to occur, and the sealing performance of the button lithium ion battery after storage or circulation is easier to improve.

The second pole piece 2 is an integrated structure, and includes a second top cap 21 and a second shell wall 22, the second shell wall 22 surrounds the edge of the second top cap 21, is located on one side of the second top cap 21, is perpendicular to the second top cap 21, and forms a semi-closed shell with an open end at one axial end and the second top cap 21 at the other axial end.

The manufacturing process of the second pole housing 2 can be, but is not limited to, implemented according to the prior art, and it can be, but is not limited to, formed by a stamping process, and it can be, but is not limited to, manufactured in a cylindrical shape with a uniform inner diameter and an outer diameter of the second housing wall 22. And when sealing, the second shell wall 22 is clamped outside the sealing ring 3 outside the first shell wall 12, and the sealing ring 3 is pressed to realize the sealing of the button type lithium ion battery shell, wherein the shape of the clamped second shell wall 22 of the first shell wall 12 is the same as that of the first shell wall 12.

The sealing ring 3 is coaxial with the first pole shell 1 and the second pole shell 2, the sealing ring 3 is tightly sleeved on the first pole shell 1, a flange at the tail end of the sealing ring 3 is tightly sleeved on the end face of an opening of the first shell wall 12, a main body of the sealing ring 3 is tightly sleeved on the outer wall of the first shell wall 12 until the sealing ring is close to or reaches the first top cover 11 (the first top cover 11 is not coated), the tail end of the sealing ring 3 close to the end of the first top cover 11 is tightly sleeved on the first shell wall 12, and the tail end of the sealing ring 3 is marked as a sealing position.

When assembling, overlap sealing washer 3 on first polar shell 1, then, put into first polar shell 1 with electric core, with the positive pole of electric core, negative pole respectively with first polar shell 1, the electric connection of second polar shell 2, realize the electrode connection, first polar shell 1 is as button cell's negative pole, and second polar shell 2 is as anodal.

And then, completing the processes of electrolyte injection, shell sealing and the like according to the prior art to obtain the button type lithium ion battery.

In the case sealing process of this embodiment, the openings of the first and second polar cases 1 and 2 are sleeved with each other, the second casing wall 22 is sleeved in the first casing wall 12, and the sleeved first and second polar cases 1 and 2 are pushed in to make the first and second top caps 11 and 21 approach each other until the two are completely sleeved with each other. Then, by adopting a shell sealing technology, a sealing device is adopted to press the second shell wall 22 outside the sealing ring section of the first shell wall 12 inwards, the second shell wall 22 deforms and is pressed against the outside of the first shell wall 12, the sealing ring 3 between the first shell wall 12 and the second shell wall 22 is pressed firmly, and the shell is sealed completely.

It can be seen from the above that, with the technical solution of this embodiment, the outer diameter of the casing of the button lithium ion battery of this embodiment is in multi-stage step change along the axial direction. In addition to the radial inward acting force on the second casing wall 22 when sealing the second casing wall 22, and when the second casing wall 22 located at the periphery is pressed inward, a pressing force is further applied to the second casing wall 22 located at the first outer convex ring section 131 to press the second casing wall 22 tightly above the first outer convex ring section 131, and the first outer convex ring section 131 provides a radial support for pressing the second casing wall 22, so that the sealing performance of pressing the second casing wall 22 is improved. In addition, the first outer convex ring segment 131 adopts a reducing structure, so that radial deformation is not easy to occur, and the sealing performance of the button lithium ion battery after storage or circulation is easier to improve.

In addition, in the embodiment, the direction from the first top cap 11 to the opening and the changing direction of the outer diameter of the first shell wall 12 are single, all from narrow to wide, and the changing direction can be realized by stamping, so that the processing technology is simple, the processing cost is low, and the deformation is not easy to occur after the processing.

Example 2:

as shown with reference to figures 5-7,

the button lithium ion battery of the embodiment is different from the button lithium ion battery of the embodiment 1 mainly in that:

the outer diameter of the first pole shell 1 of this embodiment adopts a three-section gradient structure, and the sealing ring segments on the first pole shell 1 are three sections, and the specific structure is as follows.

The sealing ring segment of the first pole shell 1 is divided into the following parts along the axial direction from the position close to the first top cover 11 to the opening direction of the first pole shell 1: the first, second and third cylindrical ring segments 121, 122, 123 are respectively a first outwardly convex ring segment 131 formed by bending between the first and second cylindrical ring segments 121, 122, and a second outwardly convex ring segment 132 formed by bending between the second and third cylindrical ring segments 122, 123.

As can be seen from the figure, the outer diameter of the first cylindrical ring segment 121 is smaller than the outer diameter of the second cylindrical ring segment 122, and the difference value is about 0.1mm to 1mm, such as but not limited to 0.4 mm. The outer diameter of the narrowest part of the first outer convex ring segment 131 is equal to the outer diameter of the first cylindrical ring segment 121, the outer diameter of the widest part is equal to the outer diameter of the second cylindrical ring segment 122, the first outer convex ring segment 131 is bent in an R-shaped manner to form a slightly flat saddle protruding outwards between the first cylindrical ring segment 121 and the second cylindrical ring segment 122, and the width of the edge (the radial width of the saddle) of the first outer convex ring segment 131 protruding outwards along the radial direction outside the first cylindrical ring segment 121 is about 0.05mm to 0.5mm, such as but not limited to 0.2 mm.

The outer diameter of the second cylindrical ring section 122 is smaller than that of the third cylindrical ring section 123, and the difference value is about 0.1mm to 1mm, such as but not limited to 0.4 mm. The outer diameter of the narrowest part of the second outer convex ring section 132 is equal to the outer diameter of the second cylindrical ring end, the outer diameter of the widest part is equal to the outer diameter of the third cylindrical ring section 123, the second outer convex ring section 132 is bent in an R-shaped angle and is a slightly flat boss protruding outwards between the second cylindrical ring section 122 and the third cylindrical ring section 123, and the width of the edge (radial width of the boss) of the second outer convex ring section 132 protruding outwards along the radial direction of the second cylindrical ring section 122 is about 0.05 mm-0.5mm, such as but not limited to 0.2 mm.

The manufacturing process of this embodiment is different from that of embodiment 1 in that, when the second casing wall 22 located at the periphery is pressed inward, pressure for pressing down the first outer convex ring segment 131 and the second outer convex ring segment 132 is further sequentially applied to the second casing wall 22 located at the first outer convex ring segment 131 and the second outer convex ring segment 132, the second casing wall 22 is pressed tightly above the first outer convex ring segment 131 and the second outer convex ring segment 132, and the first outer convex ring segment 131 and the second outer convex ring segment 132 provide radial pedestals for pressing, so that the sealing performance of pressing is improved. In addition, the first outer convex ring segment 131 and the second outer convex ring segment 132 adopt a reducing structure, so that radial deformation is not easy to occur, and the sealing performance of the button lithium ion battery after storage or circulation is easier to improve.

This embodiment is through setting up a plurality of evagination ring segments, and the axial width of every section cylindricality ring segment shortens greatly, and intensity improves greatly and be difficult for warping, more is favorable to the attenuate design of casing, and this embodiment can be through setting up each evagination ring segment's radial evagination width narrower to ensure the volume that is used for holding electric core in the casing, be favorable to improving knot formula lithium ion battery's capacity.

Example 3:

as shown with reference to figures 8-10,

the button lithium ion battery of the present embodiment is different from embodiment 2 mainly in that:

the outer wall of the sealing ring 3 of this embodiment is further provided with an annular boss 31 protruding from the outer wall and a groove 32 recessed inward relative to the outer wall of the sealing ring 3, wherein the annular boss 31 is coaxial with the sealing ring 3 and surrounds the periphery of the sealing ring 3.

The uppermost end of the groove 32 is non-through, the uppermost end of the groove 32 is located below the annular boss 31, the groove 32 extends from top to bottom along the outer wall of the sealing ring 3 to the lowest part of the sealing ring 3, and the lowest opening end is an open notch which is through downwards, so that electrolyte injected from the upper part of the groove 32 can flow out from the lowest notch.

Correspondingly, the preparation process of the button lithium ion battery of the embodiment is adaptively adjusted as follows:

before liquid injection, the openings of the first polar shell 1 and the second polar shell 2 are sleeved oppositely, the second shell wall 22 is sleeved in the first shell wall 12, the sleeved first polar shell 1 and the sleeved second polar shell 2 are pushed, the first top cover 11 and the second top cover 21 are enabled to approach oppositely until the annular boss 31 of the first shell wall 12 is not sleeved in the second shell wall 22 and is positioned outside the second shell wall 22, and the part of the groove 32 close to the annular boss 31 is not sleeved in the second wall and is positioned outside the second shell wall 22, and the pushing is suspended. Under the low dew point environment, a certain amount of electrolyte is filled into the groove 32 exposed outside the second shell wall 22, the filled electrolyte flows down along the groove 32 and flows out of the notch positioned at the opening of the first polar shell 1 to enter the cavity between the first polar shell 1 and the second polar shell 2, and the battery cell absorbs the electrolyte to complete electrolyte injection.

Specific priming processes may be, but are not limited to, participating in the prior art.

After the liquid injection is completed, the sleeving connection between the first pole piece shell 1 and the second pole piece shell 2 is further pushed until the first pole piece shell and the second pole piece shell are completely sleeved, when the first pole piece shell and the second pole piece shell are completely sleeved, the groove 32 on the sealing ring 3 is completely sleeved between the first shell wall 12 and the second shell wall 22, and all or part of the annular boss 31 is completely sleeved in the second shell wall 22, the annular boss 31 of the sealing ring 3 between the first shell wall 12 and the second shell wall 22 is in a tension compression state, the annular boss 31 seals a gap between the first shell wall 12 and the second shell wall 22, and the first pole piece shell 1 and the second pole piece shell 2 seal a battery cell between the first pole piece shell.

In order to further improve the sealing performance of the button lithium ion battery, a sealing position is further arranged on the sealing ring 3, specifically, the inner diameter of the ring section of the extreme end of the sealing ring 3 close to the first top cover 11 side is smaller than the background of the sealing ring 3, so that the extreme end of the sealing ring 3 is relatively tightly coated on the first pole shell 1.

It can be seen from above that for current before the lock bipolar shell, keep the opening of first polar shell 1 to open the prior art of annotating the liquid, adopt this embodiment technology, cup joint to certain degree back in first conch wall 12, second conch wall 22, keep this cup jointing the lock state, annotate liquid from on exposed sealing washer 3's the recess 33, thereby avoided prior art to annotate liquid operation and remove the polar shell and pull the utmost point ear of electric core and lead to utmost point ear rupture and then lead to the problem of product badness. By adopting the technical scheme of the embodiment, the convenience of liquid injection of the button type lithium ion battery is improved, the quantitative liquid injection of the button type lithium ion batteries in batches is realized, the batch consistency is favorably improved, the battery performance is improved, and the qualification rate is improved.

As an illustration of the present embodiment, the grooves 32 provided on the outer wall of the seal ring 3 may be one as shown in fig. 1 to 8; the number of the grooves 32 may be plural, and the grooves are uniformly distributed on the outer wall of the sealing ring 3 along the outer circumference thereof, which is not limited specifically.

As an illustration of the present embodiment, the depth of the groove 32 provided on the outer wall of the seal ring 3 may be, but is not limited to, about 1/2 of the wall thickness of the seal ring 3 where the groove 32 is located.

As an illustration of the present embodiment, referring to the illustration of the present embodiment, each groove 32 extends linearly to the opening of the first pole housing 1 on the outer wall of the seal ring 3, preferably parallel to the axial direction of the seal ring 3. However, the present invention is not limited to this, and the grooves 32 may be provided on the outer wall of the seal ring 3 in a winding or spiral shape.

As an illustration of the present embodiment, the height of the protrusion of the annular boss 31 of the sealing ring 3 relative to the outer wall of the sealing ring 3 is about 0.01mm to 0.2mm, such as but not limited to about 0.05mm to 0.1mm higher than the outer wall of the sealing ring 3.

As an illustration of the present embodiment, the axial distance between the groove 32 on the outer wall of the sealing ring 3 of the present embodiment and the extreme end (also called sealing position) of the sealing ring 3 near the first top cover 11 side is greater than 0.5mm, so as to reserve a position with the largest width in the axial direction for the annular boss 31, and make the axial width of the annular boss 31 between 0.1mm and 0.5mm, so as to ensure the sealing performance of the button cell.

Example 4:

as shown in fig. 11.

As an illustration of the present embodiment, the present embodiment further provides a design scheme of the second pole casing 2, a wall thickness of the first cylindrical ring segment 221 on the opening side of the second casing wall 22 of the present embodiment is thicker than a wall thickness of a ring segment between the first cylindrical ring segment 221 and the second top cover 21, when sealing is performed, the first cylindrical ring segment 221 of the second casing wall 22 is tightly pressed on the first outer convex ring segment 131 of the first casing wall 12 to be attached to the first outer convex ring segment 131, and the annular boss 31 of the seal ring 3 is tightly clamped between the first cylindrical ring segment 221 of the second pole casing 2 and the first outer convex ring segment 131 of the first pole casing 1.

As an illustration of the present embodiment, the inner wall of the second housing wall 22 is designed to have the same outer diameter, so that the outer periphery of the button cell is smooth; the inner diameter of the first cylindrical ring section 221 is designed to be smaller than the inner diameter of the ring section from the first cylindrical ring section 221 to the second top cover 21, so that the inner wall of the first cylindrical ring section 221 protrudes inwards relatively, and the gap between the first casing wall 121 and the second casing wall 222 is narrowed at the position of the first cylindrical ring section 221 of the second casing wall 22.

As an illustration of the present embodiment, the wall thickness of the first cylindrical ring segment 221 of the second casing wall 22 of the present embodiment is preferably, but not limited to, 0.15mm to 0.25 mm; the wall thickness of the second shell wall 22 at other positions than the first cylindrical ring section 221 may be, but is not limited to, 0.05mm to 0.15 mm.

In the embodiment, the wall thickness of the first cylindrical ring segment 221 with a narrow radial width at the end of the opening of the second casing wall 22 is thickened, so that the rigidity and the deformation resistance of the first cylindrical ring segment 221 of the second casing wall 22 are ensured, the second casing wall 22 is ensured to firmly press the sealing ring 3 outside the first casing wall 121, the sealing performance of the casing is ensured, and the casing deformation and further the loosening of the annular seal, which are caused by the expansion force generated in the battery charging and discharging process, are avoided to influence the air tightness of the casing to cause liquid leakage. In this embodiment, on the basis of thickening the first cylindrical ring segment 221 of the second casing wall 22, the wall thicknesses of other positions of the second pole casing 2 are thinned, so that more cavity spaces for accommodating the battery cells are reserved, and the capacity of the button-type lithium ion battery is improved. In conclusion, by adopting the embodiment, on the basis of ensuring the sealing strength of the shell, the capacity of the button type lithium ion battery is improved, and the problem that the capacity of the button type lithium ion battery in the prior art is limited is solved.

As an illustration of the present embodiment, the axial width of the first cylindrical ring segment 221 at the open end of the second pole shell 2 is designed to be ultra-narrow, and when the first pole shell is set in the non-bending state, the axial width of the first cylindrical ring segment 221 is a, but the value of a may be designed to be greater than or equal to 0.2mm and less than or equal to 1 mm. During specific design, if the specification of the current button type lithium ion battery is smaller, the value A can be a smaller value in the range; if the current specification of the button type lithium ion battery is larger, the value A can be a larger value in the range, so that the strength of the annular seal of the shell is improved, and the sealing strength of the shell is improved.

As an illustration of the present embodiment, the wall thickness of the first polar shell 1 of the present embodiment is preferably, but not limited to, an ultra-thin design, such as, but not limited to, the wall thickness of the first polar shell 1 is designed to be 0.05mm to 0.15mm, which is lower than the lower limit of 0.2mm required in the prior art.

As an illustration of the present embodiment, but not limited to, the wall thickness of the outer convex ring segment of the first pole shell 1 near the first top cover 11 section may be further thickened. The outer wall of the convex ring section is made to be level with the outer wall of the other position of the first polar shell 1, and the convex ring section is protruded inwards on the inner wall. By way of illustration of the present embodiment, it is preferable, but not limited to, to design the wall thickness of the outer convex ring section of the first pole shell 1 near the first top cover 11 section to be 0.15mm to 0.25 mm.

Referring to fig. 11, as an illustration of the present embodiment, it is also preferable, but not limited to, to thicken the wall thickness from the outer convex ring segment near the first top cover 11 segment to the first top cover 11 (including the first top cover 11), so that the wall thickness is consistent with the wall thickness of the outer convex ring segment near the first top cover 11 segment, and the inner wall and the outer wall are both flat with the outer convex ring segment near the first top cover 11 segment. Correspondingly, the wall thickness of the first pole shell 1 close to the opening side is designed to be ultrathin, and the wall thickness is preferably but not limited to 0.05 mm-0.15 mm and is lower than the lower limit of 0.2mm required in the prior art.

As an illustration of the present embodiment, the first top cover 11 and the second top cover 21 of the present embodiment are respectively circular, and form a cylindrical button lithium ion battery.

The first and second pole shells 1 and 2 are steel shells in the present embodiment, but may be made of other corrosion-resistant, rigid, and strong alloy materials.

Comparative analysis of test data:

in order to further facilitate understanding of the technical solution and the effects of the embodiments of the present invention, the button lithium ion battery 1654 is made as an illustration below, wherein the outer diameter of the widest part of the button lithium ion battery is 16mm, and the axial thickness of the button lithium ion battery is 5.4 mm.

Experimental example 1:

the button type lithium ion battery structure is shown in fig. 1-4, wherein the wall thickness of the first pole shell 1 and the wall thickness of the second pole shell 2 are both 0.2mm, and the thickness of the sealing ring 3 is 0.25 mm.

The preparation process and the specific structure are described in detail in example 1.

Experimental example 2:

the button lithium ion battery structure is shown in figures 5-7.

The same as experimental example 1, wherein the wall thickness of the first polar shell 1 and the second polar shell 2 is 0.2mm and 0.15 mm. In contrast to experimental example 1, this embodiment is provided with two convex ring segments.

The preparation process and the specific structure of the sample of the experimental example refer to the detailed description of example 2.

Experimental example 3:

button lithium ion battery structures are shown in fig. 8-10.

Wherein the wall thickness of first utmost point shell 1, second utmost point shell 2 is 0.2mm, and the thickness that is located of sealing washer 3 is 0.15 mm.

The opening side of the sealing ring 3 close to the second pole shell 2 is provided with an annular boss 31, the axial width on the annular boss 31 is 0.3mm, the thickness of the outer wall of the sealing ring 3 protruded by the annular boss 31 is 0.05mm, a groove 32 is arranged below the annular boss, the depth of the groove 32 is 0.1mm, the groove and the annular boss have a certain distance, and the groove axially extends to the opening end of the first shell wall 12.

The liquid injection of the embodiment is exposed at the parts of the first polar shell 1 and the second polar shell 2 which are sleeved in the grooves

The preparation process and the specific structure are described in detail in example 2.

Experimental example 4:

the button lithium ion battery structure is shown in fig. 11.

The present embodiment is different from experimental example 3 mainly in that:

the first outer convex ring segment 131 of the second pole casing 2 facing the first pole casing 1 is a first cylindrical ring segment 221, the wall thickness of the first cylindrical ring segment 221 is 0.25mm, and the wall thickness of the other positions of the second pole casing 2 is 0.1 mm.

Wherein the wall thickness from the first top cover 11 to the first outer convex ring section 131 (including the first outer convex ring section 131) of the first pole shell 1 is 0.25mm, and the wall thickness of other positions of the first pole shell 1 is 0.1 mm.

The rest was the same as in experimental example 3.

Experimental example 5:

the button lithium ion battery structure of experimental example 5 is shown in fig. 12.

The wall thickness of the first polar shell 1 and the wall thickness of the second polar shell 2 are both 0.2mm, and the wall thicknesses of all the parts are uniform.

The middle part of the first pole shell 1 of the present embodiment is an arc wall plate protruding outwards. However, the utility model discloses carrying out this sample trial-manufacturing in-process discovery, because this circular arc portion is the diameter from first top cap 11 to the opening direction and is narrowed down by narrow widen earlier by the width again, this outside bellied circular arc structure can't adopt the technology punching press of punching press to go out. In this experimental example, the first cylindrical pole shell 1 is first punched, and then the convex arc structure is tapped outwards through the tapping device, so as to obtain the first pole shell 1.

Assembling the battery core into the first pole shell 1, injecting liquid, assembling the first pole shell 1 and the second pole shell 2, and compressing the second pole shell 2. The inventor finds that the comparative example adopts an outward convex arc-shaped structure, and the convex arc-shaped structure shrinks inwards to restore deformation to a certain extent when the comparative example is kept still for a certain time and the second pole piece shell 2 is tightly pressed.

Leak tightness limit test:

experimental equipment: vacuum oven, electronic balance

The vacuum oven has the setting parameters of-100 Kpa of vacuum degree, 60 ℃ of set temperature and 168h of set resting time.

The test method comprises the following steps:

1. weighing the sample by using an electronic balance, and recording the weight W1;

2. placing in a vacuum oven;

3. after the placement, cooling for 2-4 hours at normal temperature;

4. weighing the sample by using an electronic balance, and recording the weight W2;

5. weight loss = W1-W2.

The following data were obtained according to the above tests:

therefore, by adopting the technical scheme of the embodiment, the sealing performance of the button type lithium ion battery is improved.

The above-described embodiments do not limit the scope of the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the above-described embodiments should be included in the protection scope of the technical solution.

Claims (21)

1. A button type lithium ion battery shell is characterized by comprising:

a first pole shell comprising a first top cover and a first shell wall which are integrally formed, wherein the first shell wall is positioned on one surface of the first top cover and surrounds the edge of the first top cover,

the first shell wall comprises at least two cylindrical ring segments and convex ring segments formed by bending between every two adjacent cylindrical ring segments, the inner diameter and the outer diameter of each cylindrical ring segment are the same, the outer diameters of any two cylindrical ring segments are different, the outer diameter of the cylindrical ring segment close to the first top cover is narrower than the outer diameter of the cylindrical ring segment close to the opening of the first polar shell,

the outer diameter of each convex ring segment is gradually narrowed from the opening of the first pole shell to the first top cover along the axial direction,

the inner diameter and the outer diameter of the sealing ring section are narrowed from wide to narrow from the opening of the first polar shell to the first top cover along the axial direction;

the sealing ring is tightly sleeved on the first pole shell;

a second diode housing including a second top cap and a second housing wall integrally formed with the second diode housing, the second housing wall surrounding an edge of the second top cap, being perpendicular to the second top cap, and being located on one side of the second top cap,

the openings of the first pole shell and the second pole shell are oppositely sleeved, the second shell wall is tightly sleeved outside the first shell wall, and the sealing ring is arranged between the first pole shell and the second pole shell at intervals;

the first top cover and the second top cover are respectively positioned at the two axial ends of the first shell wall and the second shell wall which are sleeved with each other, and the first polar shell and the second polar shell form a sealed cavity.

2. The button lithium ion battery case according to claim 1,

the sealing ring section comprises: the cylindrical ring segments are at least three, and the two convex ring segments are respectively positioned between every two adjacent cylindrical ring segments and are formed by bending.

3. The button lithium ion battery case according to claim 2,

the difference of the outer diameters of the two cylindrical ring sections positioned at the two axial end parts of any convex ring section is 0.1mm to 1 mm.

4. The button lithium ion battery case according to claim 2,

the radial protruding width of any convex ring section is 0.05 mm-0.5mm respectively.

5. The button lithium ion battery case according to claim 1,

the inner wall of the sealing ring is tightly attached to the outer wall of the first shell wall and the end face of the opening.

6. The button lithium ion battery case according to claim 5,

the outer wall of the sealing ring is also provided with a raised annular boss and an inward recessed groove,

when the opening of the first top cover is downward, the groove is positioned below the annular boss and extends to the opening position of the first pole shell,

the annular boss is pressed between the first shell wall and the second shell wall to seal a gap between the first shell wall and the second shell wall, and the groove completely enters between the first shell wall and the second shell wall.

7. The button lithium ion battery case according to claim 6,

the outer wall of the sealing ring is provided with at least two grooves.

8. The button lithium ion battery case according to claim 7,

each groove is uniformly distributed around the outer wall of the sealing ring.

9. The button lithium ion battery case according to claim 6,

the grooves are parallel to the axial direction of the sealing ring.

10. The button lithium ion battery case according to claim 6,

the axial width of the annular boss is greater than or equal to 0.1mm and less than or equal to 0.5 mm.

11. The button lithium ion battery case according to claim 6,

the depth of the groove is 1/2 the wall thickness of the first housing wall in which the groove is located.

12. The button lithium ion battery case according to claim 1,

the wall thickness of the first cylindrical ring section of the second shell wall at the tail end of the opening side is greater than that of the ring section between the first cylindrical ring section and the second top cover;

the first cylindrical ring segment of the second casing wall is compressed: and the sealing ring is positioned outside the sealing ring outside the convex ring section close to the first top cover.

13. The button lithium ion battery case according to claim 12,

the outer diameter of the second shell wall is consistent, and the inner diameter of the first cylindrical ring section of the second shell wall is smaller than the inner diameter of a ring section between the first cylindrical section and the second top cover.

14. The button lithium ion battery case according to claim 12,

the wall thickness of the first cylindrical ring section of the second shell wall is greater than or equal to 0.15mm and less than or equal to 0.25 mm.

15. The button lithium ion battery case according to claim 12,

the wall thickness on the second shell wall is greater than or equal to 0.05mm and less than or equal to 0.15mm except for the first cylindrical ring segment.

16. The button lithium ion battery case according to claim 12,

the wall thickness of the outer convex ring section of the first housing wall close to the first top cover is greater than the wall thickness of the ring section between the outer convex ring section and the opening of the first pole housing.

17. The button lithium ion battery case according to claim 16,

the wall thickness of the outer convex ring segment of the first shell wall proximate the first top cap, and the first top cap to the outer convex ring segment are uniform.

18. The button lithium ion battery case according to claim 16,

the wall thickness of the convex ring section of the first shell wall close to the first top cover is greater than or equal to 0.15mm and less than or equal to 0.25 mm.

19. The button lithium ion battery case according to claim 18,

the wall thickness of the ring section of the first shell wall from the outer convex ring section close to the first top cover to the opening of the first shell wall is greater than or equal to 0.05mm and less than or equal to 0.15 mm.

20. The button lithium ion battery case according to claim 1,

the first pole shell and the second pole shell are respectively steel shells.

21. A button type lithium ion battery is characterized by comprising:

the button lithium ion battery case according to any one of claims 1 to 20,

the battery comprises a battery cell and a battery cover, wherein the battery cell comprises positive plates, negative plates and diaphragms, the diaphragms are arranged between any adjacent positive plates and negative plates at intervals, one of the positive and negative electrodes of the battery cell is electrically connected with a first pole shell, and the other of the positive and negative electrodes of the battery cell is electrically connected with a second pole shell;

and the electrolyte is soaked in the electric core.

Images