Connection structure between current collector and cover plate and single structure of energy storage element

Abstract

The present invention discloses a connection structure between a current collector and a cover plate and a single structure of an energy storage element. The current collector is connected to a battery cell, which is inserted into a housing. The current collector includes a pole portion and a current collector. A plurality of positioning pieces and a plurality of openings are provided on the surface of the current collector. The plurality of positioning pieces are vertically arranged on the current collector and arranged on the periphery of the pole portion. A plurality of second positioning grooves are provided on the cover plate, which correspond to the positioning pieces, and the positioning pieces are inserted into the second positioning grooves. A positioning structure is provided between the current collector and the cover plate of the present invention to position the two in the axial, circumferential and radial directions respectively. After the current collector and the battery cell are fixed and then radially assembled with the cover plate, the relative position of the current collector and the cover plate can be determined by the positioning structure of the two to prevent the relative position of the two from shifting, thereby ensuring the uniformity of the distribution of the peripheral space of the battery cell and improving the energy density of the energy storage element.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage elements, and in particular to a connection structure between a current collector and a cover plate and a single structure of an energy storage element. Background Art

[0002] Energy storage components are widely used in various industries such as vehicles, electronic products, energy storage systems, transportation, smart grids, and industrial energy conservation and consumption reduction. Energy storage component technology is an important factor in their development. Energy storage component monomers are usually composed of positive electrodes, negative electrodes, shells, electrolytes, covers, and poles.

[0003] In the prior art, there is usually no positioning structure between the current collector, pole and cover of the energy storage element. During assembly, the relative positions of the current collector, pole and cover are easily offset, making the spatial distribution of the outer periphery of the battery cell uneven, thereby affecting the energy density of the energy storage element. The pole and current collector of the energy storage element are independently designed and processed, and then fixedly connected by welding. The processing and installation procedures are relatively cumbersome and costly; moreover, non-energy storage elements such as current collectors and poles need to occupy the limited space inside the energy storage element, which reduces the space of the energy storage element and reduces the utilization rate of the internal space of the energy storage element, thereby reducing the energy density of the energy storage element.

[0004] Conventional gaskets are usually used to seal between the pole and the cover of the existing energy storage element monomer. There is no additional radial force between the gasket and the pole. In order to ensure that the inner circumference of the gasket and the outer circumference of the pole are tightly sealed, the dimensional accuracy of the inner circumference of the gasket and the outer circumference of the pole is high. If the dimensional deviation is large, the gasket and the pole may not be tightly closed, which will affect the sealing effect and reduce the sealing reliability. The shell and cover of the existing energy storage element monomer are usually fixed by welding, and no seal is usually set between the two, which also affects the sealing performance inside the energy storage element, and the sealing reliability is not high enough. Summary of the invention

[0005] In view of the shortcomings of the above-mentioned existing energy storage element monomers, the applicant provides a rationally structured connection structure between the current collector and the cover plate and an energy storage element monomer structure, wherein the current collector and the cover plate are positioned by a positioning structure to prevent the relative positions of the two from shifting, thereby improving energy density and sealing reliability.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A connection structure between a current collector and a cover plate, the current collector comprising a pole part and a current collecting part, the pole part being vertically arranged in the center of the current collecting part, the pole part being passed through the cover plate, and a retaining ring being provided on the outer sleeve of the portion of the pole part passing through the cover plate for positioning; a first sealing member being provided between the pole part and the cover plate, the first sealing member being sleeved on the outer periphery of the pole part; a plurality of positioning plates and a plurality of openings being provided on the plate surface of the current collecting part, the plurality of positioning plates being vertically arranged on the current collecting part and arranged on the outer periphery of the pole part; a plurality of second positioning grooves being provided on the cover plate, the second positioning grooves corresponding to the positioning plates, the positioning plates being inserted into the second positioning grooves.

[0008] As a further improvement of the above technical solution:

[0009] The positioning piece is torn from the collector plate surface and then bent upward, and the bottom side of the positioning piece is connected to the collector plate surface; an opening is formed on the collector at the torn position of the positioning piece.

[0010] The pole part, the current collecting part and the positioning piece are integrally formed.

[0011] A first positioning groove is provided on the outer peripheral surface of the pole part, and the retaining ring is clamped in the first positioning groove.

[0012] The first sealing member is provided with a groove opening downwards, and the side surface of the groove close to the pole portion is a first inclined surface, which is inclined downwards and inwards from top to bottom.

[0013] The first sealing member is a V-ring or a Y-ring, and a V-shaped groove with an opening facing downward is formed at the bottom of the first sealing member, and two sides of the V-shape are symmetrically arranged; or a trapezoidal groove with an opening facing downward and a smaller upper part and a larger lower part is formed at the bottom of the first sealing member.

[0014] A countersunk hole is opened on the cover plate, and the first sealing member is arranged in the countersunk hole; the cover plate is made of insulating material.

[0015] A single energy storage element structure adopts the connection structure of the current collector and the cover plate, the current collector is connected to the battery core, and the battery core is inserted into the shell.

[0016] As a further improvement of the above technical solution:

[0017] A support ring and a flange are provided at the upper end of the shell, and the cover plate is located between the support ring and the flange; a second sealing member is provided between the outer peripheral surface of the cover plate and the inner peripheral surface of the shell; and the second sealing member is an O-ring.

[0018] The bottom surface of the battery cell is fixed to the bottom surface of the shell by bonding with conductive adhesive; or the battery cell is fixedly connected to the bottom surface of the shell by brazing, resistance welding or laser welding.

[0019] The beneficial effects of the present invention are as follows:

[0020] (1) A positioning structure is provided between the current collector and the cover plate of the present invention to position the two in the axial, circumferential and radial directions respectively. After the current collector and the battery cell are fixed and then assembled radially with the cover plate, the relative position of the current collector (and the battery cell) and the cover plate 4 can be determined by the positioning structure of the two, so as to prevent the relative position of the two from being offset, ensure the uniformity of the distribution of the outer peripheral space of the battery cell, and improve the energy density of the energy storage element. The pole part, the current collecting part and the positioning sheet of the current collector are integrally formed, and when the positioning sheet is processed, the opening is also processed at the same time. The opening can be used as a liquid injection hole, which saves processing steps, reduces processing difficulty and processing costs; the current collector integrates the pole part and the current collecting part into one part, which saves components and assembly steps, reduces material costs and production costs, and the integrated design avoids the problem of affecting the power transmission performance due to poor contact during the assembly process compared with the independent design and assembly method of the prior art, so that the power transmission is more reliable and the power transmission performance is better. A first positioning groove is provided on the outer peripheral surface of the pole part.

[0021] (2) The first seal between the cover plate and the pole part of the present invention is tightly attached to the cover plate under the action of the internal pressure of the energy storage element monomer, and the force acting on its first inclined surface has a radially inward component, which presses the inner side of the first seal tightly against the pole part to achieve sealing. The greater the internal pressure of the energy storage element monomer, the greater the radially inward component of force generated, the tighter the first seal is pressed against the pole part, the closer it is to the pole part, the better the sealing effect, and the higher the sealing reliability. Moreover, due to the action of the radial component of force, even if the outer peripheral surface size of the pole part has a slight deviation, the first seal can be pressed against the pole part under the action of the radial component of force, without affecting the sealing effect, the sealing reliability is high, and the processing requirements of the pole part are reduced.

[0022] (3) The battery cell of the present invention is in direct contact with the shell to achieve electrical conduction, which saves the use of the positive electrode transition collector, shortens the current flow formation, and improves the power transmission performance; and saves the transition collector, reduces the space occupied by non-energy storage components, increases the space occupied by energy storage components, and improves the space utilization rate inside the shell, thereby improving the energy density of the energy storage components. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is an exploded view of the present invention.

[0024] Figure 2 It is a cross-sectional view of the present invention.

[0025] Figure 3 for Figure 2 Enlarged view of part A in the middle.

[0026] Figure 4A three-dimensional diagram of the current collector.

[0027] Figure 5 A three-dimensional diagram of the cover.

[0028] In the figure: 1. shell; 11. support ring; 12. flange; 2. battery cell; 3. current collector; 31. pole part; 32. current collecting part; 33. positioning sheet; 34. opening; 35. first positioning groove; 4. cover plate; 41. countersunk hole; 42. sealing groove; 43. second positioning groove; 5. first sealing member; 51. groove; 52. first inclined surface; 53. second inclined surface; 6. second sealing member; 7. retaining ring. DETAILED DESCRIPTION

[0029] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0030] like Figure 1 , Figure 2 As shown, the housing 1 of the present invention is a cylinder with an open top and a closed bottom. The cylindrical battery cell 2 is inserted into the housing 1. The top of the battery cell 2 is connected to a current collector 3. The outer periphery of the current collector 3 is sleeved with a cover plate 4, which is fixed to the upper end of the housing 1. A first sealing member 5 is provided between the cover plate 4 and the current collector 3, and a second sealing member 6 is provided between the cover plate 4 and the housing 1. The cover plate 4 is made of insulating material.

[0031] like Figure 1 As shown, the bottom surface (positive electrode) of the battery cell 2 is fixed to the bottom surface of the shell 1 by conductive adhesive, and is electrically connected to the shell 1 by the conductive adhesive; the battery cell 2 can also be fixedly connected to the bottom surface of the shell 1 by brazing, resistance welding or laser welding, and is directly electrically connected to the shell 1. The battery cell 2 is directly in contact with the shell 1 to achieve electrical conduction, which saves the use of the positive electrode transfer collector, shortens the flow of current, and improves the power transmission performance; and saving the transfer collector also reduces the space occupied by non-energy storage components, increases the space occupied by energy storage components, and improves the space utilization rate inside the shell 1, thereby improving the energy density of the energy storage components.

[0032] like Figure 3 As shown, the upper end of the shell 1, located below the cover plate 4, is radially inwardly recessed to form a circle of annular support ring 11, and the upper side of the shell 1, located above the cover plate 4, is radially folded inward 90 degrees to form a circle of annular flange 12, and the flange 12 presses the cover plate 4 onto the support ring 11, and the support ring 11 and the flange 12 cooperate to axially position the cover plate 4 and fix the cover plate 4 on the shell 1.

[0033] like Figure 1 , Figure 2 , Figure 4As shown, the current collector 3 includes a pole part 31 and a current collector 32, and the pole part 31 is formed by vertically protruding upward from the center of the current collector 32. A plurality of positioning pieces 33 are arranged on the plate surface of the current collector 32 and located at the periphery of the pole part 31. The positioning pieces 33 are torn from the plate surface of the current collector 32 and bent upward by 90 degrees. The positioning pieces 33 are vertically protruded on the current collector 32, and the bottom side thereof is connected to the plate surface of the current collector 32; openings 34 are formed on the current collector 32 at the torn parts of the positioning pieces 33, and the openings 34 can be used as injection holes for the current collector 3. The electrolyte can be injected through the openings 34, which saves the process of additionally opening injection holes, reduces the processing difficulty, and reduces the processing cost. The pole part 31, the current collecting part 32 and the positioning piece 33 are integrally formed, and when the positioning piece 33 is processed, the opening 34 is also processed at the same time, which saves processing steps and reduces processing costs; the current collector 3 integrates the pole part 31 and the current collecting part 32 into one part, which saves components and assembly steps, reduces material costs and production costs, and the integrated design avoids the problem of poor contact affecting power transmission performance during assembly compared to the independent design and assembly method of the prior art, so that power transmission is more reliable and has better power transmission performance. A first positioning groove 35 is provided on the outer peripheral surface of the pole part 31. Figure 2 , Figure 3 As shown, the pole part 31 passes through the central through hole of the cover plate 4, and a retaining ring 7 is provided on the outer cover of the part where the pole part 31 passes through the cover plate 4 for positioning. The first positioning groove 35 of the pole part 31 is located on the upper side of the cover plate 4, and the retaining ring 7 is clamped in the first positioning groove 35. The retaining ring 7 cooperates with the first positioning groove 35 to form an axial positioning structure, which axially positions the current collector 3 to prevent the current collector 3 from axial movement.

[0034] like Figure 1 , Figure 2 , Figure 5 As shown, a countersunk hole 41 is provided at the lower part of the central through hole of the cover plate 4 and outside the pole part 31, and a first sealing member 5 is arranged in the countersunk hole 41 and sleeved on the outer periphery of the pole part 31. The first sealing member 5 is a V-shaped ring, and a V-shaped groove 51 with an opening facing downward is provided on its lower side, as shown in FIG. Figure 3 As shown, the side surface of the groove 51 close to the pole portion 31 is a first inclined surface 52, and the other side surface opposite is a second inclined surface 53. The first inclined surface 52 and the second inclined surface 53 are symmetrically arranged. The first inclined surface 52 is inclined downward and inward from top to bottom, and the second inclined surface 53 is inclined downward and outward from top to bottom. Figure 3As can be seen from the dotted arrow in the figure, the first seal 5 is tightly attached to the cover plate 4 under the internal pressure of the energy storage element monomer. At the same time, the force acting on the first inclined surface 52 has a radially inward component, and the radially inward component presses the inner side of the first seal 5 tightly against the pole part 31 to achieve sealing. The greater the internal pressure of the energy storage element monomer, the greater the radially inward component force generated, the more tightly the first seal 5 is pressed against the pole part 31, the closer it is to the pole part 31, the better the sealing effect, and the higher the sealing reliability. Moreover, due to the effect of the radial component force, even if the outer peripheral surface size of the pole part 31 has a slight deviation, the first seal 5 can be pressed against the pole part 31 under the action of the radial component force, without affecting the sealing effect, and the sealing reliability is high. In another embodiment, the first sealing member 5 may also be a Y-ring, and a V-shaped groove 51 with an opening facing downward is provided at the lower part of the Y-ring, and the side surface on the groove 51 close to the pole part 31 is a first inclined surface 52, and the other side surface opposite is a second inclined surface 53, and the first inclined surface 52 and the second inclined surface 53 are symmetrically arranged, and the first inclined surface 52 is inclined downwardly and inwardly from top to bottom, and the second inclined surface 53 is inclined downwardly and outwardly from top to bottom. In another embodiment, a trapezoidal groove 51 with an opening facing downward, a small upper part and a large lower part may also be provided at the lower part of the annular first sealing member 5, and the side surface on the groove 51 close to the pole part 31 is the first inclined surface 52, and the other side surface relatively symmetrically arranged is the second inclined surface 53, and the first inclined surface 52 is inclined downwardly and inwardly from top to bottom, and the second inclined surface 53 is inclined downwardly and outwardly from top to bottom. Of course, in other embodiments, a groove 51 of other shapes with an opening facing downward may also be opened on the annular first sealing member 5. As long as the side of the groove 51 close to the pole portion 31 has a first inclined surface 52 inclined downward and inward from top to bottom, the purpose of generating a radially inward component of force under the action of the internal pressure to press the first sealing member 5 onto the pole portion 31 can be achieved. The energy storage element monomer of the present invention is subjected to a closed test by a water immersion method to verify its sealing property: the energy storage element monomer is connected to an air pipe, the air pipe is connected to the inside of the energy storage element monomer, and a pressure gauge is installed on the air pipe; the energy storage element monomer is put into water, the air pipe is ventilated, and the air pressure value of the pressure gauge is adjusted to vary within the range of 0.1Mpa to 0.45Mpa (0.45Mpa is the maximum air pressure of the experimental air source), and when the air pressure reaches 0.45Mpa, it is maintained for 30s, and no bubbles are generated in the water, indicating that even when the energy storage element monomer is subjected to the maximum internal pressure (0.45Mpa), no gas leaks from the energy storage element monomer, proving that the energy storage element monomer has good sealing property even when subjected to a large internal pressure, and has high sealing reliability.

[0035] A sealing groove 42 is formed on the outer circumference of the cover plate 4. The second sealing member 6 is sleeved in the sealing groove 42 to seal the matching gap between the cover plate 4 and the housing 1, thereby improving the sealing performance of the energy storage element and improving the sealing reliability. The second sealing member 6 is an O-ring. In other embodiments, the sealing groove 42 can also be provided on the cover plate 4 and on the joint surface with the support ring 11 and the flange 12.

[0036] A plurality of second positioning grooves 43 are provided on the cover plate 4 at the outer periphery of the countersunk hole 41. The second positioning grooves 43 correspond to the positioning pieces 33 of the current collector 3. The positioning pieces 33 are inserted into the second positioning grooves 43. The positioning pieces 33 cooperate with the second positioning grooves 43 to form a positioning structure, which simultaneously positions the current collector 3 and the cover plate 4 in the circumferential and radial directions, and prevents the current collector 3 and the cover plate 4 from circumferential and radial movement. The second positioning grooves 43 are blind holes, which ensure the sealing effect of the cover plate 4 while ensuring the positioning effect in cooperation with the positioning pieces 33.

[0037] A positioning structure is provided between the current collector 3 and the cover plate 4 to position the two in the axial, circumferential and radial directions respectively. After the current collector 3 and the battery cell 2 are fixed and then radially assembled with the cover plate 4, the relative position of the current collector 3 (and the battery cell 2) and the cover plate 4 can be determined by the positioning structure of the two to prevent the relative position of the two from shifting, thereby ensuring the uniformity of the distribution of the peripheral space of the battery cell 2 and improving the energy density of the energy storage element.

[0038] The above description is an explanation of the present invention, not a limitation of the present invention. The present invention may be modified in any form without violating the spirit of the present invention.

Claims

1. A connection structure between a current collector and a cover plate, Features: The current collector (3) comprises a pole portion (31) and a current collecting portion (32); the pole portion (31) is vertically arranged at the center of the current collecting portion (32); the pole portion (31) is inserted into the cover plate (4); a retaining ring (7) is provided on the outer sleeve of the portion where the pole portion (31) passes through the cover plate (4) for positioning; a first sealing member (5) is provided between the pole portion (31) and the cover plate (4); the first sealing member (5) is sleeved on the outer periphery of the pole portion (31); a countersunk hole (41) is provided on the cover plate (4); the first sealing member (5) is arranged in the countersunk hole (41); the cover plate (4) is made of insulating material; a groove (51) with an opening facing downward is provided on the first sealing member (5); a side surface of the groove (51) close to the pole portion (31) is a first The first inclined surface (52) is inclined downward and inward from top to bottom; a plurality of positioning pieces (33) and a plurality of openings (34) are provided on the plate surface of the current collecting portion (32); the plurality of positioning pieces (33) are vertically arranged on the current collecting portion (32) and arranged on the outer periphery of the pole portion (31); a plurality of second positioning grooves (43) are provided on the cover plate (4), the second positioning grooves (43) correspond to the positioning pieces (33), and the positioning pieces (33) are inserted into the second positioning grooves (43); the positioning pieces (33) are torn from the plate surface of the current collecting portion (32) and then bent upward, and the bottom side of the positioning pieces (33) is connected to the plate surface of the current collecting portion (32); and the openings (34) are formed on the current collecting portion (32) corresponding to the torn portions of the positioning pieces (33).

2. The connection structure between the current collector and the cover plate according to claim 1, Features: The pole portion (31), the current collecting portion (32), and the positioning piece (33) are integrally formed.

3. The connection structure between the current collector and the cover plate according to claim 1, Features: A first positioning groove (35) is provided on the outer peripheral surface of the pole portion (31), and the retaining ring (7) is clamped in the first positioning groove (35).

4. The connection structure between the current collector and the cover plate according to claim 1, Features: The first sealing member (5) is a V-shaped ring or a Y-shaped ring. The first sealing member (5) has a V-shaped groove (51) with its opening facing downward at its lower portion, and two sides of the V-shape are symmetrically arranged; or the first sealing member (5) has a trapezoidal groove (51) with its opening facing downward and being smaller at the top and larger at the bottom.

5. A single energy storage element structure, Features: The connection structure between the current collector and the cover plate according to any one of claims 1 to 4 is adopted, the current collector (3) is connected to the battery cell (2), and the battery cell (2) is inserted into the housing (1).

6. The energy storage element monomer structure according to claim 5, Features: A support ring (11) and a flange (12) are provided at the upper end of the outer shell (1), and the cover plate (4) is located between the support ring (11) and the flange (12); a second sealing member (6) is provided between the outer circumferential surface of the cover plate (4) and the inner circumferential surface of the outer shell (1); and the second sealing member (6) is an O-ring.

7. The energy storage element monomer structure according to claim 5, Features: The bottom surface of the battery core (2) is fixed to the bottom surface of the shell (1) by bonding with conductive adhesive; or the battery core (2) is fixedly connected to the bottom surface of the shell (1) by brazing, resistance welding or laser welding.

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