Battery casing and battery cell

Abstract

Provided in the present application are a battery casing and a battery cell. The battery casing comprises a casing body and a casing cover, wherein the casing body encloses an accommodating cavity and an opening in communication with the accommodating cavity, the accommodating cavity being used for accommodating a bare cell, the casing body is provided with a mounting hole, the mounting hole being used for mounting a terminal post, and the casing body is of an integrally stamped structure; and the casing cover is connected to the casing body and covers the opening. In the present application, forming of the casing body can be completed simply by a stamping process.

Description

Battery casing and individual cells

[0001] This application claims priority to Chinese Patent Application No. 2024215232602, filed with the Chinese Patent Office on June 28, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, specifically to a battery casing and a single battery cell. Background Technology

[0003] With the rapid popularization of new energy sources, new energy batteries are being rapidly adopted and applied in various industries. Technical issues

[0004] Initially, new energy batteries only needed to meet the basic requirements of energy storage and discharge. However, now new energy batteries also need to improve energy density, that is, to store more electricity per unit volume. Technical solutions

[0005] In a first aspect, this application provides a battery casing, including a casing body and a casing cover; the casing body is provided with a receiving cavity and an opening communicating with the receiving cavity, the receiving cavity being used to accommodate a bare battery cell, the casing body having a mounting hole for assembling a terminal post, the casing body being an integrally stamped structure; the casing cover being connected to the casing body and covering the opening.

[0006] Secondly, this application provides a single-cell battery, including a bare cell and a battery casing provided in this application, wherein the bare cell is housed in a receiving cavity. Beneficial effects

[0007] The beneficial effects of the battery casing and single cell provided in this application are as follows: the casing is provided with mounting holes for assembling terminals, that is, the casing serves as the port for the introduction and extraction of power from the single cell; the casing can be made into a long, narrow strip; the casing can be formed by stamping; compared with the stretching process, the thickness of the casing material can be greatly reduced, so the stamped casing does not need to occupy too much space; in addition, the stamped casing does not require annealing to relieve stress, reducing damage to the appearance of the casing; compared with the bending and welding process, the casing requires more welding steps. Taking a square casing as an example, the bending and welding process requires two welding steps, which increases the probability of missed welds, incomplete welds, and weld explosions, affecting the final pass rate of the casing. In addition, the precision requirements of the welding points are particularly high, which can easily lead to unevenness and uneven thickness, resulting in uneven stress and breakage of the casing at the welding point. Attached Figure Description

[0008] Figure 1 is a cross-sectional schematic diagram of a single cell provided in this application;

[0009] Figure 2 is a cross-sectional schematic diagram of the shell provided in this application;

[0010] Figure 3 is a cross-sectional schematic diagram of the shell, the second fixing colloid, and the pole provided in this application;

[0011] Figure 4 is a cross-sectional schematic diagram of the housing, second fixing colloid, electrode post and bare cell provided in this application;

[0012] Figure 5 is a flowchart illustrating the manufacturing method provided in this application;

[0013] Figure 6 is another flowchart illustrating the manufacturing method provided in this application.

[0014] Reference numerals in the attached drawings: 100 for single cell, 20 for bare cell, 30 for terminal post, 40 for second fixing gel, 10 for battery casing, 12 for casing body, 123 for receiving cavity, 124 for opening, 125 for mounting hole, 121 for peripheral side wall, 122 for bottom wall, 14 for casing cover, 141 for covering part, 142 for overlapping part, and 16 for first fixing gel. Embodiments of the present invention

[0015] Please refer to Figures 1 to 4. Figure 1 is a cross-sectional schematic diagram of the single battery 100 provided in the embodiment of this application; Figure 2 is a cross-sectional schematic diagram of the casing 12 provided in the embodiment of this application; Figure 3 is a cross-sectional schematic diagram of the casing 12, the second fixing colloid 40, and the electrode post 30 provided in the embodiment of this application; Figure 4 is a cross-sectional schematic diagram of the casing 12, the second fixing colloid 40, the electrode post 30, and the bare cell 20 provided in the embodiment of this application.

[0016] This application provides a single-cell battery 100, which includes a bare cell 20 and a battery casing 10. The bare cell 20 includes an electrode assembly and an insulating film. The insulating film encapsulates the electrode assembly, which has a positive electrode and a negative electrode. The electrode assembly may include a positive electrode sheet, a separator, and a negative electrode sheet, which are sequentially stacked to form the electrode assembly with positive and negative electrodes. The battery casing 10 has a receiving cavity 123, in which the bare cell 20 is housed.

[0017] Specifically, the battery casing 10 includes a casing body 12 and a casing cover 14. The casing body 12 surrounds a receiving cavity 123 and an opening 124 communicating with the receiving cavity 123. The receiving cavity 123 is used to accommodate a bare battery cell 20. The casing body 12 has a mounting hole 125, which communicates with the receiving cavity 123 and is used to assemble a terminal post 30. The terminal post 30 and the bare battery cell 20 are connected to each other and thus become energized. The casing cover 14 is connected to the casing body 12 and covers the opening 124. The casing body 12 is an integral stamped structure, that is, the casing body 12 is formed into its initial shape in one step through a stamping process.

[0018] In this embodiment, the shell 12 is provided with mounting holes 125 for assembling the terminal post 30. That is, the shell 12 is the port for the introduction and extraction of power from the single battery 100. The shell 12 can be made into a long strip-shaped, short shell 12, which can be formed by stamping. Compared with the stretching process, the thickness of the material used to make the shell 12 can be greatly reduced, so the stamped shell 12 does not need to occupy too much space. In addition, the stamped shell 12 does not need to be annealed to eliminate stress, reducing the damage to the appearance of the shell 12. Compared with the bending and welding process, the shell 12 requires more welding. Taking a square shell 12 as an example, it needs to be welded twice. The probability of missing welds, incomplete welds, and weld explosions is high, affecting the final pass rate of the shell 12. In addition, the precision requirements of the welding points are particularly high, which can easily lead to uneven height and thickness, resulting in uneven stress and the shell 12 breaking off from the welding point.

[0019] The shell body 12 can be made of stainless steel. Stainless steel, as defined in GB / T20878-2007, is steel whose main characteristics are rust resistance and corrosion resistance, with a chromium content of at least 10.5% and a carbon content of no more than 1.2%. Stainless steel is an abbreviation for stainless and acid-resistant steel. Steels resistant to weak corrosive media such as air, steam, and water, or those possessing rust-resistant properties, are called stainless steel; while steels resistant to chemical corrosion media (acids, alkalis, salts, etc.) are called acid-resistant steel. A stainless steel shell body 12, when relatively thin, can withstand stamping. If the thickness of the shell body 12 is D mm, then 0.2 ≤ D ≤ 1.0, for example, D is 0.2, 0.5, 0.8, or 1.0.

[0020] The battery casing 10 also includes a first fixing adhesive 16, which is disposed at the connection between the casing cover 14 and the casing body 12 to bond the casing cover 14 to the casing body 12. The first fixing adhesive 16 can be a heat-sealing adhesive, a type of plastic adhesive whose physical state changes with temperature within a certain temperature range while its chemical properties remain unchanged. It is non-toxic, odorless, and an environmentally friendly chemical product. Alternatively, the first fixing adhesive 16 can be epoxy resin adhesive, an important thermosetting resin adhesive. Especially due to its excellent physical and mechanical properties, electrical insulation properties, chemical corrosion resistance, heat resistance, and adhesive properties, epoxy resin adhesives formulated with it are known as "all-purpose adhesives" and can be widely used in chemical, light industry, water conservancy, transportation, machinery, electronics, home appliances, automotive, and aerospace industries. Using the first fixing adhesive 16 in combination with traditional mold sealing reduces production difficulty and increases the final product qualification rate while ensuring airtightness.

[0021] Of course, the cover 14 and the body 12 can also be connected by welding. However, compared with the adhesive method, the first fixing adhesive 16 does not require a high temperature to melt and cool to fix the cover 14 and the body 12. Moreover, the first fixing adhesive 16 has a strong sealing effect and can completely seal the gap between the cover 14 and the body 12.

[0022] The cover 14 includes a covering portion 141 and an overlapping portion 142. The overlapping portion 142 is connected to the covering portion 141 and extends towards the body 12 by bending. At this time, the cross-section of the cover 14 forms a U-shaped structure. The covering portion 141 covers the opening 124, and the overlapping portion 142 is connected to the peripheral sidewall 121 of the body 12. The overlapping portion 142 and the body 12 are in surface-to-surface contact, thus increasing the contact area between the cover 14 and the body 12. In this embodiment, by bending the cover 14, the cover 14 and the body 12 achieve surface-to-surface contact, increasing their contact area. This improves the fault tolerance rate and ensures the stability and sealing of the connection between the cover 14 and the body 12, regardless of whether the cover 14 and the body 12 are bonded or welded.

[0023] In one embodiment, the overlapping portion 142 and the outer surface of the peripheral sidewall 121 are fitted together. At this time, the junction of the cover 14 and the shell body 12 faces downward, and the cover portion 141 is connected to the edge of the opening 124 formed by the shell body 12. The top surface of the opening 124 provides support for the cover 14. This connection method ensures that the cover 14 covers the opening 124 of the shell body 12, preventing water from entering due to the junction of the cover 14 and the shell body 12 facing upward. In addition, the shell body 12 can also provide some support and positioning for the cover 14, facilitating the subsequent connection of the cover 14 and the shell body 12.

[0024] The casing 12 includes a peripheral sidewall 121 and a bottom wall 122. The peripheral sidewall 121 forms an opening 124. The bottom wall 122 is connected to the end of the peripheral sidewall 121 away from the opening 124. The bottom wall 122 and the peripheral sidewall 121 form a receiving cavity 123. The height L1 of the peripheral sidewall 121 is less than the length L2 of the bottom wall 122 to facilitate the stamping of the casing 12. At this time, the battery casing 10 composed of the casing 12 and the casing cover 14 is elongated. The peripheral sidewall 121 is provided with mounting holes 125. The terminal posts 30 of the single battery 100 are also arranged along the length direction of the bottom wall 122. The mounting holes 125 can be arranged along the length direction of the bottom wall 122 in the peripheral sidewall 121, so that the terminal posts 30 can be installed along the length direction of the casing 12, avoiding the casing 12 from being too thick. Of course, the mounting holes 125 can also be arranged along the width direction of the bottom wall 122 in the peripheral sidewall 121.

[0025] Specifically, the height of the peripheral sidewall 121 is L1, and the length of the bottom wall 122 is L2, where 2L1≤L2≤5L1. That is, the length of the bottom wall 122 is between 2 and 5 times the height of the peripheral sidewall 121. Within this range, the shell 12 has the highest stability and will not deform due to the thickness of the shell 12 wall.

[0026] The single-cell battery 100 also includes a terminal post 30 and a second fixing adhesive 40. The terminal post 30 passes through the mounting hole 125 and is electrically connected to one pole of the bare cell 20, which can be the positive or negative pole of the bare cell 20. The other pole of the bare cell 20 is electrically connected to the casing 12, which can be the other pole of the positive or negative pole of the bare cell 20. The casing 12 itself is charged. The second fixing adhesive 40 is disposed at the connection between the terminal post 30 and the casing 12 to bond the terminal post 30 to the casing 12. The second fixing adhesive 40 can be a heat-sealing adhesive or an epoxy resin adhesive. In addition to fixing the terminal post 30 to the casing 12, the second fixing adhesive 40 also insulates and separates the terminal post 30 from the casing 12.

[0027] In another embodiment, there are two pole posts 30, and two mounting holes 125 are provided on the housing 12. The two mounting holes 125 are located on the peripheral sidewall 121 along the length of the bottom wall 122. The two pole posts 30 are respectively assembled in the mounting holes 125, and the positive and negative poles of the bare cell 20 are electrically connected to the two pole posts 30 respectively.

[0028] Please refer to Figures 2 to 5. Figure 5 is a flowchart illustrating the manufacturing method provided in the embodiment of this application.

[0029] S101: Stamping to form the shell 12 provided in the embodiments of this application.

[0030] The sheet metal for making the shell 12 is placed on a stamping machine and formed in one step through cold stamping. The sheet metal can be made of aluminum or steel. Stamping is a processing method that uses a press and dies to apply external force to sheet metal, strip, tube, and profiles, causing plastic deformation or separation to obtain workpieces (stamped parts) of the required shape and size. The blanks for stamping are mainly hot-rolled and cold-rolled steel plates and strips. Of the world's steel, 60-70% is sheet metal, most of which is made into finished products through stamping. Automobile bodies, chassis, fuel tanks, radiator fins, boiler drums, container shells, and silicon steel sheets for motor and electrical appliance cores are all processed by stamping. There are also a large number of stamped parts in instruments, household appliances, bicycles, office machinery, and household utensils.

[0031] The housing 12 is provided with a receiving cavity 123 and an opening 124 communicating with the receiving cavity 123. The receiving cavity 123 is used to accommodate the bare battery cell 20. The housing 12 is punched to form a mounting hole 125. The mounting hole 125 is communicating with the receiving cavity 123. The mounting hole 125 is used to assemble the terminal post 30. The terminal post 30 and the bare battery cell 20 are connected to each other and thus become energized.

[0032] The casing 12 includes a peripheral sidewall 121 and a bottom wall 122. The peripheral sidewall 121 forms an opening 124. The bottom wall 122 and the peripheral sidewall 121 are connected at the ends away from the opening 124. The bottom wall 122 and the peripheral sidewall 121 form a receiving cavity 123. The height L1 of the peripheral sidewall 121 is less than the length L2 of the bottom wall 122 to facilitate the stamping of the casing 12. At this time, the battery casing 10 composed of the casing 12 and the casing cover 14 is elongated. Along the length direction of the bottom wall 122, the peripheral sidewall 121 is provided with mounting holes 125. The terminal posts 30 of the single battery 100 are also placed along the length direction of the bottom wall 122.

[0033] Specifically, the height of the peripheral sidewall 121 is L1, and the length of the bottom wall 122 is L2, where 2L1≤L2≤5L1. That is, the length of the bottom wall 122 is between 2 and 5 times the height of the peripheral sidewall 121. Within this range, the shell 12 has the highest stability and will not deform due to the thickness of the shell 12 wall.

[0034] S102: Stamping forming of the shell cover 14 provided in the embodiments of this application.

[0035] The sheet material for making the cover 14 is placed on a stamping machine and formed into the cover 14 in one step by cold stamping. The sheet material can be aluminum or steel. The cover 14 includes a covering part 141 and an overlapping part 142. The overlapping part 142 is connected to the covering part 141 and bends and extends towards the shell body 12. At this time, the cross-section of the cover 14 forms a U-shaped structure.

[0036] Specifically, the cover 141 covers the opening 124, and the overlapping portion 142 connects to the peripheral sidewall 121 of the shell 12. The overlapping portion 142 and the shell 12 are in surface-to-surface contact, thus increasing the contact area between the cover 14 and the shell 12. In this embodiment, by bending the cover 14, the cover 14 and the shell 12 achieve surface-to-surface contact, increasing their contact area. This improves the fault tolerance rate and ensures the stability and sealing of the connection between the cover 14 and the shell 12, regardless of whether they are bonded or welded.

[0037] In one embodiment, the overlapping portion 142 and the outer surface of the peripheral sidewall 121 are fitted together. At this time, the junction of the cover 14 and the shell body 12 faces downward, and the covering portion 141 is connected to the top surface of the opening 124. The top surface of the opening 124 provides support for the cover 14. This connection method ensures that the cover 14 covers the opening 124 of the shell body 12, preventing water from entering due to the junction of the cover 14 and the shell body 12 facing upward. In addition, the shell body 12 can also provide some support and positioning for the cover 14, facilitating the subsequent connection of the cover 14 and the shell body 12.

[0038] S103: Assemble the bare battery cell 20 into the housing 12 and cover it with the housing cover 14.

[0039] After the bare battery cell 20 is placed in the housing 12, the housing cover 14 is closed, and the housing cover 14 is connected to the housing 12 and covers the opening 124. The battery housing 10 also includes a first fixing adhesive 16, which is disposed at the connection between the housing cover 14 and the housing 12 to bond the housing cover 14 to the housing 12.

[0040] Please refer to Figures 2 to 4, and Figure 6. Figure 6 is another schematic flowchart of the manufacturing method provided in the embodiment of this application.

[0041] S201: Stamping to form the shell 12 provided in the embodiments of this application.

[0042] S202: Stamping forming of the shell cover 14 provided in the embodiments of this application.

[0043] S203: Assemble the bare battery cell 20 into the housing 12.

[0044] S204: Apply the second fixing colloid 40 onto the electrode post 30.

[0045] S205: Insert the pole post 30 through the mounting hole 125, and bond the pole post 30 and the housing 12 together.

[0046] S206: Electrically connect one pole of the bare cell 20 to the terminal 30, and electrically connect the other pole of the bare cell 20 to the casing 12.

[0047] The difference between this embodiment and the previous embodiment is that step S103 is refined into S203, S204, S205, and S206. The single-cell battery 100 also includes an electrode post 30 and a second fixing adhesive 40. The electrode post 30 passes through the mounting hole 125 and is electrically connected to one pole of the bare cell 20, which can be the positive or negative pole of the bare cell 20. The other pole of the bare cell 20 is electrically connected to the casing 12, which can be the other pole of the positive or negative pole of the bare cell 20. The casing 12 itself is charged. The second fixing adhesive 40 is disposed at the connection between the electrode post 30 and the casing 12 to bond the electrode post 30 to the casing 12. The second fixing adhesive 40 can be a heat-sealing adhesive or an epoxy resin adhesive. Besides fixing the electrode post 30 to the casing 12, the second fixing adhesive 40 also insulates and separates the electrode post 30 from the casing 12.

[0048] In another embodiment, there are two pole posts 30, and two mounting holes 125 are provided on the housing 12. The two mounting holes 125 are located on the peripheral sidewall 121 along the length of the bottom wall 122. The two pole posts 30 are respectively assembled in the mounting holes 125, and the positive and negative poles of the bare cell 20 are electrically connected to the two pole posts 30 respectively.

Claims

1. A battery casing, comprising: The housing has a receiving cavity and an opening communicating with the receiving cavity. The receiving cavity is used to accommodate bare battery cells. The housing has mounting holes for mounting terminals. The housing is an integral stamped structure. A cover is connected to the shell body and covers the opening.

2. The battery casing according to claim 1 further includes a first fixing adhesive, the first fixing adhesive being disposed at the connection between the casing cover and the casing body to adhere the casing cover to the casing body.

3. The battery casing according to claim 1, wherein, The shell cover includes a covering portion and an overlapping portion, the overlapping portion and the covering portion are connected and bend towards the shell body, the covering portion covers the opening, and the overlapping portion is connected to the peripheral sidewall of the shell body.

4. The battery casing according to claim 3, wherein, The overlapping portion fits into the outer surface of the peripheral sidewall, and the covering portion is connected to the edge of the shell to form the opening.

5. The battery casing according to any one of claims 1 to 4, wherein, The shell includes a peripheral sidewall and a bottom wall. The peripheral sidewall forms the opening. The bottom wall and the peripheral sidewall are connected at the ends away from the opening. The bottom wall and the peripheral sidewall form the receiving cavity. The height of the peripheral sidewall is less than the length of the bottom wall. The peripheral sidewall is provided with the mounting hole.

6. The battery casing according to claim 5, wherein, The height of the peripheral sidewall is L1, and the length of the bottom wall is L2, where 2L1≤L2≤5L1.

7. The battery casing according to claim 5, wherein, The mounting holes are provided on the peripheral sidewalls along the length of the bottom wall.

8. The battery casing according to claim 1, wherein, The shell body is made of stainless steel, and / or the shell cover is made of stainless steel.

9. A single-cell battery, comprising: The bare battery cell and the battery casing according to any one of claims 1 to 8, wherein the bare battery cell is housed in the receiving cavity.

10. The single-cell battery according to claim 9 further includes a terminal post and a second fixing adhesive, wherein the terminal post passes through the mounting hole and is electrically connected to one pole of the bare cell, the other pole of the bare cell is electrically connected to the casing, and the second fixing adhesive is disposed at the connection between the terminal post and the casing to bond the terminal post to the casing.

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