Secondary battery and method for manufacturing the same

Abstract

The present application provides a secondary battery and a manufacturing method thereof. The method comprises installing a conductive ring in a cover mounting hole of a plastic plate to obtain a battery cover; welding an electric energy output connecting piece to a connection point of an electrode group to obtain a battery core column; welding the conductive ring of the battery cover and the electric energy output connecting piece of the battery core column to obtain a battery cell group; and inserting the battery cell group into a shell to obtain a secondary battery. The electric energy output connecting piece is first connected to the electrode group to form a battery core column, and then the electric energy output connecting piece is welded to the conductive ring, which facilitates the connection between the battery cover and the battery core column, thereby facilitating the connection between the electric energy output connecting piece and the conductive ring, and further facilitating the direct buckling of the battery cover on the end cover of the shell. The assembly of the battery cover and the shell can be completed without bending the electric energy output connecting piece, effectively improving the assembly efficiency of the secondary battery.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a secondary battery and a manufacturing method thereof. Background Art

[0002] Lithium-ion batteries have advantages such as high specific energy, high number of cycles, and long storage time. They are widely used not only in portable electronic devices such as mobile phones, digital cameras, and laptops, but also in large and medium-sized electric devices such as electric vehicles, electric bicycles, and power tools. Therefore, the performance requirements for lithium-ion batteries are becoming increasingly higher. At present, the manufacturing process of battery cells can generally be divided into two types: full-tab and cut-tab. The assembly of cut-tab is divided into two types: bent connecting tab and bent tab. For battery cells with bent tabs, the welding of the electrode group and the connecting tab is called butterfly welding. Because butterfly welding is suitable for wider battery cells, it has the highest battery cell energy ratio among these assembly types. The current butterfly welding process is: first ultrasonically weld the connecting tab to the electrode group's tab, and then laser weld the connecting tab to the cover plate.

[0003] However, in the traditional assembly method, the connecting tabs need to be bent after welding to facilitate the cover plate to seal the battery. The connecting tabs are difficult to bend and the bending height is also difficult to control, which makes the assembly process of the battery cell complicated and leads to excessively high production costs of the battery. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a secondary battery and a manufacturing method thereof that effectively improve assembly efficiency.

[0005] The object of the present invention is achieved through the following technical solutions:

[0006] A method for manufacturing a secondary battery, the method comprising:

[0007] Install the conductive ring into the cover mounting hole of the plastic plate to obtain the battery cover;

[0008] Welding the power output connecting piece to the connection point of the electrode group to obtain a battery stack column;

[0009] Welding the conductive ring of the battery cover plate and the power output connecting piece of the battery stack column to obtain a battery cell group;

[0010] The battery cell assembly is assembled into a shell to obtain a secondary battery.

[0011] In one embodiment, the step of installing the conductive ring in the cover mounting hole of the plastic plate further includes: buckling the cover insulating ring in the cover mounting hole so that the conductive ring and the plastic plate jointly clamp the cover insulating ring.

[0012] In one embodiment, the step of installing the conductive ring in the cover mounting hole of the plastic plate further includes: buckling a cover sealing ring in the cover mounting hole so that the conductive ring and the plastic plate jointly clamp the cover sealing ring.

[0013] In one embodiment, the step of installing the conductive ring in the cover mounting hole of the plastic plate further includes: sleeve-fitting a cover fixing ring onto an end of the conductive ring close to the power output connection piece.

[0014] In one embodiment, the step of sleeve-fitting the cover fixing ring onto an end of the conductive ring close to the power output connection piece further comprises: welding the connection between the cover fixing ring and the conductive ring.

[0015] In one embodiment, welding the power output connection piece to the connection point of the electrode group includes: performing butterfly welding on the power output connection piece and the electrode group.

[0016] In one embodiment, welding the conductive ring of the battery cover plate and the power output connecting piece of the battery stack column includes: penetrating welding the power output connecting piece on a side of the conductive ring facing away from the electrode group.

[0017] In one embodiment, the penetration welding comprises laser penetration welding.

[0018] In one embodiment, before inserting the battery cell assembly into a housing to obtain a secondary battery, the method further comprises: welding a conductive electrode to a side of the conductive ring facing away from the electrode assembly.

[0019] A secondary battery is manufactured using the secondary battery manufacturing method described in any one of the above embodiments.

[0020] Compared with the prior art, the present invention has at least the following advantages:

[0021] The power output connecting piece is first connected to the electrode group to form a battery stack column, and then the power output connecting piece is welded to the conductive ring, which facilitates the connection of the battery cover plate to the battery stack column, thereby facilitating the connection of the power output connecting piece to the conductive ring, and further facilitates the battery cover plate to be directly buckled on the end cover of the shell. The assembly of the battery cover plate and the shell can be completed without bending the power output connecting piece, which effectively improves the assembly efficiency of the secondary battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 FIG. 1 is a flow chart of a method for manufacturing a secondary battery in one embodiment. DETAILED DESCRIPTION

[0024] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0025] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] The present invention relates to a method for manufacturing a secondary battery. In one embodiment, the method comprises installing a conductive ring in a cover mounting hole of a plastic plate to obtain a battery cover; welding an electric energy output connecting piece to a connection point of an electrode group to obtain a battery core column; welding the conductive ring of the battery cover and the electric energy output connecting piece of the battery core column to obtain a battery cell group; and inserting the battery cell group into a shell to obtain a secondary battery. The electric energy output connecting piece is first connected to the electrode group to form a battery core column, and then the electric energy output connecting piece is welded to the conductive ring to facilitate the connection between the battery cover and the battery core column, thereby facilitating the connection between the electric energy output connecting piece and the conductive ring, and further facilitating the direct buckling of the battery cover on the end cover of the shell. The assembly of the battery cover and the shell can be completed without bending the electric energy output connecting piece, thereby effectively improving the assembly efficiency of the secondary battery.

[0028] See also Figure 1 , which is a flow chart of a secondary battery manufacturing method according to an embodiment of the present invention. The secondary battery manufacturing method includes some or all of the following steps.

[0029] S100: Install the conductive ring in the cover mounting hole of the plastic plate to obtain the battery cover.

[0030] In this embodiment, the plastic plate serves as the main end cover of the secondary battery, that is, the plastic plate is the main body of the conductive connection at the end of the secondary battery, and the conductive ring is arranged on the plastic plate. Specifically, the conductive ring is clamped in the cover mounting hole of the plastic plate, so that the conductive ring is stably mounted on the plastic plate. The conductive ring serves as the power output end of the secondary battery, that is, the conductive ring is used to connect to an external wire to facilitate the output of the power of the secondary battery. The conductive ring and the plastic plate form the end closing plate of the secondary battery to cover the end gap of the secondary battery. In this way, the conductive ring is first installed in the cover mounting hole, so that the end conductive plate of the secondary battery is formed, that is, the battery cover, which facilitates the separate assembly of the battery cover and the battery stack column of the secondary battery.

[0031] S200: Welding the power output connecting piece to the connection point of the electrode group to obtain a battery stack column.

[0032] In this embodiment, the power output connecting piece serves as a conductive connecting component between the electrode group and the conductive ring, and the power output connecting piece is directly welded to the electrode group first. Specifically, the power output connecting piece is located between the electrode group and the conductive ring, and the power output connecting piece is welded to the electrode group, so that the power output connecting piece and the electrode group form a battery stack column, and there is no need to be integrally formed with the conductive ring, so that the power output connecting piece and the conductive ring are respectively located on two components to be welded, thereby separating the power output connecting piece and the conductive ring from each other, facilitating the subsequent direct welding of the power output connecting piece to the conductive ring, that is, when the battery cover plate remains in a posture covering the end notch of the secondary battery, the welding of the conductive ring and the power output connecting piece is achieved, and there is no need to bend the power output connecting piece to achieve end sealing of the secondary battery.

[0033] S300: Welding the conductive ring of the battery cover plate and the power output connecting piece of the battery stack column to obtain a battery cell group.

[0034] In this embodiment, the plastic plate serves as the main end cap of the secondary battery, i.e., the plastic plate is the main body of the conductive connection at the end of the secondary battery. The conductive ring is disposed on the plastic plate. Specifically, the conductive ring is clamped into the cover mounting hole of the plastic plate, ensuring a stable installation of the conductive ring on the plastic plate. The conductive ring serves as the power output terminal of the secondary battery, i.e., the conductive ring is used to connect to an external wire to facilitate the output of the secondary battery's power. The conductive ring and the plastic plate form the end closure plate of the secondary battery, thereby covering the end notch of the secondary battery. The electric energy output connecting piece serves as a conductive connecting component between the electrode group and the conductive ring. The electric energy output connecting piece is directly welded to the electrode group first. Specifically, the electric energy output connecting piece is located between the electrode group and the conductive ring. The electric energy output connecting piece is welded to the electrode group, so that the electric energy output connecting piece and the electrode group form a battery stack column, and there is no need to be integrally formed with the conductive ring, so that the electric energy output connecting piece and the conductive ring are respectively located on two components to be welded, thereby separating the electric energy output connecting piece and the conductive ring from each other, facilitating the subsequent direct welding of the electric energy output connecting piece to the conductive ring, that is, when the battery cover plate remains in a posture covering the end notch of the secondary battery, the welding of the conductive ring and the electric energy output connecting piece is achieved, and there is no need to bend the electric energy output connecting piece to achieve the end sealing of the secondary battery. The conductive ring on the battery cover is in direct contact with the power output connecting piece on the battery stack column. The battery cover can correspond to the end notch of the secondary battery. At this time, the conductive ring and the power output connecting piece remain in contact with each other, which is convenient for welding the conductive ring and the power output connecting piece. Moreover, at this time, the battery cover and the pole group remain perpendicular to each other, that is, the end planes of the battery cover and the pole group are parallel to each other, so that the power output connecting piece does not need to be bent to realize the assembly of the battery cover and the battery stack column, which is convenient for the subsequent direct insertion of the battery cell group into the shell.

[0035] S400: putting the battery cell assembly into a shell to obtain a secondary battery.

[0036] In this embodiment, the battery cell pack is formed by welding the battery cover plate and the battery stack column. The plastic plate serves as the main end cap of the secondary battery, that is, the plastic plate is the main body of the conductive connection at the end of the secondary battery. The conductive ring is disposed on the plastic plate. Specifically, the conductive ring is clamped into the cover mounting hole of the plastic plate, ensuring that the conductive ring is stably mounted on the plastic plate. The conductive ring serves as the power output terminal of the secondary battery, that is, the conductive ring is used to connect to an external wire to facilitate the output of the secondary battery's power. The conductive ring and the plastic plate form the end closure plate of the secondary battery, thereby covering the end gap of the secondary battery. The electric energy output connecting piece serves as a conductive connecting component between the electrode group and the conductive ring. The electric energy output connecting piece is directly welded to the electrode group first. Specifically, the electric energy output connecting piece is located between the electrode group and the conductive ring. The electric energy output connecting piece is welded to the electrode group, so that the electric energy output connecting piece and the electrode group form a battery stack column, and there is no need to be integrally formed with the conductive ring, so that the electric energy output connecting piece and the conductive ring are respectively located on two components to be welded, thereby separating the electric energy output connecting piece and the conductive ring from each other, facilitating the subsequent direct welding of the electric energy output connecting piece to the conductive ring, that is, when the battery cover plate remains in a posture covering the end notch of the secondary battery, the welding of the conductive ring and the electric energy output connecting piece is achieved, and there is no need to bend the electric energy output connecting piece to achieve the end sealing of the secondary battery. After the battery cell group is assembled, the battery cover plate remains consistent with the end of the shell, that is, the battery cover plate is used to form a complete and closed battery shell with the shell, and the battery cell group can be assembled into the shell without bending the power output connecting piece.

[0037] In the above embodiment, the power output connecting piece is first connected to the electrode group to form a battery stack column, and then the power output connecting piece is welded to the conductive ring, which facilitates the connection of the battery cover plate to the battery stack column, thereby facilitating the connection of the power output connecting piece to the conductive ring, and further facilitates the direct buckling of the battery cover plate on the end cover of the shell. The assembly of the battery cover plate and the shell can be completed without bending the power output connecting piece, thereby effectively improving the assembly efficiency of the secondary battery.

[0038] In one embodiment, the step of installing the conductive ring in the cover mounting hole of the plastic plate also includes: buckling a cover insulating ring in the cover mounting hole so that the conductive ring and the plastic plate jointly clamp the cover insulating ring. In this embodiment, the cover insulating ring serves as an insulating component between the conductive ring and the plastic plate. The cover insulating ring separates the conductive ring from the plastic plate, so that the conductive ring and the plastic plate are insulated from each other, thereby making it difficult for the charge of the conductive ring to be transferred to the plastic plate after being energized, effectively avoiding the situation where the plastic plate is charged. Moreover, the cover insulating ring is installed before the conductive ring is installed, that is, the cover insulating ring is first buckled in the cover mounting hole, and then the conductive ring is installed, so that the cover insulating ring is squeezed against the inner wall of the cover mounting hole to improve the stability of the cover insulating ring installed on the plastic plate.

[0039] In one embodiment, the step of installing the conductive ring in the cover mounting hole of the plastic plate further includes: buckling a cover sealing ring in the cover mounting hole so that the conductive ring and the plastic plate jointly clamp the cover sealing ring. In this embodiment, the cover sealing ring serves as a sealing component between the conductive ring and the plastic plate. The cover sealing ring blocks the gap between the conductive ring and the plastic plate, thereby reducing the gap between the conductive ring and the plastic plate. This makes it difficult for the conductive ring to introduce external moisture or dust into the housing after power is applied, effectively preventing the secondary battery from being contaminated. Moreover, the cover sealing ring is installed before the conductive ring is installed, that is, the cover sealing ring is first buckled in the cover mounting hole, and then the conductive ring is installed. This facilitates squeezing the cover sealing ring against the inner wall of the cover mounting hole, thereby improving the stability of the cover sealing ring when installed on the plastic plate.

[0040] In one embodiment, the step of installing the conductive ring in the cover mounting hole of the plastic plate further includes: sleeve-fitting the cover fixing ring onto one end of the conductive ring close to the power output connection piece. In this embodiment, the cover fixing ring serves as a fixed connection component between the conductive ring and the plastic plate. The cover fixing ring connects the conductive ring and the plastic plate to each other, thereby fixing the conductive ring on the plastic plate, thereby making the connection between the conductive ring and the plastic plate more stable, and effectively avoiding the conductive ring from detaching from the plastic plate. Moreover, the cover fixing ring is installed after the conductive ring is installed, that is, the conductive ring is first buckled into the cover mounting hole, and then the cover fixing ring is fixed to the conductive ring, so that the cover fixing ring can fix the conductive ring on the plastic plate, thereby improving the stability of the conductive ring installed on the plastic plate.

[0041] Furthermore, the cover plate fixing ring is sleeved on one end of the conductive ring close to the power output connection piece, and then the cover plate fixing ring and the conductive ring are welded. In this embodiment, the cover plate fixing ring serves as a fixed connection component between the conductive ring and the plastic plate. The cover plate fixing ring connects the conductive ring and the plastic plate to each other, so that the conductive ring is fixed on the plastic plate, thereby making the connection between the conductive ring and the plastic plate more stable, and effectively avoiding the situation where the conductive ring is detached from the plastic plate. Moreover, the cover plate fixing ring is installed after the conductive ring is installed, that is, the conductive ring is first buckled into the cover plate mounting hole, and then the cover plate fixing ring is welded to the conductive ring, so that the cover plate fixing ring can weld the conductive ring to the plastic plate, so as to further improve the stability of the conductive ring installed on the plastic plate.

[0042] In one embodiment, welding the power output connecting piece to the connection point of the electrode group includes performing butterfly welding on the power output connecting piece and the electrode group. In this embodiment, the power output connecting piece and the electrode group form the battery stack column, and the power output connecting piece serves as a connecting component between the electrode group and the conductive ring. Furthermore, the power output connecting piece provides electrical conduction between the electrode group and the conductive ring, facilitating the output of power from the electrode group through the conductive ring. The butterfly welding method connects the power output connecting piece and the electrode group, thereby ensuring a more stable connection between the power output connecting piece and the electrode group.

[0043] In one embodiment, welding the conductive ring of the battery cover to the power output connection tab of the battery stack includes performing penetration welding on the power output connection tab on a side of the conductive ring facing away from the electrode group. In this embodiment, the conductive ring and the power output connection tab are welded together, and the power output connection tab is located on a side of the conductive ring proximal to the electrode group. The welding point between the power output connection tab and the conductive ring is located within the housing, i.e., the welding point between the power output connection tab and the conductive ring is inside the secondary battery. To reduce the possibility of welding slag generated during the welding process falling into the battery, penetration welding is performed on a side of the conductive ring facing away from the electrode group. This ensures that the welding slag generated during the welding process is located on the side of the conductive ring facing away from the electrode group, i.e., the welding slag is outside the secondary battery, effectively preventing the welding slag from falling into the battery. In another embodiment, the penetration welding includes laser penetration welding, i.e., the conductive ring and the power output connection tab are welded using laser penetration welding, which not only improves welding efficiency but also effectively reduces the chance of welding slag falling into the battery.

[0044] In one embodiment, prior to inserting the battery cell assembly into a housing to obtain a secondary battery, the process further includes: welding a conductive electrode to a side of the conductive ring facing away from the electrode assembly. In this embodiment, the conductive electrode is located on the conductive ring and connected to the conductive ring. Specifically, the conductive electrode is welded to the conductive ring and is respectively connected to the conductive ring and an external wire. The conductive electrode serves as a connecting component between the conductive ring and the external wire, facilitating the output of electrical energy from the electrode assembly.

[0045] During the actual assembly process of the secondary battery, cold solder joints often occur when the power output connecting piece is welded to the conductive ring. This is mainly because the electrode group formed by stacking multiple battery cells requires the use of multiple separate power output connecting pieces to connect the battery cells, and there are gaps between the multiple power output connecting pieces, which easily cause the conductive ring to be misaligned during welding, resulting in a reduction in the welding area between the power output connecting piece and the conductive ring, thereby causing unstable welding between the power output connecting piece and the conductive ring.

[0046] In order to reduce the probability of poor welding between the power output connecting piece and the conductive ring, the conductive ring is installed in the cover mounting hole of the plastic plate to obtain the battery cover, and further includes:

[0047] Installing a positioning plate on the side of the plastic plate close to the electrode group and sleeved on the conductive ring;

[0048] The conductive ring of the battery cover plate and the power output connection piece of the battery stack column are welded to obtain a battery cell group, and the method further includes:

[0049] Align the positioning plate with the power output connecting piece.

[0050] In this embodiment, the positioning plate is arranged on a side of the plastic plate close to the electrode group, that is, the positioning plate is located in the shell, that is, the positioning plate is located in the secondary battery, the positioning plate is connected to the conductive ring, and the positioning plate serves as a positioning component of the conductive ring, that is, the conductive ring uses the positioning plate as a reference plate, that is, the conductive ring is positioned relative to the positioning plate, so that the position of the conductive ring relative to the positioning plate is fixed. The positioning plate serves as the reference position of the conductive ring, and the relative position between the power output connecting piece and the positioning plate is determined by the alignment between the power output connecting piece and the positioning plate, thereby aligning the power output connecting piece with the positioning plate, making it easier to align the alignment position of the power output connecting piece with the positioning plate, thereby aligning the welding position of the power output connecting piece with the conductive ring, effectively reducing the probability of false welding between the power output connecting piece and the conductive ring.

[0051] Furthermore, the positioning plate is installed on a side of the plastic plate close to the electrode group and sleeved on the conductive ring, and then further includes:

[0052] Performing alignment drilling on the positioning plate to form alignment holes on the positioning plate;

[0053] The step of aligning the positioning plate with the power output connecting piece includes:

[0054] The alignment protrusion of the power output connecting piece is inserted into the alignment hole so that the welding point of the power output connecting piece is aligned with the conductive connection end.

[0055] In this embodiment, after the positioning plate is processed by alignment drilling, the alignment hole is formed at the specified position, and the relative position between the alignment hole and the conductive ring is fixed, so that the relative position between the positioning plate and the conductive ring is fixed, thereby making the positioning plate and the conductive ring maintain a relatively fixed position, and further making the relative position between the positioning plate and the power output connecting piece aligned. An alignment protrusion corresponding to the alignment hole is formed on the power output connecting piece. When the power output connecting piece is welded to the conductive ring, the alignment protrusion is aligned with the alignment hole, that is, the alignment protrusion of the power output connecting piece is inserted into the alignment hole on the positioning plate, so that the relative position between the power output connecting piece and the positioning plate is kept fixed, which facilitates the alignment of the welding position on the power output connecting piece with the conductive ring, thereby facilitating the alignment of the power output connecting piece with the conductive ring, and further facilitating the welding between the power output connecting piece and the conductive ring, thereby increasing the welding contact area between the power output connecting piece and the conductive ring, and further reducing the probability of cold welding between the power output connecting piece and the conductive ring.

[0056] In one embodiment, the present application also provides a secondary battery manufactured using the secondary battery manufacturing method described in any of the above embodiments. In this embodiment, the secondary battery manufacturing method includes installing a conductive ring in a cover mounting hole of a plastic plate to obtain a battery cover; welding an electric energy output connecting piece to the connection point of the electrode group to obtain a battery core column; welding the conductive ring of the battery cover and the electric energy output connecting piece of the battery core column to obtain a battery cell group; and inserting the battery cell group into a shell to obtain a secondary battery. The electric energy output connecting piece is first connected to the electrode group to form a battery core column, and then the electric energy output connecting piece is welded to the conductive ring to facilitate the connection between the battery cover and the battery core column, thereby facilitating the connection between the electric energy output connecting piece and the conductive ring, and further facilitating the direct buckling of the battery cover on the end cover of the shell. The assembly of the battery cover and the shell can be completed without bending the electric energy output connecting piece, effectively improving the assembly efficiency of the secondary battery.

[0057] In one embodiment, the present application also provides a secondary battery cover structure. The secondary battery cover structure of one embodiment includes a plastic plate and a conductive connection assembly. The plastic plate is used to connect to the shell of the secondary battery to cover the end cover of the shell, and the plastic plate is provided with a cover mounting hole connected to the interior of the shell. The conductive connection assembly includes a conductive electrode, a conductive ring and an electric energy output connecting piece. The conductive ring is inserted into the cover mounting hole, a portion of the conductive ring is located in the shell, and the conductive electrode is connected to the conductive ring. The electric energy output connecting piece is located in the shell, and the electric energy output connecting piece is connected to a side of the conductive ring facing away from the conductive electrode, and the electric energy output connecting piece is used to connect to the pole group of the secondary battery.

[0058] In this embodiment, part of the conductive ring protrudes and is arranged toward the power output connecting piece, so that the power output connecting piece can directly contact the conductive ring, and the power output connecting piece is connected to the electrode group, so that the conductive electrode is electrically connected to the power output connecting piece through the protruding arrangement of the conductive ring, thereby making the electrical connection between the power output connecting piece and the electrode group unnecessary to bend, facilitating electrical contact between the power output connecting piece and the electrode group and effectively reducing the difficulty of bending the connecting piece.

[0059] In another embodiment, the conductive connecting piece and the electrode group are welded by butterfly welding. Specifically, the conductive connecting piece has a butterfly welding area, and the butterfly welding area corresponds to the output end of the electrode group to achieve welding of the electrode group on the butterfly welding area.

[0060] In one embodiment, the conductive ring is provided with a first groove, the opening of the first groove faces away from the power output connecting piece, and at least a portion of the conductive electrode is clamped in the first groove. In this embodiment, the first groove is provided on the conductive ring, and the first groove is used to accommodate a portion of the conductive electrode, so that the conductive electrode is clamped in the first groove, thereby enabling the conductive electrode to be clamped with the conductive ring, and further enabling the conductive electrode to be sleeved in the conductive ring. The first groove serves as a receiving groove for the conductive electrode, which facilitates the clamping of the conductive electrode on the conductive ring, thereby facilitating the connection between the conductive electrode and the conductive ring, and improving the connection strength between the conductive electrode and the conductive ring. Wherein, the conductive electrode is located outside the shell, which facilitates the connection between the conductive electrode and the external conductive wire, thereby facilitating the output of electrical energy.

[0061] Furthermore, the conductive ring has a second groove connected to the first groove, and the second groove is used for penetration welding between the power output connector and the conductive ring. In this embodiment, the second groove is defined at the bottom of the first groove and is connected to the first groove, creating a continuous recessed space on the side of the conductive ring facing away from the electrode assembly, thereby accommodating a larger portion of the conductive electrode. Furthermore, the second groove is located at the bottom of the first groove. During laser penetration welding of the power output connector and the conductive ring, welding slag is confined within the second groove, preventing it from falling into the housing and effectively protecting the electrode assembly. In another embodiment, the diameter of the second groove is smaller than that of the first groove. This smaller diameter creates a stepped structure within the conductive ring, whereby the bottom of the first groove forms a step with the bottom of the second groove. When welding slag collects in the second groove, the conductive electrode is supported by the step and kept away from the welding slag in the second groove, thereby ensuring electrical conductivity between the conductive electrode and the conductive ring.

[0062] In one embodiment, the conductive connection assembly further includes a cover fixing ring, the cover fixing ring being located inside the shell, and the cover fixing ring being sleeved on the conductive ring. In this embodiment, the cover fixing ring is located between the plastic plate and the power output connection piece, that is, the cover fixing ring is located inside the shell, and the cover fixing ring is connected to the plastic plate and the power output connection piece, respectively. Moreover, the cover fixing ring is sleeved with the conductive ring, that is, the conductive ring passes through the cover mounting hole and the protruding portion is sleeved with the cover fixing ring, so that the cover fixing ring fixes the conductive ring at a position corresponding to the cover mounting hole, thereby fixing the position of the conductive ring on the plastic plate, effectively improving the installation stability of the conductive ring in the cover mounting hole. In another embodiment, the cover fixing ring has a fixing through-hole, and the conductive ring is passed through the fixing through-hole and abuts against the power output connection piece. The fixing through-hole corresponds to the cover mounting hole, and the conductive ring passes through the cover mounting hole and the fixing through-hole in sequence, that is, the conductive ring first passes through the cover mounting hole, then passes through the fixing through-hole, and finally is connected to the power output connecting piece, so that part of the conductive ring is located in the fixing through-hole, which facilitates the socketing of the conductive ring and the cover fixing ring, thereby improving the connection stability between the cover fixing ring and the conductive ring.

[0063] In one embodiment, the conductive connection assembly further comprises a cover plate sealing ring, the cover plate sealing ring being located on a side of the plastic plate facing away from the conductive electrode, at least a portion of the cover plate sealing ring being located within the cover plate mounting hole, and the cover plate sealing ring being in contact with the inner wall of the cover plate mounting hole and the outer wall of the conductive ring, respectively. In this embodiment, a portion of the cover plate sealing ring is located between the conductive ring and the plastic plate. Specifically, a portion of the cover plate sealing ring is located between the conductive ring and the inner wall of the cover plate mounting hole, thereby reducing the gap between the conductive ring and the plastic plate. This allows the cover plate sealing ring to seal the gap between the conductive ring and the inner wall of the cover plate mounting hole, thereby reducing the probability of contact between the housing and the external environment and effectively improving the sealing performance of the secondary battery.

[0064] Furthermore, the conductive connection assembly also includes a cover plate insulating ring, which is located on the side of the plastic plate away from the cover plate sealing ring. At least a portion of the cover plate insulating ring is located in the cover plate mounting hole, and the cover plate insulating ring is respectively in contact with the inner wall of the cover plate mounting hole and the outer wall of the conductive ring. In this embodiment, part of the cover plate insulating ring is located between the conductive ring and the plastic plate. Specifically, part of the cover plate insulating ring is located between the conductive ring and the inner wall of the cover plate mounting hole, so that the cover plate insulating ring separates the conductive ring and the plastic plate, thereby isolating the conductive ring and the plastic plate from each other and preventing the conductive ring from leaking electricity to the plastic plate. Moreover, the cover plate insulating ring can further reduce the gap between the conductive ring and the plastic plate, thereby further improving the sealing of the secondary battery.

[0065] Furthermore, the cover plate insulating ring and the cover plate sealing ring abut against each other, and a receiving groove is formed between the cover plate insulating ring and the cover plate sealing ring, the opening of the receiving groove facing away from the conductive ring, and the receiving groove accommodates a portion of the plastic plate. In this embodiment, the cover plate insulating ring and the cover plate sealing ring are respectively connected to the conductive ring and the plastic plate, that is, the cover plate insulating ring and the cover plate sealing ring are partially located between the conductive ring and the inner wall of the base cover plate mounting hole, and the cover plate insulating ring and the cover plate sealing ring seal and insulate between the conductive ring and the plastic plate. The receiving groove is located at the abutment point of the cover plate insulating ring and the cover plate sealing ring, and the receiving groove accommodates a portion of the plastic plate, so that the plastic plate, the cover plate insulating ring, and the cover plate sealing ring are clamped together, thereby improving the stability of the cover plate insulating ring and the cover plate sealing ring in the cover plate mounting hole, thereby improving the sealing and insulation of the conductive ring and the plastic plate.

[0066] During the actual assembly process of secondary batteries, the power output connecting piece of the secondary battery cover structure contacts the tab on the electrode group. However, the power output connecting piece is usually a copper plate with high rigidity, and the tab is a thin current collector. It is easy for the power output connecting piece to be directly pressed on the tab during the assembly process, causing the tab to contact the surface of the battery cell of the electrode group, which can easily lead to the accumulation of heat generated by the tab after power is turned on, and then easily lead to excessive local temperature on the electrode group, causing damage to the battery.

[0067] In order to facilitate the electrical connection between the power output connecting piece and the electrode group, the secondary battery cover structure also includes a plate adjustment assembly, which includes an adjusting member and a positioning plate connected to each other, the adjusting member is located on a side of the positioning plate close to the electrode group, the adjusting member is connected to the electrode group, the adjusting member is provided with an adjustment groove, the adjustment groove is used to accommodate an adjustment protrusion to adjust the distance between the positioning plate and the electrode group; the positioning plate is located on a side of the plastic plate close to the electrode group, the positioning plate is in contact with the plastic plate, the positioning plate is provided with an alignment through hole connected to the cover mounting hole, and the alignment through hole is penetrated by the conductive ring.

[0068] In this embodiment, the positioning member is located between the positioning plate and the electrode group. The positioning member lifts the positioning plate, moving it away from the electrode group, thereby moving the plastic plate away from the electrode group. This creates a height difference between the power output connecting piece and the electrode group, effectively reducing the chance of the power output connecting piece over-pressing the electrode tabs on the electrode group. The positioning member includes a positioning groove, which houses the positioning projection. The positioning projection further lifts the positioning plate. Specifically, by adjusting the mass of the positioning projection, the space occupied by the positioning projection within the positioning groove is adjustable, allowing the positioning projection to adjust the distance between the plastic plate and the electrode group by lifting the positioning plate. The positioning plate is used to support the plastic plate and lift it up. During assembly, the conductive ring passes through the cover plate mounting hole and the alignment through-hole in sequence, so that a portion of the conductive ring is located within the housing, thereby positioning the power output connecting piece within the housing and contacting the electrode assembly's tab. The alignment through-hole is aligned with the cover plate mounting hole, facilitating direct alignment of the power output connecting piece with the electrode assembly's tab during assembly of the conductive connection assembly, thereby improving the assembly efficiency of the secondary battery.

[0069] Furthermore, the positioning member is further provided with a positioning glue extrusion hole connected to the positioning accommodating groove, and the positioning protrusion is penetrated through the positioning glue extrusion hole, so that the positioning protrusion is respectively connected to the positioning plate and the pole group.

[0070] In this embodiment, the positioning protrusions are a fluid colloid, for example, plastic glue, i.e., PP glue. After the positioning protrusions are squeezed into the positioning grooves, they first fill the positioning grooves and then contact the pole group through the positioning glue extrusion holes, so that the positioning protrusions adhere to the pole group, facilitating the fixing of the positioning member to the pole group. Furthermore, as the number of positioning protrusions increases, the gap between the positioning plate and the positioning member is filled with the positioning protrusions. While improving the connection strength between the positioning plate and the positioning member, the spacing between the positioning plate and the positioning member can also be increased, facilitating adjustment of the gap between the plastic plate and the pole group, thereby facilitating adjustment of the height of the plastic plate relative to the pole group, further reducing the probability of the power output connecting piece excessively squeezing the pole lugs of the pole group.

[0071] Furthermore, the positioning plate is provided with a first alignment hole, the plastic plate is provided with a second alignment hole, the first alignment hole is communicated with the second alignment hole, and both the first alignment hole and the second alignment hole are communicated with the interior of the shell.

[0072] In this embodiment, the first alignment hole is located on the positioning plate, serving as an alignment point on the positioning plate, and the second alignment hole is located on the plastic plate, serving as an alignment point on the plastic plate. When the plastic plate and the positioning plate are assembled, the first alignment hole is aligned with the second alignment hole, i.e., the first alignment hole and the second alignment hole are aligned and connected, so that the positioning plate and the plastic plate are aligned, facilitating the alignment of the adjustment and glue extrusion holes on the positioning plate with the cover plate mounting holes on the plastic plate, thereby facilitating the sequential insertion of the conductive connection assembly through the cover plate mounting holes and the adjustment and glue extrusion holes, further improving the assembly efficiency of the secondary battery.

[0073] In one embodiment, the present application also provides a secondary battery, comprising a battery shell, a pole group, and the secondary battery cover structure described in any of the above embodiments, wherein the pole group is arranged in the battery shell, the secondary battery cover structure covers the mounting opening of the battery shell, and the conductive connecting piece of the secondary battery cover structure is connected to the pole group. In this embodiment, the secondary battery cover structure comprises a plastic plate and a conductive connecting assembly. The plastic plate is used to connect to the shell of the secondary battery to cover the end cover opening of the shell, and the plastic plate is provided with a cover mounting hole connected to the interior of the shell. The conductive connecting assembly comprises a conductive electrode, a conductive ring, and an electric energy output connecting piece. The conductive ring is inserted into the cover mounting hole, a portion of the conductive ring is located in the shell, and the conductive electrode is connected to the conductive ring. The electric energy output connecting piece is located in the shell, the electric energy output connecting piece is connected to a side of the conductive ring facing away from the conductive electrode, and the electric energy output connecting piece is used to connect to the pole group of the secondary battery. Part of the conductive ring protrudes and is arranged toward the power output connecting piece, which facilitates direct contact between the power output connecting piece and the conductive ring, and the power output connecting piece is connected to the electrode group, so that the conductive electrode is electrically connected to the power output connecting piece through the protruding arrangement of the conductive ring, thereby making the electrical connection between the power output connecting piece and the electrode group unnecessary to bend, facilitating electrical contact between the power output connecting piece and the electrode group, and effectively reducing the difficulty of bending the connecting piece.

[0074] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for manufacturing a secondary battery, characterized in that: include: Install the conductive ring into the cover mounting hole of the plastic plate to obtain the battery cover; Welding the power output connecting piece to the connection point of the electrode group to obtain a battery stack column; Welding the conductive ring of the battery cover plate and the power output connecting piece of the battery stack column to obtain a battery cell group; Mounting the battery cell assembly in a housing to obtain a secondary battery; Part of the conductive ring protrudes and is arranged toward the power output connection piece, so that the power output connection piece contacts the conductive ring; The power output connecting piece is connected to the electrode group of the secondary battery, so that the conductive electrode is electrically connected to the power output connecting piece through the protruding arrangement of the conductive ring; The conductive ring is provided with a first groove, the opening of the first groove is away from the power output connecting piece, and at least a portion of the conductive electrode is clamped in the first groove; the conductive ring is provided with a second groove connected to the first groove, and the second groove is used for penetration welding of the power output connecting piece and the conductive ring; the diameter of the second groove is smaller than the diameter of the first groove.

2. The secondary battery manufacturing method according to claim 1, wherein: The step of installing the conductive ring in the cover mounting hole of the plastic plate also includes: The cover plate insulating ring is buckled into the cover plate mounting hole so that the conductive ring and the plastic plate jointly clamp the cover plate insulating ring.

3. The secondary battery manufacturing method according to claim 1, wherein: The step of installing the conductive ring in the cover mounting hole of the plastic plate also includes: The cover plate sealing ring is buckled in the cover plate mounting hole so that the conductive ring and the plastic plate jointly clamp the cover plate sealing ring.

4. The method for manufacturing a secondary battery according to claim 1, wherein: The step of installing the conductive ring in the cover mounting hole of the plastic plate further includes: The cover plate fixing ring is sleeved on one end of the conductive ring close to the power output connecting piece.

5. The secondary battery manufacturing method according to claim 4, characterized in that: The cover plate fixing ring is sleeved onto an end of the conductive ring close to the power output connecting piece, and then the method further comprises: The connection between the cover plate fixing ring and the conductive ring is welded.

6. The secondary battery manufacturing method according to claim 1, wherein: The step of welding the power output connecting piece to the connection point of the electrode group includes: Butterfly welding is performed on the power output connecting piece and the electrode group.

7. The secondary battery manufacturing method according to claim 1, wherein: The step of welding the conductive ring of the battery cover plate and the power output connection piece of the battery stack column comprises: The power output connecting piece is penetrated and welded on a side of the conductive ring away from the electrode group.

8. The secondary battery manufacturing method according to claim 7, characterized in that: The penetration welding includes laser penetration welding.

9. The method for manufacturing a secondary battery according to claim 1, wherein: The battery cell assembly is assembled into a housing to obtain a secondary battery, and the method further comprises: A conductive electrode is welded to a side of the conductive ring facing away from the electrode group.

10. A secondary battery, characterized in that: The secondary battery is manufactured using the secondary battery manufacturing method according to any one of claims 1 to 9.

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