Semi-solid-state lithium battery with multiple positive tabs welded at double ends by aluminum sheet current collector through ultrasonic laser

Abstract

The utility model provides an aluminum sheet current collector ultrasonic laser double-end welding multi-positive-tab semi-solid-state lithium battery, the semi-solid-state lithium battery comprises a shell assembly and a battery cell assembly, the shell assembly comprises a shell and an aluminum cover, the shell is provided with a containing groove, and the aluminum cover covers the shell; the battery cell assembly comprises a roll core and an aluminum sheet current collector, the roll core is mounted in the accommodating groove, one end of the roll core is provided with a positive tab connecting part comprising a plurality of positive tabs stacked in sequence, a trapezoidal connecting end is formed on one side, deviating from the roll core, of each positive tab, one end of the aluminum sheet current collector partially covers the surface of each positive tab, and the other end of the aluminum sheet current collector partially covers the surface of each positive tab. One end of the aluminum sheet current collector is in ultrasonic welding with the plurality of positive tabs, and the other end of the aluminum sheet current collector is in laser welding with the aluminum cover. The plurality of positive electrode tabs and the aluminum sheet current collector are subjected to ultrasonic welding, the aluminum sheet current collector and the aluminum cover are subjected to laser welding, and current is gathered on the aluminum sheet current collector at the same time, so that the connection strength is improved, and the impedance is reduced.

Description

Technical Field

[0001] This disclosure relates to the technical field of lithium batteries, and in particular to a semi-solid lithium battery with multiple positive tabs welded to both ends by ultrasonic laser on an aluminum sheet current collector. Background Technology

[0002] Solid-state batteries refer to lithium batteries that use solid electrolytes instead of liquid electrolytes. Based on the amount of solid electrolyte used, they can be further divided into two main categories: semi-solid-state batteries and all-solid-state batteries. Semi-solid-state batteries use a solid-liquid hybrid electrolyte, with the liquid (electrolyte) comprising approximately 5-10% of the battery's mass. Essentially, it's a compromise between liquid lithium batteries and all-solid-state batteries.

[0003] Semi-solid-state batteries have higher rate capability and larger current output. When the battery has a single-tab or double-tab structure, the current has fewer pathways to flow out of the current collector through the single or double tabs, resulting in higher impedance in the semi-solid-state battery. When the positive electrode uses a multi-tab structure, the current collector of the multi-tab is made of aluminum-to-nickel material. The nickel sheet has high impedance, which can easily cause overheating problems in semi-solid-state batteries. In addition, the connection strength of the nickel sheet is relatively low, which can easily cause deformation of the current collector when welding it to the aluminum shell. Utility Model Content

[0004] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a semi-solid lithium battery with high connection strength and low impedance, in which multiple positive tabs are ultrasonically and laser-welded to aluminum sheet current collectors at both ends.

[0005] The purpose of this disclosure is achieved through the following technical solution:

[0006] A semi-solid lithium battery with multiple positive tabs welded to aluminum sheet current collectors by ultrasonic laser double-end welding includes a casing assembly and a cell assembly. The casing assembly includes a housing and an aluminum cover. The housing has a receiving groove, and the aluminum cover is disposed on the housing.

[0007] The battery cell assembly includes a core and an aluminum sheet current collector. The core is installed in the receiving groove. One end of the core is provided with a positive electrode tab connection portion. The positive electrode tab connection portion includes a plurality of positive electrode tabs stacked in sequence. A trapezoidal connection end is formed on the side of the positive electrode tab away from the core. One end of the aluminum sheet current collector partially covers the surface of the positive electrode tab. One end of the aluminum sheet current collector is ultrasonically welded to the plurality of positive electrode tabs, and the other end of the aluminum sheet current collector is laser welded to the aluminum cover.

[0008] In one embodiment, the aluminum sheet current collector is welded between the two positive electrode tabs at the center of the positive electrode tab connection.

[0009] In one embodiment, each positive electrode tab includes a bent tab and a lead-out tab. Each bent tab is used to connect to the positive electrode sheet of the winding core. Each bent tab is bent and arranged with the corresponding lead-out tab so that the multiple lead-out tabs are stacked sequentially. The multiple lead-out tabs are ultrasonically welded to one end of the aluminum sheet current collector.

[0010] In one embodiment, a liquid injection channel is formed at the center of the core, and the bending connection between the bending piece and the lead-out piece is located between the housing and the liquid injection channel.

[0011] In one embodiment, each of the lead-out tabs is flush with one end face of the bent tab.

[0012] In one embodiment, the surface of the positive electrode tab is provided with an ultrasonic welding groove.

[0013] In one embodiment, the number of ultrasonic welding grooves is multiple, and the multiple ultrasonic welding grooves are arranged at intervals.

[0014] In one embodiment, a dividing ring is provided in the receiving groove, which divides the receiving groove into two receiving grooves.

[0015] In one embodiment, the aluminum cover has a limiting ring protrusion on the side opposite to the aluminum sheet current collector.

[0016] Compared with the prior art, this disclosure has at least the following advantages:

[0017] The aforementioned semi-solid-state lithium battery with multiple positive tabs welded to aluminum sheet current collectors via ultrasonic laser double-end welding exhibits a more stable trapezoidal connection structure for the positive tabs, resulting in a more stable structure after multiple positive tabs are stacked sequentially, reducing the problem of positive tabs warping during the stacking process. The multiple positive tabs are ultrasonically welded to the aluminum sheet current collector, while the other end of the aluminum sheet current collector is laser-welded to the aluminum cap, resulting in a high connection strength between the multiple positive tabs, the aluminum sheet current collector, and the aluminum cap. Multiple currents are simultaneously converged on the aluminum sheet current collector via the multiple positive tabs, and the aluminum sheet current collector is connected to the aluminum cap for charging and discharging, resulting in lower impedance for the semi-solid-state lithium battery. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1This is a schematic diagram of a semi-solid lithium battery with multiple positive tabs welded to an aluminum sheet current collector using ultrasonic laser double-end welding, according to one embodiment.

[0020] Figure 2 for Figure 1 Another structural schematic diagram of a semi-solid lithium battery with multiple positive tabs welded to aluminum sheet current collectors using ultrasonic laser double-end welding.

[0021] Figure 3 for Figure 1 The diagram shows another partial structure of a semi-solid lithium battery with multiple positive tabs welded to aluminum sheet current collectors using ultrasonic laser double-end welding.

[0022] Figure 4 for Figure 1 The diagram shows the structure of the core before winding. Detailed Implementation

[0023] To facilitate understanding of this disclosure, a more complete description will be given below with reference to the accompanying drawings, which illustrate preferred embodiments of the present disclosure. However, this disclosure can 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 complete understanding of the disclosure.

[0024] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] To better understand the technical solutions and beneficial effects of this disclosure, the following detailed description is provided in conjunction with specific embodiments:

[0027] Please refer to the following, which is a semi-solid lithium battery 10 with multiple positive tabs welded to aluminum sheet current collectors by ultrasonic laser at both ends according to an embodiment of the present disclosure. It includes a housing assembly 100 and a cell assembly 200. The housing assembly 100 includes a housing 110 and an aluminum cover 120. The housing 110 has a receiving groove 1101 for receiving the core 210 and electrolyte. The aluminum cover 120 covers the housing 110.

[0028] Furthermore, the battery cell assembly 200 includes a core 210 and an aluminum sheet current collector 220. The core 210 is installed in the receiving groove 1101. One end of the core 210 is provided with a positive electrode tab connection portion 211. The positive electrode tab connection portion 211 includes a plurality of positive electrode tabs 2111 stacked sequentially. The side of the positive electrode tab 2111 facing away from the core 210 forms a trapezoidal connection end. The trapezoidal connection end of the positive electrode tab 2111 has a trapezoidal structure. One end of the aluminum sheet current collector 220 partially covers the surface of the positive electrode tab 2111. One end of the aluminum sheet current collector 220 is ultrasonically welded to the plurality of positive electrode tabs 2111, and the other end of the aluminum sheet current collector 220 is laser welded to the aluminum cover 120. The laser welding has high connection strength and good welding quality.

[0029] In this embodiment, multiple positive electrode tabs 2111 simultaneously converge the current onto the aluminum sheet current collector 220. The trapezoidal connection end of the positive electrode tab 2111 makes the structure of the positive electrode tab 2111 more stable, so that the structure of the positive electrode tab connection part 211 after multiple positive electrode tabs 2111 are stacked in sequence is more stable. The positive electrode tab connection part 211 and the aluminum sheet current collector 220 are ultrasonically welded, so that the surface of the positive electrode tab connection part 211 and the aluminum sheet current collector 220 is flat after welding. The other end of the aluminum sheet current collector 220 is laser welded to the aluminum cover 120. The connection strength between the aluminum sheet current collector 220 and the aluminum cover 120 after welding is high.

[0030] The aforementioned semi-solid lithium battery 10 with multiple positive tabs welded to aluminum sheet current collectors via ultrasonic laser double-end welding has a more stable trapezoidal connection end structure for the positive tabs 2111, resulting in a more stable structure after multiple positive tabs 2111 are stacked sequentially, reducing the problem of the positive tabs 2111 lifting during the stacking process. The multiple positive tabs 2111 are ultrasonically welded to the aluminum sheet current collector 220, and the other end of the aluminum sheet current collector 220 is laser-welded to the aluminum cover 120, resulting in a high connection strength between the multiple positive tabs 2111, the aluminum sheet current collector 220, and the aluminum cover 120. Multiple currents are simultaneously converged on the aluminum sheet current collector 220 through the multiple positive tabs 2111, and the aluminum sheet current collector 220 is connected to the aluminum cover 120 for charging and discharging, resulting in a lower impedance for the semi-solid lithium battery.

[0031] In one embodiment, the aluminum current collector 220 is welded between the two positive tabs 2111 at the center of the positive tab connection portion 211. In this embodiment, by placing the aluminum current collector 220 between the two positive tabs 2111 at the center of the positive tab connection portion 211, the paths for the current from the inner ring of the core 210 and the current from the outer ring of the core 210 to enter the aluminum current collector 220 are both shorter, resulting in a more uniform current distribution from the core 210 into the aluminum current collector 220, thereby reducing the internal resistance of the cell assembly 200.

[0032] In one embodiment, each positive electrode tab 2111 includes a bent piece 2111a and a lead-out piece 2111b. Each bent piece 2111a is used to connect to the positive electrode sheet of the winding core. Each bent piece 2111a and the corresponding lead-out piece 2111b are bent together so that multiple lead-out pieces 2111b are stacked sequentially. The multiple lead-out pieces 2111b are ultrasonically welded to one end of the aluminum sheet current collector 220. In this embodiment, after the bent pieces 2111a and the lead-out pieces 2111b are bent, the bent pieces 2111a are close to one end of the winding core 210. The bending distances of different bent pieces 2111a are different, so that the multiple lead-out pieces 2111b are more tightly attached to the aluminum sheet current collector 220 after being stacked, thereby facilitating the ultrasonic welding of the lead-out pieces 2111b to the aluminum sheet current collector 220.

[0033] In one embodiment, a liquid injection channel 2101 is formed at the center of the core 210, and the bending connection between the bending piece 2111a and the lead-out piece 2111b is located between the housing 110 and the liquid injection channel 2101. In this embodiment, by controlling the bending connection between the bending piece 2111a and the lead-out piece 2111b, the aluminum sheet current collector 220 is located between the housing 110 and the liquid injection channel 2101, thus preventing the bending connection between the bending piece 2111a and the lead-out piece 2111b from blocking the liquid injection channel 2101 and ensuring smooth liquid injection.

[0034] In one embodiment, each of the lead-out tabs 2111b is flush with one end face away from the bent tab 2111a. In this embodiment, the flushness of the end face away from the bent tab 2111a ensures that the structure of the multiple lead-out tabs 2111b is consistent, thereby making the welded surfaces of the multiple lead-out tabs 2111b and the aluminum sheet current collector 220 more flat and facilitating the assembly of the multiple lead-out tabs 2111b and the aluminum sheet current collector 220.

[0035] In one embodiment, the surface of the positive electrode tab 2111 is provided with an ultrasonic welding groove 2102. In this embodiment, the ultrasonic welding groove 2102 can guide ultrasonic vibration and frictional heat to act more concentratedly on the contact surface between the positive electrode tab 2111 and the aluminum sheet current collector 220, thereby improving the ultrasonic welding quality between the positive electrode tab 2111 and the aluminum sheet current collector 220.

[0036] In one embodiment, there are multiple ultrasonic welding grooves 2102, which are spaced apart. In this embodiment, the spaced arrangement of multiple ultrasonic welding grooves 2102 increases the contact area and the number of welding points between the positive electrode tab 2111 and the aluminum sheet current collector 220, thereby further increasing the connection strength between the positive electrode tab 2111 and the aluminum sheet current collector 220 and improving the overall stability of the ultrasonic welding part.

[0037] In one embodiment, a dividing ring 111 protrudes from the inner wall of the housing 110, dividing the receiving groove 1101 into two receiving grooves. In this embodiment, the dividing ring 111 divides the receiving groove 1101 into two receiving grooves, with the core 210 installed in the bottom receiving groove and the aluminum cover 120 installed in the upper receiving groove, making more efficient use of the limited space within the receiving groove 1101, thereby ensuring a reasonable layout of the internal battery components.

[0038] In one embodiment, the aluminum cover 120 has a limiting ring protrusion 121 protruding on the side opposite to the adjacent aluminum sheet current collector 220. In this embodiment, the limiting ring protrusion 121 can press and hold the aluminum sheet current collector 220, improving the stability of the core 210 and the aluminum sheet current collector 220 inside the housing 110, thereby optimizing battery performance and improving safety.

[0039] Compared with the prior art, this disclosure has at least the following advantages:

[0040] The aforementioned semi-solid lithium battery 10 with multiple positive tabs welded to aluminum sheet current collectors via ultrasonic laser double-end welding has a more stable trapezoidal connection end structure for the positive tabs 2111, resulting in a more stable structure after multiple positive tabs 2111 are stacked sequentially, reducing the problem of the positive tabs 2111 lifting during the stacking process. The multiple positive tabs 2111 are ultrasonically welded to the aluminum sheet current collector 220, and the other end of the aluminum sheet current collector 220 is laser-welded to the aluminum cover 120, resulting in a high connection strength between the multiple positive tabs 2111, the aluminum sheet current collector 220, and the aluminum cover 120. Multiple currents are simultaneously converged on the aluminum sheet current collector 220 through the multiple positive tabs 2111, and the aluminum sheet current collector 220 is connected to the aluminum cover 120 for charging and discharging, resulting in a lower impedance for the semi-solid lithium battery.

[0041] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the disclosed patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the protection scope of this disclosure. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A semi-solid lithium battery with aluminum sheet current collector ultrasonic laser dual-end welding multi-positive tab, characterized in that, The battery includes a shell assembly and an electric core assembly, the shell assembly includes a shell and an aluminum cover, the shell is provided with a receiving groove, and the aluminum cover covers the shell; The electric core assembly includes a winding core and an aluminum sheet current collector, the winding core is installed in the receiving groove, one end of the winding core is provided with a positive tab connecting part, the positive tab connecting part includes a plurality of positive tabs which are stacked in sequence, the side of the positive tab away from the winding core is formed with a trapezoidal connecting end, part of one end of the aluminum sheet current collector covers the surface of the positive tab, one end of the aluminum sheet current collector is ultrasonically welded with a plurality of the positive tabs, and the other end of the aluminum sheet current collector is laser welded with the aluminum cover.

2. The semi-solid lithium battery of aluminum sheet current collector ultrasonic laser double-end welding multi-positive electrode tab according to claim 1, characterized in that, The aluminum sheet current collector is welded between two positive tabs at the center of the positive tab connecting part.

3. The semi-solid lithium battery of aluminum sheet current collector ultrasonic laser double-end welding multi-positive electrode tab according to claim 1, characterized in that, Each positive tab includes a bending sheet and a lead-out sheet, each bending sheet is used to connect with a positive sheet of the winding core, and each bending sheet is bent with the corresponding lead-out sheet to make the plurality of lead-out sheets be stacked in sequence, and the plurality of lead-out sheets are ultrasonically welded with one end of the aluminum sheet current collector.

4. The semi-solid lithium battery of aluminum sheet current collector ultrasonic laser double-end welding multi-positive electrode tab according to claim 3, characterized in that, The center of the winding core is formed with a liquid injection channel, and the bending connection between the bending sheet and the lead-out sheet is located between the shell and the liquid injection channel.

5. The semi-solid lithium battery of aluminum sheet current collector ultrasonic laser double-end welding multi-positive electrode tab according to claim 3, characterized in that, Each lead-out sheet is flush with one end surface of the bending sheet.

6. The semi-solid lithium battery of aluminum sheet current collector ultrasonic laser double-end welding multi-positive electrode tab according to claim 1, characterized in that, The surface of the positive tab is provided with an ultrasonic welding groove.

7. The semi-solid lithium battery of aluminum sheet current collector ultrasonic laser double-end welding multi-positive electrode tab according to claim 6, characterized in that, The number of the ultrasonic welding grooves is a plurality, and the plurality of ultrasonic welding grooves are arranged at intervals.

8. The semi-solid lithium battery of aluminum sheet current collector ultrasonic laser double-end welding multi-positive electrode tab according to claim 1, characterized in that, The receiving groove is provided with a separation convex ring, and the separation convex ring separates the receiving groove into two receiving grooves.

9. The semi-solid lithium battery of aluminum sheet current collector ultrasonic laser double-end weld multi-positive tab of claim 1, wherein, The aluminum cover is provided with a limiting ring protrusion on the side away from the aluminum sheet current collector.

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