A lithium battery pack method

Abstract

The present invention proposes a lithium battery pack method. Through steps one to six, a battery cell module is transported to a liquid cooling plate by a conveyor for assembly. At the same time, the conveyor returns the module base to the assembly station in step one. Glue is applied to the liquid cooling plate. The battery cell module is hoisted to separate it from the module base. The battery cell module is moved to the glued liquid cooling plate for press assembly. Multiple inspections are performed during assembly to ensure the quality of the lithium battery pack and improve the yield rate. At the same time, manual transportation and assembly are eliminated, and intelligent processing is used to greatly improve assembly efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery assembly processing, and more particularly, to a lithium battery PACK method. Background Art

[0002] Lithium batteries are a type of battery that uses lithium metal or lithium alloys as the positive and negative electrode materials and a non-aqueous electrolyte solution. In the early days, lithium battery packs primarily referred to the processing and assembly of lithium-ion battery packs. This process involved combining lithium cells, lithium-ion battery protection boards, and battery connectors into the desired product. With the recent development of new energy vehicles, smartphones, laptops, and other products, demand for lithium batteries has steadily increased, along with the increasing energy density of lithium-ion batteries. Traditional lithium battery pack processes employed simple packaging without strict requirements, resulting in a high incidence of substandard lithium batteries.

[0003] The closest technology to the existing one is the publication number: CN111463393A, a battery pack PACK method, and the production process of lithium battery PACK: battery cell appearance and thickness inspection → battery cell testing → 3M double-sided tape on battery cell → bottom film on battery cell → nickel sheet on positive and negative electrodes of battery cell → spot welding nickel sheet on battery cell → spot welding protection plate → welding effect inspection → bracket sticking → initial performance inspection → finished product performance test → label sticker alignment → label packaging → full appearance inspection → high temperature aging → load test → tape installation → boxing.

[0004] The existing PACK method has high labor intensity, low assembly efficiency, and low assembly precision, and cannot meet higher assembly requirements.

[0005] In view of this, the present invention proposes a lithium battery PACK method with high assembly yield and high assembly efficiency. Summary of the Invention

[0006] The purpose of the present invention is to provide a lithium battery PACK method with high assembly yield and high assembly efficiency.

[0007] A lithium battery packing method, characterized by comprising the following steps:

[0008] Step 1: Multiple individual cells are assembled into a cell module. A module base is provided at the bottom of the cell module to support the cell module. After multiple individual cells are assembled into the cell module, each cell in the group is scanned and verified. If successful, a module QR code is output, printed by a printer, and then pasted to the module end plate or laser printed on the module end plate. If unsuccessful, an inspection is performed;

[0009] Step 2: Scan the cell module and perform CCS harness assembly. Scanning the cell module involves scanning the cell module QR code and comparing it with the module base end plate code to determine whether the cell module and the module base are bound. If the binding is successful, proceed to step 3. If not, perform another inspection.

[0010] Step 3: Perform CCS welding on the battery module and conduct a post-weld inspection. During CCS welding, the input power is 3800w-4000w, the welding speed is 100-120mm / s, and the welding height is 33.9-34.1cm. If the welding inspection meets the requirements, proceed to step 4. If not, proceed to inspection.

[0011] Step 4: Perform an automatic total voltage and internal resistance test and module-level EOL test on the soldered battery module. If the test passes, proceed to step 5. If not, perform an inspection.

[0012] Step 5: The cell module is transported to the top of the liquid cooling plate by a conveyor for assembly. At the same time, the conveyor returns the module base to the assembly station in step 1. Glue is applied to the top of the liquid cooling plate, the cell module is hoisted to separate it from the module base, and the cell module is moved to the top of the glue-coated liquid cooling plate for press assembly.

[0013] Step 6: PACK assembly of the battery cell module;

[0014] Step 7: Perform PACK-level EOL testing on the assembled PACK. If it meets the PACK-level EOL test, the processing is completed. If not, inspection is carried out.

[0015] In some embodiments, in step three, during CCS welding, the welding speed is 90 mm / s, the idle speed is 2000 mm / s, the power is 65%, the waveform number is 15, the frequency is 85 Hz, the duty cycle is 100%, the light-on delay is 60 microseconds, the light-off delay is 10 microseconds, the corner delay is 50 microseconds, and the red light speed is 500 mm / s.

[0016] In some embodiments, before step one, single cell material selection, automatic polarity detection, and automatic pole cleaning are sequentially provided. Single cell material selection is used to select a cell material body that meets processing parameters, automatic polarity detection is used to set the polarity of the cell module, and automatic pole cleaning is used to clean the cell pole for subsequent CCS welding.

[0017] Furthermore, the selection of a single battery cell includes battery cell appearance inspection, battery cell sorting, battery cell stacking, battery cell extrusion, and manual code scanning. Among them, the battery cell appearance inspection is to perform an appearance inspection on the battery cell to check whether the battery cell blue film is damaged, whether there are foreign objects on the blue film, whether the pole is dirty, and whether the explosion-proof valve is damaged. The battery cell sorting is to place the battery cells that have passed the visual inspection during the battery cell appearance inspection on the assembly line tray, and use a sorting machine to automatically sort the single battery cells. Battery cell stacking and battery cell extrusion are to stack and extrude the single battery cells after the sorting is completed to obtain a battery cell module, and collect the battery cell code of the battery cell module from left to right. The battery cell code of the battery cell module generates a module base QR code, and the module base QR code is affixed to the module base.

[0018] Furthermore, the cleaning parameters during automatic pole cleaning include cleaning height, cleaning speed, and cleaning power. The cleaning height is 33.5-34 cm, the cleaning speed is 1000-1400 mm / s, and the cleaning power is 80-120 w.

[0019] Furthermore, the sorting parameters are voltage: 3.29V-3.3V and internal resistance: 0-0.3mΩ.

[0020] In some embodiments, in step three, the battery cell module is visually inspected after welding to ensure that the weld has no offset, black holes, excess height less than 1mm, weld width>3mm, and the gap between the tab and the pole is less than 0.3mm. A crowbar is used to pry the welded tab to ensure that the tab does not shake. The post-weld inspection parameters include weld width, excess height, tab gap, pits, and track diameter. The weld width is 3mm-6mm, the excess height is 0-1mm, the tab gap is 0-0.3mm, the pits are -0.5mm-0mm, and the track diameter is 10mm.

[0021] In some embodiments, in step three, an automatic total voltage internal resistance test is performed on the welded battery cell module, and a voltage internal resistance testing device is used to test the welded battery cell module. The total voltage internal resistance setting parameters include total voltage and internal resistance. The total voltage is 42.77V-42.9V, and the internal resistance is <4mΩ.

[0022] In some embodiments, in step five, the glue is applied above the liquid cooling plate. Specifically, a first glue strip is provided at both ends of the liquid cooling plate, three second glue strips are provided in parallel and spaced apart between adjacent first glue strips, and glue application areas are formed between adjacent first glue strips and second glue strips. The glue application areas are coated with AB structure glue strips, and the AB structure glue strips are wavy folded.

[0023] Furthermore, the gluing area is coated with AB structural adhesive strips, and the time from the start of gluing to the pressing and assembling needs to be less than 30 minutes.

[0024] In some embodiments, in step six, the battery cell module is PACK assembled, and the PACK assembly includes the installation of the positive and negative sockets of the battery cell module, the installation of the communication port, the installation of the explosion-proof valve, the installation of the copper plate, and the installation of the BMU.

[0025] Furthermore, the BMU detection battery management unit is installed specifically by setting a BMU bracket on the side of the liquid cooling plate of the battery cell module, and the BMU detection battery management unit is set in the BMU bracket.

[0026] Beneficial effects of the present invention: The present invention proposes a lithium battery PACK method. Through steps one to six, the battery cell module is transported to the top of the liquid cooling plate by a conveying device for assembly. At the same time, the conveying device returns the module base to the assembly station in step one, glue is applied on the top of the liquid cooling plate, the battery cell module is hoisted to separate it from the module base, and the battery cell module is moved to the top of the glue-coated liquid cooling plate for press assembly. Multiple inspections are performed during assembly to ensure the quality of the lithium battery PACK and improve the yield rate. At the same time, no manual transportation and assembly are required, and intelligent processing is used, which greatly improves assembly efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a flow chart of a lithium battery PACK method of the present application.

[0028] Description of main component symbols

[0029] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0030] The following examples are described to assist in understanding the present application, and the examples are not and should not be interpreted in any way as limiting the scope of protection of the present application.

[0031] In the following description, those skilled in the art will recognize that throughout this discussion, components may be described as separate functional units (which may include sub-units), but those skilled in the art will recognize that various components or portions thereof may be divided into separate components or may be integrated together (including within a single system or component).

[0032] At the same time, the connections between components or systems are not intended to be limited to direct connections. Instead, data between these components may be modified, reformatted, or otherwise changed by intermediate components. In addition, additional or fewer connections may be used. It should also be noted that the terms "coupled," "connected," or "input" should be understood to include direct connections, indirect connections through one or more intermediate devices, and wireless connections.

[0033] Example 1:

[0034] like Figure 1FIG. 1 is a flow chart of a lithium battery PACK method of the present application.

[0035] A lithium battery packing method, characterized by comprising the following steps:

[0036] Step 1: Multiple individual cells are assembled into a cell module. A module base is provided at the bottom of the cell module to support the cell module. After multiple individual cells are assembled into the cell module, each cell in the group is scanned and verified. If successful, a module QR code is output, printed by a printer, and then pasted to the module end plate or laser printed on the module end plate. If unsuccessful, an inspection is performed;

[0037] Step 2: Scan the cell module and perform CCS harness assembly. Scanning the cell module involves scanning the cell module QR code and comparing it with the module base end plate code to determine whether the cell module and the module base are bound. If the binding is successful, proceed to step 3. If not, perform another inspection.

[0038] Step 3: Perform CCS welding on the battery module and conduct a post-weld inspection. During CCS welding, the input power is 3800w-4000w, the welding speed is 100-120mm / s, and the welding height is 33.9-34.1cm. If the welding inspection meets the requirements, proceed to step 4. If not, proceed to inspection.

[0039] Step 4: Perform an automatic total voltage and internal resistance test and module-level EOL test on the soldered battery module. If the test passes, proceed to step 5. If not, perform an inspection.

[0040] Step 5: The cell module is transported to the top of the liquid cooling plate by a conveyor for assembly. At the same time, the conveyor returns the module base to the assembly station in step 1. Glue is applied to the top of the liquid cooling plate, the cell module is hoisted to separate it from the module base, and the cell module is moved to the top of the glue-coated liquid cooling plate for press assembly.

[0041] Step 6: PACK assembly of the battery cell module;

[0042] Step 7: Perform PACK-level EOL testing on the assembled PACK. If it meets the PACK-level EOL test, the processing is completed. If not, inspection is carried out.

[0043] In step three, the specific conditions for CCS welding are: welding speed 90 mm / s, idle speed 2000 mm / s, power 65%, waveform number 15, frequency 85 Hz, duty cycle 100%, light on delay 60 microseconds, light off delay 10 microseconds, corner delay 50 microseconds, and red light speed 500 mm / s.

[0044] Before step one, there are also single battery cell selection, automatic polarity detection, and automatic pole cleaning in sequence. Single battery cell selection is used to select battery cell materials that meet the processing parameters, automatic polarity detection is used to set the polarity of the battery cell module, and automatic pole cleaning is used to clean the battery cell poles to facilitate subsequent CCS welding.

[0045] The selection of a single battery cell includes battery cell appearance inspection, battery cell sorting, battery cell stacking, battery cell extrusion, and manual code scanning. Among them, the battery cell appearance inspection is to perform an appearance inspection on the battery cell to check whether the battery cell blue film is damaged, whether there are foreign objects on the blue film, whether the pole is dirty, and whether the explosion-proof valve is damaged. The battery cell sorting is to place the battery cells that have passed the visual inspection during the battery cell appearance inspection on the assembly line tray, and use a sorting machine to automatically sort the single battery cells. Battery cell stacking and battery cell extrusion are to stack and extrude the single battery cells after the sorting is completed to obtain a battery cell module, and collect the battery cell code of the battery cell module from left to right. The battery cell code of the battery cell module generates a module base QR code, and the module base QR code is affixed to the module base.

[0046] The cleaning parameters of automatic pole cleaning include cleaning height, cleaning speed, and cleaning power. The cleaning height is 33.5-34cm, the cleaning speed is 1000-1400mm / s, and the cleaning power is 80-120w.

[0047] The sorting parameters are voltage: 3.29V-3.3V and internal resistance: 0-0.3mΩ.

[0048] Perform a post-weld visual inspection on the battery cell module to ensure that the weld has no offset, black holes, excess height less than 1mm, weld width>3mm, and the gap between the tab and the pole is less than 0.3mm. Use a pry bar to pry the welded tab to check that the tab does not shake. The post-weld inspection parameters include weld width, excess height, tab gap, pits, and track diameter. The weld width is 3mm-6mm, the excess height is 0-1mm, the tab gap is 0-0.3mm, the pit is -0.5mm-0mm, and the track diameter is 10mm.

[0049] In step three, the welded battery cell module is automatically tested for total voltage and internal resistance using a voltage and internal resistance tester. The total voltage and internal resistance setting parameters include total voltage and internal resistance. The total voltage is 42.77V-42.9V, and the internal resistance is less than 4mΩ.

[0050] In step three, the battery module after welding is subjected to module-level EOL test. The module-level EOL test includes insulation detection, continuity detection, module size detection, module appearance detection, and module-ACR detection. The insulation detection is performed on the positive terminal plate and the negative terminal plate. The detection voltage is 1500VDC, the voltage stabilization test time is 60s, and the insulation detection meets the standard parameters of ≥500mΩ; the continuity test meets the standard parameters of the module total voltage of 42.77V-42.9V; the module size detection includes module length, module installation center distance (X direction), module width, module installation center distance (Y direction), module height, and the distance from the bottom of the module to the bottom of the end plate. The standard parameter of the module length is 994.45±1 .0mm, the standard parameter for the module installation center distance (X direction) is 977.45±0.5mm, the standard parameter for the module width is 177.5±1.0mm, the standard parameter for the module installation center distance (Y direction) is 159±0.5mm, the standard parameter for the module height is 216±1mm, and the standard parameter from the bottom of the module to the bottom of the end plate is 17.3±0.3mm; the standard parameter for the low-voltage connector pin inspection is a visual inspection to ensure that the pins are not skewed; the standard parameter for the steel strip insulation layer inspection is a visual inspection to ensure that there is no damage or exposed metal; the standard parameter for the output pole is that the output pole bolt hole is free of foreign matter and no blockage; the module-ACR test is to measure the ACR between the total positive and total negative of the battery cross-group, and the standard ACR parameter is ≤7mΩ.

[0051] In step four, glue is applied on the top of the liquid cooling plate. Specifically, a first glue strip is provided at both ends of the liquid cooling plate, three second glue strips are provided in parallel with each other between adjacent first glue strips, and glue application areas are formed between adjacent first glue strips and second glue strips. AB structural glue strips are applied in the glue application areas, and the AB structural glue strips are wave-folded.

[0052] The gluing area is coated with AB structural adhesive strips, and the time from the start of gluing to the pressing and assembly needs to be less than 30 minutes.

[0053] In step 4, the assembled PACK is subjected to a PACK-level EOL test. The PACK-level EOL test includes insulation resistance detection, withstand voltage detection, water cooling system air tightness detection, and box air tightness detection. The insulation resistance detection is for the positive and negative poles to the shell, the detection voltage is 1500VDC, and the voltage stabilization test time is 30s; the withstand voltage detection is for the positive and negative poles to the shell, the detection voltage is 4400VDC, and the voltage stabilization test time is 60s; the water cooling system air tightness detection is specifically to charge the electric box with a maximum pressure of 350kPa, maintain the pressure at 350±5kPa, and last for 60s, and measure. The measurement time is 60s. When the test result is ≤65Pa / min; the box air tightness detection is specifically to charge the electric box with a maximum pressure of 3.5kPa, maintain the pressure at 3.5±0.5kPa, and last for 60s, and measure. The measurement time is 60s. When the test result is ≤60Pa / min

[0054] In step six, the battery cell module is PACK assembled, which includes the installation of the positive and negative sockets of the battery cell module, the installation of the communication port, the installation of the explosion-proof valve, the installation of the copper plate, and the installation of the BMU.

[0055] The BMU detection battery management unit is installed specifically as follows: a BMU bracket is set on the side of the liquid cooling plate of the battery cell module, and a BMU detection battery management unit is installed in the BMU bracket.

[0056] Beneficial effects of the present invention: The present invention proposes a lithium battery PACK method. Through steps one to six, the battery cell module is transported to the top of the liquid cooling plate by a conveying device for assembly. At the same time, the conveying device returns the module base to the assembly station in step one, glue is applied on the top of the liquid cooling plate, the battery cell module is hoisted to separate it from the module base, and the battery cell module is moved to the top of the glue-coated liquid cooling plate for press assembly. Multiple inspections are performed during assembly to ensure the quality of the lithium battery PACK and improve the yield rate. At the same time, no manual transportation and assembly are required, and intelligent processing is used, which greatly improves assembly efficiency.

[0057] Although this application has disclosed various aspects and embodiments, other aspects and embodiments will be readily apparent to those skilled in the art. Variations and modifications may be made without departing from the spirit of this application, and all such variations and modifications are within the scope of this application. The various aspects and embodiments disclosed in this application are provided for illustrative purposes only and are not intended to limit this application. The actual scope of this application is determined by the claims.

Claims

1. A lithium battery packing method, characterized in that: The following steps are involved: Step 1: Multiple single cells are assembled into a cell module. A module base is provided at the bottom of the cell module. The module base is used to support the cell module. After multiple single cells are assembled into a cell module, each cell in the group is scanned and verified. If successful, the module QR code is output. After printing, it is pasted on the module end plate or laser printed on the module end plate. If unsuccessful, conduct an inspection; Step 2: Scan the cell module and perform CCS harness assembly. Scanning the cell module involves scanning the cell module QR code and comparing it with the module base end plate code to determine whether the cell module and the module base are bound. If the binding is successful, proceed to step 3. If not, perform another inspection. Step 3: Perform CCS welding on the battery module and conduct a post-weld inspection. During CCS welding, the input power is 3800w-4000w, the welding speed is 100-120mm / s, and the welding height is 33.9-34.1cm. If the welding inspection meets the requirements, proceed to step 4. If not, proceed to inspection. Step 4: Perform an automatic total voltage internal resistance test and a module-level EOL test on the welded cell module. If the test passes, proceed to step 5. If not, perform an inspection. Specifically, glue is applied to the top of the liquid cooling plate. A first glue strip is provided at each end of the liquid cooling plate. Three second glue strips are provided in parallel between adjacent first glue strips. A glue area is formed between adjacent first and second glue strips. The glue area is coated with an AB structure glue strip, which is a wave-folded type. Step 5: The cell module is transported to the top of the liquid cooling plate by a conveyor for assembly. At the same time, the conveyor returns the module base to the assembly station in step 1. Glue is applied to the top of the liquid cooling plate, the cell module is hoisted to separate it from the module base, and the cell module is moved to the top of the glue-coated liquid cooling plate for press assembly. Step 6: PACK assembly of the battery cell module; Step 7: Perform PACK-level EOL testing on the assembled PACK. If it meets the PACK-level EOL test, the processing is completed. If not, inspection is carried out.

2. The lithium battery packing method according to claim 1, wherein: In step three, the specific conditions for CCS welding are: welding speed 90 mm / s, idle speed 2000 mm / s, power 65%, waveform number 15, frequency 85 Hz, duty cycle 100%, light on delay 60 microseconds, light off delay 10 microseconds, corner delay 50 microseconds, and red light speed 500 mm / s.

3. The lithium battery packing method according to claim 1, wherein: Before step one, there are also single battery cell selection, automatic polarity detection, and automatic pole cleaning in sequence. Single battery cell selection is used to select battery cell materials that meet the processing parameters, automatic polarity detection is used to set the polarity of the battery cell module, and automatic pole cleaning is used to clean the battery cell poles to facilitate subsequent CCS welding.

4. The lithium battery packing method according to claim 3, wherein: The selection of a single battery cell includes battery cell appearance inspection, battery cell sorting, battery cell stacking, battery cell extrusion, and manual code scanning. Among them, the battery cell appearance inspection is to perform an appearance inspection on the battery cell to check whether the battery cell blue film is damaged, whether there are foreign objects on the blue film, whether the pole is dirty, and whether the explosion-proof valve is damaged. The battery cell sorting is to place the battery cells that have passed the visual inspection during the battery cell appearance inspection on the assembly line tray, and use a sorting machine to automatically sort the single battery cells. Battery cell stacking and battery cell extrusion are to stack and extrude the single battery cells after the sorting is completed to obtain a battery cell module, and collect the battery cell code of the battery cell module from left to right. The battery cell code of the battery cell module generates a module base QR code, and the module base QR code is affixed to the module base.

5. The lithium battery packing method according to claim 3, wherein: The cleaning parameters during automatic pole cleaning include cleaning height, cleaning speed, and cleaning power. The cleaning height is 33.5-34cm, the cleaning speed is 1000-1400mm / s, and the cleaning power is 80-120w.

6. The lithium battery packing method according to claim 4, wherein: The sorting parameters are voltage: 3.29V-3.3V and internal resistance: 0-0.3mΩ.

7. The lithium battery packing method according to claim 1, wherein: In step three, perform a post-weld visual inspection on the battery cell module to ensure that the weld has no offset, black holes, excess height less than 1mm, weld width > 3mm, and the gap between the tab and the pole is less than 0.3mm. Use a crowbar to pry the welded tab to check that the tab does not shake. The post-weld inspection parameters include weld width, excess height, tab gap, pits, and track diameter. The weld width is 3mm-6mm, the excess height is 0-1mm, the tab gap is 0-0.3mm, the pits are -0.5mm-0mm, and the track diameter is 10mm.

8. The lithium battery packing method according to claim 1, wherein: In step three, the welded battery cell module is automatically tested for total voltage and internal resistance using a voltage and internal resistance tester. The total voltage and internal resistance setting parameters include total voltage and internal resistance. The total voltage is 42.77V-42.9V, and the internal resistance is less than 4mΩ.

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