CN111370605A - A kind of electrochemical device and preparation method thereof - Google Patents

Abstract

The invention discloses an electrochemical device and a preparation method thereof, comprising a square shell, an electric core is arranged in the shell, two ends of the electric core are respectively connected with an electrode assembly, the electrode assembly includes an electrode pole, and one end of the shell is provided with a power supply core The opening of the pole entering from the outside to the inside, the middle of the end face of the other end is provided with an opening, the opening end of the end face is injected with a transparent insulating gasket, the electrode assembly close to the open end of the shell is connected with an end cap, and the edge of the end cap is connected to the shell. The open end of the body is welded and sealed, the electrode pole close to the opening end of the shell is pierced from the opening, and the electrode pole close to the opening end of the shell is injected with an insulating sealing ring, and the insulating sealing ring is in contact with the transparent insulating gasket. And the contact surfaces are bonded and sealed with each other and welded by laser penetration welding. The invention has the advantages of low difficulty in entering the shell, simple process and strong operability, and can effectively improve the production efficiency and energy density; the two processes of bonding and laser penetration welding are combined together to ensure the sealing of the joint and effectively prevent the electrolyte in the shell. overflow.

Description

A kind of electrochemical device and preparation method thereof

technical field

The invention belongs to the technical field of electrochemistry, and in particular relates to an electrochemical device and a preparation method thereof.

Background technique

The square aluminum shell lithium battery was mainly used in small digital electronic products in the early days. With the development of technology and the expansion of the field, the square aluminum shell lithium battery began to develop into the fields of motorcycles, automobiles, power tools and electric vehicles, especially in the recent past. The high-power charging and discharging power supply for vehicles has developed rapidly, but the traditional lithium battery design adopts the design of steel shell, aluminum-plastic film or plastic shell. , Blocking, this way of entering the shell makes the connector easy to break or may be short-circuited with the shell, making it difficult to enter the shell, and there is a problem of poor sealing.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides an electrochemical device and a preparation method thereof, which can reduce the difficulty of inserting the battery into the shell, the connecting piece is not easily damaged, the sealing is tight and the strength is high, and the energy density of the battery is increased.

The purpose of this invention is to realize in the following way:

An electrochemical device includes a square shell, a battery core is arranged in the shell, two ends of the battery core are respectively connected to an electrode assembly, the electrode assembly includes an electrode pole, and one end of the shell is provided with a power supply core pole from The opening that enters from outside to inside has an opening in the middle of the end face of the other end. The open end of the end face is injected with a transparent insulating gasket. The electrode assembly near the open end of the casing is connected with an end cap, and the edge of the end cap is connected to the open end of the casing. Welding and sealing, the electrode pole near the opening end of the casing is pierced from the opening, and an insulating sealing ring is injected on the electrode pole near the opening end of the casing. The insulating sealing ring is in contact with the transparent insulating gasket, and the contact surface After being bonded and sealed to each other, they are welded by laser penetration welding.

The transparent insulating gasket is a U-shaped body, the inner side of the U-shaped body is close to and wraps the end of the opening of the casing, the insulating sealing ring is flat, and the lower surface of the transparent insulating sealing gasket contact with the top surface.

The electrode assembly close to the open end of the casing includes a pole II and an insulating sealing ring II, the pole II protrudes from the middle of the end cover I, the pole II is connected with the end cover I and the insulating sealing ring II, and the insulating sealing ring II is connected together. Also U-shaped.

The transparent insulating gasket is flat and is located outside the casing, the insulating sealing ring is L-shaped, and one side of the L-shaped extends along the electrode pole to the opening of the casing and is located between the end face of the opening of the casing and the electrode pole. In between, the transparent insulating gasket is in contact with the insulating sealing ring.

The structure of the electrode assembly close to the open end of the casing is the same as that of the electrode assembly close to the open end of the casing, and the connection between the electrode assembly close to the open end of the casing and the end cap is the same as that of the electrode assembly close to the open end of the casing The end faces of the holes are connected in the same way.

The transparent insulating gasket is a transparent plastic insulating gasket.

Both ends of the battery core are formed with positive all-pole tabs and negative all-pole tabs, which are respectively welded to the electrode assembly.

The preparation method of the electrochemical device comprises the following steps:

(1) Preparation of the shell: the shell is formed by cold drawing and precise extraction, and a transparent insulating gasket is injected into the opening of the shell;

(2) Preparation of the end cap: use the stamping method to form the end cap I with the opening in the middle;

(3) Preparation of battery core: The battery core is prepared by winding all-pole tabs, and positive all-pole tabs and negative all-pole tabs are formed on the battery core;

(4) Preparation of electrode assembly: connect the electrode pole I and the busbar I together, the insulating sealing ring I is injection-molded on the electrode pole I, and the outer surface of the insulating sealing ring I is coated with insulating glue to form an opening close to the shell. The electrode assembly I at the end of the hole; the pole II and the busbar II are connected together, and an insulating sealing ring II is injected into the opening in the middle of the end cover I. The pole II passes through the middle of the end cover I, and the insulating sealing ring II and the pole II are connected together to form electrode assembly II near the open end of the shell;

(5) Connect the electrode assembly to the cell: Use ultrasonic welding or ultrasonic welding followed by laser welding enhancement or electromagnetic pulse welding to fix the electrode assembly I and the electrode assembly II to the all-pole lugs on the cell, respectively, to form a cell electrode column;

(6) Assembling into the shell: the pole of the battery core enters from the open end of the shell, the electrode assembly I faces up, and the electrode assembly II faces downward, so that the pole I penetrates through the opening of the shell, first use laser welding or friction The welding process welds, seals and fixes the end cap I on the electrode assembly II to the opening edge of the shell, then presses and bonds the insulating sealing ring I and the transparent insulating gasket, and then uses laser penetration welding to open the shell through the shell. In the gap part between the hole end and the electrode pole, the transparent insulating gasket and the insulating sealing ring I are welded and sealed, and the assembly is completed into the shell; the electrolyte is injected from the end of the shell, and the injection port is welded and sealed to make lithium Battery.

The preparation method of the electrochemical device comprises the following steps:

(1) Preparation of the shell: The shell is formed by cold drawing and precise extraction, and a transparent insulating gasket is injected at the opening of the shell;

(2) Preparation of end cap: use stamping method to form end cap II with an opening in the middle, and a transparent insulating gasket is injected on the outside of the opening in the middle of end cap II;

(3) Preparation of battery core: The battery core is prepared by winding all-pole tabs, and positive all-pole tabs and negative all-pole tabs are formed on the battery core;

(4) Preparation of the electrode assembly: connect the pole III and the busbar III together, the pole III is injected with an insulating sealing ring III, and the outer surface of the insulating sealing ring III is coated with insulating glue to form a surface close to the opening end of the shell. Electrode assembly III; connect the pole IV and the busbar IV together, the insulating sealing ring IV is injected on the pole IV, the outer side of the insulating sealing ring IV is coated with insulating glue, and the pole IV passes through the middle of the end cover II, The insulating sealing ring IV and the transparent insulating sealing gasket are pressed and bonded together to form the electrode assembly IV close to the open end of the shell;

(5) Connect the electrode assembly to the cell: Use ultrasonic welding or ultrasonic welding followed by laser welding enhancement or electromagnetic pulse welding to fix and connect the electrode assembly III and electrode assembly IV to the all-pole lugs on the cell to form a cell electrode. column;

(6) Assembling into the shell: the pole of the battery core enters from the open end of the shell, the electrode assembly III faces up, and the electrode assembly IV faces downward, so that the pole III passes through the opening of the shell, first use laser welding or friction The welding process welds, seals and fixes the end cap II connected to the electrode assembly IV on the opening edge of the shell, then presses and bonds the insulating sealing ring III and the transparent insulating gasket, and then uses laser penetration welding to seal the transparent insulating The sealing gasket is welded and sealed with the insulating sealing ring III, and then the insulating sealing ring IV and the transparent insulating sealing gasket are welded and sealed by laser penetration welding, and the assembly is completed into the shell; the electrolyte is injected from the end of the shell, and the injection port is welded and sealed , thus making a lithium battery.

The shell and the end cover are made of aluminum material or aluminum-magnesium alloy.

Compared with the prior art, the advantages of the present invention are as follows:

1. Pass the welded electrode pole through the shell with openings, so that the insulating sealing ring on the pole and the transparent insulating gasket at the opening of the shell are pressed and sealed, the difficulty of entering the shell is low, and the process is simple. It has strong operability, effectively improves production efficiency, is suitable for large-scale production, reduces the reserved assembly space, improves the space utilization rate of the battery, and thus improves the energy density.

2. After the insulating sealing ring and the transparent insulating sealing gasket are bonded with insulating glue, the insulating sealing ring and the transparent insulating sealing gasket are welded by laser penetration welding. The two processes are combined to ensure the sealing of the joint, which is effective Prevent the electrolyte from overflowing in the shell;

3. The insulating sealing ring and the transparent insulating sealing gasket are welded and sealed by laser penetration welding, which can achieve precise sealing and ensure that it is sealed within a very fine interval between the opening end of the shell and the electrode pole, and does not affect the connection parts. make an impact.

Description of drawings

Figure 1 is a schematic structural diagram of the present invention.

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1 in Example 1. FIG.

FIG. 3 is a partially enlarged view of FIG. 2 .

4 is a cross-sectional view taken along line A-A of FIG. 1 of Example 2. FIG.

FIG. 5 is a partially enlarged view of FIG. 4 .

Among them, 1 is the shell; 2 is the electrode assembly I, 21 is the pole I, 22 is the busbar I, 23 is the insulating sealing ring I; 3 is the battery core; 4 is the electrode assembly II, 41 is the pole II, 42 is the busbar II, 43 is the end cap I, 44 is the insulating sealing ring II; 5 is the transparent insulating gasket I; 6 is the end cap II; 7 is the electrode assembly III, 71 is the insulating sealing ring III, 72 is the transparent insulating seal Gasket II; 8 is electrode assembly IV, 81 is insulating sealing ring IV, 82 is transparent insulating sealing gasket III.

Detailed ways

Example 1

As shown in Fig. 1, Fig. 2, Fig. 3, an electrochemical device includes a square casing 1, a battery cell 3 is arranged in the casing 1, and the two ends of the battery cell 3 are respectively connected to an electrode assembly, and the electrode assembly includes an electrode The pole, one end of the casing 1 is provided with an opening for the entry of the core pole from the outside to the inside, that is, the lower end of the casing 1 in FIG. The upper end of the body 1, the open end of the end face is injected with a transparent insulating gasket I5, the electrode assembly close to the open end of the shell 1 is connected with an end cover I43, and the edge of the end cover I43 is welded and sealed with the open end of the shell 1, close to the shell The electrode pole at the opening end protrudes from the opening, and an insulating sealing ring I23 is injected on the electrode pole near the opening end of the casing. The insulating sealing ring I23 is in contact with the transparent insulating sealing gasket I5, and the contact surface is bonded and sealed. The part of the transparent insulating sealing gasket I5 located between the opening end of the casing 1 and the electrode pole is welded with the insulating sealing ring I23 by laser penetration welding.

The above electrode assembly is divided into electrode assembly I2 and electrode assembly II4, one of which is a positive electrode and the other is a negative electrode. The electrode assembly I2 is composed of a pole I21, a busbar I22 and an insulating seal ring I23. The pole I21, the busbar I22 and the insulating seal Ring I23 is pre-connected or injection-molded. Electrode assembly II4 is composed of pole II41, busbar II42 and insulating seal ring II44. Pole II41, busbar II42, end cap I43 and insulating seal ring II44 are pre-connected or injection-molded. There is technology. The aluminum shell of the present invention can be pure aluminum or aluminum-magnesium alloy.

Preferably, the transparent insulating sealing gasket I5 is a U-shaped body, and the inner side of the U-shaped body is in close contact with and wraps the end of the opening of the casing 1. As shown in FIG. 3 , the insulating sealing ring I23 is flat. The lower surface of the transparent insulating gasket I5 is in contact with the upper surface of the insulating sealing ring I23.

The electrode assembly II4 near the open end of the casing 1 includes a pole II41 and an insulating sealing ring II44. The pole II41 protrudes from the middle of the end cap I43. The pole II41 is connected with the end cap I43 and the insulating sealing ring II44, and the insulating seal is Circle II 44 is also U-shaped.

Preferably, the transparent insulating gasket I5 is a transparent plastic insulating gasket, of course, it can also be other transparent materials that can be bonded to rubber.

Further, both ends of the battery core 3 are formed with positive all-pole tabs and negative all-pole tabs, and the positive all-pole tabs and the negative all-pole tabs are welded to electrode assembly I2 and electrode assembly II4 respectively.

The preparation method of the electrochemical device of the present invention is as follows:

(1) Preparation of shell 1: Using aluminum material or aluminum-magnesium alloy as raw material, the shell 1 is formed by cold drawing and fine drawing method, and a transparent insulating gasket is injected at the opening of shell 1, that is, transparent insulating gasket I5;

(2) Preparation of end caps: Use aluminum or aluminum-magnesium alloy as raw materials, and use stamping method to form end caps I43 with holes in the middle;

(3) Preparation of battery core 3: The battery core 3 is prepared by winding all-pole tabs, and positive all-pole tabs and negative all-pole tabs are formed on the battery core 3;

(4) Preparation of electrode assembly: connect the pole I21 and the busbar I22 together, the pole I21 is injected with an insulating sealing ring I23, and the outer side of the insulating sealing ring I23 is coated with insulating glue to form an opening close to the shell 1. The electrode assembly I2 at the end; the pole II41 and the busbar II42 are connected together, the insulating sealing ring II44 is injected at the opening in the middle of the end cover I43, the pole II41 is pierced from the middle of the end cover I43, and the insulating sealing ring II44 and the pole II41 connected together to form an electrode assembly II4 close to the open end of the shell 1;

(5) Connect the electrode assembly to the cell 3: Use ultrasonic welding or ultrasonic welding followed by laser welding enhancement or electromagnetic pulse welding to fix the electrode assembly I2 and the electrode assembly II4 to the all-pole lugs on the cell 3, respectively, to form an electrical connection. core pole;

(6) Assemble into the shell: the pole of the battery core enters from the open end of the shell 1, the electrode assembly I2 faces up, and the electrode assembly II4 faces down, so that the pole I21 passes through the opening of the shell 1, and the laser welding is used first. Or friction welding welding process to weld, seal and fix the end cap I43 on the electrode assembly II4 to the opening edge of the casing 1, then press the insulating sealing ring I23 and the transparent insulating sealing gasket I5 to bond, and then use laser penetration welding. Through the gap between the opening end of the casing 1 and the electrode pole, the transparent insulating gasket I5 and the insulating sealing ring I23 are welded and sealed, and the assembly into the casing is completed; the electrolyte is injected from the end of the casing 1, and the injection port is Welded and sealed to make a lithium battery. Here, the injection port is provided on the end cap I43, which is the prior art, and will not be repeated here.

Example 2

As shown in Fig. 1, Fig. 4, Fig. 5, an electrochemical device includes a square shell 1, a battery cell 3 is arranged in the shell 1, and the two ends of the battery cell 3 are respectively connected to an electrode assembly, and the electrode assembly includes an electrode The pole, one end of the casing 1 is provided with an opening for the entry of the core pole from the outside to the inside, that is, the lower end of the casing 1 in FIG. The upper end of the body 1, the open end of the end face is injected with a transparent insulating gasket II72, the electrode assembly close to the open end of the shell 1 is connected with an end cover II6, and the edge of the end cover II6 is welded and sealed with the open end of the shell 1, close to the shell 1. The electrode pole at the opening end passes through the opening, and the electrode pole near the opening end of the casing 1 is injected with an insulating sealing ring III71. The insulating sealing ring III71 is in contact with the transparent insulating sealing gasket II72, and the contact surface is bonded. For sealing, the upper part of the transparent insulating sealing gasket II72 located between the opening end of the casing 1 and the electrode pole is welded with the insulating sealing ring III71 by laser penetration welding.

The above-mentioned electrode assembly is divided into electrode assembly III7 and electrode assembly IV8, one of which is a positive electrode and the other is a negative electrode. The electrode assembly IV8 is composed of the pole IV (not marked in the figure), the busbar IV (not marked in the figure) and the insulating seal It is composed of a ring IV81, and the pole IV, the busbar IV and the insulating sealing ring IV81 are connected or injection molded in advance, which is the prior art. The aluminum shell of the present invention can be pure aluminum or aluminum-magnesium alloy.

Preferably, the transparent insulating gasket II72 and the transparent insulating gasket III82 are both transparent plastic insulating gaskets, but of course they can also be other transparent materials that can be bonded to rubber.

Further, the transparent insulating sealing gasket II72 and the transparent insulating sealing gasket III82 are both planar and located outside the housing 1, the insulating sealing ring IV81 and the insulating sealing ring III71 are both L-shaped, and one side of the L-shaped is along the electrode pole. The column IV extends to the opening of the casing 1 and is located between the opening end face of the casing 1 and the electrode pole IV. The transparent insulating gasket II72 and the transparent insulating gasket III82 are in contact with the insulating sealing ring III71 and the insulating sealing ring IV81 respectively. .

The electrode assembly IV8 close to the open end of the case 1 has the same structure as the electrode assembly III7 close to the open end of the case 1, and the connection between the electrode assembly IV8 close to the open end of the case 1 and the end cap II6 is the same as that close to the open end of the case 1. The connection method of the electrode assembly III7 at the hole end and the opening end face of the shell 1 is the same, that is, the transparent insulating gasket III82 is pre-injected on the end cover II6. The insulating sealing ring IV81 and the transparent insulating sealing gasket III82 are bonded together by laser penetration welding.

Further, both ends of the battery core 3 are formed with positive all-pole tabs and negative all-pole tabs, which are welded to electrode assembly IV8 and electrode assembly III7 respectively.

The preparation method of the electrochemical device of the present invention is as follows:

(1) Preparation of shell 1: Using aluminum material or aluminum-magnesium alloy as raw material, the shell 1 is formed by cold drawing and fine drawing method, and a transparent insulating gasket is injected at the opening of shell 1, that is, transparent insulating gasket II72;

(2) Preparation of end cover: Using aluminum or aluminum-magnesium alloy as raw material, the end cover II6 with the middle opening is formed by stamping method, and the outer side of the opening in the middle of the end cover II6 is injected with a transparent insulating gasket III82;

(3) Preparation of battery core 3: The battery core 3 is prepared by winding all-pole tabs, and positive all-pole tabs and negative all-pole tabs are formed on the battery core 3;

(4) Preparation of the electrode assembly: connect the pole III and the busbar III together, the pole III is injected with an insulating sealing ring III71, and the outer surface of the insulating sealing ring III71 is coated with insulating glue to form the electrode assembly III7; Column Ⅳ and busbar Ⅳ are connected together, and the insulating sealing ring Ⅳ81 is injected on the pole Ⅳ. The outer side of the insulating sealing ring Ⅳ81 is coated with insulating glue. The pole Ⅳ passes through the middle of the end cap Ⅱ6. The insulating gasket III82 is pressed and bonded together to form the electrode assembly IV8;

(5) Connect the electrode assembly to the battery core 3: Use ultrasonic welding or ultrasonic welding followed by laser welding enhancement or electromagnetic pulse welding to fix the electrode assembly III7 and electrode assembly IV8 to the all-pole lugs on the battery core 3, respectively, to form an electric circuit. core pole;

(6) Assembling into the shell: the pole of the battery core enters from the open end of the shell 1, the electrode assembly III7 faces up, and the electrode assembly IV8 faces downwards, so that the pole III passes through the opening of the shell 1, and the laser welding is used first. Or friction welding process to weld, seal and fix the end cap II6 connected to the electrode assembly IV8 on the opening edge of the shell 1, and then press and bond the insulating sealing ring III71 and the transparent insulating sealing gasket II72, and then use the laser to penetrate Weld and seal the transparent insulating gasket II72 and the insulating gasket III71, and then use laser penetration welding to weld and seal the insulating gasket IV81 and the transparent insulating gasket III82, and the assembly into the shell is completed; inject electrolysis from the end of shell 1 liquid, and the injection port is welded and sealed to make a lithium battery. Here, the injection port is provided on the end cap II6, which is the prior art, and will not be repeated here.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, some changes and improvements can be made without departing from the overall concept of the present invention, and these should also be regarded as the present invention. the scope of protection, these will not affect the effect of the implementation of the present invention and the practicability of the patent.

Claims (10)

1. The utility model provides an electrochemical device, includes square casing, is equipped with electric core in the casing, and electrode subassembly is connected respectively at the both ends of electric core, and electrode subassembly includes electrode utmost point post, its characterized in that: the one end of casing is equipped with the opening that is used for supplying electric core utmost point post to get into from outside to inside, the terminal surface middle part of the other end is equipped with the trompil, the trompil of terminal surface is served and is moulded plastics transparent insulating sealing pad, the electrode subassembly that is close to the casing open end is connected with the end cover, the end cover edge welds the shutoff with the casing open end, the electrode utmost point post that is close to the casing open end is worn out from the trompil, it has moulded plastics insulating seal circle on the electrode utmost point post that is close to the casing open end, insulating seal circle contacts with transparent insulating sealing pad, and the contact.

2. The electrochemical device of claim 1, wherein: transparent insulating sealed the pad is the U type body, and the medial surface of the U type body is hugged closely and is wrapped up casing trompil end tip, insulating seal circle is planar, and transparent insulating sealed lower surface that fills up contacts with insulating seal circle's upper surface.

3. The electrochemical device of claim 2, wherein: electrode subassembly that is close to the casing open end includes utmost point post II and insulating sealing washer II, and utmost point post II is worn out from the end cover middle part, and utmost point post II links together with end cover, insulating sealing washer II, and insulating sealing washer II also is the U type.

4. The electrochemical device of claim 1, wherein: transparent insulating sealed pad is planar and is located outside the casing, insulating sealing washer is the L type, and one edge electrode utmost point post of L type just is located between casing trompil terminal surface and the electrode utmost point post to casing trompil department extension, and transparent insulating sealed pad contacts with insulating sealing washer.

5. The electrochemical device of claim 4, wherein: the electrode assembly near the open end of the shell has the same structure as the electrode assembly near the open end of the shell, and the connection mode between the electrode assembly near the open end of the shell and the end cover is the same as the connection mode between the electrode assembly near the open end of the shell and the open end face of the shell.

6. The electrochemical device of claim 1, wherein: the transparent insulating sealing gasket is made of transparent plastic.

7. The electrochemical device of claim 1, wherein: and a positive full lug and a negative full lug are formed at two ends of the battery cell and are respectively welded with the electrode assembly.

8. A method of manufacturing an electrochemical device according to claim 3, wherein: the method comprises the following steps:

(1) preparing a shell: forming a shell by adopting a cold-drawing fine-pumping method, and injecting a transparent insulating sealing gasket at the opening of the shell;

(2) preparing an end cover: forming an end cover I with a hole in the middle by a stamping method;

(3) preparing an electric core: preparing a battery cell by adopting a full-lug winding mode, wherein a positive full lug and a negative full lug are formed on the battery cell;

(4) preparation of electrode assembly: connecting an electrode pole I and a confluence piece I together, wherein an insulating sealing ring I is injected on the electrode pole I, and insulating glue is coated on the outer side surface of the insulating sealing ring I to form an electrode assembly I close to the opening end of the shell; connecting the pole II and the confluence piece II together, wherein an insulating sealing ring II is injected at a hole in the middle of the end cover I, the pole II penetrates out of the middle of the end cover I, and the insulating sealing ring II is connected with the pole II to form an electrode assembly II close to the opening end of the shell;

(5) connecting the electrode assembly with the battery cell: respectively fixedly connecting an electrode assembly I and an electrode assembly II to full lugs on a battery cell by adopting ultrasonic welding or laser welding reinforcement after ultrasonic welding or electromagnetic pulse welding technology to form a battery cell pole;

(6) assembling into a shell: the method comprises the following steps that a battery core pole enters from the opening end of a shell, an electrode assembly I faces upwards, an electrode assembly II faces downwards, the pole I penetrates out of an opening of the shell, an end cover I on the electrode assembly II is welded and sealed and fixed on the edge of the opening of the shell by adopting a laser welding or friction welding process, then an insulating sealing ring I and a transparent insulating sealing gasket are pressed and bonded, then the transparent insulating sealing gasket and the insulating sealing ring I are welded and sealed through a gap part between the opening end of the shell and the electrode pole by adopting laser penetration welding, and the assembly into the shell is completed; electrolyte is injected from the end of the case, and the injection port is welded and sealed, thereby producing a lithium battery.

9. The method of manufacturing an electrochemical device according to claim 5, wherein: the method comprises the following steps:

(1) preparing a shell: forming a shell by adopting a cold-drawing fine-pumping method, and injecting a transparent insulating sealing gasket at the opening of the shell;

(2) preparing an end cover: forming an end cover II with a hole in the middle by a stamping method, and injecting a transparent insulating sealing gasket outside the hole in the middle of the end cover II;

(3) preparing an electric core: preparing a battery cell by adopting a full-lug winding mode, wherein a positive full lug and a negative full lug are formed on the battery cell;

(4) preparation of electrode assembly: connecting the pole III and the bus piece III together, wherein an insulating sealing ring III is injected on the pole III, and insulating glue is coated on the outer side surface of the insulating sealing ring III to form an electrode assembly III close to the opening end of the shell; connecting an electrode post IV and a bus bar IV together, injecting an insulating sealing ring IV on the electrode post IV, coating insulating glue on the outer side surface of the insulating sealing ring IV, penetrating the electrode post IV out of the middle part of an end cover II, and tightly pressing and bonding the insulating sealing ring IV and a transparent insulating sealing gasket together to form an electrode assembly IV close to the opening end of the shell;

(5) connecting the electrode assembly with the battery cell: respectively fixedly connecting an electrode assembly III and an electrode assembly IV to full lugs on a battery cell by adopting ultrasonic welding or laser welding reinforcement after ultrasonic welding or electromagnetic pulse welding technology to form a battery cell pole;

(6) assembling into a shell: the battery cell pole enters from the opening end of the shell, the electrode assembly III faces upwards, the electrode assembly IV faces downwards, the pole III penetrates out of the opening of the shell, an end cover II connected to the electrode assembly IV is welded and sealed and fixed on the edge of the opening of the shell by adopting a laser welding or friction welding process, then the insulating sealing ring III is tightly pressed and bonded with the transparent insulating sealing gasket, then the transparent insulating sealing gasket is welded and sealed with the insulating sealing ring III by adopting laser penetration welding, the insulating sealing ring IV and the transparent insulating sealing gasket are welded and sealed by adopting laser penetration welding at the other end, and the assembly into the shell is finished; electrolyte is injected from the end of the case, and the injection port is welded and sealed, thereby producing a lithium battery.

10. The electrochemical device of claim 1, wherein: the shell and the end cover are both made of aluminum or aluminum magnesium alloy.

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