A square aluminum shell lithium battery

Abstract

A square aluminum-shell lithium battery comprises an aluminum shell, a top cover, and a battery cell. The battery cell comprises a plurality of sequentially arranged positive and negative electrode sheets, and a diaphragm, the diaphragm being disposed between the positive and negative electrode sheets. The battery cell is disposed within the aluminum shell, and the top cover is removably sealed and disposed on the upper opening of the aluminum shell. At least one lithium replenishment structure is disposed on the end surface of the top cover facing the aluminum shell. The lithium replenishment structure includes a lithium replenishment cavity, and at least one lithium replenishment hole is disposed on the other end surface of the top cover, communicating with the lithium replenishment cavity. At least one lithium replenishment channel is disposed on the bottom surface of the lithium replenishment cavity, aligned with the negative electrode sheet. The lithium replenishment structure replenishes the negative electrode of the battery cell by injecting lithium powder into the lithium replenishment hole through the lithium replenishment cavity and the lithium replenishment channel. The present invention can replenish lithium in the battery cell after the battery cell is filled with liquid, preventing the lithium powder from being oxidized by air and improving the utilization rate of the lithium powder.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to a square aluminum shell lithium battery. Background Art

[0002] The high energy density and lack of memory effect of lithium-ion batteries are one of the core advantages that have led to their widespread use. However, whether it is to increase the driving range of new energy vehicles or to increase the standby time of electronic products, the energy density of lithium-ion batteries needs to be further improved. When lithium-ion batteries are first charged and discharged, the formation of the negative electrode SEI film or side reactions will consume a portion of the active lithium in the positive electrode, reducing the energy available. The continuous consumption of active lithium during use will also continuously reduce the energy available. Therefore, timely replenishment of active lithium is an effective way to maintain available energy and increase energy density. Currently, there are two commonly used methods of lithium replenishment, one is positive electrode lithium replenishment and the other is negative electrode lithium replenishment. Positive electrode lithium replenishment usually involves adding lithium-rich materials to the positive electrode slurry for lithium replenishment; negative electrode lithium replenishment involves adding a metal lithium source to the negative electrode for lithium replenishment.

[0003] In the prior art, when replenishing lithium on the negative electrode, the negative electrode material is generally coated on the electrode and then a layer of ultra-thin lithium sheet is rolled or a layer of metallic lithium powder is plated on the electrode. However, due to the high activity of metallic lithium, after replenishing lithium on the electrode, the lithium powder or lithium sheet on the electrode easily reacts with substances in the air, resulting in the inactivation of the lithium sheet or lithium powder on the electrode, low utilization rate of the lithium powder, and affecting the lithium replenishment effect. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a square aluminum shell lithium battery, which solves the problem in the prior art that when lithium is replenished on the negative electrode sheet, the lithium source on the negative electrode sheet easily reacts with substances in the air, resulting in the deactivation of the lithium sheet or lithium powder on the negative electrode sheet, low utilization rate of the lithium powder, and affecting the lithium replenishment effect.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A square aluminum-shell lithium battery comprises an aluminum shell, a top cover, and a battery cell, wherein the battery cell comprises a plurality of positive electrode sheets, negative electrode sheets, and a diaphragm arranged in sequence, the diaphragm being arranged between the positive electrode sheets and the negative electrode sheets, the battery cell being arranged in the aluminum shell, the top cover being detachably and sealedly arranged on the upper end opening of the aluminum shell, at least one lithium replenishing structure being provided on one end surface of the top cover facing the aluminum shell, the lithium replenishing structure comprising a lithium replenishing cavity, at least one lithium replenishing hole being provided on the other end surface of the top cover and communicating with the lithium replenishing cavity, at least one lithium replenishing channel being provided on the bottom surface of the lithium replenishing cavity and aligned with the negative electrode sheet, the lithium replenishing channel being communicated with the lithium replenishing cavity.

[0007] Furthermore, the number of lithium replenishment channels provided on the bottom surface of the lithium replenishment cavity is equal to the number of the negative electrode sheets, and each of the lithium replenishment channels is aligned and provided directly above a negative electrode sheet.

[0008] Furthermore, the length of the diaphragm toward one end of the top cover is longer than that of the positive electrode sheet and the negative electrode sheet, the lithium replenishing channel is arranged between the diaphragms at both ends of the negative electrode sheet, and the top of the diaphragm is higher than the bottom of the lithium replenishing channel.

[0009] Furthermore, a lithium replenishing cavity is provided at both ends of the end surface of one side of the top cover facing the aluminum shell, and the lithium replenishing cavity is arranged along the "L" direction. The top cover is evenly provided with a plurality of lithium replenishing holes along the "L" direction. The number of the lithium replenishing holes is equal to the number of the lithium replenishing channels, and each of the lithium replenishing holes is aligned with a lithium replenishing channel.

[0010] Furthermore, the lithium replenishment channel is a flat square cavity structure, the top of the lithium replenishment channel is connected to the lithium replenishment cavity, and a plurality of lithium powder through-holes are evenly opened on the bottom surface of the lithium replenishment channel. The lithium powder in the lithium replenishment channel can enter the end of the negative electrode sheet through the lithium powder through-holes, and the bottom of the lithium replenishment channel extends below the liquid level of the electrolyte in the aluminum shell.

[0011] Furthermore, a positive electrode column and a negative electrode column are respectively provided at both ends of the top cover, the positive electrode column is electrically connected to the positive electrode tab of the battery cell, and the negative electrode column is electrically connected to the negative electrode tab of the battery cell. The top cover is also provided with a liquid injection hole and an explosion-proof valve.

[0012] Furthermore, the lithium replenishing hole can be sealed by welding sealing pins.

[0013] Furthermore, one end of the diaphragm extending out of the negative electrode sheet can be overlapped on the lithium replenishing channel.

[0014] According to the present invention, after the electrolyte is injected into the square aluminum shell lithium battery, lithium powder can be replenished into the end of the negative electrode sheet of the battery cell through the lithium replenishment hole on the top cover and the lithium replenishment cavity and the lithium replenishment channel. The replenished lithium powder directly reacts with the electrolyte to generate active lithium ions embedded in the negative electrode sheet, thereby replenishing lithium. After the lithium replenishment is completed, the lithium replenishment hole can be sealed by welding a sealing nail.

[0015] The present invention has the following beneficial effects: 1) lithium replenishment can be carried out after the electrolyte is injected. During the lithium replenishment process, the lithium source will not come into contact with the air, which can ensure the activity of the replenished lithium ions and improve the lithium replenishment effect; 2) the contact area between the replenished metallic lithium powder and the electrolyte and the negative electrode sheet is large, which reduces the probability of dead lithium during the activation process of the battery cell, can reduce the amount of lithium powder used, and reduce the cost of lithium replenishment; 3) each lithium replenishment channel can be aligned with the end of a negative electrode sheet, which can ensure that each negative electrode sheet can be replenished with an equal amount of lithium powder, thereby ensuring the uniformity of lithium replenishment and improving the consistency of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is an exploded structural diagram of the square aluminum shell lithium battery in the present invention;

[0017] Figure 2 Schematic diagram of the position structure between the lithium replenishment channel and the battery cell in the present invention;

[0018] Figure 3 Schematic diagram of the top cover and lithium replenishing structure in specific embodiment 1 of the present invention;

[0019] Figure 4 Schematic diagram of the top cover and lithium replenishing structure in specific embodiment 2 of the present invention;

[0020] In the figure: 1. Aluminum shell, 2. Top cover, 3. Battery cell, 31. Positive electrode sheet, 32. Negative electrode sheet, 33. Diaphragm, 4. Lithium replenishment structure, 41. Lithium replenishment cavity, 42. Lithium replenishment channel, 5. Lithium replenishment hole, 6. Positive electrode column, 7. Negative electrode column, 8. Liquid injection hole, 9. Explosion-proof valve. DETAILED DESCRIPTION

[0021] The present invention will be described in further detail below with reference to the accompanying drawings. Specific embodiment 1

[0023] like Figure 1-3The square aluminum shell lithium battery shown includes an aluminum shell 1, a top cover 2 and a battery cell 3, wherein the battery cell 3 includes a plurality of positive electrode sheets 31, negative electrode sheets 32 and a diaphragm 33 arranged in sequence, wherein the diaphragm 33 is arranged between the positive electrode sheets 31 and the negative electrode sheets 32, and the battery cell 3 is arranged in the aluminum shell 1, and the top cover 2 is detachably and sealedly arranged on the upper end opening of the aluminum shell 1, characterized in that at least one lithium replenishing structure 4 is provided on the end surface of the top cover 2 facing the aluminum shell 1, and the lithium replenishing structure 4 includes a lithium replenishing cavity 41, and a lithium replenishing hole 5 is provided on the other end surface of the top cover 2, which is connected to the lithium replenishing cavity 41, and the lithium replenishing channel 42 is connected to the lithium replenishing cavity 41; the number of lithium replenishing channels 42 provided on the bottom surface of the lithium replenishing cavity 41 is equal to the number of the negative electrode sheets 32, and each The lithium replenishment channels 42 are all aligned and arranged directly above a negative electrode sheet 32; the length of the diaphragm 33 at one end facing the top cover 2 is longer than the positive electrode sheet 31 and the negative electrode sheet 32, and the lithium replenishment channels 42 are arranged between the diaphragms 33 at both ends of the negative electrode sheet 32, and the top of the diaphragm 33 is higher than the bottom of the lithium replenishment channels 42; the lithium replenishment channels 42 are flat square cavity structures, and the top of the lithium replenishment channels 42 is connected to the lithium replenishment cavity. A plurality of lithium powder through-holes are evenly opened on the bottom surface of the lithium replenishment channels 42, and the lithium powder in the lithium replenishment channels 42 can enter the end of the negative electrode sheet 32 ​​through the lithium powder through-holes. The bottom of the lithium replenishment channels 42 extends below the liquid level of the electrolyte in the aluminum shell 1; the end of the diaphragm 33 extending from the negative electrode sheet 32 ​​can overlap the lithium replenishment channels 42.

[0024] The present invention can be used for lithium replenishment after the lithium battery electrolyte injection is completed. When lithium replenishment is needed, an external lithium source (preferably lithium powder) can be connected through the lithium replenishment hole 5 on the top cover 2. The lithium source is introduced into the lithium replenishment cavity 41 through the lithium replenishment hole 5 on the top cover, and then introduced into the end of the negative electrode sheet 32 ​​of the battery cell 3 through the lithium replenishment channel 42 at the bottom of the lithium replenishment cavity 41. After the lithium replenishment is completed, the lithium replenishment hole 5 is sealed by welding a sealing nail, and finally the battery cell is activated. The replenished lithium powder can react to generate active lithium ions and embed into the negative electrode, thereby completing the negative electrode lithium replenishment.

[0025] When replenishing lithium in a lithium battery, this embodiment can effectively avoid contact between the lithium source and the air, effectively prevent the lithium source replenished in the battery cell from being damaged and inactivated, and ensure the effect of lithium replenishment. The contact area between the replenished metallic lithium powder and the electrolyte and the negative electrode sheet is large, which reduces the probability of dead lithium during the activation process of the battery cell, reduces the amount of lithium powder used, and reduces the cost of lithium replenishment. Specific embodiment 2

[0027] like Figure 4As shown, the difference between this embodiment and embodiment 1 is that: a lithium replenishing cavity 41 is provided at both ends of the end surface of the top cover 2 facing the aluminum shell 1, and the lithium replenishing cavity 41 is arranged along the "L" direction. The top cover 2 is evenly provided with a plurality of lithium replenishing holes 5 along the "L" direction. The number of the lithium replenishing holes 5 is equal to the number of the lithium replenishing channels 42, and each of the lithium replenishing holes 5 is aligned with a lithium replenishing channel 42.

[0028] The present invention can be used for lithium replenishment after the lithium battery electrolyte injection is completed. When lithium replenishment is needed, a plurality of lithium replenishment holes 5 on the top cover 2 can be used to connect external lithium sources (the lithium source is preferably lithium powder). The lithium source is introduced into the lithium replenishment cavity 41 through the lithium replenishment holes 5 on the top cover, and then introduced into the end of the negative electrode sheet 32 ​​of the battery cell 3 through the lithium replenishment channel 42 at the bottom of the lithium replenishment cavity 41. After the lithium replenishment is completed, the lithium replenishment holes 5 are sealed by welding sealing nails. Finally, the battery cell is activated, and the replenished lithium powder can react to generate active lithium ions embedded in the negative electrode, thereby completing the negative electrode lithium replenishment.

[0029] This embodiment effectively prevents the lithium source from coming into contact with air when replenishing lithium batteries, effectively preventing the lithium source replenished into the battery cell from being damaged and inactivated, thereby ensuring the effectiveness of lithium replenishment. The large contact area between the replenished metallic lithium powder, the electrolyte, and the negative electrode sheet reduces the probability of dead lithium during the battery cell activation process, reduces the amount of lithium powder used, and reduces the cost of lithium replenishment. In this embodiment, lithium replenishment can be performed simultaneously on lithium batteries through multiple lithium replenishment holes 5, and each lithium replenishment hole 5 is associated with a lithium replenishment channel 42. The introduced lithium source can directly enter the end of the negative electrode sheet 22 of the battery cell 2 through the lithium replenishment channel 42, reducing the amount of lithium powder remaining in the lithium replenishment cavity 41 and ensuring that the amount of lithium replenished at the end of each negative electrode sheet 22 is approximately equal, thereby improving the uniformity of lithium replenishment.

[0030] In summary, the lithium replenishment of the present invention can be carried out after the electrolyte is injected. During the lithium replenishment process, the lithium source will not come into contact with the air, which can ensure the activity of the replenished lithium ions and improve the lithium replenishment effect. The contact area between the replenished metal lithium powder and the electrolyte and the negative electrode sheet 22 is large, which reduces the probability of dead lithium during the activation process of the battery cell, reduces the amount of lithium powder used, and reduces the cost of lithium replenishment. Each lithium replenishment channel 42 can be aligned with the end of a negative electrode sheet 22, which can ensure that each negative electrode sheet 22 can be replenished with an equal amount of lithium powder, thereby ensuring the uniformity of lithium replenishment and improving the consistency of the battery cell.

[0031] The above-mentioned embodiments are illustrative of the present invention, not limiting thereof. It is understood that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A square aluminum shell lithium battery, comprising an aluminum shell (1), a top cover (2) and a battery cell (3), wherein the battery cell (3) comprises a plurality of positive electrode sheets (31), negative electrode sheets (32) and a diaphragm (33) arranged in sequence, wherein the diaphragm (33) is arranged between the positive electrode sheets (31) and the negative electrode sheets (32), the battery cell (3) is arranged in the aluminum shell (1), and the top cover (2) is detachably sealed and arranged on the upper end opening of the aluminum shell (1), characterized in that: At least one lithium replenishing structure (4) is provided on one end face of the top cover (2) facing the aluminum shell (1), the lithium replenishing structure (4) including a lithium replenishing cavity (41), at least one lithium replenishing hole (5) communicating with the lithium replenishing cavity (41) is provided on the other end face of the top cover (2), at least one lithium replenishing channel (42) aligned with the negative electrode sheet (32) is provided on the bottom face of the lithium replenishing cavity (41), the lithium replenishing channel (42) communicating with the lithium replenishing cavity (41); the number of the lithium replenishing channels (42) provided on the bottom face of the lithium replenishing cavity (41) is the same as the number of the negative electrode sheet (32). (32) are equal in number, and each of the lithium replenishing channels (42) is aligned and arranged directly above a negative electrode sheet (32); the length of the diaphragm (33) toward one end of the top cover (2) is longer than the positive electrode sheet (31) and the negative electrode sheet (32), and the lithium replenishing channel (42) is arranged between the diaphragms (33) at both ends of the negative electrode sheet (32), and the top of the diaphragm (33) is higher than the bottom of the lithium replenishing channel (42); a lithium replenishing cavity (41) is provided at both ends of the end surface of one side of the top cover (2) toward the aluminum shell (1), and the lithium replenishing cavity (41) is along the " The top cover (2) is evenly provided with a plurality of lithium replenishing holes (5) along the "L" direction, the number of the lithium replenishing holes (5) is equal to the number of the lithium replenishing channels (42), and each of the lithium replenishing holes (5) is aligned with a lithium replenishing channel (42); and one end of the diaphragm (33) extending out of the negative electrode sheet (32) can be overlapped on the lithium replenishing channel (42).

2. A square aluminum shell lithium battery according to claim 1, characterized in that: The lithium replenishment channel (42) is a flat square cavity structure. The top of the lithium replenishment channel (42) is connected to the lithium replenishment cavity. A plurality of lithium powder through-holes are evenly opened on the bottom surface of the lithium replenishment channel (42). The lithium powder in the lithium replenishment channel (42) can enter the end of the negative electrode sheet (32) through the lithium powder through-holes. The bottom of the lithium replenishment channel (42) extends below the liquid level of the electrolyte in the aluminum shell (1).

3. The square aluminum shell lithium battery according to claim 1, characterized in that: A positive pole (6) and a negative pole (7) are respectively provided at both ends of the top cover (2); the positive pole (6) is electrically connected to the positive pole tab of the battery cell (3); and the negative pole (7) is electrically connected to the negative pole tab of the battery cell (3); and the top cover (2) is also provided with a liquid injection hole (8) and an explosion-proof valve (9).

4. The square aluminum shell lithium battery according to claim 1, characterized in that: The lithium replenishing hole (5) can be sealed by welding sealing pins.

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