阅读说明：本技术 一种锂离子电池及其应用 (Lithium ion battery and application thereof ) 是由 李跃飞 刘金成 刘建华 于 2021-01-12 设计创作，主要内容包括：本发明提供一种锂离子电池及其应用,所述锂离子电池中正极耳的材质包括铝,所述正极耳的材质还包括锰和/或硅；所述正极耳中锰的质量分数为0.01～0.1wt％；所述正极耳中硅的质量分数为0.5～1wt％,通过在正极耳中掺杂锰和/或硅,进而降低熔点,实现了在电池内阻和倍率放电性能不受影响的前提下,及时反应熔断,提升了锂离子电池在低线阻短路过程中的安全性能,可用于功率型电池中。(The invention provides a lithium ion battery and application thereof, wherein the material of a positive lug in the lithium ion battery comprises aluminum, and the material of the positive lug also comprises manganese and/or silicon; the mass fraction of manganese in the positive tab is 0.01-0.1 wt%; the mass fraction of silicon in the positive tab is 0.5-1 wt%, and the melting point is reduced by doping manganese and/or silicon in the positive tab, so that timely reaction fusing is realized on the premise that the internal resistance and the rate discharge performance of the battery are not affected, the safety performance of the lithium ion battery in the low-line-resistance short-circuit process is improved, and the lithium ion battery can be used in a power battery.)

1. A lithium ion battery is characterized in that the material of a positive tab in the lithium ion battery comprises aluminum;

the positive tab is made of manganese and/or silicon;

the mass fraction of manganese in the positive tab is 0.01-0.1 wt%;

the mass fraction of silicon in the positive tab is 0.5-1 wt%.

2. The lithium ion battery according to claim 1, wherein the mass fraction of manganese in the positive tab is 0.05 to 0.1 wt%.

3. The lithium ion battery according to claim 1 or 2, wherein the mass fraction of silicon in the positive tab is 0.6 to 0.9 wt%.

4. The lithium ion battery according to any one of claims 1 to 3, wherein a material of the negative electrode tab in the lithium ion battery comprises nickel or a copper-nickel alloy.

5. The lithium ion battery according to any one of claims 1 to 4, wherein the thickness of the positive electrode tab is 0.1 to 0.15 mm.

6. The lithium ion battery according to any one of claims 1 to 5, wherein the width of the positive tab is 3 to 6 mm.

7. The lithium ion battery according to any one of claims 1 to 6, wherein the positive electrode tab has a melting point of 500 to 660 ℃.

8. The lithium ion battery according to any one of claims 1 to 7, wherein the short circuit current of the lithium ion battery in a short circuit test is 180 to 250A.

9. The lithium ion battery according to any one of claims 1 to 8, wherein the lithium ion battery has a duration of 5s or less in a short circuit test.

10. Use of a lithium ion battery according to any of claims 1 to 9 in a power cell.

Technical Field

The invention relates to the technical field of lithium batteries, in particular to a lithium ion battery and application thereof.

Background

Because the lithium ion battery has the advantages of high energy density, high power density, multiple recycling times, long storage time and the like, the lithium ion battery is widely used on portable electronic equipment such as mobile phones, digital cameras, portable computers and the like, has wide application prospect in the aspects of large and medium-sized electric equipment such as electric vehicles, electric bicycles and other electric vehicles, energy storage facilities and the like, and becomes a key for solving global problems such as energy crisis, environmental pollution and the like.

Before the lithium ion battery is used, a short circuit test is required to verify the safety performance of the battery. Generally, the battery has CID and VENT safety means on the cap, a large amount of heat and gas are internally generated during a short circuit, and CID and VENT are opened by increasing the internal pressure of the battery, thereby passing the test. In the short-circuit process of low line resistance, the short-circuit current is overlarge, the heat generated in a short time is overlarge, and CID and VENT safety devices cannot report in time, so that the battery short-circuit test fails.

CN201229959Y discloses a lithium ion battery with short circuit prevention function, which includes a casing, and a positive electrode tab and a negative electrode tab disposed on the casing, wherein a short circuit prevention adhesive tape is covered between the positive electrode tab and the negative electrode tab, and the adhesive tape is adhered to the side surfaces of the positive electrode tab and the negative electrode tab, but increases the internal resistance in the battery application, which has negative effects.

CN207624793U discloses a prevent short circuit lithium cell utmost point ear and improve structure, including first utmost point ear, second utmost point ear, the first electricity connection piece in first utmost point ear cavity to and the second electricity connection piece in the second utmost point ear cavity, with first electricity connection piece and second electricity connection piece fixed connection's thermal energy electricity connection bridge piece, this thermal energy electricity connection bridge piece is connected with first electricity connection piece and second electricity connection piece electricity and is connected, first electricity connection piece and second electricity connection piece all are bow-shaped piece, nevertheless all have negative influence to the internal resistance of battery and the big multiplying power discharge temperature rise.

CN210778793U discloses a novel lithium ion battery prevents short circuit utmost point ear, including lithium cell and protection connector, the protection connector includes thermistor body, first connection pin and second connection pin, the stiff end of first connection pin and the stiff end of second connection pin respectively with thermistor body electricity is connected, the link of first connection pin with the contact jaw of first pole piece is connected, the link of second connection pin with the contact jaw of second pole piece is connected, nevertheless has negative influence to the internal resistance of cell and the big multiplying power discharge temperature rise.

Therefore, it is necessary to develop a battery with improved low line resistance short circuit performance on the premise that the internal resistance and rate discharge performance of the battery are not affected, so as to improve the safety performance of the battery and improve the product competitiveness.

Disclosure of Invention

In order to solve the technical problem, the invention provides a lithium ion battery, wherein a material of a positive lug in the lithium ion battery comprises aluminum; through adding manganese and/or silicon in positive ear, and then reduce positive ear's melting point to make lithium ion battery in low line resistance short circuit performance test, in time react the fusing, realized having promoted the security performance under the unaffected prerequisite of battery internal resistance and multiplying power discharge performance, lithium ion battery can be used to power type battery.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a lithium ion battery, wherein a material of a positive tab in the lithium ion battery includes aluminum; the positive tab is made of manganese and/or silicon; the mass fraction of manganese in the positive tab is 0.01-0.1 wt%; the mass fraction of silicon in the positive tab is 0.5-1 wt%.

The mass fraction of manganese in the positive electrode tab is 0.01-0.1 wt%, and may be, for example, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, or 0.1 wt%.

The mass fraction of silicon in the positive electrode tab is 0.5 to 1 wt%, and may be, for example, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, or 1 wt%.

In the lithium ion battery, the positive tab is arranged at one end of the battery shell, the melting point of the positive tab is reduced by adding manganese and/or silicon into the positive tab, wherein only manganese or only silicon can be added, or manganese and silicon can be added simultaneously, the influence on the melting point is different, so that lithium ions can be fused in time in the bottom line short circuit resistance process when the short circuit current is overlarge and the heat generated in a short time is overlarge, the safety performance is improved, meanwhile, the manganese and/or silicon are added, the mass content of the manganese is 0.01-0.1 wt%, the mass fraction of the silicon is 0.5-1 wt%, the melting point of the positive tab can be reduced, the short circuit safety protection effect can be achieved, the tab hardness change caused by overlarge silicon and manganese ratio adjustment can be avoided, the welding effect is influenced, the tab specification is not changed, and the internal resistance and the rate discharge performance of the battery are not influenced, has little influence on production.

Preferably, the mass fraction of manganese in the positive electrode tab is 0.05 to 0.1 wt%, and may be, for example, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, or 0.1 wt%.

Preferably, the mass fraction of silicon in the positive tab is 0.6 to 0.9 wt%, and may be, for example, 0.6 wt%, 0.65 wt%, 0.7 wt%, 0.75 wt%, 0.8 wt%, 0.85 wt%, or 0.9 wt%.

Preferably, the material of the negative electrode tab in the lithium ion battery comprises nickel or a copper-nickel alloy.

The material of the negative electrode tab of the lithium ion battery is usually nickel or copper-nickel alloy, and when the copper-nickel alloy is adopted, the mass ratio of copper to nickel is 1:1, 3:7 or 7: 3.

The thickness of the positive electrode tab is preferably 0.1 to 0.15mm, and may be, for example, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, or 0.15 mm.

Preferably, the width of the positive tab is 3-6 mm, and may be 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, or 6mm, for example.

The positive electrode tab preferably has a melting point of 500 to 660 ℃, and may be, for example, 500 ℃, 520 ℃, 530 ℃, 550 ℃, 560 ℃, 580 ℃, 590 ℃, 600 ℃, 620 ℃, 630 ℃, 660 ℃, or the like.

Preferably, the short-circuit current of the lithium ion battery in the short-circuit test is 180-250A, for example, 180A, 190A, 200A, 210A, 220A, 230A, 240A or 250A.

Preferably, the duration time of the lithium ion battery in the short circuit test is ≦ 5s, such as 1s, 2s, 3s, 4s, or 5 s.

In a second aspect, the present invention provides a use of the lithium ion battery of the first aspect, wherein the lithium ion battery is used in a power type battery.

According to the lithium ion battery, the melting point of the positive lug is adjusted by adding manganese and/or silicon into the positive lug, so that the lithium ion battery can react in time in a low-linear-resistance short-circuit performance test, the safety performance of the battery is improved on the premise that the internal resistance and the rate discharge performance of the battery are not influenced, and the lithium ion battery can be applied to a power type battery and can bear power operation of more than 300W.

Compared with the prior art, the invention has at least the following beneficial effects:

(1) according to the lithium ion battery provided by the invention, the mode of changing the melting point is realized by doping manganese and/or silicon in the positive electrode tab and the negative electrode tab, so that the safety performance of the lithium ion battery in the low-wire-resistance short circuit process is improved, and the short circuit duration is less than or equal to 4.5 s;

(2) the lithium ion battery provided by the invention has the advantages that the specifications of the lugs are not changed, the internal resistance and the rate discharge performance of the battery are not influenced, and the influence on the production is small.

Detailed Description

For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

First, an embodiment

Example 1

The embodiment provides a lithium ion battery, wherein a positive tab in the lithium ion battery comprises 99.13 wt% of aluminum, 0.07 wt% of manganese and 0.8 wt% of silicon, the thickness is 0.13mm, the width is 4.5mm, and the melting point is 600 ℃; the material of the negative electrode tab is nickel.

Example 2

The embodiment provides a lithium ion battery, wherein a positive tab in the lithium ion battery comprises 98.99 wt% of aluminum, 0.01 wt% of manganese and 1 wt% of silicon, the thickness is 0.15mm, the width is 6mm, and the melting point is 660 ℃; the material of the negative electrode tab is copper-nickel alloy, wherein the mass ratio of copper to nickel in the copper-nickel alloy is 1: 1.

Example 3

The embodiment provides a lithium ion battery, wherein a positive tab in the lithium ion battery comprises 99.4 wt% of aluminum, 0.1 wt% of manganese and 0.5 wt% of silicon, the thickness is 0.1mm, the width is 3mm, and the melting point is 500 ℃; the material of the negative electrode tab is nickel.

Example 4

This example provides a lithium ion battery in which the composition of the positive tab is 99.93 wt% aluminum and 0.07 wt% manganese, the remainder being the same as in example 1.

Example 5

This example provides a lithium ion battery in which the composition of the positive tab is 99.2 wt% aluminum and 0.8 wt% silicon, the remainder being the same as in example 1.

Example 6

This example provides a lithium ion battery in which the composition of the positive tab is 99.19 wt% aluminum, 0.01 wt% manganese, and 0.8 wt% silicon, all the remainder being the same as in example 1.

Example 7

This example provides a lithium ion battery in which the composition of the positive tab is 99.1 wt% aluminum, 0.1 wt% manganese, and 0.8 wt% silicon, all the remainder being the same as in example 1.

Example 8

This example provides a lithium ion battery in which the composition of the positive tab and the negative tab are 99.15 wt% of aluminum, 0.05 wt% of manganese, and 0.8 wt% of silicon, and the rest is the same as in example 1.

Example 9

This example provides a lithium ion battery having a positive tab with a composition of 99.43 wt% aluminum, 0.07 wt% manganese, and 0.5 wt% silicon, all as in example 1.

Example 10

This example provides a lithium ion battery having a positive tab with a composition of 98.93 wt% aluminum, 0.07 wt% manganese, and 1 wt% silicon, all as in example 1.

Example 11

This example provides a lithium ion battery having a positive tab with a composition of 99.33 wt% aluminum, 0.07 wt% manganese, and 0.6 wt% silicon, all as in example 1.

Example 12

This example provides a lithium ion battery having a positive tab with a composition of 99.03 wt% aluminum, 0.07 wt% manganese, and 0.9 wt% silicon, all as in example 1.

Second, comparative example

Comparative example 1

The comparative example provides a lithium ion battery in which the composition of the positive tab is unmodified aluminum, and the rest is the same as in example 1.

Unmodified aluminum in this comparative example represents aluminum without added manganese or silicon.

Third, test and results

The test method of the lithium ion battery low line resistance short circuit process comprises the following steps: after the lithium ion battery is fully charged according to a standard charging system, the lithium ion battery is welded into a battery pack in series and parallel connection according to needs to perform short circuit test, and an external 10m omega line set is connected externally to perform external short circuit test.

The test results of the above examples and comparative examples are shown in table 1.

TABLE 1

	Duration(s)
		Example 1	2.2
Example 2	4.3
		Example 3	3.6
Example 4	4.5
		Example 5	4.2
Example 6	3.9
		Example 7	2.1
Example 8	2.3
		Example 9	3.5
Example 10	3.4
		Example 11	2.4
Example 12	1.7
		Comparative example 1	11

From table 1, the following points can be seen:

(1) the invention provides a lithium ion battery, wherein the melting point of a positive lug is reduced by adding manganese and/or silicon into the positive lug of the lithium ion battery, so that the lithium ion battery can be timely reacted and fused in a low-line-resistance short-circuit performance test, and the safety performance is improved, and particularly, the duration time of the lithium ion battery in the low-line-resistance short-circuit process in embodiments 1-12 is less than or equal to 4.5 s;

(2) as can be seen from the combination of examples 1 and 6 to 8, the mass fractions of manganese in the positive tab of examples 1 and 7 to 8 are respectively controlled to be 0.07 wt%, 0.1 wt%, and 0.05 wt%, and compared with the mass fraction of manganese in the positive tab of example 6 being controlled to be 0.01 wt%, the duration times of the lithium ion battery in the low-line-resistance short-circuit process in examples 1 and 7 to 8 are respectively 2.2s, 2.1s, and 2.3s, and the duration time of the lithium ion battery in the low-line-resistance short-circuit process in example 6 is 3.9s, so that the control of the mass fraction of manganese in the positive tab of the lithium ion battery to be in the range of 0.05 to 0.1 wt% can further reduce the duration time of the lithium ion battery in the low-line-resistance short-circuit process, and improve the safety performance;

(3) as can be seen from the combination of examples 1 and 9 to 12, the mass fractions of silicon in the positive tab of examples 1 and 11 to 12 are respectively controlled to be 0.8 wt%, 0.6 wt% and 0.9 wt%, and compared with the mass fractions of silicon in the positive tab of examples 9 to 10 being respectively controlled to be 0.5 wt% and 1 wt%, the durations of the lithium ion battery in the low-line-resistance short-circuit process in examples 1 and 11 to 12 are respectively 2.2s, 2.4s and 1.7s, and the durations of the lithium ion battery in the low-line-resistance short-circuit process in examples 9 to 10 are respectively 3.5s and 3.4s, which indicates that the mass fraction of silicon in the positive tab of the lithium ion battery is controlled to be within a range of 0.6 to 0.9 wt%, so that the durations of the lithium ion battery in the low-line-resistance short-circuit process can be further reduced, and the safety performance can be improved;

(4) it can be seen from the combination of example 1 and comparative example 1 that, when manganese and silicon are added to the positive tab in example 1, the duration time of the lithium ion battery in the low-line-resistance short-circuit process in example 1 is 2.2s, and the duration time of the lithium ion battery in the low-line-resistance short-circuit process in comparative example 1 is 11s, compared with the case that manganese and silicon are not added to the positive tab in comparative example 1, which shows that, when manganese and silicon are added to the positive tab of the lithium ion battery, the duration time of the lithium ion battery in the low-line-resistance short-circuit process can be reduced, and the safety performance can be improved.

In summary, according to the lithium ion battery provided by the invention, the melting point of the positive tab is reduced by adding manganese and/or silicon into the positive tab of the lithium ion battery, the safety performance of the lithium ion battery in a low-line-resistance short-circuit performance test is improved, and the duration time of the lithium ion battery in the low-line-resistance short-circuit process is less than or equal to 4.5 s.

The applicant states that the present invention is illustrated by the above examples to show the detailed process equipment and process flow of the present invention, but the present invention is not limited to the above detailed process equipment and process flow, i.e. it does not mean that the present invention must rely on the above detailed process equipment and process flow to be implemented. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.