Soft package battery capable of improving utilization rate of negative electrode

Abstract

The utility model discloses a soft package battery capable of improving the utilization rate of a negative electrode. The soft package battery comprises a soft package shell and a winding battery cell arranged in the soft package shell, the winding battery cell comprises a positive plate, a negative plate and electrolyte, a diaphragm is arranged between the positive plate and the negative plate, the positive plate is connected with a positive guide plate, and the negative plate is connected with a negative guide plate; wherein at least one surface of the negative plate is provided with an electrolyte microgroove which is formed by sinking inwards, and the electrolyte microgroove is used for loading electrolyte and increasing the specific surface area of the negative plate. The electrolyte microgroove arranged on the negative plate can improve the electrolyte loading function, provides more sufficient electrolyte infiltration, is beneficial to more sufficient and smoother reaction, further improves the utilization rate of the negative electrode, and effectively reduces the material consumption of the negative plate under the same battery capacity so as to reduce the cost.

Description

Technical Field

[0001] The utility model relates to the field of soft-pack batteries, in particular to a soft-pack battery capable of improving the utilization rate of a negative electrode. Background Art

[0002] As society progresses, there are more and more types of small electronic products, and electronic products cannot do without batteries, which also leads to an increase in the use of batteries as the number of electronic products increases.

[0003] In the traditional design of primary lithium batteries, in order to easily obtain high-capacity electrical performance, the theoretical electrochemical equivalent value of the negative electrode of the battery is greater than that of the positive electrode, and the electrochemical capacity of the active material in the negative electrode design is greater than that of the positive electrode. The negative electrode electrochemical equivalent: positive electrode electrochemical equivalent is usually (105-110:100), and the extra 5-10% of the negative electrode active material does not participate in the reaction. The utilization rate of the negative electrode is between 90% and 95%, which ensures the high capacity value of the battery.

[0004] However, the existing technology adopts the solution of excessive negative electrode design in pursuit of capacity, which will cause energy waste. As the use of batteries becomes more and more widespread, the energy waste phenomenon becomes more obvious, which also leads to an increase in production costs. In the promotion of environmentally friendly and low-carbon modern production, it is necessary to improve the utilization rate of the negative electrode of the battery. How to achieve less energy consumption and reduce the unit capacity cost on the basis of using less negative electrode active material while obtaining the same discharge capacity value is a problem that needs to be solved in this field. Utility Model Content

[0005] In order to at least partially solve the defects of the prior art, the main purpose of the utility model is to provide a soft-pack battery that can improve the utilization rate of the negative electrode.

[0006] In order to achieve the above-mentioned main purpose, the utility model provides a soft-pack battery capable of improving the utilization rate of the negative electrode, comprising a soft-pack shell and a wound battery cell arranged in the soft-pack shell; the wound battery cell comprises a positive electrode sheet, a negative electrode sheet and an electrolyte, a separator is provided between the positive electrode sheet and the negative electrode sheet, a positive electrode guide sheet is connected to the positive electrode sheet, and a negative electrode guide sheet is connected to the negative electrode sheet; wherein, an electrolyte microgroove formed by an inward depression is provided on at least one surface of the negative electrode sheet, and the electrolyte microgroove is used to load the electrolyte and increase the specific surface area of ​​the negative electrode sheet.

[0007] According to a specific implementation of the utility model, the depth of the electrolyte microgroove does not exceed 40% of the total thickness of the negative electrode sheet.

[0008] Furthermore, the depth of the electrolyte microgrooves accounts for 10%-30% of the thickness of the negative electrode sheet.

[0009] Furthermore, the depth of the electrolyte microgrooves accounts for 25% of the thickness of the negative electrode sheet.

[0010] According to a specific implementation of the utility model, the electrolyte microgroove includes a plurality of nail-point-shaped microgrooves, and the plurality of nail-point-shaped microgrooves are connected or not connected.

[0011] According to a specific implementation of the utility model, a plurality of nail-point-shaped microgrooves are distributed in an array or arranged in groups.

[0012] According to a specific implementation of the utility model, the longitudinal section of the nail-shaped microgroove is V-shaped, U-shaped or square.

[0013] According to a specific implementation of the utility model, the electrolyte microgroove includes a plurality of strip grooves, and the plurality of strip grooves are arranged in an array manner or in a cross manner.

[0014] Furthermore, the projection of the strip-shaped groove on the surface of the negative electrode sheet is in a straight line, an arc or a corrugated shape.

[0015] The utility model has the following beneficial effects: a soft-pack battery capable of improving the utilization rate of the negative electrode is provided, wherein an electrolyte microgroove formed by an inward depression is provided on at least one surface of the negative electrode sheet, and the electrolyte microgroove is used to load the electrolyte and increase the specific surface area of ​​the negative electrode sheet; wherein the battery cell of the soft-pack battery is a wound battery cell, and since the surface of the negative electrode sheet has the electrolyte microgroove, during the working reaction of the soft-pack battery, the electrolyte is required between the positive electrode sheet and the negative electrode sheet as a carrier for ion conduction, and the electrolyte microgroove in the utility model can enhance the electrolyte loading function, provide more sufficient electrolyte infiltration, and facilitate a more sufficient and smooth reaction, thereby improving the utilization rate of the negative electrode, and effectively reducing the material usage of the negative electrode sheet and reducing the cost under the same battery capacity.

[0016] In order to more clearly illustrate the purpose, technical solutions and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural diagram of the wound battery cell in Example 1 of the soft-pack battery of the utility model;

[0018] Figure 2 It is a top view of the negative electrode sheet in Example 1 of the soft-pack battery of the utility model;

[0019] Figure 3 It is a cross-sectional view of the negative electrode sheet in Example 1 of the soft-pack battery of the utility model;

[0020] Figure 4 It is a top view of the negative electrode sheet in Example 2 of the soft-pack battery of the utility model;

[0021] Figure 5 It is a cross-sectional view of the negative electrode sheet in Example 2 of the soft-pack battery of the utility model;

[0022] Figure 6 It is a top view of the negative electrode sheet in Example 3 of the soft-pack battery of the utility model;

[0023] Figure 7 It is a top view of the negative electrode sheet in Example 4 of the soft-pack battery of the utility model. DETAILED DESCRIPTION

[0024] In order to more clearly understand the above-mentioned purpose, features and advantages of the utility model, the utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0025] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0026] The soft-pack battery of the embodiment of the utility model comprises a soft-pack shell and a wound battery cell 1 arranged in the soft-pack shell. The soft-pack shell can be specifically made of an aluminum-plastic film. After the wound battery cell 1 is manufactured, it is wrapped with the aluminum-plastic film for sealing and forming to obtain the soft-pack battery.

[0027] like Figure 1 As shown, the wound battery cell 1 includes a positive electrode sheet 101, a negative electrode sheet 102 and an electrolyte, a separator 103 is provided between the positive electrode sheet 101 and the negative electrode sheet 102, a positive electrode guide sheet 104 is connected to the positive electrode sheet 101, and a negative electrode guide sheet 105 is connected to the negative electrode sheet 102; wherein, after the separator 103 and the positive electrode sheet 101 are attached to the negative electrode sheet 102, they are wound, for example, using a winding machine to form the wound battery cell 1, and then loaded into a soft-pack shell, and the electrolyte is added, and then the positive electrode guide sheet 104 and the negative electrode guide sheet 105 are connected, and the soft-pack battery is obtained by sealing and forming.

[0028] Exemplarily, the soft-pack battery in the embodiment is specifically a lithium manganese soft-pack battery. The negative electrode sheet 102 is preferably made of high-purity lithium strip. To increase the strength, 10 to 100 PPM of aluminum or magnesium metal may be added to make the ultra-thin lithium strip less likely to deform and break.

[0029] In the embodiment, at least one surface of the negative electrode sheet 102 is provided with an electrolyte microgroove 106 formed by an inward depression, and the electrolyte microgroove 106 is used to load electrolyte and increase the specific surface area of ​​the negative electrode sheet 102. The depth of the electrolyte microgroove 106 does not exceed 40% of the total thickness of the negative electrode sheet 102; preferably, the depth of the electrolyte microgroove 106 accounts for 10%-30% of the thickness of the negative electrode sheet 102. Specifically, the depth of the electrolyte microgroove 106 accounts for 25% of the thickness of the negative electrode sheet 102, which will not significantly affect the normal use of the negative electrode sheet 102, and can also accommodate an appropriate amount of electrolyte.

[0030] The electrolyte microgrooves 106 may be obtained by simultaneous processing when manufacturing the negative electrode sheet 102 , or may be obtained by processing during the process of assembling the battery cell; preferably, the electrolyte microgrooves 106 are obtained by processing during the process of assembling the battery cell to have fresh electrolyte microgrooves 106 .

[0031] like Figure 2-3 In the embodiment 1 shown, the electrolyte microgroove 106 includes a plurality of nail-shaped microgrooves, which are not connected to each other and are preferably distributed in an array. In other embodiments, the plurality of nail-shaped microgrooves may be connected to each other, or may be arranged in groups, for example, which will not be described in detail here. The electrolyte microgroove 106 may be formed on one of the two surfaces of the negative electrode sheet 102, or the electrolyte microgroove 106 may be formed on both surfaces of the negative electrode sheet 102, which is not limited here.

[0032] For example, a roller with convex thorns can be used to process the originally smooth surface of the negative electrode metal strip to obtain the electrolyte microgroove 106. Among them, the longitudinal section of the nail-shaped microgroove is V-shaped, U-shaped or square, and other shapes, which can be selected and designed according to needs, and no examples are given here.

[0033] Please continue reading Figure 1 , in progress Figure 1 After the winding battery cell 1 is assembled, it is placed in a soft-pack shell, filled with electrolyte, and the positive electrode guide sheet 104 and the negative electrode guide sheet 105 are connected, and the sealing is formed. Among them, since the surface of the negative electrode sheet 102 has an electrolyte microgroove 106, part of the electrolyte in the battery is stored in the electrolyte microgroove 106. At the same time, the specific surface area of ​​the negative electrode sheet 102 is increased and the infiltration effect of the electrolyte microgroove 106 is utilized, so that the negative electrode sheet 102 is more fully utilized, which is conducive to improving the utilization rate of the material, so that the negative electrode utilization rate reaches 98% and above, the battery capacity of the same negative electrode material is increased or the negative electrode lithium of the same battery capacity is reduced, so that the cost performance of the battery is higher.

[0034] like Figure 4-5The main difference between the embodiment 2 shown and the embodiment 1 is that the electrolyte microgrooves 106 include a plurality of strip grooves, and the plurality of strip grooves are arranged in a linear array; wherein the plurality of strip grooves are not interconnected.

[0035] Specifically, the projection of the strip-shaped groove on the surface of the negative electrode sheet 102 is a straight line; Figure 6 In the illustrated embodiment 3, the projection of the strip-shaped groove on the surface of the negative electrode sheet 102 may also be a corrugated shape; in another optional embodiment, the projection of the strip-shaped groove on the surface of the negative electrode sheet 102 may also be an arc shape; wherein, the strip-shaped groove may be set to other shapes according to specific needs, and examples are not given one by one here.

[0036] As an extension of Example 2, in Figure 7 In the embodiment 4 shown, a plurality of strip-shaped grooves are arranged in a cross manner, specifically, in a cross manner in horizontal and vertical directions; in other embodiments, a mesh structure may also be formed, which will not be described in detail here.

[0037] Parts not mentioned above, such as the positive electrode sheet 101 and the separator 103, etc., are all applicable to the existing technology.

[0038] Although the present invention is described above through embodiments, it should be understood that the above embodiments are only used to exemplarily describe the feasible implementation methods of the present invention, and should not be interpreted as limiting the scope of protection of the present invention. That is, any replacement or change made by those skilled in the art in accordance with the present invention should also be covered by the scope of protection of the claims of the present invention.

Claims

1. A soft-pack battery capable of improving negative electrode utilization, comprising a soft-pack shell and a wound battery cell disposed in the soft-pack shell; the wound battery cell comprises a positive electrode sheet, a negative electrode sheet and an electrolyte, a separator is provided between the positive electrode sheet and the negative electrode sheet, a positive electrode guide sheet is connected to the positive electrode sheet, and a negative electrode guide sheet is connected to the negative electrode sheet; characterized in that: An electrolyte microgroove formed by an inward depression is provided on at least one surface of the negative electrode sheet, and the electrolyte microgroove is used to load electrolyte and increase the specific surface area of ​​the negative electrode sheet.

2. The soft-pack battery capable of improving negative electrode utilization as claimed in claim 1, characterized in that: The depth of the electrolyte microgrooves does not exceed 40% of the total thickness of the negative electrode sheet.

3. The soft-pack battery capable of improving negative electrode utilization as claimed in claim 2, characterized in that: The depth of the electrolyte microgroove accounts for 10%-30% of the thickness of the negative electrode sheet.

4. The soft-pack battery capable of improving negative electrode utilization as claimed in claim 3, characterized in that: The depth of the electrolyte microgroove accounts for 25% of the thickness of the negative electrode sheet.

5. The soft-pack battery capable of improving negative electrode utilization as claimed in claim 1, characterized in that: The electrolyte microgrooves include a plurality of nail-point-shaped microgrooves, and the plurality of nail-point-shaped microgrooves are connected or not connected.

6. The soft-pack battery capable of improving negative electrode utilization as claimed in claim 5, characterized in that: The plurality of nail-shaped microgrooves are distributed in an array or arranged in groups.

7. The soft-pack battery capable of improving negative electrode utilization as claimed in claim 5, characterized in that: The longitudinal section of the nail-shaped microgrooves is V-shaped, U-shaped or square-shaped.

8. The soft-pack battery capable of improving negative electrode utilization as claimed in claim 1, characterized in that: The electrolyte microgrooves include a plurality of strip-shaped grooves, and the plurality of strip-shaped grooves are arranged in an array or in a cross manner.

9. The soft-pack battery capable of improving negative electrode utilization as claimed in claim 8, characterized in that: The projection of the strip-shaped groove on the surface of the negative electrode sheet is in a straight line, an arc or a corrugated shape.

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