Diaphragm structure and battery

Abstract

The utility model discloses a diaphragm piece structure and a battery, the diaphragm piece structure comprises a diaphragm piece body, a first blocking boss and a second blocking boss, and two side edges of the diaphragm piece body respectively extend towards the direction far away from a negative plate to form a first diaphragm lug boss and a second diaphragm lug boss; the first blocking boss is arranged on one side surface, facing the negative plate, of the first diaphragm lug boss; and the second blocking boss is arranged on one side surface, facing the negative plate, of the second diaphragm lug boss. Therefore, after the negative plate, the diaphragm plate body and the positive plate are overlapped, the active substances falling off from the negative plate can be prevented from crossing the diaphragm plate body to be in contact with the positive plate through the first blocking boss and the second blocking boss, so that the problem of short circuit of the battery is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of battery production, in particular to a diaphragm sheet structure and a battery. Background Art

[0002] The diaphragm is a critical component in the battery, and its material is non-conductive. The diaphragm not only ensures that electrons in the battery cannot pass between the positive and negative electrodes, but also ensures that ions in the electrolyte can pass freely between the positive and negative electrodes. During the manufacture and use of the battery, it is necessary to prevent the negative and positive electrodes from coming into direct contact. This is crucial to improving the performance and safety of the battery. Usually, an insulating diaphragm is required between the negative and positive electrodes to prevent direct contact between the negative and positive electrodes, thereby ensuring that the battery does not short-circuit or fail.

[0003] During the actual battery manufacturing process, the negative and positive electrode sheets need to be cut and kneaded after coating or slurrying, drying, and rolling. For example, when using hardware molds or laser cutting to cut the positive and negative electrode sheets, the active material of the electrode sheets will inevitably fall off the surface of the current collector. For another example, during the kneading process, although the pores created by kneading help the penetration of the electrolyte, the active material can also easily fall off the surface of the negative electrode sheet.

[0004] Furthermore, during actual battery use, although the active material on the negative electrode sheet is primarily attached to the surface or pores of the current collector via organic or inorganic binders, shedding and dusting can still be a problem. For lithium-ion batteries, for example, since lithium is incorporated into the negative electrode active material during charging, the negative electrode sheet is susceptible to volume expansion, which can cause the active material to shed from the current collector surface or become dust. Generally speaking, internal short circuits in lithium-ion batteries can easily lead to safety issues such as thermal runaway. Furthermore, in alkaline nickel-zinc batteries, for example, the negative electrode sheet is susceptible to deformation during charge and discharge. After prolonged cycling, the zinc oxide active material in the negative electrode sheet can undergo localized migration, easily crossing the separator and reaching the surface of the positive electrode sheet, resulting in a decrease in the battery's electrochemical performance. It's worth noting that, to ensure sufficient wetting of the alkaline electrolyte, alkaline nickel-zinc batteries typically use a water-based binder, which can easily cause the active material zinc oxide to shed and dust in the alkaline electrolyte.

[0005] Usually, the active material will have the opportunity to cross the diaphragm and directly contact the positive electrode after falling off, which may cause local micro-short circuits in the battery or even battery short circuits, thereby affecting the battery's discharge performance, cycle life, and even safety performance. Utility Model Content

[0006] The purpose of the utility model is to overcome the shortcomings of the prior art and provide a diaphragm sheet structure, thereby being able to prevent the active material of the negative electrode sheet from directly contacting the positive electrode sheet.

[0007] The purpose of this utility model is achieved through the following technical solutions:

[0008] A diaphragm structure includes: a diaphragm body, a first barrier boss and a second barrier boss, the two side edges of the diaphragm body extending away from the negative electrode sheet to form a first diaphragm protrusion and a second diaphragm protrusion; the first barrier boss is arranged on a side surface of the first diaphragm protrusion facing the negative electrode sheet; the second barrier boss is arranged on a side surface of the second diaphragm protrusion facing the negative electrode sheet.

[0009] In one embodiment, the first blocking boss includes a first connecting portion and a first blocking portion, one end of the first connecting portion is connected to the first diaphragm protrusion, and one end of the first connecting portion away from the first diaphragm protrusion is connected to the first blocking portion, and the first diaphragm protrusion, the first connecting portion and the first blocking portion together form a first blocking groove.

[0010] In one embodiment, the second blocking boss includes a second connecting portion and a second blocking portion, one end of the second connecting portion is connected to the second diaphragm protrusion, and one end of the second connecting portion away from the second diaphragm protrusion is connected to the second blocking portion, and the second diaphragm protrusion, the second connecting portion and the second blocking portion together form a second blocking groove.

[0011] In one embodiment, the cross section of the first blocking boss is a rectangular structure.

[0012] In one embodiment, the cross section of the first blocking boss is a semicircular structure.

[0013] In one embodiment, the height of the first barrier boss is greater than or equal to the thickness of the negative electrode sheet.

[0014] In one embodiment, the height of the second barrier protrusion is greater than or equal to the thickness of the negative electrode sheet.

[0015] In one embodiment, the diaphragm body is one of a polyethylene diaphragm, a polypropylene diaphragm, a polypropylene / polyethylene diaphragm or a polypropylene non-woven fabric diaphragm.

[0016] In one embodiment, the first baffle boss and the second baffle boss are connected to the diaphragm body through an adhesive, and the adhesive is one of sodium carboxymethyl cellulose adhesive, styrene-butadiene latex adhesive, polyvinyl alcohol adhesive or polyethylene oxide adhesive.

[0017] A battery comprises the above-mentioned diaphragm sheet structure, and further comprises: a battery shell, a negative electrode sheet and a positive electrode sheet, wherein the negative electrode sheet, the diaphragm sheet structure and the positive electrode sheet are stacked in sequence, and the negative electrode sheet, the diaphragm sheet structure and the positive electrode sheet are all arranged in the battery shell.

[0018] Compared with the prior art, the present invention has at least the following advantages:

[0019] 1. The diaphragm structure of the present invention is provided with a first blocking boss and a second blocking boss on the diaphragm body, and the first blocking boss and the second blocking boss are directed toward one side of the negative electrode sheet. In this way, after the negative electrode sheet, the diaphragm body and the positive electrode sheet are superimposed, the first blocking boss and the second blocking boss can prevent the active material falling off the negative electrode sheet from passing through the diaphragm body and contacting the positive electrode sheet, thereby avoiding local micro-short circuit or even short circuit phenomenon in the battery.

[0020] 2. The diaphragm structure of the present invention has the advantages of simple overall structure and simple manufacturing process, so it can save manufacturing costs and improve production efficiency to achieve low cost and high benefit.

[0021] 3. The diaphragm structure of the present invention uses an adhesive with strong electrochemical stability to bond the first barrier boss and the second barrier boss to the diaphragm body, which not only improves the bonding strength of the first barrier boss and the second barrier boss, but also ensures the stability of the chemical environment inside the battery, thereby improving the cycle life and safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for use in the embodiments.

[0023] Figure 1 This is a schematic diagram of the stacking structure of the diaphragm sheet structure in the first embodiment of the present utility model;

[0024] Figure 2 for Figure 1 A schematic diagram of the partially enlarged structure of the diaphragm structure at point A;

[0025] Figure 3 This is a schematic diagram of the stacking structure of the diaphragm sheet structure in the second embodiment of the present invention;

[0026] Figure 4 Schematic diagram of the stacking structure of the diaphragm sheet structure in the third embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings.

[0028] A battery includes: a battery shell, a negative electrode sheet 100, a diaphragm sheet structure 200 and a positive electrode sheet 300, wherein the negative electrode sheet 100, the diaphragm sheet structure 200 and the positive electrode sheet 300 are stacked in sequence, and the negative electrode sheet 100, the diaphragm sheet structure 200 and the positive electrode sheet 300 are all arranged in the battery shell.

[0029] It should be noted that batteries are generally divided into cylindrical batteries and square batteries. The positive electrode sheet 300, diaphragm sheet structure 200 and negative electrode sheet 100 on the cylindrical battery are generally wound, while the square battery adopts a stacking method. The diaphragm sheet structure 200 is used to separate the negative electrode sheet 100 and the positive electrode sheet 300 to avoid direct contact between the positive electrode sheet 300 and the negative electrode sheet 100, which may cause an internal short circuit in the battery. In order to further prevent the active material that falls off the negative electrode sheet 100 (taking alkaline nickel-zinc batteries as an example, the active material of the negative electrode sheet is zinc oxide) from crossing the diaphragm sheet body 210 and contacting the positive electrode sheet 300, it is necessary to use the diaphragm sheet structure 200 of the present invention to solve this problem. The diaphragm sheet structure 200 is described below:

[0030] Please combine Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, a diaphragm structure 200 includes: a diaphragm body 210, a first barrier boss 220 and a second barrier boss 230. The two side edges of the diaphragm body 210 extend in a direction away from the negative electrode sheet 100 to form a first diaphragm protrusion 211 and a second diaphragm protrusion 212; the first barrier boss 220 is arranged on a side surface of the first diaphragm protrusion 211 facing the negative electrode sheet 100; the second barrier boss 230 is arranged on a side surface of the second diaphragm protrusion 212 facing the negative electrode sheet 100.

[0031] It should be noted that by providing a first blocking boss 220 and a second blocking boss 230 on the diaphragm body 210, and making the first blocking boss 220 and the second blocking boss 230 face one side of the negative electrode sheet 100, after the negative electrode sheet 100, the diaphragm body 210 and the positive electrode sheet 300 are superimposed, the first blocking boss 220 and the second blocking boss 230 can prevent the active material detached from the negative electrode sheet 100 from passing over the diaphragm body 210 and contacting the positive electrode sheet 300, thereby effectively avoiding a short circuit in the battery, thereby improving the discharge performance, cycle life and safety performance of the battery. Taking an alkaline nickel-zinc battery as an example, the diaphragm structure of the present invention can prevent the active material zinc oxide detached from the negative electrode sheet from contacting the positive electrode sheet, thereby ensuring the discharge performance and cycle life of the alkaline nickel-zinc battery. Most importantly, the short circuit and failure problems of alkaline nickel-zinc batteries can be effectively solved. In addition, the diaphragm structure of the present invention has the advantages of simple overall structure and simple manufacturing process, so it can save costs and improve production efficiency to achieve low cost and high benefits.

[0032] See also Figure 1 and Figure 2 As shown, in the first embodiment, the first barrier protrusion 220 includes a first connecting portion 221 and a first barrier portion 222. One end of the first connecting portion 221 is connected to the first diaphragm protrusion 211, and the end of the first connecting portion 221 away from the first diaphragm protrusion 211 is connected to the first barrier portion 222. The first diaphragm protrusion 211, the first connecting portion 221, and the first barrier portion 222 together form a first barrier groove 223. One side of the negative electrode sheet 100 is located within the first barrier groove 223. After the negative electrode sheet 100, the diaphragm sheet body 210, and the positive electrode sheet 300 are superimposed, the first barrier protrusion 220 can effectively prevent the active material on the negative electrode sheet 100 from passing through the diaphragm sheet body 210 and contacting the positive electrode sheet 300.

[0033] Similarly, the second barrier protrusion 230 includes a second connecting portion and a second barrier portion. One end of the second connecting portion is connected to the second diaphragm protrusion 212, and the end of the second connecting portion away from the second diaphragm protrusion 212 is connected to the second barrier portion. The second diaphragm protrusion 212, the second connecting portion, and the second barrier portion together form a second barrier groove. The other side of the negative electrode sheet 100 is located in the second barrier groove. After the negative electrode sheet 100, the diaphragm sheet body 210, and the positive electrode sheet 300 are superimposed, the second barrier protrusion 230 effectively prevents the active material on the negative electrode sheet 100 from passing through the diaphragm sheet body 210 and contacting the positive electrode sheet 300.

[0034] See also Figure 3 As shown, in the second embodiment, preferably, the cross section of the first blocking boss 220 is a rectangular structure.

[0035] See also Figure 4 As shown, in the third embodiment, preferably, the cross section of the first blocking boss 220 is a semicircular structure.

[0036] In one embodiment, the height of the first blocking protrusion 220 is greater than or equal to the thickness of the negative electrode sheet 100. Thus, when the negative electrode sheet 100, the diaphragm body 210, and the positive electrode sheet 300 are superimposed, the side of the first blocking protrusion 220 facing away from the diaphragm body 210 abuts against the adjacent diaphragm body 210. Similarly, the height of the second blocking protrusion 230 is greater than or equal to the thickness of the negative electrode sheet 100, so that the side of the second blocking protrusion 230 facing away from the diaphragm body 210 abuts against the adjacent diaphragm body 210. Consequently, a confining space is formed by the first blocking protrusion 220 and the second blocking protrusion 230, positioning the negative electrode sheet 100 within the confining space. This further reduces the risk of active material falling off the negative electrode sheet 100 passing through the diaphragm body 210 and contacting the positive electrode sheet 300.

[0037] Furthermore, the material of the diaphragm body 210 varies in different battery systems. For example, in a lithium-ion battery system, the diaphragm body 210 is preferably a polyethylene (PE) diaphragm, a polypropylene (PP) diaphragm, or a polypropylene / polyethylene (PP / PE) diaphragm. In an alkaline nickel-metal hydride battery system, the diaphragm body 210 is preferably a polypropylene (PP) non-woven fabric diaphragm. In an alkaline nickel-zinc battery system, the diaphragm body 210 is primarily a composite diaphragm, for example, a composite of a polypropylene (PP) non-woven fabric diaphragm and a hydrophilic polypropylene / polyethylene (PP / PE) diaphragm.

[0038] It should also be noted that the material used for the first blocking boss 220 and the second blocking boss 230 can be the same as the material of the diaphragm body 210. At the same time, the first blocking boss 220 and the second blocking boss 230 can be set on the diaphragm body 210 by pasting, that is, the first blocking boss 220 and the second blocking boss 230 are respectively connected to the diaphragm body 210 by adhesive; they can also be integrally formed with the diaphragm body 210.

[0039] Furthermore, when an adhesive is used to connect the first barrier boss 220 and the second barrier boss 230 to the diaphragm body, the adhesive used is an adhesive with strong electrochemical stability, such as sodium carboxymethyl cellulose (CMC) adhesive, styrene-butadiene latex (SBR) adhesive, polyvinyl alcohol (PVA) adhesive, polyethylene oxide (PEO) adhesive, or the like. An adhesive with strong electrochemical stability can maintain its chemical and electrochemical properties in the battery operating environment, thereby not chemically and electrochemically reacting with substances such as the electrolyte inside the battery. This not only ensures the stability of the chemical environment inside the battery, but also ensures the strong bonding between each barrier boss and the diaphragm body 210, thereby preventing the first barrier boss 220 and the second barrier boss 230 from falling off and losing their barrier effect on the active material.

[0040] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person of ordinary skill in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present utility model patent shall be determined by the appended claims.

Claims

1. A diaphragm structure, characterized in that: include: A diaphragm body, wherein two side edges of the diaphragm body extend away from the negative electrode sheet to form a first diaphragm protrusion and a second diaphragm protrusion; a first barrier boss, the first barrier boss being arranged on a side of the first diaphragm protrusion facing the negative electrode sheet; and The second barrier boss is arranged on a side surface of the second diaphragm protrusion facing the negative electrode sheet.

2. The diaphragm structure according to claim 1, characterized in that: The first blocking boss includes a first connecting portion and a first blocking portion, one end of the first connecting portion is connected to the first diaphragm protrusion, and one end of the first connecting portion away from the first diaphragm protrusion is connected to the first blocking portion, and the first diaphragm protrusion, the first connecting portion and the first blocking portion together form a first blocking groove.

3. The diaphragm structure according to claim 2, characterized in that: The second blocking boss includes a second connecting portion and a second blocking portion, one end of the second connecting portion is connected to the second diaphragm protrusion, and one end of the second connecting portion away from the second diaphragm protrusion is connected to the second blocking portion, and the second diaphragm protrusion, the second connecting portion and the second blocking portion together form a second blocking groove.

4. The diaphragm structure according to claim 1, characterized in that: The cross section of the first blocking boss is a rectangular structure.

5. The diaphragm structure according to claim 1, characterized in that: The cross section of the first blocking boss is a semicircular structure.

6. The diaphragm structure according to claim 1, characterized in that: The height of the first barrier boss is greater than or equal to the thickness of the negative electrode sheet.

7. The diaphragm structure according to claim 6, characterized in that: The height of the second barrier boss is greater than or equal to the thickness of the negative electrode sheet.

8. The diaphragm structure according to claim 1, characterized in that: The diaphragm body is one of a polyethylene diaphragm, a polypropylene diaphragm, a polypropylene / polyethylene diaphragm or a polypropylene non-woven fabric diaphragm.

9. The diaphragm structure according to claim 1, characterized in that: The first barrier boss and the second barrier boss are respectively connected to the diaphragm body through an adhesive; and the adhesive is one of sodium carboxymethyl cellulose adhesive, styrene-butadiene latex adhesive, polyvinyl alcohol adhesive or polyethylene oxide adhesive.

10. A battery, characterized in that: The invention comprises the diaphragm sheet structure described in any one of claims 1 to 9, and further comprises: a battery shell, the negative electrode sheet and the positive electrode sheet, the negative electrode sheet, the diaphragm sheet structure and the positive electrode sheet are stacked in sequence, and the negative electrode sheet, the diaphragm sheet structure and the positive electrode sheet are all arranged in the battery shell.

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