WO2012000303A1

WO2012000303A1 - Button lithium battery and preparing method thereof

Info

Publication number: WO2012000303A1
Application number: PCT/CN2011/000670
Authority: WO
Inventors: 王建; 黄建昌; 陈汉珠; 王启明
Original assignee: 博特科科技(深圳)有限公司; 力佳电源科技(深圳)有限公司
Priority date: 2010-07-02
Filing date: 2011-04-18
Publication date: 2012-01-05
Also published as: WO2012000303A8; CN102315480A

Abstract

The invention discloses a button lithium battery, which comprises a negative electrode, a positive electrode, a separator, an electrolyte, a positive electrode shell and a negative electrode shell. The separator is sandwiched between the positive electrode and the negative electrode. One side of the positive electrode is the separator and the other side is coated with a current collector. A metal ring is disposed on the outside of the positive electrode. The metal ring and the current collector are integrated to form a ring mesh integrative positive electrode ring, and a ring mesh integrative positive electrode is formed after a positive electrode compact powder is coated by the ring mesh integrative positive electrode ring. The button lithium battery provides a high discharge platform and excellent power discharge characteristics, the utilization rate of the positive or negative electrode active material is greatly improved and the battery capacity is enhanced.

Description

Button type lithium battery and preparation method thereof

Technical field

The invention relates to the field of batteries, in particular to a button type lithium battery and a preparation method thereof.

Background technique

The button-type lithium battery is a new type of chemical power source. As a major force in chemical power supply, it has a wide market prospect and can be used as a power source and a memory power source. As a power source, lithium batteries are increasingly used in medical products and remote control technologies. As a memory power source, they have been widely used in computer main boards and other fields. In particular, lithium batteries have been promoted for use in RFID, and with the development of RFID technology, its application range will be extremely broad. However, the lithium-ion battery used in these fields has higher electrical performance requirements, and it requires a lithium battery with better "power discharge characteristics, stable discharge platform and higher capacity".

As shown in Fig. 1, the general button battery includes a negative electrode casing, a negative current collector, a negative electrode, a 'diaphragm, an electrolyte, a sealing apron, a positive electrode, a positive current collector, and a positive electrode casing; wherein there is a set between the positive and negative electrodes and the outer casing. fluid. The original button-type lithium battery technology, the type of its positive structure.

Figure 2: Positive collector with only current collector: The positive electrode is embedded in a stainless steel mesh or the positive electrode is coated with conductive paste only as a current collector.

Figure 2a: General-purpose positive electrode with a stainless steel mesh as a current collector, and the cross-sectional metal network pressed into the positive electrode powder increases the current collecting area and electrical conductivity.

Figure 2b: Based on Figure 2a, the stainless steel collecting grid is pressed into a wave pattern to increase the flow area.

Figure 2c: There is no current collector on the positive electrode of the battery. Conductive glue is applied to the inner wall of the positive electrode casing to achieve the current collecting function. Due to the easy formation of an arc in the plane of the shell when sealing, the outer casing and the positive electrode are in poor contact.

Fig. 2d: The positive electrode is the same as Fig. 2c, and a metal piece is spot-welded on the inner wall of the positive electrode case and coated with a conductive paste to compensate for the deformation defect of Fig. 2c.

Figure 3: Ring-solid positive electrode: The ring-shaped positive ring prevents the radial expansion of the positive electrode. Fluid action. It is a simple combination of positive electrodes.

During the electrochemical reaction of the battery, when the lithium ion is embedded in the positive electrode crystal, the positive electrode will expand, and the axial expansion can keep the positive and negative electrodes in close contact, which is necessary for the discharge process of the battery, but the radial expansion of the positive electrode causes The positive electrode is stuck in the radial direction, so that the positive electrode and the negative electrode are not in good contact, and the battery capacity cannot be completely released. Therefore, some battery manufacturers have added various "positive pole rings" on the positive powder cake to ensure that the battery does not have radial expansion during discharge. This kind of positive electrode is called "ring-solid positive electrode". Its structure type has four types as shown in Figure 3:

Figure 3a: Ring ring positive

Figure 3b: Through-hole positive electrode

Figure 3c: Positive pressure ring

Figure 3d: Seal ring positive

The positive electrodes of the above eight structures, due to their structural characteristics, exhibit a separation or current collecting effect or a ring-solid effect, and the electrical properties of the produced battery cannot fully satisfy the "power discharge characteristics, stable discharge platform and higher". The requirements of the "capacity"; and the manufacturing process is complex, costly, and inefficient, and it is difficult to meet the application needs of new fields.

Summary of the invention

The object of the present invention is to provide a button type lithium battery and a preparation method thereof. The button type lithium battery has a high discharge platform and excellent power discharge characteristics, and the utilization ratio of the positive and negative active materials is greatly improved. Battery capacity has increased.

In order to achieve the above object, the technical solution adopted by the present invention is: a button type lithium battery comprising a negative electrode, a positive electrode, a separator, an electrolyte, a positive and negative electrode casing, wherein a separator is disposed between the negative electrode and the positive electrode, and the positive electrode side a diaphragm is disposed, the opposite side is covered by a current collector, and a metal ring is disposed outside the positive electrode, and the metal ring and the current collector are integrally disposed to form a ring-shaped integrated positive ring, and the ring-shaped integrated positive ring covers the positive electrode Forming a ring-connected positive electrode.

The button type lithium battery has a concave-convex point at the bottom of the ring-shaped integrated positive electrode ring.

The button type lithium battery has a concave-convex point at the bottom of the ring-shaped integrated positive electrode ring, and the shape thereof is Round, square, triangle, diamond.

In the above-mentioned button type lithium battery, a through hole is formed in the bottom of the ring-shaped integrated positive electrode ring, and the through hole forms a crack-like burr.

In the above-mentioned button type lithium battery, the inner side of the ring-shaped integrated positive electrode is coated with a conductive adhesive.

In the above-mentioned button type lithium battery, the ring-shaped integrated positive electrode ring has a wave pattern or a ring-shaped ring shape. In the above-mentioned button type lithium battery, the metal used for the ring-shaped integrated positive electrode ring is stainless steel, stainless steel, nickel, aluminum metal conductor.

The button type lithium battery has a thickness of a metal material used for the ring-shaped integrated positive electrode ring.

0. 02 ~ 1. 0 hidden.

A method for preparing a button-type lithium battery, the steps of which are: fabricating a ring-shaped integrated positive electrode ring, forming a concave-convex shape on the bottom and sides of the ring-shaped integrated positive electrode ring; and coating a conductive adhesive on the inner side of the ring-shaped integrated positive electrode ring; The ring-shaped integrated positive electrode covers the positive electrode, and the ring-shaped integrated positive ring is pressed into a wave pattern; the positive electrode, the negative electrode, the diaphragm and the outer casing of the lithium battery are packaged together. A method for preparing a button type lithium battery, the steps of which are: forming a ring-shaped integrated positive electrode ring, forming a through hole at the bottom and side of the ring-shaped integrated positive electrode ring; and applying a conductive adhesive on the inner side of the ring-shaped integrated positive electrode ring; The net integrated ^ positive ring covers the positive electrode, and the ring net is integrated with the 4 匕 positive ring into a ring-shaped ring; the lithium battery positive electrode, the negative electrode, the diaphragm and the outer casing are packaged together. The positive electrode in the button lithium battery is an innovative positive structure type, which can be called "ring net integrated positive electrode", and the ring covering the positive electrode powder cake is called "ring net integrated positive ring", which is designed as one body. It not only acts as a current collector, but also prevents the radial expansion of the positive electrode during the discharge of the battery, and guides the positive electrode only for axial expansion, thereby ensuring the close contact of the positive and negative electrodes during the discharge process. The obvious increase of the current collecting effect leads to the improvement of the power discharge performance of the lithium battery. After the positive electrode is solidified, the radial expansion of the positive electrode during the electrochemical reaction is made, so that the positive and negative electrodes are in the electrochemical reaction process of the entire discharge. It maintains close contact at all times, ensuring uniform discharge and a high discharge platform. At the same time, the utilization of positive and negative active materials is greatly improved, and the battery capacity is also increased.

The "ring integrated positive ring" of the button type lithium battery is both a positive current collector and a solid ring; In the "ring-integrated positive electrode", the shape of the current collecting effect is increased by pressing a wave pattern or a ring-shaped ring pattern.

The button lithium battery not only improves the electrical performance of the button battery, but also adapts to the market demand; it provides convenient conditions for the battery manufacturing process, especially in achieving automation. If the thickness of the battery is less than 1.6, the thin film of the original technology has high breakage rate and low efficiency, and it is difficult to automate the assembly; and the positive electrode piece manufactured by this patent is easy to realize automation and high efficiency. Less damage, and automation is easy to assemble. On the other hand, the present invention can improve the comprehensive utilization of materials and greatly reduce the cost of the battery.

DRAWINGS

Figure 1 shows the structure of the existing button lithium battery;

2a is a schematic view of a positive electrode of a conventional general-purpose type only current collector; FIG. 2b is a schematic view of a positive electrode in which only a current collector stainless steel current collecting net is pressed into a wave pattern; FIG. 2c is a schematic diagram of a current collector on a positive electrode of the prior art battery;

Figure 2d is a schematic diagram of the current collector without a current collector on the positive electrode of the battery;

3a is a schematic view of a positive ring of a ring ring of a prior art ring-solid positive electrode;

FIG. 3b is a schematic diagram of a positive electrode of a through-hole ring of a prior art ring-solid positive electrode; FIG.

Figure 3c is a schematic view of the positive pressure ring of the prior art ring-solid positive electrode;

3d is a schematic view of a positive electrode of a sealing ring of a prior art ring-solid positive electrode;

4 is a schematic structural view of an embodiment of the present invention;

Figure 5a is a schematic view of an embodiment of the present invention;

Figure 5b is a schematic view of an embodiment of the present invention;

Figure 5c is a schematic view of an embodiment of the present invention;

Figure 5d is a schematic view of an embodiment of the present invention;

Figure 5e is a schematic view of an embodiment of the present invention; Figure 5f is a schematic view of an embodiment of the invention.

detailed description

As shown in FIG. 4, a button type lithium battery includes a negative electrode case 401, a negative electrode current collector 402, a negative electrode 403, a positive electrode 406, a diaphragm 404 (including an electrolyte), a sealant 405, and a ring-shaped integrated positive ring.

407. A positive electrode casing 408 is disposed between the negative electrode 403 and the negative electrode casing 401, and a ring-shaped integrated positive electrode ring 407 is disposed between the positive electrode 406 and the positive electrode casing 408. The separator 404 is disposed on the negative electrode 403 and the positive electrode 406. The separator 404 is disposed on the side of the positive electrode 406, the opposite side is covered by the current collector, and the outer side of the positive electrode is provided with a metal ring. The metal ring and the current collector are integrally provided to form a ring-shaped integrated positive electrode ring 407. The button lithium battery is a creative positive structure type, called

"Circular integrated positive electrode", the ring covering the positive powder cake is called "ring integrated positive ring", which is designed as one body. It not only acts as a current collector, but also prevents the positive radial direction during battery discharge. The expansion guides the positive electrode only for axial expansion, thereby ensuring the close contact of the positive and negative electrodes during discharge. In the button type lithium battery, the ring-shaped integrated positive electrode 407 has a concave-convex point at the bottom of the ring, and the shape is a circular shape, a square shape, a triangle shape, a diamond shape and the like. The through hole can also be provided at the bottom of the ring 407 ring of the positive pole of the ring network, and the through hole forms a cracked burr.

A button type lithium battery comprising a negative electrode casing 401, a negative electrode current collector 402, a negative electrode 403, a positive electrode 406, a diaphragm 404 (including an electrolyte), a sealing rubber ring 405, a ring-shaped integrated positive electrode ring 407, and a positive electrode casing.

408, a negative electrode current collector 402 is disposed between the negative electrode 403 and the negative electrode housing 401, and a ring-shaped integrated positive electrode ring 407 is disposed between the positive electrode 406 and the positive electrode housing 408, wherein the separator 404 is disposed between the negative electrode 403 and the positive electrode 406. A separator 404 is disposed on the side of the positive electrode 406, and the opposite side is covered by the current collector. The outer side of the positive electrode is provided with a metal ring, and the metal ring and the current collector are integrally provided to form a ring-shaped integrated positive electrode ring 407. The button type lithium battery is an innovative positive structure type, which is called "ring net integrated positive electrode", and the ring covering the positive electrode powder cake is called "ring net integrated positive ring", which is designed as one body, which The function of the current collector prevents the radial expansion of the positive electrode during the discharge of the battery, and guides the positive electrode only for axial expansion, thereby ensuring the close contact of the positive and negative electrodes during the discharge process. The inner side of the ring-connected positive electrode ring 407 is coated with a conductive adhesive. The ring-shaped integrated positive ring 407 is pressed out of the shape of a wave pattern or a ring-shaped ring. The metal used in the ring-connected positive ring 407 is stainless steel, stainless steel, nickel, aluminum, etc. A metal conductor that cannot chemically react with the positive electrode material. The thickness of the metal material used for the ring-shaped integrated positive ring is 0. 02 - 1. 0 wake up.

As shown in FIG. 5a, a ring-shaped composite structure is shown. A button-type lithium battery includes a positive electrode ring 501, a positive electrode net 502, and a positive electrode 503, wherein the positive electrode 503 is provided with a positive electrode ring 501; The positive ring 501 and the positive electrode mesh 502 are integrally disposed, and the positive electrode ring 501 and the positive electrode mesh 502 are integrally formed as a ring-shaped integrated positive ring 407.

FIG. 5b is a schematic structural view of a ring-network composite plus conductive adhesive. A button-type lithium battery includes a positive electrode ring 501, a positive electrode mesh 502, and a positive electrode 503, wherein the positive electrode 503 is provided with a positive electrode ring 501; The positive electrode net 502, wherein the positive electrode ring 501 and the positive electrode net 502 are integrally disposed, is coated with a layer of conductive adhesive 504 on the positive electrode net 502, and the positive electrode ring 501 and the positive electrode net 502 are integrally formed into a ring net integrated positive electrode ring 407.

FIG. 5c is a schematic structural view of a ring-network composite plus conductive adhesive. A button-type lithium battery includes a positive electrode ring 501, a positive electrode mesh 502, and a positive electrode 503, wherein the positive electrode 503 is provided with a positive electrode ring 50.1; The positive electrode net 502, wherein the positive electrode ring 501 and the positive electrode net 502 are integrally disposed, the positive electrode net 502 is coated with a layer of conductive adhesive 504, and the positive electrode ring 501 and the positive electrode net 502 are integrally formed into a ring net integrated positive ring 407. The ring-shaped integrated positive electrode 407 is pressed into a wavy shape.

Figure 5d is a schematic diagram of a ring network composite structure, a button lithium battery including a positive ring 501 is a pinhole positive ring 501, a positive electrode net 502 and a positive electrode 503, wherein the positive electrode 503 is provided with a pinhole positive ring 501; A positive electrode mesh 502 is disposed on one side of the positive electrode 503, wherein the pinhole positive electrode ring 501 and the positive electrode mesh 502 are integrally disposed, and the pinhole positive electrode ring 501 and the positive electrode mesh 502 are integrally formed into a ring net integrated positive electrode ring 407.

Figure 5e is a schematic diagram of a ring network composite structure, a button type lithium battery including a positive electrode ring 501 is a pinhole positive ring 501, a positive electrode net 502 and a positive electrode 503, wherein the positive electrode 503 is provided with a pinhole positive ring 501; A positive electrode mesh 502 is disposed on the positive electrode 503 side, and a conductive adhesive 504 is coated on the positive electrode mesh 502. The pinhole positive electrode ring 501 and the positive electrode mesh 502 are integrally disposed, and the pinhole positive electrode ring 501 and the positive electrode mesh 502 are integrally formed into a ring. The mesh integrates the positive ring 407.

FIG. 5f is a schematic structural diagram of a ring network composite, and a button type lithium battery includes a positive ring. 501 is a pinhole positive ring 501, a positive electrode net 502 and a positive electrode 503, wherein the positive electrode 503 is provided with a pinhole positive ring 501; the positive electrode 503 is provided with a positive electrode net 502, and a positive conductive mesh 502 is coated with a conductive paste 504, wherein the pin The positive electrode ring 501 and the positive electrode mesh 502 are integrally disposed, and the positive electrode ring 501 and the positive electrode mesh 502 are integrally formed into a ring-shaped integrated positive ring 407, and the ring-shaped integrated positive electrode 407 is ring-shaped into a wavy shape.

The positive electrode implemented by the present invention is referred to as "ring integrated positive electrode", and includes a positive electrode powder cake and a "ring net integrated positive electrode ring". "Circular integrated positive ring" It not only acts as a positive current collector, but also prevents radial expansion of the positive electrode during battery discharge, guiding the positive electrode to expand only axially, thus ensuring close contact between the positive and negative electrodes during discharge. Moreover, its current collecting effect is significantly better than the original technology current collector. The "ring net integrated positive electrode ring" is coated with the positive electrode powder cake, and the "ring net integrated positive electrode" is coated with the conductive adhesive side in close contact with the positive electrode outer casing, and the other side is in contact with the diaphragm.

A method for preparing a button-type lithium battery, the steps of which are: fabricating a ring-shaped integrated positive electrode ring, forming a concave-convex shape on the bottom and sides of the ring-shaped integrated positive electrode ring; and coating a conductive adhesive on the inner side of the ring-shaped integrated positive electrode ring; The ring-connected positive electrode ring covers the positive electrode, and the ring-shaped integrated positive electrode ring is pressed into a wave pattern; the lithium battery positive electrode, the negative electrode, the separator, the electrolyte and the outer casing are packaged together. In the embodiment of the present invention, a "ring net integrated positive electrode ring" is punched out, and a through hole or a concave-convex shape is punched thereon, and a cracked burr is formed on the inner side of the ring; and then a conductive adhesive is coated on the bottom of the ring. The second step is to press the positive electrode cake into the positive electrode ring; finally, the undulations such as wavy lines or ring lines are pressed on the "ring integrated positive electrode".

A method for preparing a button type lithium battery, the steps of which are: forming a ring-shaped integrated positive electrode ring, forming a through hole at the bottom and side of the ring-shaped integrated positive electrode ring; and applying a conductive adhesive on the inner side of the ring-shaped integrated positive electrode ring; The integrated positive electrode ring covers the positive electrode, and the ring-shaped integrated positive electrode ring is pressed into a ring-shaped ring; the positive electrode, the negative electrode, the separator, the electrolyte and the outer casing of the lithium battery are packaged together. In the embodiment of the present invention, the "ring net integrated positive electrode ring" is punched out, and a through hole or a concave-convex shape is punched thereon, and a cracked bristles are formed on the inner side of the ring; then a conductive adhesive is coated on the bottom of the ring. The second step is to press the positive electrode cake into the positive electrode ring; finally, the undulations such as wavy lines or ring lines are pressed on the "ring integrated positive electrode".

The technical solutions provided by the embodiments of the present invention are described in detail above, and the application is applied in this paper. The present invention is only applicable to the understanding of the principles of the embodiments of the present invention. At the same time, in the embodiments of the present invention, there are some changes in the specific embodiments and application scopes. The description should not be construed as limiting the invention.

Claims

Claim

A button-type lithium battery comprising a negative electrode, a positive electrode, a separator, an electrolyte, a positive and negative electrode housing, wherein a separator is disposed between the negative electrode and the positive electrode, wherein the positive electrode side is provided with a diaphragm, and the opposite side is assembled The fluid is coated, and the outer side of the positive electrode is provided with a metal ring. The metal ring and the current collector are integrally arranged to form a ring-shaped integrated positive electrode ring, and the ring-shaped integrated positive electrode covers the positive electrode to form a ring-shaped integrated positive electrode.

2. The button type lithium battery according to claim 1, wherein the bottom of the ring-shaped integrated positive electrode ring is provided with a concave-convex point.

3. The button type lithium battery according to claim 2, wherein the bottom of the ring-shaped integrated positive electrode ring is provided with a concave-convex point, and the shape thereof is a circle, a square, a triangle, and a diamond.

4. The button type lithium battery according to claim 1, wherein a through hole is formed in a bottom portion and a side surface of the ring-shaped integrated positive electrode ring, and the through hole forms a crack-like burr.

The button-type lithium battery according to claim 1, wherein the inner side of the ring-connected positive electrode is coated with a conductive paste.

6. The button type lithium battery according to claim 1, wherein the ring-shaped integrated positive electrode ring presses a wave pattern or a ring-shaped ring pattern.

7. The button type lithium battery according to claim 1, wherein the metal used for the ring-shaped integrated positive electrode ring is stainless steel, stainless steel, nickel, or aluminum.

The thickness of the metal material used for the ring-shaped integrated positive ring is 0. 02 ~ 1. 0 hidden.

A method for preparing a button-type lithium battery, comprising the steps of: fabricating a ring-shaped integrated positive electrode ring, forming a concave-convex shape at the bottom and sides of the ring-shaped integrated positive electrode ring; The inner side is coated with a conductive adhesive; the ring-shaped integrated positive electrode covers the positive electrode, and the ring-shaped integrated positive electrode ring is pressed into a wave pattern; the lithium battery positive electrode, the pole, the diaphragm and the outer casing are packaged together.

The method for preparing a button type lithium battery according to claim 9, wherein the step of: forming a ring-shaped integrated positive electrode ring, forming a pass in the ring-shaped integrated positive ring bed portion and the side surface Hole; the inner side of the ring-shaped integrated positive electrode is coated with conductive adhesive; the ring-shaped integrated positive ring covers the positive electrode, and the ring-shaped integrated positive ring is pressed into a ring-shaped ring; the lithium battery positive electrode, the negative electrode, the diaphragm and the outer casing are packaged in together.