CN111244381A - An all-tab type button battery and its manufacturing method - Google Patents

Abstract

The invention discloses a full-tab button battery and a manufacturing method thereof, belonging to the technical field of lithium batteries, wherein the button battery comprises a shell, and a cylindrical winding core is formed by winding a positive plate, a diaphragm and a negative plate; sequentially stacking the anode, the diaphragm and the cathode, wherein the narrow edges of the blank foils of the anode and the cathode are positioned at two sides, and forming a cylindrical roll core in a winding mode; then respectively compacting the narrow edges of the blank foils at the two ends of the winding core to form positive and negative full tabs which can allow large current to pass through, and welding and connecting the positive and negative full tabs to positive and negative shell covers of the button battery through conductive metal sheets; and insulating sealant is filled in the positive and negative electrode shells to form a perfect button battery. The full-lug button cell has small internal resistance and can discharge large current; is an indispensable configuration choice for the portability and long endurance of the battery of the electronic equipment.

Description

An all-tab type button battery and its manufacturing method

technical field

The invention belongs to the technical field of lithium batteries, and particularly relates to an all-tab type button battery and a manufacturing method thereof.

Background technique

With the development of economy and social progress, people's life is becoming more and more intelligent and convenient. The emergence of various electronic devices has reduced people's labor and made more efforts with less effort. Products in the field of smart wear are emerging one after another, bringing people's lives into a new era of digital experience. Among them, the lightness and long battery life of the battery of the electronic device are essential configurations of the device.

Button battery is a metal sealed shell battery, which is characterized by small battery size, strong sealing, small battery self-discharge and high energy density. Therefore, it is widely used in various electronic products such as computers, hearing aids, electronic watches, radios and so on. However, at present, the tabs of the battery cells of the button battery are drawn out by the guide bar or by the small tabs, resulting in high internal resistance and poor discharge rate of the battery. The disadvantage of high failure rate is due to the small number of solder joints.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an all-tab type button battery and a manufacturing method thereof. The all-tab type button battery includes a shell, which is composed of a positive electrode sheet, a separator, a negative electrode sheet and a winding core; it is characterized in that, in the positive electrode sheet The narrow side of the blank foil and the negative electrode sheet in the length direction are reserved; the positive electrode, the separator, and the negative electrode are stacked in sequence, and the narrow side of the positive and negative blank foil is placed on both sides to form a cylindrical core by winding; The blank foils at both ends are compacted with narrow edges to form positive and negative pole lugs, which can allow large current to pass through, and are welded to the positive and negative electrode shells of the button battery through conductive metal sheets; the positive and negative electrode shells are filled with insulating seals glue to form a perfect coin cell battery.

A method for manufacturing an omnipolar button battery, characterized in that the specific steps are as follows:

1) Reserve a small-sized and narrow-sided blank foil on one side of the length direction of the positive pole piece;

2) Reserve a small-sized and narrow-sided blank foil on one side of the length direction of the negative pole piece;

3) The positive and negative pole pieces are separated by the diaphragm, and the positive and negative electrodes are stacked in sequence, and the narrow sides of the positive and negative blank foils are placed on both sides to form a cylindrical core by winding;

4) The narrow sides of the blank foil at both ends of the cylindrical core are squeezed and compacted to form full tabs; then the conductive metal sheets are welded by laser welding;

5) Weld the conductive metal sheets drawn from both ends of the positive and negative electrodes to the positive and negative electrode shell covers; obtain a semi-finished button lithium battery;

6) After baking, liquid injection, packaging, aging, and testing, the button lithium battery is manufactured.

The positive electrode is composed of one or more of lithium cobalt oxide, nickel-cobalt-manganese ternary material or lithium iron phosphate, which can be extracted and intercalated with lithium-containing metal oxides embedded in lithium ions. It is made by attaching to metal aluminum foil; the weight ratio of lithium metal oxide, conductive agent and binder is 50%-80%: 1%-20%: 1%-20%; the conductive agent is conductive carbon black, One or more combinations of conductive graphite, nanotubes, and carbon fibers; the binder is one or more combinations of PEFT, PVDF, SBR, CMC, and sodium alginate.

The negative electrode is made of graphite, hard carbon, lithium titanate or silicon material that can be extracted and embedded in lithium ions, and one or more negative electrode active materials composed of conductive agents and binders are adhered to the metal aluminum foil. The weight ratio of graphite, hard carbon, lithium titanate or silicon material, conductive agent and binder: 50%-80%: 1%-20%: 1%-20%.

The separator is porous PP, PE or non-woven fabric; wherein, the length of the separator is longer than that of the negative electrode, and the width of the separator is wider than the width of the negative electrode, so as to ensure that the positive and negative electrodes can be separated and ensure the safety of the battery.

The conductive metal sheets welded with the full-pole tabs at both ends of the positive and negative electrodes are nickel foil, titanium foil or steel foil; and are welded and connected to the positive and negative electrode shell covers of the button battery, so that the positive and negative electrodes of the battery can be led to the outer shell. , and has good electrical conductivity.

The length of the negative electrode is longer than that of the positive electrode, and the width of the negative electrode is wider than that of the positive electrode, so that the lithium ions released from the positive electrode can be received and embedded by the corresponding negative electrode active material, thereby ensuring the safety and efficiency of the battery.

The step 4) compaction of the narrow sides of the blank foil at both ends of the cylindrical core is compacted with a pressing force of 50N-10000N, so that the blank foils are closely attached together to form a well-conducted full-pole lug, ensuring that the full-pole lug allows large The effect of current passing through.

The shell cover of the positive and negative electrodes is made of stainless steel or nickel; it is insulated by a rubber ring and sealed by a metal extrusion rubber ring; wherein the rubber ring is made of polymer material PP, PE or EPDM.

The liquid injection is to soak the obtained semi-finished button lithium battery into LiPF6-EC/PC/DEC electrolyte; the electrolyte can also be any one or more of LiPF6, LiBF4, LiCLF6, LiAsF6, LiTFSi, LiTf and LiPF6. Any one or more of solvents EC, PC, DEC and EMC are mixed to form.

The beneficial effect of the present invention is that the narrow sides of the blank foil at both ends of the cylindrical core made by the present invention are respectively squeezed and compacted to form full tabs; and then the conductive metal sheets are welded by laser welding, and then welded to the positive and negative electrodes. Therefore, the all-pole-tab type button battery has low internal resistance and can discharge large currents.

Description of drawings

Figure 1 is a schematic diagram of a positive electrode piece.

FIG. 2 is a schematic diagram of a negative pole piece.

3 is a schematic cross-sectional view of the winding core.

FIG. 4 is a schematic diagram of the full tab of the winding core.

Figure 5 Schematic diagram of the battery structure.

Detailed ways

The present invention provides an all-tab type button battery and a manufacturing method thereof. The present invention will be described in more detail below with reference to the accompanying drawings and embodiments.

FIG. 5 is a schematic diagram showing the structure of an all-tab type coin cell battery. The all-tab type button battery is assembled in the positive and negative electrode casings by winding the positive electrode sheet, the separator and the negative electrode sheet to form a cylindrical core; wherein the positive blank foil narrow side 2 (such as As shown in Figure 1); keep the narrow side 4 of the negative blank foil on one side of the length direction of the negative electrode sheet 3 (as shown in Figure 2); stack the positive electrode sheet 1, the separator 5, and the negative electrode sheet 3 in sequence, and the narrow side of the negative electrode blank foil 4 is on the upper side, and the narrow side 2 of the positive blank foil is on the lower side (as shown in Figure 3), and a cylindrical winding core 6 is formed by winding; 7 and the negative electrode all-pole tab 8 (as shown in Figure 4), the all-pole lug can allow a large current to pass, and the positive electrode conductive metal sheet 9 is welded on the positive electrode all-pole lug 7, and is welded with the positive electrode 1 shell, and the negative electrode is fully welded. The negative electrode conductive metal sheet 10 is welded on the tab 8, and is welded with the negative electrode 3 shell; the positive and negative electrode shells are filled with insulating sealant 11 to form a perfect button battery.

A manufacturing method of an omnipolar button battery, the specific steps are as follows:

1) Reserve a blank foil narrow side 2 on one side of the length direction of the positive electrode sheet 1;

2) Reserve a narrow side 4 of blank foil material on one side of the length direction of the negative electrode sheet 3;

3) The positive and negative electrodes are separated by the separator 5, the positive electrode 1, the separator 5, and the negative electrode 3 are stacked in sequence, and the narrow sides of the positive and negative blank foils are on both sides, and a cylindrical core 6 is formed by winding; Among them, the separator is made of porous PP, PE or non-woven fabric; the length of the separator is longer than that of the negative electrode, and the width of the separator is wider than that of the negative electrode, so as to ensure that the positive and negative electrodes can be separated, so that the lithium ions released from the positive electrode can have corresponding negative electrode activity. Substances are embedded to ensure the safety and efficiency of the battery.

4) The narrow sides of the blank foil at both ends of the cylindrical core are compacted with a 1000N extrusion force, so that the foils are closely attached together to form a well-conducted full-pole lug to ensure the effect of allowing a large current to pass through the full-pole lug; then use The conductive metal sheet (nickel foil, titanium foil or steel foil) is welded by laser welding;

5) Weld the conductive metal sheets drawn from both ends of the positive and negative electrodes to the positive and negative electrode shell cover, and have good electrical conductivity; so that the positive and negative electrodes of the battery can be led to the shell to obtain a semi-finished button lithium battery;

6) After baking and liquid injection: soak in LiPF6-EC/PC/DEC electrolyte for 30 minutes at room temperature, and fill the 304 stainless steel positive and negative housings with insulating sealing rubber rings made of PP material for sealing, aging and testing Then complete the manufacture of omnipolar button lithium battery.

The positive electrode is composed of one or more of lithium cobalt oxide, nickel cobalt manganese ternary material or lithium iron phosphate, which can be extracted from lithium-containing metal oxides embedded in lithium ions, and conductive agents (conductive carbon black, conductive graphite, nanometer The positive electrode active material composed of one or more combinations of tubes, carbon fibers, etc.) and binders (one or more combinations of PEFT, PVDF, SBR, CMC, sodium alginate, etc.) is adhered to the metal aluminum foil. into; wherein the weight ratio of lithium metal oxide, conductive agent and binder is 50%-80%: 1%-20%: 1%-20%.

The negative electrode is made of graphite, hard carbon, lithium titanate or silicon material that can be extracted and embedded in lithium ions, and one or more negative electrode active materials composed of conductive agents and binders are adhered to the metal aluminum foil. The weight ratio of graphite, hard carbon, lithium titanate or silicon material, conductive agent and binder is 50%-80%: 1%-20%: 1%-20%.

Example 1

An all-tab type button battery and a manufacturing method thereof, the steps are as follows:

(1) Process the lithium ion positive pole piece and negative pole piece into the shapes shown in Figure 1 and Figure 2, and select the lithium ion battery separator and cut it to match the size.

(2) Use a manual winding machine to wind the separator, the positive electrode, and the negative electrode separator into a roll core, extrude empty foil at both ends of the roll core, weld nickel foil at both ends, connect the shell, bake at 120 °C for 8 hours, and soak at room temperature. Into LiPF6-EC/PC/DEC electrolyte for 30 minutes, encapsulated into cells with a sealing machine, put into 304 stainless steel positive and negative shells with a shell size of 12mm in diameter and a thickness of 5.4mm; filled with PP insulating sealant The ring is sealed, and the manufacture of omnipolar button lithium battery is completed.

(3) Charge and discharge and related performance tests are carried out after aging and standing for 24 hours; the test results are shown in Table 1:

Table 1 Charge and discharge and related performance test results

type Internal resistance mΩ CapacitymAh Standard discharge current (mA) Peak current (mA) product of the present invention 300 55 200 2000 Market LIR1254 Products 600 55 100 1000

Claims (10)

1. A full-lug button battery comprises a shell, a battery cover and a battery cover, wherein the shell comprises a positive plate, a diaphragm, a negative plate and a winding core; the method is characterized in that a blank foil narrow edge is reserved on one side of the positive plate and the negative plate in the length direction; sequentially stacking the anode, the diaphragm and the cathode, wherein the narrow edges of the blank foils of the anode and the cathode are positioned at two sides, and forming a cylindrical roll core in a winding mode; then respectively compacting the narrow edges of the blank foils at the two ends of the winding core to form positive and negative full tabs which can allow large current to pass through, and welding and connecting the positive and negative full tabs to positive and negative shell covers of the button battery through conductive metal sheets; and insulating sealant is filled in the positive and negative electrode shells to form a perfect button battery.

2. A manufacturing method of a full-polar button cell is characterized in that: the method comprises the following specific steps:

1) reserving a small-size narrow-edge blank foil on one edge of the positive pole piece in the length direction;

2) reserving a small-size narrow-edge blank foil on one edge of the negative pole piece in the length direction;

3) the positive and negative pole pieces are isolated by a diaphragm, the positive pole, the diaphragm and the negative pole are sequentially stacked, the narrow edges of the positive and negative blank foils are respectively arranged at two sides, and a cylindrical winding core is formed in a winding mode;

4) the narrow edges of the blank foils at the two ends of the cylindrical winding core are respectively compacted by extrusion to form a full tab; then welding a conductive metal sheet by a laser welding mode;

5) welding conductive metal sheets led out from the two ends of the positive electrode and the negative electrode on the positive electrode shell cover and the negative electrode shell cover; obtaining a semi-finished button lithium battery;

6) and baking, injecting liquid, packaging, aging and testing to finish the manufacture of the button lithium battery.

3. The method for manufacturing a full-polar button cell according to claim 2, wherein the positive electrode is made by adhering one or more of lithium cobaltate, nickel-cobalt-manganese ternary material or lithium iron phosphate lithium-containing metal oxide capable of releasing and inserting lithium ions, and a positive active material consisting of a conductive agent and a binder to a metal aluminum foil; wherein the weight ratio of the lithium-containing metal oxide to the conductive agent to the binder is 50-80%: 1% -20%: 1% -20%; the conductive agent is one or a combination of more of conductive carbon black, conductive graphite, carbon fiber and nano-tubes; the binder is one or a combination of more of PEFT, PVDF, SBR, CMC and sodium alginate.

4. The method for manufacturing the all-polar button cell according to claim 2, wherein the negative electrode is made by adhering one or more of graphite, hard carbon, lithium titanate or silicon materials capable of extracting and intercalating lithium ions, a conductive agent and a binder to a metal aluminum foil; wherein the weight ratio of graphite, hard carbon, lithium titanate or silicon material, conductive agent and binder is as follows: 50% -80%: 1% -20%: 1 to 20 percent.

5. The method of manufacturing an all-polar button cell according to claim 2, wherein the separator is a porous PP, PE or non-woven fabric; the length of the diaphragm is longer than that of the negative electrode, and the width of the diaphragm is wider than that of the negative electrode, so that the positive electrode and the negative electrode can be isolated, and the safety of the battery is ensured.

6. The method for manufacturing the all-polar button battery according to claim 2, wherein the conductive metal sheet welded to the all-tabs at the two ends of the positive and negative electrodes is a nickel foil, a titanium foil or a steel foil; and the positive and negative electrode covers are welded and connected to the shell covers of the button battery, so that the positive and negative electrodes of the battery can be led to the shell, and the button battery has good conductive property.

7. The method for manufacturing a full-polar button cell according to claim 2, wherein the length of the negative electrode is longer than that of the positive electrode, and the width of the negative electrode is wider than that of the positive electrode, so that lithium ions extracted from the positive electrode can be received and inserted by the corresponding negative electrode active material, and the safety and efficiency of the cell are ensured.

8. The method for manufacturing the full-polar button battery according to claim 2, wherein the step 4) of compacting the narrow edges of the blank foils at the two ends of the cylindrical winding core is performed by adopting a 50N-10000N extrusion force, so that the blank foils are tightly attached together to form a good conductive full tab, and the effect that the full tab allows a large current to pass through is ensured.

9. The method for manufacturing a full-polar button battery according to claim 2, wherein the positive and negative electrode case covers are made of stainless steel or nickel; rubber ring insulation is adopted, and metal extrudes the rubber ring for sealing; wherein the rubber ring is made of high polymer materials PP, PE or EPDM.

10. The method for manufacturing a fully polar button cell as claimed in claim 2, wherein the liquid injection is carried out by immersing the semi-finished button cell into LiPF6-EC/PC/DEC electrolyte; the electrolyte can also be formed by mixing any one or more of LiPF6, LiBF4, LiClF6, LiAsF6, LiTFSi and LiTf with any one or more of solvents EC, PC, DEC and EMC.

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