KR102155547B1 - Moderate type lithium primary battery with excellent output characteristic - Google Patents

Abstract

MR type that improves output characteristics by increasing the input amount of the current collector while optimizing the thickness of the cathode by applying a cathode in which at least 2 or more sheets of powder-coated sub-electrodes are stacked. Disclosed is a lithium primary battery.
The MR-type lithium primary battery with improved output characteristics according to the present invention has an upper side open and a case for accommodating an electrolyte therein; A winding element inserted into the case; And a header covering an upper side of the case into which the winding element is inserted. And the winding element includes a first electrode and a second electrode, a first separator disposed on one surface of the first electrode, and a second separator disposed on one surface of the second electrode, and the first The electrode is characterized by having a plurality of first current collectors in which at least two or more sheets are stacked, and first electrode materials respectively formed on both surfaces of the plurality of first current collectors.

Description

MR type lithium primary battery with improved output characteristics {MODERATE TYPE LITHIUM PRIMARY BATTERY WITH EXCELLENT OUTPUT CHARACTERISTIC}

The present invention relates to an MR-type lithium primary battery with improved output characteristics, and more specifically, a thickness of a cathode by applying a cathode in which at least two sheets of powder-coated sheet-type sub-electrodes are stacked. It relates to an MR-type lithium primary battery in which output characteristics are improved by optimizing and increasing the input amount of the current collector.

In general, a battery is a driving source that generates electricity by inducing an electrochemical reaction, and is widely used for supplying electricity to various types and purposes of equipment due to its small size and easy portability.

In particular, lithium primary batteries have a high energy density due to the nature of using lithium metal as an electrode. For this reason, the lithium primary battery has a risk of rupture during use, and the high-temperature battery used in more severe conditions than a general battery increases the risk accordingly.

In order to improve this, demand for a moderate rate (MR) battery that secures safety by reducing the area of an electrode compared to a high rate (HR) battery so that a certain level of current does not flow even during internal and external short circuits is increasing.

However, the reduction of the area inevitably leads to a decrease in the battery output, and when the MR battery is used in a high rate pulse discharge environment, which is an actual use condition, a capacity decrease occurs. In particular, the capacity decrease is more severe in high-temperature batteries used at 100°C or higher.

Accordingly, the MR type lithium primary battery exhibits a capacity reduction of approximately 30% or more compared to the HR type lithium primary battery during high rate pulse discharge based on the DD size battery.

As a related prior document, there is Korean Patent Publication No. 10-1801543 (announced on November 27, 2017), which describes a positive electrode of a lithium primary battery and a method of manufacturing the same.

An object of the present invention is to optimize the thickness of the cathode by applying a cathode in which at least two or more sheets of powder-coated sheet-type sub-electrodes are stacked, and at the same time increase the input amount of the current collector. It is to provide an MR type lithium primary battery with improved efficiency.

The MR-type lithium primary battery with improved output characteristics according to an embodiment of the present invention for achieving the above object has an upper side open and a case for accommodating an electrolyte therein; A winding element inserted into the case; And a header covering an upper side of the case into which the winding element is inserted. Including, wherein the winding element includes a first electrode and a second electrode, a first separator disposed on one surface of the first electrode, and a second separator disposed on one surface of the second electrode, wherein the first The electrode is characterized in that it has a plurality of first current collectors in which at least two or more sheets are stacked, and first electrode materials each formed on both surfaces of the plurality of first current collectors.

Here, the first current collector includes a plurality of first horizontal portions in which at least two or more sheets are spaced apart from each other in parallel; A connecting portion connecting one end of the plurality of first horizontal portions to one; And a second horizontal portion extending in a direction opposite to the first horizontal portion from the connection portion.

In this case, two to three first current collectors are vertically stacked, and the first electrode material is disposed between the two to three first current collectors.

One sheet of the first current collector and the first electrode material disposed on both surfaces of the first sheet of the first current collector form a sub-electrode.

In particular, it is preferable that the sub-electrode has a thickness of 0.5 to 2.0 mm.

Here, it is preferable that the first electrode is a cathode, and the second electrode is an anode.

The MR-type lithium primary battery with improved output characteristics according to the present invention applies a sheet method in which an electrode material is coated on the current collector, so that it is possible to form a cathode of uniform quality, as well as to enable automation. The castle also becomes excellent.

In addition, the MR type lithium primary battery with improved output characteristics according to the present invention has the effect of reducing electrode deviation and improving workability by changing the first electrode to a sheet method that coats powder instead of the conventional granule method. Can exert.

In particular, since the MR-type lithium primary battery with improved output characteristics according to the present invention can expand the specific surface area by applying a plurality of first current collectors stacked at least two sheets, both surfaces of the plurality of first current collectors It is possible to improve the electrical conductivity between the first electrode material each coated on.

In addition, the MR-type lithium primary battery with improved output characteristics according to the present invention optimizes the thickness of the cathode by applying a cathode in which two or more sub-electrodes of a sheet type coated with powder are stacked. By increasing the total input amount, it is possible to improve the output characteristics.

As a result, the MR-type lithium primary battery with improved output characteristics according to the present invention can improve performance in a high-rate pulse discharge environment by improving output characteristics, and reduce deviation and work when forming a cathode. The effect of improving sex can also be promoted.

1 is a perspective view showing a sectional view of an MR type lithium primary battery with improved output characteristics according to an embodiment of the present invention.
2 is a cross-sectional view illustrating an example of the first electrode of FIG. 1.
3 is a cross-sectional view showing another example of the first electrode of FIG. 1.
4 is a graph showing an evaluation result of output characteristics for Comparative Example 1. FIG.
5 is a graph showing the result of evaluating output characteristics for Example 1. FIG.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only this embodiment is to complete the disclosure of the present invention, and the general knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

Hereinafter, a detailed description will be given of an MR type lithium primary battery having improved output characteristics according to a preferred embodiment of the present invention with reference to the accompanying drawings.

1 is a perspective view showing a cutaway view of an MR type lithium primary battery with improved output characteristics according to an embodiment of the present invention.

Referring to FIG. 1, an MR type lithium primary battery 100 having improved output characteristics according to an exemplary embodiment of the present invention includes a case 110, a winding element 160, and a header 170.

The upper side of the case 110 is opened, and the electrolyte is accommodated therein. In this case, the case 110 may have a cylindrical shape in which the upper side is opened, or may be designed in a rectangular shape such as a rectangular parallelepiped or a hexagonal column. Stainless steel (SUS) may be used as the material of the case 110, but is not limited thereto.

The inside of the case 110 is impregnated with an electrolyte. In this case, the electrolyte solution may include a solute expressing the capacity of the winding element 160 and a solvent for dissolving the solute.

The solute of the electrolyte is 1-ethyl-3-methylimidazonium tetrafluoro-borate {1-ethyl-3-methylimidazolium tetrafluoro-borate (EMIBF ₄ )}, 1-ethyl-3-methylimidazonium bisimide {1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl)imide(EMITFSI)}, 1-butylpyridinium tetrafluoro-borate {1-butylpyridinium tetrafluoro-borate(BPBF ₄ )}, 1-ethyl-3methylimidazolium Hexafluoro-Forspacet {1-ethyl-3-methylimidazolium hexafluorophosphate (EMIPF ₆ )}, 1-butylpyridinium bis imide {1-buthylpyridinium bis (trifluoromethylsulfonyl) imide (BPTFSI)}, gallium chloride (GaCl ₃ ), At least one selected among aluminum chloride (AlCl ₃ ) may be used.

In addition, as a solvent for the electrolyte, propylene carbonate, ethylene carbonate, butylene carbonate, vinylene carbonate, vinyl ethylene carbonate, dimethyl carbonate, diethyl carbonate DiethylCarbonate), EthylMethylCarbonate, γ-Butyrolactone {γ-Butyrolactone(GBL)}, γ-Valerolactone {γ-Valerolactone(GVL)}, N-methyl-2-pyrrolidone {N- Methyl-2-Pyrrolidone(NMP)}, N,N-dimethyl formamide {N,N-Dimethyl Formamide(DMF)}, 1,3-mimethyl-2-imidazolidinone{1,3-Dimethyl-2 -Imidazolidinone(DMI)}, N,N Dimethylacetamide {N,N DimethylAcetamide(DMAC)}, Sulfolane, Dimethyl Sulfoxide, Acetonitorile, Propionitorile , Tetrahydrofuran (Tetrahydrofuran), thionyl chloride (SOCl ₂ ), sulfuryl chloride (SO ₂ Cl ₂ ) at least one selected from among may be used.

The winding element 160 is inserted into the case 110. The winding element 160 includes a first electrode 120, a second electrode 130, a first separator 140, and a second separator 150.

This winding element 160 is manufactured in a roll form by winding the first electrode 120, the second electrode 130, the first separator 140, and the second separator 150 with a winder. After that, it can be manufactured by attaching an adhesive tape (not shown) or the like around the roll.

The first electrode 120 includes a plurality of first current collectors in which at least two or more sheets are stacked, and first electrode materials respectively formed on both surfaces of the plurality of first current collectors. In addition, the second electrode 130 includes a second current collector and a second electrode material formed on both surfaces of the second current collector. Here, it is preferable that the first electrode 120 is a cathode, and the second electrode 140 is an anode.

Each of the first and second current collectors may be made of at least one material selected from nickel, stainless steel, titanium, tantalum, niobium, and aluminum. Metal foil may be used for each of the first and second current collectors, but in addition, a form having holes penetrating the front and rear surfaces such as etched metal foil, expanded metal, punched metal, net, foam, etc. may be used. .

Each of the first and second electrode materials may include activated carbon activated by steam activation, a conductive material, and a binder.

The first separator 150 is disposed on one surface of the first electrode 120, and the second separator 160 is disposed on one surface of the second electrode 140.

It is preferable that the first and second separation membranes 150 and 160 are formed of a material having heat resistance of 100°C or higher. To this end, the materials of each of the first and second separators 150 and 160 include glass fiber, polybutylene terephralate resin (PBT), polyphenylene sulfide (PPS), silicon dioxide (SiO ₂ ), and poly One or more selected from among ether ether ketones (PEEK) may be used.

The header 170 serves to cover and seal the upper side of the case 110. The header 170 may be bonded to the case 110 by spot welding, laser welding, or the like. The header 170 may be provided with an electrolyte injection hole (not shown). At this time, the winding element 160 is inserted and disposed inside the case 110 in which the upper side is opened, and then sealed by welding while covering the upper side of the case 110 with the header 170. Thereafter, the electrolyte is impregnated into the case 110 through the electrolyte injection port provided in the header 170, and finally, the sealing is performed by welding with a subball (not shown) as a finishing material.

The support 190 is disposed in the inner central portion of the case 110 and serves to stably support the winding element 160. The support 190 may be made of stainless steel, but is not limited thereto. At this time, the support body 190 may have a cylindrical shape, but this is exemplary and the shape may be variously changed.

The MR-type lithium primary battery with improved output characteristics according to the above-described embodiment of the present invention applies a powder-coated sheet-type cathode, but includes at least two sub-electrodes having a thickness of 0.5 to 2.0 mm. By using the stacked ones, it is possible to optimize the thickness of the cathode, and at the same time, it is possible to improve the output characteristics of the battery by increasing the input amount of the current collector.

This will be described in more detail below with reference to the accompanying drawings.

FIG. 2 is a cross-sectional view illustrating an example of the first electrode of FIG. 1, and FIG. 3 is a cross-sectional view illustrating another example of the first electrode of FIG. 1.

2 and 3, the first electrode 120 of the present invention includes a plurality of first current collectors 124 in which at least two or more sheets are stacked, and both sides of the plurality of first current collectors 124 It has a first electrode material 126 each formed on the surface.

At this time, the first current collector 124 includes a plurality of first horizontal portions 121 in which at least two or more sheets are spaced apart from each other in parallel, and a connection portion connecting one end of the plurality of first horizontal portions 121 into one ( 122 and a second horizontal portion 123 extending in a direction opposite to the first horizontal portion 121 from the connection portion 122.

Here, the second horizontal portion 123 may be disposed at the central portion of the first current collector 124, but this is exemplary and its position may be variously applied. That is, the second horizontal portion 123 may be disposed on the upper or lower portion of the first current collector 124.

In particular, it is preferable that 2 to 3 sheets of the first current collector 124 are vertically stacked, and the first electrode material 126 is disposed between the 2 to 3 sheets of the first current collector 124, respectively.

At this time, one sheet of the first current collector 124 and the first electrode materials 126 disposed on both surfaces of the first sheet 124 form the sub-electrode 125.

Accordingly, the first electrode 120 of the present invention has a structure in which at least two or more sub-electrodes 125 are vertically stacked.

Here, in FIG. 2, a structure in which two first current collectors 124 and two sub-electrodes 125 coated with a first electrode material 126 are stacked on both surfaces of the two first current collectors 124 are stacked. Indicated.

3, a structure in which three first current collectors 124 and three sub-electrodes 125 coated with a first electrode material 126 are stacked on both surfaces of the three first current collectors 124 Indicated.

It is preferable that the sub-electrode 125 has a thickness of 0.5 to 2.0 mm. When the thickness of the sub-electrode 125 is less than 0.5 mm, it may be difficult to properly exhibit an effect of improving battery output due to a decrease in the thickness of the first current collector 124. Conversely, when the thickness of the sub-electrode 125 exceeds 2.0 mm, winding may be difficult due to a decrease in elongation due to excessive thickness design.

In the conventional MR type lithium primary battery, in order to reduce the area of the electrode and maintain the input amount of the cathode, the thickness of the cathode is formed to be thicker than that of the HR type lithium primary battery. Accordingly, conventionally, when manufacturing a cathode, a process of forming a cathode and molding it by a granulation method is applied.In this case, it is disadvantageous in terms of the uniformity of the cathode, and workability is also It wasn't good.

On the other hand, the MR-type lithium primary battery with improved output characteristics according to an embodiment of the present invention applies a sheet method in which an electrode material is coated on a current collector, so it is not only possible to form a cathode of uniform quality, Because automation is possible, workability is also excellent.

In addition, the MR-type lithium primary battery with improved output characteristics according to an embodiment of the present invention changes the first electrode to a powder-coated sheet method instead of the conventional granule method, thereby reducing electrode deviation and working It can exert a sex improvement effect.

In particular, the MR-type lithium primary battery with improved output characteristics according to an exemplary embodiment of the present invention can expand its specific surface area by applying a plurality of first current collectors in which at least two or more sheets are stacked, so that a plurality of first current collectors It is possible to improve the electrical conductivity between the first electrode material each coated on both surfaces of the.

In addition, the MR-type lithium primary battery with improved output characteristics according to an embodiment of the present invention optimizes the thickness of the cathode by applying a cathode in which two or more sheet-type sub-electrodes coated with powder are stacked. At the same time, it is possible to improve the output characteristics by increasing the input amount of the current collector.

As a result, the MR-type lithium primary battery with improved output characteristics according to an exemplary embodiment of the present invention can improve performance in a high rate pulse discharge environment by improving output characteristics, and variations in formation of a cathode It is also possible to achieve reduction and workability improvement effects.

Example

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention and cannot be construed as limiting the present invention in any sense.

Contents not described herein can be sufficiently technically inferred by those skilled in the art, and thus description thereof will be omitted.

1. Battery manufacturing

Example One

A winding element was manufactured by winding the electrode and the separator with a winder.

Next, after the winding element was inserted into the case with the upper side open, the header was inserted into the case and sealed.

Next, after welding the case and the header through laser welding, the electrolyte is injected into the case through the electrolyte injection port provided on one side of the header, and the electrolyte injection port is finally sealed by laser welding with a susball to form a DD size MR. A lithium primary battery was prepared.

Here, a stack of two 1.4 mm thick sub-electrodes was applied as a cathode.

Comparative example One

A MR lithium primary battery of DD size was manufactured in the same manner as in Example 1, except that a cathode having a thickness of 3.7 mm manufactured by a granule molding method was applied.

2. Evaluation of battery output characteristics

Table 1 shows the battery output characteristics evaluation results for the MR lithium primary batteries prepared according to Example 1 and Comparative Example 1. In addition, FIG. 4 is a graph showing the result of evaluation of output characteristics for Comparative Example 1, and FIG. 5 is a graph showing the result of evaluation of output characteristics for Example 1. In this case, FIGS. 4 and 5 show the results measured under the 3A pulse condition at 165°C.

1) Discharge condition

3A pulse (3.0A,0.2s/0.5A,0.8s/3.0A,0.2s/0.5A,9.3s), after discharging at 25℃ for 8 hours, rest and temperature rise for 1 hour, at discharge temperature Discharge proceeded to 2.5V.

[Table 1]

As shown in Tables 1, 4, and 5, as a result of checking the battery output characteristics, the MR lithium primary battery manufactured according to Example 1 was compared with the MR lithium primary battery manufactured according to Comparative Example 1 in continuous discharge for each temperature range. It can be seen that the performance is equivalent or higher.

In addition, the MR lithium primary battery manufactured according to Example 1 has a capacity of about 15% or more compared to the MR lithium primary battery manufactured according to Comparative Example 1 when discharging under the 3A pulse condition closest to the actual use condition. It increased, and the deviation also decreased.

This is because Example 1 in which a sheet-type cathode applied with a powder coating process instead of granule molding was applied has better uniformity and electrical conductivity, and the current collector became closer to the surface of the cathode, It is judged that the cause is that the input amount of the current collector is also increased and the current flows smoothly compared to Comparative Example 1.

That is, the MR lithium primary battery manufactured according to Comparative Example 1 had a current collector input amount of 68.9 cm ² based on the area, but the MR lithium primary battery manufactured according to Example 1 was 153.4 cm ^{2, which} was about 2.23 times that of Comparative Example 1. It is believed to be due to the increase.

In the above, the embodiments of the present invention have been described mainly, but various changes or modifications can be made at the level of those of ordinary skill in the art to which the present invention pertains. Such changes and modifications can be said to belong to the present invention as long as they do not depart from the scope of the technical idea provided by the present invention. Therefore, the scope of the present invention should be determined by the claims set forth below.

100: lithium primary battery 110: case
120: first electrode 121: first horizontal portion of the first current collector
122: connection portion of the first current collector 123: second horizontal portion of the first current collector
124: first current collector 125: sub electrode
126: first electrode material 130: second electrode
140: first separation membrane 150: second separation membrane
160: winding element 170: header
180: header pin 190: support

Claims (6)

A case having an upper side open and accommodating an electrolyte therein;
A winding element inserted into the case; And
A header covering an upper side of the case into which the winding element is inserted; Including,
The winding element includes a first electrode and a second electrode, a first separator disposed on one surface of the first electrode, and a second separator disposed on one surface of the second electrode,
The first electrode has a plurality of first current collectors in which at least two or more sheets are stacked, and first electrode materials respectively formed on both surfaces of the plurality of first current collectors,
The first current collector includes a plurality of first horizontal portions in which at least two or more sheets are spaced apart from each other in parallel; A connection part connecting one end of the plurality of first horizontal parts to one; And a second horizontal portion extending in a direction opposite to the first horizontal portion from the connection portion,
The MR type lithium primary battery with improved output characteristics, wherein the first electrode is a cathode and the second electrode is an anode.
delete The method of claim 1,
The first current collector
2 to 3 sheets are vertically stacked, and the first electrode material is disposed between the 2 to 3 first current collectors. The MR type lithium primary battery with improved output characteristics.
The method of claim 3,
One sheet of the first current collector,
The MR type lithium primary battery with improved output characteristics, characterized in that the first electrode material disposed on both surfaces of the one first current collector forms a sub-electrode.
The method of claim 4,
The sub electrode is
MR type lithium primary battery with improved output characteristics, characterized in that it has a thickness of 0.5 ~ 2.0mm.
delete

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