KR20200031728A - Moderate type lithium primary battery with excellent output characteristic - Google Patents

Abstract

Disclosed is an MR type lithium primary battery with improved output characteristics, which optimizes the thickness of a cathode by applying the cathode where at least two sheets of powder-coated sheet-type sub-electrodes are stacked while improving output characteristics by increasing the input amount of current collectors. According to the present invention, the MR type lithium primary battery with improved output characteristics comprises: a case which has an upper side opened and accommodates an electrolyte solution therein; a winding element which is inserted into the case; and a header which covers the upper side of the case into which the winding element is inserted. 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 on which at least two or more sheets are stacked, and first electrode materials which are formed on both surfaces of the plurality of first current collectors, respectively.

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 having improved output characteristics, and more specifically, to apply a cathode coated with at least two or more sheet-type sub-electrodes coated with powder to form a thickness of the cathode. The present invention relates to an MR type lithium primary battery having improved output characteristics by optimizing and increasing an input amount of a 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 because it can be manufactured in a compact manner and is easily portable.

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

To improve this, there is an increasing demand for MR (moderate rate) batteries that secure safety by reducing the area of electrodes compared to HR (high rate) batteries so that currents do not flow above a certain level even when internal and external short circuits occur.

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

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

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

The object of the present invention is to optimize the thickness of the cathode (Cathode) by applying at least two or more sheets of powder-coated sheet-type sub-electrodes stacked at the same time, and at the same time increase the input capacity of the current collector. It is to provide an improved MR type lithium primary battery.

An 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 receiving an electrolyte therein; A winding element inserted into the case; And a header covering the upper side of the case in which the winding element is inserted. The winding element includes a first electrode and a second electrode, a first separation layer disposed on one surface of the first electrode, and a second separation layer disposed on one surface of the second electrode. The electrode is characterized in that it has a plurality of first current collectors on 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.

Here, the first current collector may include a plurality of first horizontal portions having at least two or more spaced apart parallel to each other; 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 connecting portion.

At this time, 2 to 3 sheets of the first current collector are vertically stacked, and the first electrode material is disposed between the 2 to 3 first current collectors.

One sheet of the first current collector and the first electrode material disposed on both surfaces of the first current collector of the one sheet 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.

Since the MR type lithium primary battery with improved output characteristics according to the present invention applies a sheet method of coating an electrode material on a current collector, it is possible not only to form a cathode of uniform quality, but also to automate and work. The castle is also excellent.

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

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

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 applied. The output characteristics can be improved by increasing the total input amount.

As a result, the MR type lithium primary battery with improved output characteristics according to the present invention has improved output characteristics, thereby improving performance in a high rate pulse discharge environment, and reducing and working on deviations when forming a cathode. Sex improvement effect can also be promoted.

1 is a perspective view showing a cut surface 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 showing 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 the output characteristic evaluation results for Comparative Example 1.
5 is a graph showing the output characteristic evaluation results for Example 1.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to 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 various different forms, and only the present embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention pertains. It is provided to fully inform the holder of the scope of the invention, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same components throughout the specification.

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

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

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

The case 110 has an upper side open and accommodates an electrolyte solution therein. At this time, 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 electrolyte is impregnated inside the case 110. At this time, the electrolytic 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-3methylimidizonium Hexafluoro-phosphatate {1-ethyl-3-methylimidazolium hexafluorophosphate (EMIPF ₆ )}, 1-butylpyridinium bisimide (1-buthylpyridinium bis (trifluoromethylsulfonyl) imide (BPTFSI)), gallium chloride (GaCl ₃ ), One or more selected from aluminum chloride (AlCl ₃ ) may be used.

And, as the solvent of the electrolyte, propylene carbonate (PropyleneCarbonate), ethylene carbonate (EthyleneCarbonate), butylene carbonate (ButyleneCarbonate), vinylene carbonate (VinyleneCarbonate), vinyl ethylene carbonate (VinylEthyleneCarbonate), dimethyl carbonate (DimethylCarbonate), diethyl carbonate ( DiethylCarbonate), EthylMethylCarbonate, γ-butylrolactone {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-methyl-2-imidazolidinone {1,3-Dimethyl-2 -Imidazolidinone (DMI)}, N, N dimethylacetamide {N, N DimethylAcetamide (DMAC)}, sulfolane, dimethyl sulfoxide, acetonitorile, propiononitorile , Tetrahydrofuran, Thionyl Chloride (SOCl ₂ ), Sulfuryl Chloride (SO ₂ Cl ₂ ) One or more selected among them may be used.

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

The 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. Then, it can be manufactured by attaching an adhesive tape (not shown) or the like around the roll.

The first electrode 120 has a plurality of first current collectors on which at least two or more sheets are stacked, and a first electrode material respectively formed on both surfaces of the plurality of first current collectors. In addition, the second electrode 130 has a second current collector and a second electrode material formed on both surfaces of the second current collector. Here, the first electrode 120 is a cathode (Cathode), the second electrode 140 is preferably an anode (Anode).

Each of the first and second current collectors may be made of one or more materials 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 shape having holes through the front and back surfaces such as etched metal foil, expanded metal, punching metal, net, foam, or the like 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.

The first and second separators 150 and 160 are preferably formed of a material having heat resistance of 100 ° C or higher. To this end, the first and second separators 150 and 160 are made of glass fiber, polybutylene terephthalate resin (PBT), polyphenylene sulfide (PPS), silicon dioxide (SiO ₂ ), and poly One or more selected from 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 joined to the case 110 by spot welding or laser welding. The header 170 may be provided with an electrolyte injection port (not shown). At this time, after the winding element 160 is inserted and disposed inside the case 110 in which the upper side is opened, the upper side of the case 110 is welded and sealed in a state covered with a header 170. Thereafter, the electrolyte is impregnated into the inside of the case 110 through the electrolyte injection hole provided in the header 170, and finally sealed by welding with a sub-ball (not shown), which is 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 190 may have a cylindrical shape, but this is exemplary and the shape may be variously changed.

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

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

2 is a cross-sectional view showing an example of the first electrode of FIG. 1, and FIG. 3 is a cross-sectional view showing 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 on 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 formed on each surface.

At this time, the first current collector 124 has a plurality of first horizontal portions 121, at least two of which are spaced parallel to each other, and a connecting portion connecting one end of the plurality of first horizontal portions 121 to 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 in 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, the first current collector 124, it is preferable that 2 to 3 sheets are vertically stacked, and that the first electrode material 126 is disposed between the 2 to 3 first collectors 124, respectively.

At this time, one sheet of the first current collector 124 and the first electrode material 126 disposed on both surfaces of the first sheet of current collector 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, two first electrodes 124 and two sub-electrodes 125 coated with the first electrode material 126 on both surfaces of the first collector 124 are stacked. Shown.

And, in FIG. 3, three first electrodes 124 and three sub-electrodes 125 coated with first electrode materials 126 on both surfaces of the first collectors 124 are stacked. Shown.

The sub-electrodes 125 preferably have 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 a battery power improvement effect 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 reduction 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 thicker than that of the HR type lithium primary battery. Accordingly, conventionally, when manufacturing a cathode, a process of forming a cathode and forming it by a granulation method is applied. In this case, it is disadvantageous in terms of uniformity of the cathode and workability It was not good.

On the other hand, the MR type lithium primary battery with improved output characteristics according to an embodiment of the present invention is not only capable of forming a cathode of uniform quality because a sheet method of coating an electrode material on a current collector is applied, Automation is possible, and workability is also excellent.

In addition, the MR type lithium primary battery with improved output characteristics according to an embodiment of the present invention reduces the deviation of the electrode and works by changing the first electrode to a sheet method of coating powder instead of the existing granule method. It can exert a sex improvement effect.

In particular, in the MR type lithium primary battery with improved output characteristics according to an embodiment of the present invention, since the specific surface area can be expanded by applying a plurality of first current collectors stacked with at least two or more sheets, the plurality of first current collectors It is possible to improve the electrical conductivity between the first electrode material that is 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 sub-electrodes of sheet type coated with powder are laminated. 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 embodiment of the present invention has improved output characteristics, thereby improving performance in a high-rate pulse discharge environment, and deviation in the formation of a cathode. The effect of reducing and improving workability can also be achieved.

Example

Hereinafter, the configuration and operation of the present invention through a preferred embodiment of the present invention will be described in more detail. However, this is provided as a preferred example of the present invention and cannot be interpreted as limiting the present invention by any means.

The contents not described here will be sufficiently technically inferred by those skilled in the art, and thus the description thereof will be omitted.

1. Battery manufacturing

Example  One

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

Next, after the winding element was inserted into the case where the upper side was opened, 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 inside of the case through the electrolyte injection hole provided on one side of the header, and the electrolyte injection hole is finally sealed by laser welding with a susball, so that the MR of DD size A lithium primary battery was prepared.

Here, two 1.4 mm thick sub-electrodes were stacked with a cathode.

Comparative example  One

A DD size MR lithium primary battery 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. Battery output characteristics evaluation

Table 1 shows the results of evaluation of the battery output characteristics for the MR lithium primary battery prepared according to Example 1 and Comparative Example 1. 4 is a graph showing the output characteristic evaluation results for Comparative Example 1, and FIG. 5 is a graph showing the output characteristic evaluation results for Example 1. At this time, FIGS. 4 and 5 show the results of measurement under 3A pulse conditions at 165 ° C.

1) Discharge conditions

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

[Table 1]

As shown in Table 1, FIGS. 4 and 5, as a result of checking the battery output characteristics, the MR lithium primary battery manufactured according to Example 1 and the MR lithium primary battery produced according to Comparative Example 1 in continuous discharge for each temperature range It turns out that it shows the performance equivalent or more.

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 produced according to Comparative Example 1 when discharged under a 3A pulse condition closest to the actual use condition. It increased, and the deviation was also reduced.

This is in Example 1 to which a sheet-type cathode to which a coating process using powder was applied instead of granule molding was applied, the uniformity and electrical conductivity were better, and the current collector was closer to the surface side of the cathode, It was determined that the current input was also increased and the current flow was smooth compared to Comparative Example 1.

In other words, the MR lithium primary battery prepared according to Comparative Example 1 was 68.9 cm ² based on the area of the current collector, but the MR lithium primary battery prepared according to Example 1 was 153.4 cm ^{2, which} was about 2.23 times that of Comparative Example 1 It seems to be due to the increase.

In the above, the embodiments of the present invention have been mainly described, but various changes or modifications can be made at the level of a person skilled in the art to which the present invention pertains. Such changes and modifications can be said to belong to the present invention without departing from the scope of the technical idea provided by the present invention. Therefore, the scope of the present invention should be judged by the claims set forth below.

100: lithium primary battery 110: case
120: first electrode 121: a 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 separator 150: second separator
160: winding element 170: header
180: header pin 190: support

Claims (6)

A case in which the upper side is opened and accommodates an electrolyte solution therein;
A winding element inserted into the case; And
A header covering an upper side of the case in which the winding element is inserted; It includes,
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 is a MR type with improved output characteristics, characterized in that it has a plurality of first current collectors on 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. Lithium primary battery.
According to claim 1,
The first current collector
A plurality of first horizontal parts at least two 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 connecting portion;
MR type lithium primary battery having improved output characteristics, comprising a.
According to claim 2,
The first current collector
MR type lithium primary battery with improved output characteristics, characterized in that 2 to 3 sheets are vertically stacked and the first electrode material is disposed between the 2 to 3 first collectors.
According to claim 3,
One sheet of the first current collector,
An MR type lithium primary battery with improved output characteristics, characterized in that the first electrode material disposed on both surfaces of the first collector of the first sheet forms a sub-electrode.
According to claim 4,
The sub-electrode
MR type lithium primary battery with improved output characteristics, which has a thickness of 0.5 to 2.0 mm.
According to claim 1,
The first electrode is a cathode (Cathode),
The second electrode is an anode (Anode) characterized in that the output characteristics are improved MR type lithium primary battery.

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