KR20240112126A - Electrode structure with active layer of vertical direction - Google Patents

Abstract

The present invention relates to an electrode structure, and more specifically, to a battery using a separator, ion exchange membrane, or solid electrolyte, which has the effect of increasing capacity per unit area.

Description

Electrode structure having a vertical active layer {ELECTRODE STRUCTURE WITH ACTIVE LAYER OF VERTICAL DIRECTION}

The present invention relates to an electrode structure for a battery, and more specifically, to a cathode structure for a battery to which a separator, ion exchange membrane, or solid electrolyte is applied.

When one electrode has sufficient capacity, such as the seawater anode of a seawater battery or the oxygen anode of a metal-air battery, the total battery capacity is determined by the capacity of the remaining electrode. These systems require a separate electrode structure with a specific thickness using a solid electrolyte or membrane. Since electrodes with a structure such as the jelly roll electrode commercialized in existing lithium-ion batteries cannot be used, one electrode itself has a high A structure that can implement capacity is needed.

The existing electrode structure to obtain high capacity per area can be manufactured by increasing the loading level of the active material or thickly laminating the electrode on the support, but the thickened electrode structure results in low ion diffusion and low electronic conductivity within the electrode. As a result, the capacity development rate is low. In addition, various studies are being developed to increase the capacity per area of the electrode, but it is difficult to find cases of achieving a high capacity per area of ~20 mAh/cm ² or more, and the thickness of the electrode cannot be utilized and is accompanied by difficulties in manufacturing.

Korean Patent Publication No. 2022-0136147

The present invention allows the capacity development rate to be increased through efficient ion and electron movement even in thick electrodes.

In order to achieve the above object, an electrode structure according to one form of the present invention includes a planar member that separates the anode and the cathode; and an electrode whose active layer surface is disposed perpendicular to one surface of the planar member.

The planar member may be a solid electrolyte.

The solid electrolyte may be LISICON or NASICON.

The electrode is a long member, and the long member may have a structural shape such that the surface of the active layer is arranged perpendicular to one surface of the planar member.

The electrode may have the active layer formed on one or both sides of the current collector.

The electrode may have a spiral shape or a zig-zag shape of the length member.

The current collector may be copper or aluminum.

The active layer may be graphite, hard carbon, phosphorus, tin, or antimony.

The present invention has the effect of increasing the capacity per unit area in batteries using a separator, ion exchange membrane, or solid electrolyte.

Figure 1a shows a cross-section of an electrode structure according to an embodiment of the present invention.
Figure 1b is a schematic diagram of an electrode structure according to an embodiment of the present invention applied as a cathode (anode) in a battery.
Figure 2 shows a longitudinal cross-section of an electrode of an electrode structure according to an embodiment of the present invention.
3A and 3B show an example of an electrode structure according to an embodiment of the present invention.
FIG. 4A shows a front view of the electrode in the direction of the planar member in the electrode structure shown in FIG. 3A.
Figure 4b shows a front view of the electrode in the direction of the planar member in the electrode structure shown in Figure 3b.
Figure 5 shows a front view of an electrode of an electrode structure according to an embodiment of the present invention.
Figure 6 shows the configuration of a Na metal half-cell to which an electrode structure according to an embodiment of the present invention is applied.
Figure 7 shows capacity development result data depending on the electrode area of the electrode structure according to an embodiment of the present invention.
Figure 8 shows capacity development result data according to the electrode length of the electrode structure according to an embodiment of the present invention.
Figure 9 shows capacity development result data according to the active layer loading amount of the electrode structure according to an embodiment of the present invention.
Figure 10 shows capacity development result data according to the electrode shape of the electrode structure according to an embodiment of the present invention.
Figure 11 shows a configuration diagram of an electrode cell manufactured using an electrode structure according to an embodiment of the present invention.
Figure 12 shows the results of a life test in a full-cell seawater battery of the electrode structure according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement it. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

Figure 1a shows a cross-section of the electrode structure 10 according to an embodiment of the present invention.

Referring to FIG. 1A, the electrode structure 10 according to an embodiment of the present invention includes a planar member 100; and an electrode 200, and more specifically, a planar member 100; and an electrode 200 in which the surface of the active layer 220 is arranged perpendicularly to one surface of the solid electrolyte 100.

A battery according to an embodiment of the present invention is a lithium-ion battery (LIB), an all-solid-state battery, having an electrode area divided into an anode and a cathode by a separator, an ion-exchange membrane, or a solid electrolyte. It may be -air battery, Na-air battery, seawater battery, desalination battery, etc., but is not limited thereto.

The planar member 100 separates the anode and cathode of an electrode in a battery. The planar member 100 may be a planar member with a predetermined area, and physically separates the anode and cathode of the electrode. It may be to do so.

The planar member 100 may be a separator, an ion-exchange membrane, or a solid electrolyte, and may be any member that physically separates the anode and cathode of an electrode.

The solid electrolyte may be a cation exchange membrane, and the cation exchange membrane may be a lithium (Li) ion exchange membrane or a sodium (Na) ion exchange membrane. More specifically, the solid electrolyte is LISICON (Li _2+2x Zn _1-x GeO ₄ , 0<x<1) or NASICON (Na _1+x Zr ₂ Si _x P _3-x O ₁₂ , 0<x<3) It can be.

Figure 1b is a schematic diagram of the electrode structure 10 according to an embodiment of the present invention applied as a cathode (anode) in a battery.

Referring to FIG. 1B, the electrode structure 10 according to an embodiment of the present invention may be a cathode structure and includes a planar member 100; electrode 200; and an opposite electrode 300, wherein the electrode 200 may be a cathode (anode) and the opposite electrode 300 may be an anode (cathode).

1A and 1B show that the unit electrodes 200a and 200b constituting the electrode 200 in the electrode structure 10 are not vertically stacked, but the electrode 200 of the long member, which will be described later, is configured in a spiral or zigzag shape. A cross section of the electrode 200 is shown, and the electrode 200 consists of unit electrodes 200a and 200b that are all continuous as a single structure (see FIGS. 2 to 4B described later).

Figure 2 shows a longitudinal cross-section of the electrode 200 of the electrode structure 10 according to an embodiment of the present invention.

Referring to FIG. 2, the electrode 200 may be a long member, and the electrode 200 may be formed on one side ((a) of FIG. 2) or both sides ((b) of FIG. 2) on the current collector 210 of the long member. The active layers 220, 220a, and 220b may be formed.

Referring to the inset of FIG. 1A and FIG. 2, the electrode 200 is a long member, and the long member is arranged so that the surfaces of the active layers 220, 220a, 220b are perpendicular to one surface of the planar member 100. It may have a structural shape. More specifically, the surface of the active layer 220 of the electrode 200 is not arranged parallel to one surface of the planar member 100, but is arranged in a perpendicular direction, and as a result, the surface of the active layer 220 of the electrode 200 is arranged in a perpendicular direction with respect to one surface of the planar member 100. The active layer (220) of (200) may have a structure in which the surface is arranged vertically.

FIGS. 3A and 3B show an example of an electrode structure according to an embodiment of the present invention. FIG. 3A shows an electrode structure having a spiral-shaped electrode, and FIG. 3B shows a zigzag-shaped electrode. It shows an electrode structure having a . FIG. 4A is a front view of the electrode 200 in the direction of the planar member 100 in the electrode structure shown in FIG. 3A, and FIG. 4B is a front view of the electrode 200 in the direction of the planar member 100 in the electrode structure shown in FIG. 3B. This shows a front view of the electrode 200.

Referring to FIGS. 3A and 3B, the electrode 200 may have a spiral shape (FIG. 3A) or a zig-zag shape (FIG. 3B), and more specifically, a spiral shape from the length member. ) The electrode 200 may be configured in a shape, or the electrode 200 may be configured in a zigzag shape from the length member.

More specifically, referring to FIG. 4A, the electrode 200 may have a spiral shape (FIG. 3A), and is composed of a spiral-shaped electrode 200 of the electrode 200 of a long member, so that the electrode 200 In the structure 10, the surface of the active layer 220 of the electrode 200 may be arranged perpendicular to one surface of the planar member 100. The electrode 200 having a spiral shape in FIGS. 3A and 4A has unit electrodes 200a and 200b continuous as a single length member, and more specifically, one unit electrode 200a and the other unit electrode 200b. is a single electrode 200 along a single length member, and the electrode 200 may have a spiral shape such that one unit electrode 200a and the other unit electrode 200b are spaced apart at a predetermined interval. At this time, the gap between one unit electrode 200a and the other unit electrode 200b is the total length (L, see FIG. 5) of the electrode 200 of the long member, and the overall diameter when the electrode 200 is configured in a spiral shape. ( Ф ) and may be calculated through the number of unit electrodes 200a and 200b formed in the spiral-shaped electrode 200.

In addition, more specifically, referring to FIG. 4b, the electrode 200 may have a zigzag shape (FIG. 3b), and the electrode 200 of the long member has a zigzag shape. By configuring the electrode structure 10, the surface of the active layer 220 of the electrode 200 may be arranged perpendicular to one surface of the planar member 100. The electrode 200 having a zigzag shape in FIGS. 4A and 4A has unit electrodes 200a and 200b continuous as a single length member, and more specifically, one unit electrode 200a and the other unit electrode 200b. is a single electrode 200 along a single length member, and the electrode 200 may have a zigzag shape so that one unit electrode 200a and the other unit electrode 200b are spaced apart at a predetermined interval. At this time, the gap between one unit electrode 200a and the other unit electrode 200b is the total length (L, see FIG. 5) of the electrode 200 of the length member, the unit when the electrode 200 is configured in a zigzag shape. It may be calculated through the total height (H) of the electrode 200 in the direction in which the electrodes 200a and 200b are formed and the number of unit electrodes 200a and 200b formed in the zigzag-shaped electrode 200.

Figure 5 shows a front view of the electrode 200 of the electrode structure 10 according to an embodiment of the present invention.

Referring to FIG. 5, the electrode 200 is a long member and may have a predetermined length (L) and a predetermined area (W). The length (L) may be 12 to 60 cm, and the area (W ) may be 2 to 4 mm.

The current collector 210 may be an electrode substrate of a length member, and the current collector 210 may be copper or aluminum.

The electrode 200 may be a cathode, and the active layer 220 may be a cathode active material of graphite, hard carbon, phosphorus, tin, or antimony.

The present invention is explained in more detail through the following examples. The following examples are examples of the present invention and do not limit the scope of the present invention.

Manufacturing example. Manufacturing of long member electrodes (cathode)

In manufacturing the electrode 200 in the present invention, copper (Cu foil) is used as a current collector (electrode base material) of a length member having the length and width shown in Table 1 below, and an active layer is applied to one or both sides of the current collector. Hard carbon (mPAC Hard carbon, Aekyung Petrochemical, d50 particle size 8 μm) was used as the main material, and the active layer composition consisted of hard carbon powder: PVDF (Polyvinylidene fluoride): Super P (Carbon black) at 90 wt%. : 9 wt% : After preparing 100g of the active layer mixture composed of 1 wt%, 100g of NMP (N-Methyl-2-pyrrolidone) solvent was added to the prepared active layer mixture to produce an active layer in the form of a slurry, then 7 mg/cm One or both sides of the current collector were coated at a loading level of ² , and after coating was dried at 80°C for 12 hours (hr) to evaporate all NMP solvent, the coated active layer was formed to a thickness of 50 to 100 ㎛ using a roll press. By pressing, the electrode 200 of the length member according to Table 1 below was manufactured.

Length (L) Area (W) Active layer coated surface Hard carbon coating amount Manufacturing Example 1 12cm 2mm One side (one side) 18mg Production example 2 12cm 3mm One side (one side) 27mg Production example 3 12cm 4mm One side (one side) 36 mg Production example 4 36cm 3mm One side (one side) 81mg Production example 5 12cm 3mm both sides 54mg Production example 6 60cm 3mm both sides 270mg Production example 7 140cm 3mm both sides 630mg

Example 1. Spiral electrode and electrode structure (cathode structure)

As shown in FIGS. 3A and 4A, the electrode of the long member manufactured in the above production example was wound in a spiral shape to manufacture a spiral electrode with a diameter of 16 Ф (16 mm) (area of the spiral shape: 2.01 cm ² ), and the solid Using NASICON as an electrolyte, the electrode structure (cathode structure) of the solid battery was applied so that the active layer of the electrode was oriented perpendicular to one side of NASICON.

Example 2. Zig-zag electrode and electrode structure (cathode structure)

As shown in FIGS. 3B and 4B, the electrode of the length member manufactured in the above production example was folded in a zigzag fashion to a length of 0.5cm/1cm/1.5cm//1cm/0.5cm (unit electrode) to manufacture a zigzag electrode. Using NASICON as a solid electrolyte, an electrode structure (cathode structure) was applied so that the active layer of the electrode was oriented perpendicular to one side of NASICON.

Preparation Example 1. Preparation of Na Metal half-cell

As shown in the schematic diagram shown in FIG. 6, the electrode structure manufactured according to the above Preparation Examples and Examples 1 and 2 was formed into a Na metal helf-cell (working electrode (WE): a spiral electrode or zigzag electrode according to the Preparation Examples and Examples. type electrode, reference electrode (RE): Na metal, counter electrode (CE): same as the reference electrode, solid electrolyte: NASICON) were constructed, and the following experimental example was performed. The schematic diagram in FIG. 6 shows a lower cell cap (Bottom), a spacer, a spiral electrode or zigzag electrode 200, a solid electrolyte (NASICON) 100, a separator, Na metal, and a spacer. , spring, and upper cell cap.

Experimental Example 1. Comparison of capacity according to electrode width

The electrode structure (spiral electrode) of Example 1 manufactured using the electrodes of Preparation Examples 1 to 3 was manufactured with the Na metal half-cell in Preparation Example 1, and capacity development was confirmed, and the confirmation results are shown in Figure 7 It is shown in . In FIG. 7, the electrode of Preparation Example 1 is indicated by “2mm”, the electrode of Preparation Example 2 is indicated by “3mm”, and the electrode of Preparation Example 3 is indicated by “4mm”.

Referring to (a) of FIG. 7, it can be seen that as the area of the electrode increases, the total hard carbon material content increases and the areal capacity increases accordingly. Referring to (b) of FIG. 7, it can be seen that all electrodes of Preparation Examples 1 to 3 are expressed close to 250 mAh/g, which is the specific capacity of general hard carbon, and the electrodes with a width of 2 mm (manufactured In Example 1), a lower specific capacity was observed compared to the electrodes of 3 mm (Preparation Example 2) and 4 mm (Preparation Example 3).

Experimental Example 2. Comparison of capacity according to electrode length

For the electrode structure (spiral electrode) of Example 1 manufactured using the electrode of Preparation Example 2 (length: 12 cm) and the electrode of Preparation Example 4 (length: 36 cm), the Na metal half- Cells were manufactured to confirm capacity development, and the confirmation results are shown in Figure 8. In FIG. 8, the electrode of Preparation Example 2 is indicated as “12cm”, and the electrode of Preparation Example 4 is indicated as “36cm”.

Referring to Figure 8, it can be seen that as the length increases, the total hard carbon material content increases and the areal capacity increases accordingly.

Experimental Example 3. Comparison of capacity according to active layer loading

Electrode of Preparation Example 2 (length: 12 cm, one side of active layer), electrode of Preparation Example 5 (length: 12 cm, both sides of active layer), electrode of Preparation Example 6 (length: 60 cm, both sides of active layer), and electrode of Preparation Example 7. (Length: 140 cm, both sides of active layer) The electrode structure (spiral electrode) of Example 1 was manufactured using the Na metal half-cell in Preparation Example 1, and the capacity development was confirmed, and the confirmation results were It is shown in Figure 9. In Figure 9, the electrode of Preparation Example 2 is “12cm”, the electrode of Preparation Example 5 is “Double side 12cm”, the electrode of Preparation Example 6 is “Double side 60cm”, and the electrode of Preparation Example 7 is “Double side 140 cm”. It is indicated as .

Referring to FIG. 9, it was confirmed that the longer the length of the electrode and the thicker the thickness, the more area capacity was developed. When confirmed through the electrode of Preparation Example 6 (both sides of the active layer), it was about ~21 mAh/cm. It can be confirmed that an areal capacity of ² is expressed, and when confirmed through the electrode (both sides of the active layer) of Preparation Example 7, it is confirmed that an areal capacity of about ~66 mAh/cm ² can be expressed. did.

Experimental Example 4. Verification of electrode capacity expression by electrode type

The electrode structure of Example 2, which was manufactured using the electrode of Preparation Example 3, was manufactured with the Na metal half-cell of Preparation Example 1, and the expression of specific capacitance was confirmed. The confirmation results are shown in Figure 10. It is shown in . In Figure 10, the control example was compared with the comparative example (a general disk-shaped electrode having the same active area as the zigzag electrode in Example 2).

Referring to FIG. 10, it can be seen that capacity development is also achieved in the cathode structure using the zigzag electrode (Example 2).

Experimental Example 5. Seawater battery full-cell evaluation

For the electrode structure of Example 1 manufactured using the electrode of Preparation Example 2, an electrode cell (bottom, spacer, spiral electrode 200, solid electrolyte 100) is used as shown in FIG. 11. ) was manufactured, and a lifespan test was performed on a full-cell seawater battery consisting of the spiral electrode in Example 1 as a cathode, NASICON as a solid electrolyte, and seawater as an anode (number of cycles: 1 ^st , 2 ^nd , 10 ^th , 20 ^th ). was performed, and the results are shown in Figure 12.

Referring to FIG. 12, there was no decrease in capacity even after driving for more than 20 cycles ( ^20th ).

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims are also possible. falls within the scope of rights.

10: electrode structure
100: planar member
200: electrode
300: Opposite electrode

Claims (8)

A planar member separating the anode and cathode; and
Comprising an electrode whose active layer surface is disposed perpendicular to one surface of the planar member,
Electrode structure.
According to paragraph 1,
The planar member is a solid electrolyte,
Electrode structure.
According to paragraph 2,
The solid electrolyte is LISICON or NASICON,
Electrode structure.
According to paragraph 1,
The electrode is a long member,
The long member has a structural shape such that the active layer surface is arranged perpendicular to one surface of the planar member,
Electrode structure.
According to paragraph 4,
The electrode has the active layer formed on one or both sides of the current collector,
Electrode structure.
According to paragraph 1,
The electrode is in a spiral shape or zig-zag shape of the length member,
Electrode structure.
According to clause 5,
The current collector is copper or aluminum,
Electrode structure.
According to paragraph 1,
The active layer is graphite, hard carbon, phosphorus, tin, or antimony,
Electrode structure.

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