JP7741852B2 - Wound electrode assembly manufacturing device and battery cell manufacturing method - Google Patents

Description

This technology relates to a manufacturing device for wound electrode bodies and a manufacturing method for battery cells.

Conventionally, electrode wound bodies are produced by stacking and winding an electrode sheet and a separator around a winding core. For example, Japanese Patent Application Laid-Open No. 2009-259722 (Patent Document 1) discloses that when removing a produced electrode wound body from a winding core, the electrode body is gripped with chuck claws to prevent removal slippage (winding slippage) from occurring.

Japanese Patent Application Laid-Open No. 2009-259722 International Publication No. 2018/025785 JP 2014-133652 A JP 2012-182046 A Japanese Patent Application Laid-Open No. 2003-17110 JP 2015-5390 A Japanese Patent Application Laid-Open No. 2002-222645

While gripping the electrode body can be expected to have a certain effect in suppressing miswinding, it can also have unintended effects on the electrode surface of the gripped electrode body. From the perspective of manufacturing highly reliable electrode bodies, there is room for improvement in conventional technology.

The purpose of this technology is to provide a manufacturing device for wound electrode bodies that can produce highly reliable electrode bodies, and a manufacturing method for battery cells that include such electrode bodies.

This technology provides the following wound electrode assembly manufacturing apparatus and battery cell manufacturing method.

[1] A wound electrode manufacturing apparatus comprising: a core body having an outer peripheral surface and extending in a first direction; a first drive unit that rotates the core body about an axis in the first direction when winding the wound electrode body and moves the core body along the first direction when removing the wound electrode body; a transport mechanism provided on the outer peripheral surface of the core body and that moves the wound electrode body wound on the outer peripheral surface in a direction opposite to the first direction; and a second drive unit that drives the transport mechanism; wherein the transport mechanism moves the wound electrode body in the direction opposite to the first direction at a speed that offsets the movement of the core body in the first direction by the first drive unit; and the second drive unit that drives the transport mechanism is located closer to the tip of the core body than the first drive unit.

[2] The wound electrode manufacturing apparatus described in [1], wherein the conveying mechanism includes a chain-like member provided on the outer peripheral surface of the core body.

[3] The wound electrode manufacturing apparatus described in [1], wherein the conveying mechanism includes a belt-like member provided on the outer peripheral surface of the core body.

[4] The wound electrode manufacturing apparatus described in any one of [1] to [3], wherein a plurality of the conveying mechanisms are provided so as to be aligned in the circumferential direction of the outer peripheral surface of the core body.

[5] A method for manufacturing a battery cell, comprising the steps of: manufacturing the wound electrode body using the wound electrode body manufacturing apparatus described in any one of [1] to [4]; electrically connecting an electrode terminal to the wound electrode body; housing the wound electrode body in an outer casing; and sealing the outer casing containing the wound electrode body.

This technology eliminates the need to grip the electrode winding with a chuck or the like when removing the electrode winding wound around the core body, reducing the impact on the electrode surface and making it possible to manufacture highly reliable electrode bodies.

FIG. 10 is a diagram showing a state in which the electrode body is wound using a manufacturing device for a wound type electrode body. FIG. 2 is a diagram showing the configuration of a manufacturing device for a wound electrode body. 1A and 1B are diagrams showing an example of a core body and a transport mechanism provided on the outer peripheral surface thereof. FIG. 10 is a diagram (part 1) showing a modified example of the transport mechanism. FIG. 10 is a diagram (part 2) showing a modified example of the transport mechanism. FIG. 10 is a diagram (part 3) showing a modified example of the transport mechanism. FIG. FIG. 2 is a diagram showing the configuration of an electrode body.

The following describes an embodiment of the present technology. Note that the same or corresponding parts are designated by the same reference symbols, and their descriptions may not be repeated.

Note that in the embodiments described below, when numbers, amounts, etc. are mentioned, the scope of the present technology is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the embodiments described below, each component is not necessarily essential to the present technology, unless otherwise specified. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects mentioned in the present embodiments.

In this specification, the terms "comprise," "include," and "have" are open-ended. In other words, when a certain feature is included, other features may or may not be included.

In addition, when geometric terms and terms expressing positional or directional relationships are used in this specification, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along," these terms allow for manufacturing errors and slight variations. When terms expressing relative positional relationships, such as "upper side" and "lower side," are used in this specification, these terms are used to indicate relative positional relationships in a single state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

In this specification, "battery" is not limited to lithium-ion batteries, but may include other batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, "electrode" may collectively refer to positive and negative electrodes. Also, "electrode plate" may collectively refer to positive and negative plates.

In this specification, "battery cells" can be installed in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). However, the use of "battery cells" is not limited to in-vehicle use.

Figure 1 shows the state in which the electrode body 1 is wound using a wound-type electrode body manufacturing device, and Figure 2 shows the configuration of the wound-type electrode body manufacturing device.

As shown in Figures 1 and 2, the electrode assembly manufacturing apparatus according to this embodiment is a manufacturing apparatus for a winding-type electrode assembly 1, and includes a core body 100, a first drive unit 200, a conveying mechanism 300, and a second drive unit 400.

The core body 100 has a central axis 100A, an outer peripheral surface 100B, and a hole 100C. The first drive unit 200 drives the core body 100 to rotate around the central axis 100A. The first drive unit 200 can move the core body 100 back and forth along the direction of the central axis 100A (the direction of arrow DR1 in Figure 1).

When winding the wound electrode assembly 1, the electrode plates and separators that make up the electrode assembly 1 are supplied onto the outer peripheral surface 100B of the winding core body 100 while the winding core body 100 is rotated. This causes the electrode plates and separators to be wound onto the outer peripheral surface 100B.

A conveying mechanism 300 is provided on the outer peripheral surface 100B. In the example shown in Figures 1 and 2, the conveying mechanism 300 is composed of a chain-like member (a belt-like member). However, the conveying mechanism 300 may also be composed of a belt-like member, for example, or a combination of a chain-like member and a belt-like member may be used.

The transport mechanism 300 is driven by a second drive unit 400. As shown in FIG. 2, the second drive unit 400 includes storage units 410, 420 for the chain-like members that make up the transport mechanism 300. The storage units 410, 420 are provided with a drive mechanism (e.g., a motor, not shown) for unwinding and rewinding the chain-like members. When the transport mechanism 300 is driven in the direction of arrow DR2 in FIG. 1, one end of the chain-like member is unwound from the storage unit 410, and the other end of the chain-like member is rewound into the storage unit 420.

The chain-like member that constitutes the transport mechanism 300 extends from the storage section 410 along the central axis 100A of the core body 100, on the outer peripheral surface 100B of the core body 100, toward the tip (first end) of the core body 100. The transport mechanism 300 is folded back at the tip of the core body 100 and extends inside the core body 100 toward the base (second end) of the core body 100 along the central axis 100A of the core body 100. The transport mechanism 300 is pulled out from inside the core body 100 onto the outer peripheral surface 100B through a hole 100C located closer to the base of the core body 100 than the storage section 410. The transport mechanism 300 pulled out onto the outer peripheral surface 100B of the core body 100 reaches the storage section 420.

The electrode body 1 formed on the outer peripheral surface 100B of the core body 100 is removed from the core body 100 and proceeds to the next process. At this time, the core body 100 is driven in the direction of arrow DR1 (first direction) by the first drive unit 200. The transport mechanism 300 is driven in the direction of arrow DR2 by the second drive unit 400. As a result, the electrode body 1 on the outer peripheral surface 100B is driven in the direction (arrow DR3) opposite to the movement direction of the core body 100 (arrow DR1 direction).

As shown in FIG. 2, the second drive unit 400 is provided on the outer periphery of the core body 100. The second drive unit 400 is also located closer to the tip of the core body 100 than the first drive unit 200.

Here, the transport mechanism 300 moves the electrode body 1 in the direction of arrow DR3 at a speed that offsets the movement of the core body 100 in the direction of arrow DR1 by the first drive unit 200. Therefore, when the electrode body 1 is removed from the core body 100, the electrode body 1 does not displace in the stationary coordinate system. In this way, by driving the electrode body 1 in the opposite direction (direction of arrow DR3) to the removal direction of the core body 100 (direction of arrow DR1) at a speed substantially the same as the removal speed of the core body 100, the core body 100 can be removed from the electrode body 1 without gripping the electrode body 1.

In manufacturing equipment that does not have a transport mechanism 300, the electrode body 1 must be gripped with a chuck or the like when removing it from the winding core body 100. Gripping the electrode body 1 can cause miswinding of the electrode body 1 (a state in which part of the electrode body 1 is deformed in the direction of the winding axis) due to sliding resistance generated at the innermost periphery of the electrode body 1. Furthermore, gripping the electrode body 1 can have some effect on the electrode surface.

In contrast, in the manufacturing apparatus according to this embodiment, the electrode body 1 can be moved in the opposite direction (in the direction of arrow DR3) at a speed that offsets the movement of the core body 100 in the direction of arrow DR1 by the first drive unit 200. This eliminates the need to grip the electrode body 1 with a chuck or the like when removing the electrode body 1 wound around the core body 100, reducing winding misalignment and the impact on the electrode surface. As a result, the reliability of the electrode body 1 can be improved, resulting in a high-quality battery.

Figure 3 is a diagram showing an example of a core body 100 and a transport mechanism 300 provided on its outer peripheral surface 100B. As shown in Figure 3, multiple transport mechanisms 300 (six in the example of Figure 3) are provided so as to be arranged at approximately equal intervals in the circumferential direction of the outer peripheral surface 100B of the core body 100.

Figures 4 to 6 show modified examples of the conveying mechanism 300. As shown in Figures 4 to 6, the number and arrangement of the conveying mechanisms 300 can be changed as appropriate. In addition, the width of the chain-like or belt-like members that make up the conveying mechanism 300 can also be made wider, for example, as shown in Figure 4.

Figure 7 is an exploded perspective view of a battery cell. As shown in Figure 7, the battery according to this embodiment includes an electrode body 1, a rectangular outer casing 2, and a cover member 3.

The electrode body 1 has a positive electrode 11 and a negative electrode 12 aligned in the X-axis direction (longitudinal direction). The electrode body 1 has an outer surface 10A (first outer surface) and an outer surface 10B (second outer surface) positioned on opposite sides along the Y-axis direction (transverse direction).

The rectangular outer casing 2 has an opening 21 that opens upward. Inside the rectangular outer casing 2, the electrode assembly 1 and an electrolyte (not shown) are contained.

The lid member 3 seals the opening 21 of the rectangular outer casing 2. A positive electrode external terminal 31A and a negative electrode external terminal 32A are provided on the upper surface of the lid member 3 with a gap in the X-axis direction. A positive electrode side current collector 31 and a negative electrode side current collector 32 are provided on the lower surface of the lid member 3. The positive electrode side current collector 31 is electrically connected to the positive electrode external terminal 31A. The negative electrode side current collector 32 is electrically connected to the negative electrode external terminal 32A.

Furthermore, the current collector 31 is connected to the positive electrode 11 of the electrode body 1, and the current collector 32 is connected to the negative electrode 12 of the electrode body 1. This electrically connects the positive electrode 11 and negative electrode 12 of the electrode body 1 to the positive electrode external terminal 31A and negative electrode external terminal 32A of the cover member 3.

Figure 8 is a diagram showing the configuration of the electrode assembly 1. As shown in Figure 8, the electrode assembly 1 includes a positive electrode plate 11A that constitutes the positive electrode 11, a negative electrode plate 12A that constitutes the negative electrode 12, and separators 13 and 14.

The positive electrode plate 11A has a first region 11B in which a positive electrode active material mixture layer (first active material layer) containing a positive electrode active material (such as lithium-nickel-cobalt-manganese composite oxide), a binder (such as polyvinylidene fluoride (PVdF)), and a conductive material (such as a carbon material) is formed on both sides of a positive electrode core (first electrode core) made of aluminum foil; a second region 11C in which no active material layer is formed and the positive electrode core is exposed; and a boundary 11D between the first region 11B and the second region 11C. A protective layer (not shown) containing alumina particles, a binder, and a conductive material may be provided on part of the second region 11C (the portion adjacent to the first region 11B).

The negative electrode plate 12A has a first region 12B in which a negative electrode active material layer (second active material layer) is formed on both sides of a negative electrode core (second electrode core) made of copper foil, a second region 12C in which no active material layer is formed and the negative electrode core is exposed, and a boundary 12D between the first region 12B and the second region 12C.

The positive electrode plate 11A and the negative electrode plate 12A are wound around the X-axis (winding axis) using the manufacturing equipment described above. The positive electrode plate 11A and the negative electrode plate 12A are stacked with separators 13, 14 interposed between them. The positive electrode plate 11A and the negative electrode plate 12A removed from the winding core body 100 are formed into a flat shape. This forms the electrode body 1, which has the positive electrode 11 located at one end along the X-axis direction and the negative electrode 12 located at the other end.

Next, the electrode body 1 and the current collectors 31 and 32 are electrically connected. After that, the electrode body 1 and the current collectors 31 and 32 are housed in the prismatic outer casing 2, and the prismatic outer casing 2 is sealed with the lid member 3. Then, an electrolyte is poured into the prismatic outer casing 2, and an airtightness test is performed to complete the battery cell. Note that the batteries to which this technology can be applied are not limited to prismatic batteries, and may also be cylindrical batteries, for example.

In this embodiment, the size or number of turns of the electrode body 1 is not particularly limited. However, the reliability of the electrode body 1 can be more effectively improved with a larger number of turns and a wider width. For example, in an electrode body with a width of approximately 120 mm in the X-axis direction, comparing winding the positive electrode plate 11A and negative electrode plate 12A or separators 13, 14 approximately 40 times with winding them approximately 60 times, it is believed that the sliding resistance of the innermost periphery of the electrode body 1 is greater when wound approximately 60 times. Therefore, by using the manufacturing apparatus according to this embodiment, winding slippage and its impact on the electrode surface can be effectively suppressed. Similarly, even with the same number of turns, a larger electrode body 1 will have greater sliding resistance. Therefore, by using the manufacturing apparatus according to this embodiment, winding slippage and its impact on the electrode surface can be effectively suppressed.

The above describes embodiments of the present technology, but the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims.

1 Electrode body, 2 Rectangular outer casing, 3 Lid member, 21 Opening, 10A Outer surface, 10B Outer surface, 11 Positive electrode, 11A Positive electrode plate, 11B First region, 11C Second region, 11D Boundary, 12 Negative electrode, 12A Negative electrode plate, 12B First region, 12C Second region, 12D Boundary, 13, 14 Separator, 31 Current collector, 31A Positive electrode external terminal, 32 Current collector, 32A Negative electrode external terminal, 100 Core body, 100A Central axis, 100B Outer periphery, 100C Hole, 200 First drive unit, 300 Conveying mechanism, 400 Second drive unit, 410, 420 Storage unit.

Claims (5)

A manufacturing apparatus for a wound electrode body,
a core body having an outer circumferential surface and extending in a first direction;
a first drive unit that drives the core body to rotate about an axis in the first direction when the wound electrode body is wound, and that moves the core body along the first direction when the wound electrode body is removed;
a conveying mechanism provided on the outer peripheral surface of the core body and capable of moving the wound electrode body wound on the outer peripheral surface in a direction opposite to the first direction;
a second drive unit that drives the transport mechanism,
the transport mechanism moves the wound electrode body in a direction opposite to the first direction at a speed that offsets the movement of the core body in the first direction by the first drive unit,
The manufacturing device for a wound electrode body, wherein the second drive unit that drives the transport mechanism is located closer to the tip end of the core body than the first drive unit. The wound electrode manufacturing apparatus of claim 1, wherein the transport mechanism includes a chain-like member provided on the outer peripheral surface of the core body. The wound electrode manufacturing apparatus of claim 1, wherein the transport mechanism includes a belt-like member provided on the outer peripheral surface of the core body. The wound electrode manufacturing apparatus according to any one of claims 1 to 3, wherein a plurality of the transport mechanisms are provided and aligned circumferentially around the outer circumferential surface of the core body. a step of manufacturing the wound electrode body using the wound electrode body manufacturing apparatus according to any one of claims 1 to 3;
a step of electrically connecting an electrode terminal and the wound electrode body;
a step of housing the wound electrode body in an outer casing;
and sealing the exterior body that houses the wound electrode body.