Battery pole piece and battery

Abstract

The utility model provides a battery pole piece and a battery, the battery pole piece comprises a current collector and a coating, the current collector is provided with a liquid passing hole extending along the thickness direction of the current collector, the coating is arranged on the surface of one side of the current collector along the thickness direction of the current collector, a coating gap is formed in the coating, the liquid passing hole is communicated with the coating gap, and the liquid passing hole is communicated with the coating gap. And the liquid passing hole and the coating are in clearance fit to form a liquid guide channel for the electrolyte to flow. Through the arrangement of the liquid guide channels, multi-direction flowing of the electrolyte is realized, so that the permeability of the electrolyte in the pole piece is effectively improved, the problems of infiltration and liquid retention capability of the electrolyte in the use process of the battery in the prior art are solved, the active substance loading capacity is ensured, and the service life of the battery is prolonged. And the volume energy density and the mass energy density of the battery are improved, so that the problem that the use performance and the service life of the battery are affected due to poor wettability and poor electrolyte retention capacity of the battery in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery pole piece and a battery. BACKGROUND

[0002] With the development of new energy technology, battery technology is also constantly improving, especially lithium ion batteries are widely used in new energy vehicles and other electric tools.

[0003] Currently, in the field of lithium ion battery technology, the wettability and liquid retention capacity of electrolyte are one of the key factors affecting the performance and life of the battery. In the charge and discharge cycle of the battery, the uniformity and durability of the electrolyte distribution are crucial to maintaining the stability of the battery and prolonging its service life. Insufficient wetting of electrolyte in electrode materials can lead to poor contact between active materials and electrolyte, reducing the charge and discharge efficiency of the battery, and may also cause local overheating and uneven reactions, thereby shortening the cycle life of the battery. Poor liquid retention capacity means that electrolyte is easily lost, especially under high temperature or high rate charge and discharge conditions, the loss of electrolyte will increase the internal resistance of the battery, reduce the capacity, and even may cause safety problems.

[0004] The copper foil of the lithium ion battery in the prior art as the negative electrode current collector often limits the wettability of the electrolyte, thereby affecting the ion transmission efficiency inside the battery. In addition, the surface area of the copper foil is limited, which means that its ability to adsorb and store electrolyte is also limited, which directly affects the energy density and overall performance of the battery, thereby affecting the performance and life of the lithium ion battery. UTILITY MODEL CONTENT

[0005] The main purpose of the present application is to provide a battery pole piece and a battery to solve the problem of poor wettability and liquid retention capacity of electrolyte in related art batteries, which affects the performance and life of the battery.

[0006] In order to achieve the above purpose, according to one aspect of the present application, a battery pole piece is provided, which comprises a current collector and a coating, the current collector has a liquid passing hole extending along the thickness direction of the current collector, along the thickness direction of the current collector, the coating is arranged on the surface of at least one side of the current collector, the coating forms a coating gap, the liquid passing hole and the coating gap are arranged in communication, and the liquid passing hole and the coating gap cooperate to form a liquid guide channel for the electrolyte to flow.

[0007] Further, the coating gap is provided with one or more, and along the extension direction of the coating gap, each coating gap is in communication with at least one liquid passing hole.

[0008] Further, the coating gap is arranged in communication with a plurality of liquid passing holes along the extending direction of the coating gap, and the distance H1 between two adjacent liquid passing holes satisfies 0.5mm≤H1≤1mm.

[0009] Further, the coating gap extends along the length and / or width direction of the current collector, and when a plurality of coating gaps are arranged, the plurality of coating gaps are arranged at intervals along the length or width direction of the current collector, or the plurality of coating gaps are arranged in a cross manner along the length and width direction of the current collector.

[0010] Further, the width of the coating gap is not greater than the width of the coating layer, and / or the width H2 of the coating gap satisfies 0mm<H2≤0.05mm.

[0011] Further, the diameter of the liquid passing hole is greater than the width of the coating gap, and part of the liquid passing hole is exposed through the coating gap.

[0012] Further, the diameter R of the liquid passing hole and the width H2 of the coating gap satisfy R-H2≥0.05mm.

[0013] Further, along the thickness direction of the current collector, the coating layer is arranged on both sides of the current collector, and the projection regions of the coating gaps on the coating layers on the two sides of the current collector partially overlap or are arranged at intervals.

[0014] Further, the coating gap is a groove, and along the extending direction of the groove, the groove is open at both ends, and the groove bottom surface has a hole structure in communication with the liquid passing hole.

[0015] Further, the coating layer is one of a metal coating layer, a fluoride coating layer and an oxide coating layer, or the coating layer comprises at least two of the metal coating layer, the fluoride coating layer and the oxide coating layer, and the at least two of the metal coating layer, the fluoride coating layer and the oxide coating layer are stacked.

[0016] In order to achieve the above-mentioned purpose, according to another aspect of the present application, a battery is provided, which comprises the above-mentioned battery pole piece.

[0017] By applying the technical solution of the present application, the liquid passing hole and the coating gap on the current collector of the battery pole piece are arranged in communication to form a liquid guide channel, the liquid guide channel has a flow path along the thickness direction of the current collector provided by the liquid passing hole, and the liquid guide channel also has a flow path along the surface of the current collector perpendicular to the thickness direction provided by the coating gap, the liquid guide channel forms a multi-directional permeation path, the arrangement of the liquid guide channel of the present application realizes the multi-directional flow of the electrolyte, thereby effectively improving the permeability of the electrolyte in the pole piece, solving the problems of electrolyte infiltration and liquid retention capacity of the battery in the use process in the prior art, ensuring the active material loading, improving the volume energy density and mass energy density of the battery, and thereby improving the charge-discharge efficiency and cycle life of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an example embodiment of the application and together with the description, serve to explain the application. In the drawings,

[0019] Figure 1 A perspective view of the structure of the current application is shown, which shows the structure of the current application of the collector and the coating;

[0020] Figure 2 A top view of the current application is shown, which shows the structure of the current application of the collector and the coating;

[0021] Figure 3 A side view of the current application is shown, which shows the structure of the current application of the collector and the coating, wherein the collector is provided with a coating on one side;

[0022] Figure 4 A side view of the current application is shown, which shows the structure of the current application of the collector and the coating, wherein the collector is provided with a coating on both sides;

[0023] Figure 5 A sectional view of the current application is shown, which shows the structure of the current application of the collector and the coating, wherein the collector is provided with a coating on one side;

[0024] Figure 6 A sectional view of the current application is shown, which shows the structure of the current application of the collector and the coating, wherein the collector is provided with a coating on both sides.

[0025] Wherein the above drawings include the following reference signs:

[0026] 10, collector; 20, coating; 30, coating gap; 40, liquid passage hole. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. The following description of at least one example embodiment is actually only illustrative, but not as any limitation on the application and its application or use. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0028] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the example embodiments according to the application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0029] The foregoing merely illustrates the principles of the application. It will thus be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the application and are thus within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be only for pedagogical purposes to aid the reader in understanding the principles of the application and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Thus, the examples provided herein are illustrative only and should not be considered to narrow the scope of the application in any way. Rather, they provide examples of structures that are included within the scope of the application, and that can be used as a basis for designing or modifying other structures for carrying out the same purposes of the application. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific examples described herein. It is therefore to be understood that the application covers any such equivalents. The contents of any references, patents or patent documents mentioned in this application are hereby incorporated by reference in their entirety as if each were incorporated individually. This application can have preferred embodiments other than those explicitly described or shown. Therefore, the true scope and spirit of the application are indicated by the appended claims, along with the full scope of equivalents to which such claims are entitled. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. Any specific units and values are for illustrative purposes only and are not limiting. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. Various substitutions and changes can be made by those skilled in the art to adapt the application to various embodiments without departing from the true spirit and scope of the application. In addition, while the application has been described above with particularity, the descriptions and examples above are no way limitative, but rather serve as illustrative examples of how to make and use the application. It is therefore intended that the application not be limited to the specifically described application herein, but rather only by the claims that follow.

[0030] Embodiment one

[0031] The embodiment provides a battery, the battery comprising a battery pole piece, the application forms a liquid guide channel on the battery pole piece, the liquid guide channel is formed with a plurality of permeation paths, thereby solving the problem that the battery in the related art has poor wettability and liquid retention capacity of electrolyte, which affects the use performance and service life of the battery.

[0032] In the embodiment, the battery is a lithium electronic battery.

[0033] As shown in Figures 1 to 3 and Figure 5 , the battery pole piece comprises a current collector 10 and a coating layer 20, the current collector 10 has a liquid passing hole 40 extending along the thickness direction of the current collector 10, along the thickness direction of the current collector 10, the coating layer 20 is arranged on the surface of one side of the current collector 10, the coating layer 20 is formed with a coating layer gap 30, the liquid passing hole 40 is arranged in communication with the coating layer gap 30, and the liquid passing hole 40 and the coating layer gap 30 cooperate to form a liquid guide channel for flowing electrolyte.

[0034] In the embodiment, the liquid passing hole 40 extends along the thickness direction of the current collector 10 and penetrates through the current collector 10.

[0035] In the embodiment, the width direction of the current collector 10 and the width direction of the coating layer gap 30 are X directions as shown in Figure 1 , the length direction of the current collector 10 and the length direction of the coating layer gap 30 are Y directions as shown in Figure 1 , and the thickness direction of the current collector 10 is a Z direction as shown in Figure 1 It can be understood that the length, width and height of the current collector 10 in the application are not limited by the placement position.

[0036] In the embodiment, the liquid passage is formed by the communication between the liquid passing hole 40 on the current collector 10 of the battery pole piece and the coating gap 30, the liquid passage has a flow path along the thickness direction of the current collector 10 provided by the liquid passing hole 40, and the liquid passage also has a flow path along the surface of the current collector 10 perpendicular to the thickness direction provided by the coating gap 30, the liquid passage forms a multidirectional permeation path, and has better liquid retention and infiltration effect. In the embodiment, the plane where the coating gap 30 is located is perpendicular to the extension direction of the liquid passing hole 40, thereby realizing the formation of the liquid passage into a three-dimensional flow channel.

[0037] In the process of electrolyte flow, the setting of the liquid passage of the present application realizes the multidirectional flow of the electrolyte, thereby effectively improving the permeability of the electrolyte in the pole piece, solving the problem of the liquid retention and infiltration ability of the electrolyte in the battery in the prior art during use, ensuring the active material load, improving the volume energy density and mass energy density of the battery, and thereby improving the charge-discharge efficiency and cycle life of the battery.

[0038] In the embodiment, the current collector 10 is a copper foil, and the coating 20 is arranged on the surface of the current collector 10. The coating 20 not only has the effect of forming the coating gap 30 for the flow of the electrolyte, but also has the effect of improving the strength of the current collector 10 and protecting the current collector 10.

[0039] In the embodiment, the coating 20 can be arranged in a single-layer structure or a multi-layer structure.

[0040] In one specific embodiment, the coating 20 is a single-layer structure.

[0041] Specifically, the coating 20 is one of a metal coating, a fluoride coating, and an oxide coating, to form a single-layer structure of the coating 20.

[0042] It should be noted that the material of the coating 20 can also be other materials with high liquid absorption capacity and high flexibility.

[0043] In another specific embodiment, the coating 20 is a multi-layer structure.

[0044] Specifically, the coating 20 includes at least two of a metal coating, a fluoride coating, and an oxide coating, and the at least two of the metal coating, the fluoride coating, and the oxide coating are stacked to form a multi-layer structure of the coating 20.

[0045] It should be noted that the metal coating can improve the electrical conductivity, while the fluoride coating and the oxide coating can enhance the chemical stability, reduce the side reaction with the electrolyte, and prolong the battery life. In this application, the metal coating, the fluoride coating, and the oxide coating are not listed, which are materials that can be adaptively set in the prior art. The material of the coating 20 can also be other materials with high liquid absorption capacity and high flexibility.

[0046] As Figures 1 to 3 shown, in the embodiment, the coating gap 30 can be provided with one or multiple, when the coating gap 30 is provided with multiple, multiple liquid guiding channels can be formed, which is conducive to further improving the permeation effect of the electrolyte, and also conducive to the uniform permeation of the electrolyte and improving the flow efficiency of the electrolyte at the battery pole piece.

[0047] In one specific embodiment, the coating gap 30 is provided with one, which can extend along the length direction of the current collector 10 or the width direction of the current collector 10.

[0048] In another specific embodiment, the coating gap 30 is provided with multiple, which are arranged along the length or width direction of the current collector 10.

[0049] Among them, multiple coating gaps 30 can be arranged along the length direction of the current collector 10, and the multiple coating gaps 30 can be arranged in parallel or intersected; similarly, multiple coating gaps 30 can be arranged along the width direction of the current collector 10, and the multiple coating gaps 30 can be arranged in parallel or intersected.

[0050] In another specific embodiment, the coating gap 30 is provided with multiple, which are arranged along the length and width directions of the current collector 10.

[0051] In the embodiment, the extension direction of the coating gap 30 can extend along a straight line or an arc.

[0052] As Figures 1 to 3 and Figure 5 shown, each coating gap 30 is in communication with at least one liquid passing hole 40, thereby forming a liquid guiding channel for the electrolyte to flow, so as to facilitate the flow of the electrolyte between the coating gap 30 and the liquid passing hole 40.

[0053] Among them, the extension direction of the coating gap 30 is the length direction of the current collector 10.

[0054] In order to improve the flow efficiency of the electrolyte, in the present embodiment, a coating gap 30 is provided in communication with a plurality of liquid passing holes 40, and the plurality of liquid passing holes 40 are arranged at intervals along the extension direction of the coating gap 30. When the number of liquid passing holes 40 is not less than three, the distance between adjacent two liquid passing holes 40 can be the same or different.

[0055] In the present embodiment, the distance H1 between adjacent two liquid passing holes 40 satisfies 0.5mm≤H1≤1mm. By controlling the distance between the liquid passing holes 40, the flow path of the electrolyte can be further optimized, the uniform distribution of the electrolyte in the battery is ensured, the local overheating phenomenon is reduced, and the safety and overall performance of the battery are improved. Specifically, H1 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc.

[0056] In the present embodiment, the width of the coating gap 30 is not greater than the width of the coating 20, thereby ensuring that the electrolyte can contact the coating 20 to realize penetration.

[0057] Specifically, the width H2 of the coating gap 30 satisfies 0mm<H2≤0.05mm, which can ensure that the penetration path of the electrolyte neither excessively large affects the structural stability of the battery, nor excessively small hinders the flow of the electrolyte, and is suitable for battery applications requiring high energy density and long life. H2 is 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, etc.

[0058] As shown in Figure 1 and Figure 2 , the diameter of the liquid passing hole 40 is greater than the width of the coating gap 30, and part of the liquid passing hole 40 is exposed through the coating gap 30.

[0059] In the process of electrolyte flow, the part of the through hole exposed through the coating gap 30 realizes communication with the coating gap 30 to provide a path for the flow of the electrolyte.

[0060] In the present embodiment, the diameter of the liquid passing hole 40 is greater than the width of the coating gap 30, which increases the contact area between the electrolyte and the active material, improves the charge and discharge efficiency of the battery, and is beneficial to be suitable for fast charge and discharge and high power output.

[0061] In the present embodiment, the diameter R of the liquid passing hole 40 and the width H2 of the coating gap 30 satisfy R-H2≥0.05mm. By ensuring the reasonable difference between the diameter of the liquid passing hole 40 and the width of the coating gap 30, the flow mode of the electrolyte in the pole piece can be optimized, the bottleneck effect of the electrolyte flow is avoided, and the charge and discharge rate and energy density of the battery are further improved.

[0062] In this embodiment, the coating gap 30 is a groove, and along the extending direction of the groove, both ends of the groove are open, and the bottom surface of the groove has a hole structure connected to the liquid hole 40.

[0063] Among them, the coating 20 includes a first coating and a second coating, the first coating and the second coating are arranged on the same side of the current collector 10, the first coating is arranged on the current collector 10 at intervals, and the second coating is arranged between two adjacent first coatings. The second coating has a pore structure connected to the liquid hole 40, the thickness of the second coating is less than the thickness of the first coating, and the first coating and the second coating cooperate to form a coating gap 30.

[0064] Specifically, a mounting area is formed between two adjacent first coatings, and the second coating is arranged inside the mounting area. Since the first coating is thicker than the second coating, a groove is formed between the two, and the hole structure on the second coating is connected to the groove.

[0065] In this embodiment, the two first coatings can be spaced apart along the length direction of the current collector 10 to form a coating gap 30 extending in the length direction; they can also be spaced apart along the width direction of the current collector 10 to form a coating gap 30 extending in the width direction; or they can be spaced apart in a direction at an angle along the length direction of the current collector 10.

[0066] Example 2

[0067] Different from the first embodiment, Figure 4 and Figure 6 As shown, the current collector 10 in this embodiment is formed with coatings 20 on both sides along the thickness direction.

[0068] Specifically, by providing the coating 20 on both sides of the current collector 10 , it is beneficial to further improve the electrolyte infiltration efficiency and liquid retention effect, and also has a better protection effect.

[0069] In one specific implementation of this embodiment, along the thickness direction of the current collector 10 , the coatings 20 on both sides are symmetrically arranged with respect to the current collector 10 .

[0070] The symmetrically arranged coating 20 is beneficial to improving the circulation efficiency of the electrolyte, thereby accelerating the electrolyte infiltration efficiency and improving the electrolyte retention effect.

[0071] In another specific implementation of this embodiment, a coating 20 is provided on both sides of the current collector 10 along the thickness direction of the current collector 10, and the coating gaps 30 on the coatings 20 on both sides partially overlap or are spaced apart in the projected areas on the current collector 10 to form a coating gap 30 with a staggered structure.

[0072] The coating gaps 30 on both sides are misaligned, thereby forming misaligned liquid guide channels. The misaligned liquid guide channels are beneficial for better liquid retention and more uniform wetting during electrolyte flow, and are beneficial for improving the ability to absorb and store electrolyte.

[0073] From the above description, it can be seen that the above-mentioned embodiments of the application achieve the following technical effects:

[0074] The liquid passing hole 40 on the current collector 10 of the battery pole piece and the coating gap 30 are communicatively arranged to form a liquid guide channel. The liquid guide channel has a flow path along the thickness direction of the current collector 10 provided by the liquid passing hole 40, and has a flow path along the surface of the current collector 10 perpendicular to the thickness direction provided by the coating gap 30. The liquid guide channel forms a multidirectional permeation path. The arrangement of the liquid guide channel of the application realizes multidirectional flow of electrolyte, thereby effectively improving the permeability of electrolyte in the pole piece, solving the problems of electrolyte wetting and liquid retention in the prior art during battery use, ensuring the active material load, and improving the volume energy density and mass energy density of the battery, thereby improving the charge-discharge efficiency and cycle life of the battery.

[0075] In the description of the application, it should be understood that the orientation words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description. Without making the opposite statement, these orientation words do not indicate and imply that the devices or elements referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the scope of protection of the application; the orientation words "inner, outer" refer to the inner and outer of the contour of each component itself.

[0076] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper" and the like can be used to describe the spatial positional relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the devices described in the drawings. For example, if the devices in the drawings are inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0077] In addition, it should be noted that the use of "first", "second", and the like words to qualify parts is merely for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as limiting the scope of protection of the present application.

[0078] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Various modifications and changes can be made by those skilled in the art based on the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A battery pole piece, characterized by, The battery pole piece comprises: a current collector (10) having a liquid passage hole (40) extending along the thickness direction of the current collector (10); a coating layer (20) arranged on the surface of at least one side of the current collector (10) in the thickness direction, the coating layer (20) being formed with a coating layer gap (30), the liquid passage hole (40) being arranged in communication with the coating layer gap (30), and the liquid passage hole (40) and the coating layer gap (30) cooperating to form a liquid guide channel for the electrolyte to flow.

2. The battery pole piece according to claim 1, wherein the coating layer gap (30) is provided with one or more coating layer gaps (30) in communication with at least one liquid passage hole (40) along the extension direction of the coating layer gap (30).

3. The battery pole piece of claim 2, wherein, along the extension direction of the coating layer gap (30), the coating layer gap (30) is in communication with a plurality of liquid passage holes (40), and the distance H1 between two adjacent liquid passage holes (40) satisfies 0.5mm≤H1≤1mm.

4. The battery pole piece of claim 1, wherein, the coating layer gap (30) extends along the length and / or width direction of the current collector (10), and when the coating layer gap (30) is provided with a plurality of coating layer gaps (30), a plurality of coating layer gaps (30) are arranged in the length or width direction of the current collector (10); or a plurality of coating layer gaps (30) are arranged in the length and width directions of the current collector (10).

5. The battery pole piece according to claim 1, wherein the width of the coating layer gap (30) is not greater than the width of the coating layer (20); and / or the width H2 of the coating layer gap (30) satisfies 0mm<H2≤0.05mm.

6. The battery pole piece of claim 1, wherein, the diameter of the liquid passage hole (40) is greater than the width of the coating layer gap (30), and part of the liquid passage hole (40) is exposed through the coating layer gap (30).

7. The battery pole piece of claim 6, wherein, the diameter R of the liquid passage hole (40) and the width H2 of the coating layer gap (30) satisfy R-H2≥0.05mm.

8. The battery pole piece of any one of claims 1-7, wherein, along the thickness direction of the current collector (10), the coating layer (20) is arranged on both sides of the current collector (10), and the coating layer gaps (30) on the coating layers (20) on both sides are partially overlapped or arranged in intervals on the projection area of the current collector (10).

9. The battery pole piece of any one of claims 1-7, wherein, the coating layer gap (30) is a groove, both ends of the groove are open along the extension direction of the groove, and the groove bottom surface has a hole structure in communication with the liquid passage hole (40).

10. The battery pole piece according to any one of claims 1 to 7, wherein the coating layer (20) is one of a metal coating layer, a fluoride coating layer, and an oxide coating layer; or the coating layer (20) comprises at least two of a metal coating layer, a fluoride coating layer, and an oxide coating layer, and at least two of the metal coating layer, the fluoride coating layer, and the oxide coating layer are stacked.

11. A battery, characterized by The battery comprises the battery pole piece according to any one of claims 1 to 10.

Images