CN219979603U - Negative pole piece structure, battery and vehicle - Google Patents

Abstract

The disclosure relates to the technical field of batteries, and in particular relates to a negative electrode plate structure, a battery and a vehicle. The negative pole piece structure is provided with a pole piece body, the pole piece body comprises a first area and a second area arranged on two sides of the first area in the width direction of the pole piece body, the thickness of the first area is larger than that of the second area, the compaction density of the first area is smaller than that of the second area, more electrolyte is finally stored in the first area of the pole piece body, after the pole piece body begins to expand in the process of recycling the battery cell, part of electrolyte in the pole piece body is extruded out of the pole piece body, normal operation of the battery cell is not affected, so that the time point of rapid reduction of the capacity of the battery cell is delayed, and the service life of the battery cell is prolonged.

Description

Negative pole piece structure, battery and vehicle

Technical Field

The disclosure relates to the technical field of batteries, and in particular relates to a negative electrode plate structure, a battery and a vehicle.

Background

The battery cell has certain volume expansion in the cyclic use process, and the cyclic expansion of the battery cell is larger in the middle of the battery cell and smaller in the edge. The battery cell structure is generally that the positive pole piece and the negative pole piece are oppositely arranged, the positive pole piece and the negative pole piece are soaked in electrolyte, when the battery cell is recycled, the middle part of the negative pole piece is easy to expand and is extruded by the battery cell shell, so that the number of gaps inside the negative pole piece is reduced, the storage capacity of electrolyte inside the negative pole piece is reduced, the ion exchange between the positive pole piece and the negative pole piece is influenced, and the capacity of the battery cell is quickly attenuated.

Disclosure of Invention

In order to solve the technical problems described above or at least partially solve the technical problems described above, the present disclosure provides a negative electrode tab structure, a battery, and a vehicle.

The first aspect of the present disclosure provides a negative electrode pole piece structure, including a pole piece body, along the width direction of pole piece body, the pole piece body includes first region and sets up the second region of first region both sides, the thickness of first region is greater than the thickness of second region, the compaction density of first region is less than the compaction density of second region.

Optionally, the ratio of the maximum thickness dimension of the first region to the maximum thickness dimension of the second region is 1.1 to 1.4.

Optionally, along the width direction of the pole piece body, the middle part of the side of the pole piece body perpendicular to the thickness direction of the pole piece body is protruded to form an arc surface, the part of the thickness dimension of the two ends of the pole piece body, which is smaller than 0.7 to 0.9 in the ratio of the maximum thickness dimension of the pole piece body, is a second area, and the rest areas of the pole piece body are the first areas.

Optionally, the volume ratio of the first area in the pole piece body is 10% to 30%.

Optionally, the pole piece body is of a symmetrical structure, and the pole piece body (1) is symmetrical with respect to the first plane.

The negative pole piece structure that this disclosure provided is equipped with the pole piece body, in the width direction along the pole piece body, the pole piece body includes first region and sets up the second region in first region both sides, and the thickness of first region is greater than the thickness of second region, make the compaction density of first region be less than the compaction density of second region, finally make the inside of the first region of pole piece body store more electrolyte, after the pole piece body begins the inflation in the battery cell cyclic utilization process, the inside of partial electrolyte in the pole piece body is extruded the pole piece body can not influence the normal work of battery cell, thereby the time point of battery cell capacity quick decline has been postponed, the life of battery cell has been promoted.

A second aspect of the present disclosure provides a battery comprising a negative electrode tab structure as defined in any one of the preceding claims.

Optionally, the positive electrode comprises a positive electrode plate and a plate body, wherein the plate body and the positive electrode plate are stacked and staggered.

Optionally, a gap is formed between the pole piece body and the positive pole piece, and a diaphragm is arranged in the gap.

Optionally, along the direction that the positive pole piece faces the pole piece body, the projection of the positive pole piece on the pole piece body is at least partially overlapped with the pole piece body.

The battery provided by the disclosure delays the time point of rapid decline of the battery capacity after the battery is recycled by using the negative electrode plate structure, and prolongs the service life of the battery.

A third aspect of the present disclosure provides a vehicle comprising a battery as claimed in any one of the preceding claims.

According to the vehicle provided by the disclosure, the battery is used, so that the user experience of the vehicle in the using process is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure.

In order to more clearly illustrate the embodiments of the present disclosure or the solutions in the prior art, the drawings that are required for the description of the embodiments or the prior art will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.

Fig. 1 is a schematic structural diagram of a negative electrode sheet according to an embodiment of the present disclosure;

FIG. 2 is a front cross-sectional view of a negative electrode tab according to an embodiment of the present disclosure;

fig. 3 is an exploded view of a battery according to an embodiment of the present disclosure.

1, a pole piece body; 11. a first region; 12. a second region; 2. a positive electrode sheet; 3. a diaphragm; 4. a housing.

Detailed Description

In order that the above objects, features and advantages of the present disclosure may be more clearly understood, a further description of aspects of the present disclosure will be provided below. It should be noted that, without conflict, the embodiments of the present disclosure and features in the embodiments may be combined with each other.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure, but the present disclosure may be practiced otherwise than as described herein; it will be apparent that the embodiments in the specification are only some, but not all, embodiments of the disclosure.

Referring to fig. 1 to 3, a first aspect of the disclosed embodiment provides a negative electrode tab structure, which includes a tab body 1, wherein the tab body 1 includes a first region 11 and second regions 12 disposed at both sides of the first region 11 along a width direction of the tab body 1, a thickness of the first region 11 is greater than a thickness of the second region 12, and a compaction density of the first region 11 is less than a compaction density of the second region 12.

Specifically, the directions indicated by arrows in fig. 1 and 2 are a length direction a, a width direction b, and a thickness direction c of the pole piece body 1; the pole piece body 1 can be selected to be rectangular plate, the first area 11 can be selected to be rectangular area, the length direction of the first area 11 of the pole piece body 1 is consistent with the length direction a of the pole piece body 1, along the width direction b of the pole piece body 1, the first area 11 is located in the middle of the pole piece body 1, along the width direction b of the pole piece body 1, rectangular bulges are formed in the middle of one side surface of the pole piece body 1 perpendicular to the thickness direction c, the length direction of each rectangular bulge is consistent with the length direction a of the pole piece body 1, the length of each rectangular bulge is equal to the length of the pole piece body 1, so that the rectangular bulge and the pole piece body 1 located below each rectangular bulge are the first area 11, the end areas of the two ends of the pole piece body 1 on two sides of each rectangular bulge are the second area 12, the sum of the thickness of each rectangular bulge of the first area 11 and the thickness of each rectangular plate of the pole piece body 1 is the thickness of the first area 11, and the thickness of the two ends of the pole piece body 1 on two sides of each rectangular bulge is the thickness of each rectangular bulge, and the thickness of the first area 12 is larger than the thickness of the second area 12.

Of course, rectangular protrusions may be disposed on both sides of the pole piece body 1 perpendicular to the thickness direction c of the pole piece body 1 along the width direction b of the pole piece body 1, the two rectangular protrusions have the same shape and volume, the length directions of the two rectangular protrusions are identical to the length direction a of the pole piece body 1, the two rectangular protrusions and a portion of the pole piece body 1 between the two rectangular protrusions are the first region 11, and the portion of the pole piece body 1 on both sides of the two rectangular protrusions is the second region 12 along the width direction b of the pole piece body 1. The thickness of the first region 11 is the thickness of the pole piece body 1 located inside the first region 11, the thickness of the second region 12 is the thickness of the pole piece body 1 located inside the second region 12, and the thickness of any part of the pole piece body 1 inside the first region 11 is larger than the thickness of any part of the pole piece body 1 inside the second region 12.

It can be appreciated that in some embodiments, the pole piece body 1 may be selected to have a rectangular structure, and in the width direction b of the pole piece body 1, a middle portion of a side surface of the pole piece body 1 perpendicular to the thickness of the pole piece body 1 is protruded to form an arc surface, so that in the width direction b of the pole piece body 1, the thickness of the pole piece body 1 gradually decreases from the middle portion to the two ends of the pole piece body 1; the region where the ratio of the thickness of the end portions of the two ends of the pole piece body 1 to the maximum thickness dimension of the middle portion of the pole piece body 1 in the width direction b of the pole piece body 1 is smaller than 0.8 may be selected as the second region 12, and the remaining regions of the pole piece body 1 are the first regions 11, so that the thickness of the first regions 11 is larger than that of the second regions 12.

The above mentioned compaction density is the ratio between the surface density and the thickness of the material, when the material density of the pole piece body 1 is uniform in all parts, the thickness of the pole piece body 1 in the first area 11 is larger than the thickness of the pole piece body 1 in the second area 12, so that the compaction density of the first area 11 is smaller than the compaction density of the second area 12, of course, the first area 11 and the second area 12 can be selected to change the material density of the pole piece body 1 by changing the material deposition rate or depositing materials with different densities on the side surface of the formed panel, so that the material density of the first area 11 can be selected to be smaller than the material density of the second area 12, and the material thickness of the first area 11 is larger than the material thickness of the second area 12, so that the compaction density of the first area 11 is smaller than the compaction density of the second area 12; the compacted density of the first region 11 is less than the compacted density of the second region 12, and the first region 11 has more pores that can store electrolyte, thereby increasing the volume of electrolyte stored within the first region 11.

When the battery is specifically used, the pole piece body 1 is arranged inside the battery, the pole piece body 1 is soaked in electrolyte, the electrolyte enters the hole in the pole piece body 1 and is stored in the pole piece body 1, after the battery is electrified, the pole piece body 1 and the positive pole piece of the battery exchange ions through the electrolyte, after the pole piece body 1 is used for a long time, the middle part of the pole piece body 1 begins to expand in the width direction b of the pole piece body 1, the hole in the middle part of the pole piece body 1 is reduced, the internal electrolyte in the middle part of the pole piece body 1 is extruded out of the pole piece body 1, and because the thickness of the middle part of the pole piece body 1 is greater than the thickness of the end part of the pole piece body 1, the mass of the electrolyte stored in the middle part of the pole piece body 1 is greater than the mass of the electrolyte stored in the end part of the pole piece body 1, and the electrolyte in the middle part of the pole piece body 1 is extruded out of the pole piece body 1, so that the ion exchange between the pole piece body 1 and the positive pole piece is not influenced, thereby the time point that the capacity of the battery is rapidly reduced is prolonged, and the service life of the battery is prolonged.

Through being equipped with negative pole piece structure and including pole piece body 1, in the width direction b along pole piece body 1, pole piece body 1 includes first region 11 and sets up the second region 12 in first region 11 both sides, the thickness of first region 11 is greater than the thickness of second region 12, the compaction density of messenger's first region 11 is less than the compaction density of second region 12, finally, more electrolyte is stored to the inside of the first region 11 of messenger's pole piece body 1, after pole piece body 1 begins to expand in the battery cell cyclic utilization, the inside that partial electrolyte in the pole piece body 1 was extruded pole piece body 1 can not influence the normal work of battery cell, thereby delay the time point that the battery cell capacity descends fast, the life of battery cell has been promoted.

Referring to fig. 1 and 2, in some embodiments, the ratio of the maximum thickness dimension of the first region 11 to the maximum thickness dimension of the second region 12 is 1.1 to 1.4, and specifically, the ratio of the maximum thickness dimension of the pole piece body 1 in the range of the first region 11 to the maximum thickness dimension of the pole piece body 1 in the second region 12 may be selected to be any value between 1.1 and 1.4.

When the ratio of the maximum thickness dimension of the first region 11 to the maximum thickness dimension of the second region 12 is 1.1, the difference between the maximum thickness and the minimum thickness of the pole piece body 1 is small, so that the shape of the pole piece body 1 can be still approximate to a rectangle, the pole piece body 1 can be conveniently installed in a battery, and small parts of cutting can be directly performed at two ends of the rectangular pole piece body 1, so that the pole piece body 1 with the ratio of the maximum thickness to the minimum thickness of the pole piece body 1 of 1.1 is obtained; when the ratio of the maximum thickness dimension of the first region 11 to the maximum thickness dimension of the second region 12 is 1.4, the first region 11 of the pole piece body 1 has a large thickness, and can accommodate more electrolyte, so that the time point of the decrease of the battery capacity caused by extrusion of the electrolyte in the pole piece body 1 when the pole piece body 1 starts to expand is delayed, and when the ratio of the maximum thickness dimension of the first region 11 to the maximum thickness dimension of the second region 12 is 1.4, the occupancy rate of the pole piece body 1 to the battery inner space is still smaller, and the occupation of the battery inner space caused by the excessive thickness of the first space 11 of the pole piece body 1 is avoided, so that the battery volume needs to be increased to increase the overall manufacturing cost of the battery; the ratio of the maximum thickness dimension of the first region 11 to the maximum thickness dimension of the second region 12 is 1.1 to 1.4, which is set by integrating various considerations such as prolonging the service time of the battery, manufacturing cost of the pole piece body 1, and occupation space of the pole piece body 1.

By setting the ratio of the maximum thickness dimension of the first region 11 to the maximum thickness dimension of the second region 12 to be 1.1 to 1.4, the maximum thickness dimension of the first region 11 is larger than the maximum thickness dimension of the second region 12, and the manufacturing cost of the pole piece body 1 is not increased more due to the overlarge thickness of the first region 11, and the manufacturing cost of the pole piece body 1 is saved under the condition that the thickness of the first region 11 of the pole piece body 1 is larger than the thickness of the second region 12.

Referring to fig. 1 and 2, in some embodiments, along the width direction b of the pole piece body 1, the middle of the side of the pole piece body 1 perpendicular to the thickness direction c of the pole piece body 1 is protruded to form an arc surface, the thickness of the pole piece body 1 gradually decreases along the middle of the pole piece body 1 toward both ends of the pole piece body 1, a portion where the ratio of the thickness dimension of both ends of the pole piece body 1 to the maximum thickness dimension of the pole piece body 1 is less than 0.72 to 0.9 is the second region 12, and the remaining regions of the pole piece body 1 are the first region 11.

Specifically, in the width direction b of the pole piece body 1, the middle part of one side surface of the pole piece body 1 perpendicular to the thickness direction c of the pole piece body 1 can be selected to be convex to form an arc surface, or the middle parts of two side surfaces of the pole piece body 1 perpendicular to the thickness direction c of the pole piece body 1 can be selected to be convex to form arc surfaces, so that the cross section of the pole piece body 1 along the width direction b of the pole piece body 1 and perpendicular to the length direction a of the pole piece body 1 is spindle-shaped; in the width direction b along the pole piece body 1, the maximum thickness dimension of the pole piece body 1 is located in the middle of the pole piece body 1, and the part of the ratio of the thickness dimension of the two ends of the pole piece body 1 to the maximum thickness dimension of the pole piece body 1 is smaller than any value between 0.72 and 0.9 is the second area 12.

Through setting up along the width direction b of pole piece body 1, the protruding arcwall face that forms in the middle part of the side of the thickness direction c of pole piece body 1 perpendicular to pole piece body 1, make the thickness of pole piece body 1 reduce gradually towards pole piece body 1 both ends direction along the middle part of pole piece body 1, wherein the ratio of the thickness size at the both ends of pole piece body 1 and the biggest thickness size of pole piece body 1 is less than 0.72 to 0.9's part is second region 12, the other regions of pole piece body 1 are first region 11, finally make the side of the thickness direction c of pole piece body 1 perpendicular to pole piece body 1 be the arcwall face, make things convenient for the processing preparation of pole piece body 1, practice thrift the manufacturing cost of pole piece body 1.

Referring to fig. 1 and 2, in some embodiments, the volume ratio of the first region 11 in the pole piece body 1 is 10% to 30%, specifically, the volume of the first region 11 may be selected to be 10% of the volume of the pole piece body 1, or the volume of the first region 11 may be selected to be 30% of the volume of the pole piece body 1, or may not be limited to any value between 10% and 30% of the volume of the first region 11.

The volume ratio of the first area 11 in the pole piece body 1 is 10-30% by setting, so that the volume ratio of the first area 11 in the pole piece body 1, which can store more electrolyte, is controlled, and on the basis that the electrolyte can be stored in the pole piece body 1, the material quality required for manufacturing the pole piece body 1 is reduced, the processing difficulty of the pole piece body 1 is reduced, and the manufacturing cost of the pole piece body 1 is reduced.

Referring to fig. 1 and 2, in some embodiments, the pole piece body 1 is symmetrical about a first plane, and specifically, the first plane may be selected to be a plane perpendicular to the width direction b of the pole piece body 1, and the center point of the pole piece body 1 is located on the first plane, so that the second region 12 of the pole piece body 1 is symmetrical about the first plane, and the first region 11 of the pole piece body 1 is symmetrical about the first plane.

Through setting up pole piece body 1 for symmetrical structure, pole piece body 1 is symmetrical about first plane, uses the mould to process when making things convenient for pole piece body 1 to pole piece body 1's symmetrical structure has avoided when installing pole piece body 1 in the battery the installation direction that needs restriction pole piece body 1, thereby has promoted pole piece body 1 installation operation's convenience.

Referring to fig. 3, a second aspect of the presently disclosed embodiment provides a battery including the negative electrode tab structure as described above.

Through using the negative pole piece structure as described above, when the negative pole piece expands in the use process of the battery, the first area 11 stores more electrolyte, so that the time point of rapid reduction of the battery capacity is delayed, and the service life of the battery is prolonged.

Referring to fig. 3, in some embodiments, the positive electrode sheet 2 and the electrode sheet body 1 are included, the electrode sheet body 1 and the positive electrode sheet 2 are stacked and staggered, specifically, a rectangular casing 4 may be selected for the battery, the positive electrode sheet 2, the electrode sheet body 1 and the positive electrode sheet 2 may be selected to be stacked in the casing 4 in sequence along the vertical direction, and of course, the positive electrode sheet 2, the electrode sheet body 1 and the positive electrode sheet 2 may be selected to be stacked in the casing 4 in sequence along the horizontal direction; electrolyte is filled in the shell 4, so that the positive pole piece 2 and the pole piece body 1 in the shell 4 are soaked in the electrolyte, and the positive pole piece 2 and the pole piece body 1 exchange ions through the electrolyte, thereby realizing the function of battery power supply.

The positive pole piece 2 and the pole piece body 1 are suitable for being soaked in electrolyte, the electrolyte enters the pole piece body 1, the electrolyte can be particularly selected to fill the inside of the shell 4, and the electrolyte enters a plurality of holes in the pole piece body 1, so that the effect of storing the electrolyte in the pole piece body 1 is realized, and the electrolyte can conduct ions between the positive pole piece 2 and the pole piece body 1, so that the power supply function of the battery is realized.

Through setting up the battery and including anodal pole piece 2 and pole piece body 1, the pole piece body 1 stacks crisscross setting with anodal pole piece 2, makes anodal pole piece 2 and pole piece body 1's distance reduce, promotes the efficiency of pole piece body 1 and anodal pole piece 2 exchange ion to promote the result of use of battery.

Referring to fig. 3, in some embodiments, a gap is formed between the pole piece body 1 and the positive pole piece 2, and a diaphragm 3 is disposed in the gap, specifically, the diaphragm 3 may be a rectangular film, the area of the diaphragm 3 may be selected to be larger than the area of a side surface of the pole piece body 1 opposite to the positive pole piece 2, or the area of the diaphragm 3 may be selected to be equal to the area of a side of the pole piece body 1 opposite to the positive pole piece 2; the diaphragm 3 is made of an electronic insulating material, and the diaphragm 3 is arranged between the pole piece body 1 and the positive pole piece 2, so that the pole piece body 1 and the positive pole piece 2 are mechanically isolated, and electronic exchange between the pole piece body 1 and the positive pole piece 2 is avoided.

Through having the clearance between pole piece body 1 and positive pole piece 2, be equipped with diaphragm 3 in the clearance, make diaphragm 3 with pole piece body 1 and positive pole piece 2 mechanical isolation, avoid pole piece body 1 and positive pole piece 2 to contact each other and form the short circuit and make the battery damage.

Referring to fig. 3, in some embodiments, the projection of the positive electrode sheet 2 onto the sheet body 1 at least partially coincides with the sheet body 1 in the direction of the positive electrode sheet 2 toward the sheet body 1. The projection of the positive pole piece 2 on the pole piece body 1 can be selected to be completely overlapped, and the projection of the positive pole piece 2 on the pole piece body 1 can be selected to be overlapped with the two-thirds area of the pole piece body 1.

Through setting up along the direction of anodal pole piece 2 towards pole piece body 1, the projection of anodal pole piece 2 on pole piece body 1 at least partially coincides with pole piece body 1, shortens the distance when the ion removes between anodal pole piece 2 and pole piece body 1, makes the ion can be faster remove between anodal pole piece 2 and pole piece body 1, has promoted the removal efficiency of ion between anodal pole piece 2 and pole piece body 1 to promote the power supply effect of battery.

A third aspect of the disclosed embodiments provides a vehicle comprising a battery as described above.

By using the battery as described above in a vehicle, the pole piece body 1 increases the service life of the battery, improving the user experience of the vehicle during use.

When the battery is specifically used, the positive electrode plate 2, the electrode plate body 1 and the positive electrode plate 2 are sequentially stacked in the vertical direction in the shell 4 of the battery, the diaphragm 3 is arranged between each positive electrode plate 2 and each electrode plate body 1, and electrolyte is filled in the shell 4 of the battery, so that the positive electrode plate 2 and the electrode plate body 1 are soaked in the electrolyte; in the recycling process of the battery, along the width direction b of the pole piece body 1, the middle part of the pole piece body 1 begins to expand, so that part of electrolyte in the middle part of the pole piece body 1 is extruded out of the inside of the pole piece body 1, and as the compaction density of the first area 11 of the pole piece body 1 is smaller than that of the second area 12, more electrolyte can be stored in the internal pores of the first area 11, and after the pole piece body 1 begins to expand, the part of electrolyte is extruded out of the inside of the pole piece body 1 without affecting the normal operation of the battery, so that the battery has longer service life.

It should be noted that in this document, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing is merely a specific embodiment of the disclosure to enable one skilled in the art to understand or practice the disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown and described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. The utility model provides a negative pole piece structure, its characterized in that includes the pole piece body, follows the width direction of pole piece body, the pole piece body includes first region and sets up the second region of first region both sides, the thickness of first region is greater than the thickness of second region, the compaction density of first region is less than the compaction density of second region.

2. The negative electrode tab structure of claim 1 wherein the ratio of the maximum thickness dimension of the first region to the maximum thickness dimension of the second region is from 1.1 to 1.4.

3. The negative electrode tab structure according to claim 1, wherein, in the width direction of the tab body, the middle portion of the side surface of the tab body perpendicular to the thickness direction of the tab body is convex to form an arc surface, a portion of the tab body having a ratio of the thickness dimension at both ends to the maximum thickness dimension of the tab body of less than 0.72 to 0.9 is a second region, and the remaining regions of the tab body are the first regions.

4. The negative pole piece structure of claim 1, wherein the first region is present in the pole piece body at a volume ratio of 10% to 30%.

5. The negative pole piece structure of claim 1, wherein the pole piece body is a symmetrical structure, the pole piece body being symmetrical about a first plane.

6. A battery comprising the negative electrode tab structure of any one of claims 1 to 5.

7. The battery of claim 6, comprising a positive electrode tab and the tab body, the tab body being stacked interleaved with the positive electrode tab.

8. The battery of claim 7, wherein a gap is provided between the pole piece body and the positive pole piece, and a separator is disposed in the gap.

9. The battery of claim 7, wherein a projection of the positive electrode sheet onto the sheet body at least partially coincides with the sheet body in a direction of the positive electrode sheet toward the sheet body.

10. A vehicle comprising a battery as claimed in any one of claims 6 to 9.