WO2021243611A1

WO2021243611A1 - Insulating tape, electrode plate and electrochemical device

Info

Publication number: WO2021243611A1
Application number: PCT/CN2020/094221
Authority: WO
Inventors: 戴志芳; 龙海
Original assignee: 宁德新能源科技有限公司
Priority date: 2020-06-03
Filing date: 2020-06-03
Publication date: 2021-12-09
Also published as: CN112805347A

Abstract

Provided are an insulating tape, and an electrode plate and electrochemical device using the insulating tape. The insulating tape comprises a substrate and a coating layer. The substrate comprises a first surface and a second surface arranged opposite to each other. The coating layer is arranged on the first surface. The coating layer comprises hard particles and an adhesive, wherein the weight of the hard particles is 30-99% of the total weight of the coating layer. In the present application, by using the hard particles in the coating layer, there is no shrinkage in the insulating tape during a nail penetration test of an electrochemical device, so that the pass rate of the nail penetration test of the electrochemical device can be improved.

Description

Insulating tape, pole piece and electrochemical device

Technical field

This application relates to the field of electrochemical devices, and in particular to an insulating tape, a pole piece using the insulating tape, and an electrochemical device.

Background technique

Lithium-ion batteries have many advantages such as large volume and mass energy density, long cycle life, high nominal voltage, low self-discharge rate, small size, and light weight, and have a wide range of applications in the field of consumer electronics. With the rapid development of electric vehicles and portable electronic devices in recent years, people have higher and higher requirements for the energy density, safety, and cycle performance of lithium-ion batteries.

The nail penetration test is a more stringent safety test for lithium-ion batteries. It is used to test the ability of the lithium-ion battery to withstand short circuits. Since there is an empty foil area in the inner ring of the lithium-ion battery, an aluminum-anode short circuit will occur during the nail penetration test, which will cause the lithium-ion battery to fail. In order to improve the pass rate of the nail penetration test, a common method is to extend the green glue at the starting position of the cathode diaphragm to cover the empty foil area to avoid short circuit of the aluminum anode. However, because green glue tends to shrink at high temperatures, it cannot solve the problem of nail penetration failure, so new technical solutions need to be developed.

Summary of the invention

Based on the above shortcomings of the prior art, the present application provides an insulating tape capable of improving the nail penetration rate of an electrochemical device, as well as a pole piece and an electrochemical device using the insulating tape.

The embodiment of the present application provides an insulating tape, which includes a substrate and a coating. The substrate includes a first surface and a second surface that are oppositely disposed. The coating is provided on the first surface. The coating includes hard particles and an adhesive, wherein the weight of the hard particles accounts for 30% to 99% of the total weight of the coating, and the hardness of the hard particles is ≥3 Mohs' hardness.

The insulating tape provided by the present application utilizes the high hardness characteristics of hard particles, so that the insulating tape still maintains stiffness even when the base material shrinks, and continues to play an insulating role. When applied to an electrochemical device, the current collector is continuously insulated and isolated during the nail penetration test, so as to avoid the short circuit of the aluminum anode caused by the exposure of the current collector during the nail penetration test, thereby improving the pass rate of the nail penetration test.

In some embodiments, the insulating tape further includes an adhesive layer, and the adhesive layer is disposed on the second surface or the side of the coating away from the substrate. By providing the adhesive layer, the viscosity of the insulating tape can be increased, and when the adhesive layer is placed on the coating, the coating can be prevented from falling off.

In some embodiments, the thickness of the adhesive layer is 1 μm-10 μm, so that the insulating tape can have suitable adhesion.

In some embodiments, the weight of the hard particles accounts for 85% to 99% of the total weight of the coating.

In some embodiments, the weight of the hard particles accounts for 85% to 90% of the total weight of the coating, so that the insulating tape can maintain high stiffness and viscosity.

In some embodiments, the hard particles are ceramic particles, and the ceramic particles include at least one of alumina, boehmite, magnesium hydroxide, barium sulfate, calcium silicate, or titanium dioxide.

In some embodiments, the thickness of the coating is 3 μm to 19 μm, and the thickness of the substrate is 6 μm to 30 μm. The thickness of the coating and the substrate meets the above requirements, so that the coating can resist the shrinking force of the substrate, thereby suppressing the shrinkage of the substrate.

In some embodiments, the adhesive includes carboxymethyl cellulose, styrene butadiene rubber, polyvinylidene fluoride, polytetrafluoroethylene, fluorinated rubber, polyurethane, polyacryl alcohol, sodium polyacrylate, polyether amide or acrylic At least one of esters.

In some embodiments, the substrate includes at least one of polyethylene terephthalate, polyimide, polyvinyl chloride, polypropylene, or polyethylene.

The embodiment of the present application also provides a pole piece, which includes a current collector, an active material layer, and the above-mentioned insulating tape. The active material layer is provided on at least one surface of the current collector. The insulating tape is arranged on the current collector and connected with at least one end of the active material layer.

The embodiment of the present application also provides an electrochemical device, including a battery cell, the battery cell includes a first pole piece, a second pole piece, and a diaphragm arranged between the first pole piece and the second pole piece, the first pole piece and At least one of the second pole pieces is the above pole piece.

Description of the drawings

In order to more clearly explain the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some implementations of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

FIG. 1 is a schematic diagram of the structure of an insulating tape provided by an embodiment of the application.

FIG. 2 is a schematic diagram of the structure of an insulating tape provided by another embodiment of the application.

FIG. 3 is a schematic structural diagram of an insulating tape provided by another embodiment of this application.

FIG. 4 is a schematic structural diagram of an electrochemical device provided by an embodiment of the application.

Symbol description of main components

Insulating tape 100

Base material 120

First surface 121

The second surface 123

Coating 140

Hard particles 141

Adhesives 143

Glue layer 160

Cell 200

The first pole piece 210

The second pole piece 220

Diaphragm 250

The first episode of fluid 221

The first active material layer 213

The first uncoated area 214

Coating area 215

The second uncoated area 216

The second episode of fluid 221

The second active material layer 223

The following specific embodiments will further illustrate this application in conjunction with the above-mentioned drawings.

detailed description

The following describes the technical solutions in the embodiments of the present application clearly and completely in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of them. Based on the implementation manners in this application, all other implementation manners obtained by a person of ordinary skill in the art without creative work shall fall within the protection scope of this application.

Please refer to FIG. 1, an embodiment of the present application provides an insulating tape 100 including a substrate 120 and a coating 140. The substrate 120 includes a first surface 121 and a second surface 123 opposite to each other. The coating 140 is disposed on the first surface 121. In this embodiment, the coating 140 completely covers the first surface 121. In other embodiments, the coating 140 may partially cover the first surface 121.

The substrate 120 is used to carry the coating 140, and its material can be polyethylene terephthalate (PET), polyimide (PI), polyvinyl chloride (PVC), polypropylene (PP) or polyethylene ( Single components such as PE) can also be combined with two or more materials.

The coating 140 includes hard particles 141 and an adhesive 143. The hard particles 141 have high structural strength. Ceramic particles with high hardness and light weight can be used, such as at least one component selected from alumina, boehmite, magnesium hydroxide, barium sulfate, calcium silicate, and titanium dioxide. . The weight of the hard particles 141 accounts for 30% to 99% of the total weight of the coating 140, that is, the mass percentage of the hard particles 141 in the coating 140 is 30% to 99%. The hard particles 141 in the coating 140 make the coating 140 have a higher stiffness. When the substrate 120 shrinks, the coating 140 will maintain its stiffness under the action of the hard particles 141 without shrinking with the substrate 120, that is, the insulating tape 100 still maintains its stiffness, so that it can shrink on the substrate 120. Under the circumstance, continue to insulate and protect the covered components. When the insulating tape 100 is applied to a lithium-ion battery, the local heat generated by the nail penetration test will only shrink the substrate 120, while the coating 140 still maintains stiffness, which can avoid the short circuit of the aluminum anode caused by the exposed current collector. Improve the nail penetration rate of lithium-ion batteries. The hard particles 141 are particles with a hardness ≥ 3 Mohs hardness.

When the mass percentage of the hard particles 141 is less than 30%, the coating 140 cannot maintain its stiffness when the substrate 120 shrinks, and will shrink as the substrate 120 shrinks. When the mass percentage of the hard particles 141 is greater than 99%, the coating layer 140 cannot have sufficient viscosity to make it adhere to the substrate 120, and the problem of shedding may easily occur.

In some embodiments, the mass percentage of the hard particles 141 in the coating 140 is 85% to 90%, so that the stiffness of the coating 140 can be optimized and the coating 140 has a suitable viscosity.

The thickness of the coating 140 will affect the shrinkage of the substrate 120. In this embodiment, the thickness of the coating layer 140 is 3 μm to 19 μm, and the thickness of the substrate 120 is 6 μm to 30 μm. After the thickness of the coating layer 140 and the thickness of the substrate 120 meet the above conditions, the coating layer 140 can resist the shrinkage force of the substrate 120, thereby suppressing the shrinkage of the substrate 120. If the thickness of the coating layer 140 is less than 3 μm, it cannot resist the shrinkage force of the substrate 120. In some embodiments, the thickness of the coating 140 is 8 μm-10 μm, and the thickness of the substrate 120 is 6 μm-10 μm.

The adhesive 143 is used to bond a large number of hard particles 141 together to form the coating 140 and make the coating 140 sticky. The adhesive 143 can be made of a material with strong oxidation resistance, so that it can maintain a more stable chemical performance in a lithium ion battery environment. In some embodiments, the adhesive 143 includes carboxymethyl cellulose, styrene butadiene rubber, polyvinylidene fluoride, polytetrafluoroethylene, fluorinated rubber, polyurethane, polyacryl alcohol, sodium polyacrylate, polyether amide, or At least one of acrylates.

In some embodiments, the substrate 120 is a release substrate, and the first surface 121 is a release surface, and relative slippage may occur between the coating 140 and the substrate 120. When the insulating tape 100 is needle-punched, the substrate 120 slips relative to the coating 140, and the coating 140 does not shrink.

Please refer to FIG. 2. In some embodiments, the insulating tape 100 further includes an adhesive layer 160. The adhesive layer 160 is disposed on the second surface 123 of the substrate 120 to increase the adhesiveness of the insulating tape 100. The adhesive layer 160 includes at least one of a pressure sensitive adhesive and a hot melt adhesive. The material of the adhesive layer 160 can be any currently known adhesive, such as a single component such as polyacrylic, polyurethane, epoxy, silicone, etc., or a mixed group of two or more. point. The thickness of the adhesive layer 160 is 1 μm-10 μm, and the viscosity of the adhesive layer 160 is greater than 20 N/m. In some embodiments, the thickness of the adhesive layer 160 is 4 μm to 8 μm.

Please refer to FIG. 3, in some embodiments, the glue layer 160 is disposed on the side of the coating layer 140 away from the substrate 120. By arranging the adhesive layer 160 on the side of the coating 140 away from 120, the coating 140 is sandwiched between the adhesive layer 160 and the substrate 120, which increases the viscosity of the insulating tape 100 and prevents the coating 140 from falling off. .

Please refer to FIG. 4, the electrochemical device provided by an embodiment of the present application includes a battery cell 200. The cell 200 includes a first pole piece 210, a second pole piece 220 and a diaphragm 250. The diaphragm 250 is disposed between the first pole piece 210 and the second pole piece 220. The first pole piece 210, the diaphragm 250, and the second pole piece 220 are sequentially stacked and wound to form the battery core 200. In this embodiment, the first pole piece 210 is a cathode pole piece, and the second pole piece 220 is an anode pole piece.

The first pole piece 210 includes a first current collector 211, a first active material layer 213, and the aforementioned insulating tape 100. The first active material layer 213 is disposed on two opposite surfaces of the first current collector 211. In some embodiments, the first active material layer 213 may be provided on only one surface of the first current collector 211. The first current collector 211 includes a first uncoated area 214, a coated area 215, and a second uncoated area 216 along the winding direction, wherein the first uncoated area 214 and the second uncoated area 216 are not The first active material layer 213 is provided, and at least one surface of the coating area 215 is provided with the first active material layer 213. The winding direction in this application is counterclockwise. The first uncoated area 214 is located at the position where the steel nails pass during the nail penetration test of the electrochemical device. The insulating tape 100 is disposed in the first uncoated area 214 and connected to an end of the first active material layer 213 adjacent to the first uncoated area 214. During the nail penetration test, the substrate 120 of the insulating tape 100 shrinks at the local high temperature caused by the local aluminum anode short circuit, but the hard particles 142 in the coating 140 prevent it from shrinking at high temperatures, so that The first current collector 211 covered by the insulating tape 100 will not be exposed, thereby preventing further aluminum anode short circuit.

In some embodiments, the insulating tape 100 may also be arranged in the second uncoated area 216 and connected to the end of the first active material layer 213 away from the first uncoated area 214; or arranged in the coated area 215 The side of the first current collector 211 facing away from the first active material layer 213. It should be noted that the insulating tape 100 can be disposed at any position on the first pole piece 210 that needs to be insulated, such as a tab position.

The second pole piece 220 includes a second current collector 221 and a second active material layer 223. The second active material layer 223 is disposed on two opposite surfaces of the second current collector 221. In some embodiments, the second pole piece 220 may further include the above-mentioned insulating tape 100, and the insulating tape 100 may be disposed on the second pole piece 220 where insulation is required.

In some embodiments, the materials of the first current collector 221 and the second current collector 221 can be selected from Ni, Ti, Cu, Ag, Au, Pt, Fe, Co, Cr, W, Mo, Al, Mg, K , Na, Ca, Sr, Ba, Si, Ge, Sb, Pb, In, Zn, and at least one of combinations (alloys) thereof.

In some embodiments, the first active material layer 213 includes a cathode active material capable of absorbing/releasing lithium (Li). For example, it may include lithium cobalt oxide, lithium nickel cobalt manganate, lithium nickel cobalt aluminate, lithium manganate, and phosphoric acid. Lithium iron, lithium vanadium phosphate, lithium vanadyl phosphate, lithium iron phosphate, lithium titanate, and lithium-rich manganese-based materials; the second active material layer 223 includes an anode active material capable of absorbing/releasing lithium (Li), for example, it may include carbon Materials, metal compounds, oxides, sulfides, lithium nitrides such as LiN3, lithium metal, metals that form alloys with lithium, and polymer materials.

The preparation process of the lithium ion battery in the examples of the application and the comparative example is as follows.

Example 1

(1) Preparation of insulating tape

Using PI film as the substrate, mixing alumina ceramic particles and carboxymethyl cellulose adhesive and coating on one side of the PI film to form a coating, and coating polyacrylate glue on the side of the coating away from the substrate An adhesive layer is formed, and an insulating tape is obtained after curing. The thickness of the substrate is 6 μm, the thickness of the adhesive layer is 1 μm, the viscosity of the adhesive layer is 20 N/m, the coating thickness is 19 μm, and the mass percentage of ceramic particles in the coating is 85%.

(2) Preparation of cathode electrode piece

The cathode active material lithium cobalt oxide, conductive agent acetylene black, and binder polyvinylidene fluoride (PVDF) are mixed thoroughly in the N-methylpyrrolidone solvent system at a mass ratio of 94:3:3, and then coated on After drying, cold pressing and slitting on the anode current collector Al foil, anode pole pieces are obtained.

(3) Preparation of anode pole piece

The cathode active material artificial graphite, conductive agent acetylene black, binder styrene butadiene rubber (SBR), thickener sodium carboxymethyl cellulose (CMC) in a deionized water solvent system at a mass ratio of 96:1:1.5:1.5 After being fully stirred and mixed uniformly, it is coated on the cathode current collector Cu foil to form a cathode active material layer, and the insulating tape is attached to the surface of the Cu foil and connected to one end of the cathode active material layer to obtain a negative electrode piece.

(4) Preparation of electrolyte

The solution prepared by lithium salt LiPF ₆ and non-aqueous organic solvent (ethylene carbonate (EC): propylene carbonate (PC) = 50:50, mass ratio) at a mass ratio of 8:92 is used as the electrolysis of lithium ion batteries liquid.

(5) Preparation of lithium ion battery

The cathode electrode piece and the anode electrode piece are wound, and the cathode electrode piece and the anode electrode piece are separated by a PE isolation film, thereby obtaining a battery cell as shown in FIG. 4. Put the electric core in the packaging shell, inject the electrolyte and encapsulate to obtain the lithium ion battery.

Example 2

The preparation method is consistent with the preparation method of Example 1, except that the thickness of the adhesive layer of Example 2 is 4 μm, the thickness of the coating is 3 μm, and the mass percentage of ceramic particles in the coating is 95%.

Example 3

The preparation method is consistent with the preparation method of Example 1, except that in Example 3, a PET film is used as the substrate, the adhesive layer has a viscosity of 100 N/m, and the mass percentage of ceramic particles in the coating is 95%.

Example 4

The preparation method is consistent with the preparation method of Example 1, except that in Example 4, a PET film is used as the substrate, the thickness of the adhesive layer is 4 μm, and the viscosity of the adhesive layer is 100 N/m.

Example 5

The preparation method is consistent with the preparation method of Example 1, except that the thickness of the substrate of Example 5 is 30 μm, the viscosity of the adhesive layer is 100 N/m, and the coating thickness is 3 μm.

Example 6

The preparation method is consistent with the preparation method of Example 5, except that the thickness of the adhesive layer of Example 6 is 4 μm, the thickness of the coating is 19 μm, and the mass percentage of ceramic particles in the coating is 95%.

Example 7

The preparation method is the same as in Example 5, except that in Example 7, PET is used as the substrate. The adhesive layer has a viscosity of 20N/m, the thickness of the coating is 19μm, and the mass percentage of ceramic particles in the coating is 95 %.

Example 8

The preparation method is consistent with the preparation method of Example 5, except that PET is used as the substrate in Example 8, the thickness of the adhesive layer is 4 μm, and the viscosity of the adhesive layer is 20 N/m.

Example 9

The preparation method is the same as that of Example 5, except that PET is used as the substrate in Example 7, and the mass percentage of ceramic particles in the coating is 80%.

Example 10

The preparation method is consistent with the preparation method of Example 5, except that in Example 7 PET is used as the substrate, the adhesive layer has a viscosity of 20 N/m, and the mass percentage of ceramic particles in the coating is 75%.

Example 11

It is consistent with the preparation method of Example 1, except that the preparation method of the insulating tape of Example 11 is:

Using PI film as the substrate, mixing alumina ceramic particles and carboxymethyl cellulose adhesive and coating on one side of the PT film to form a coating, and coating polyacrylate glue on the side of the substrate facing away from the coating An adhesive layer is formed, and an insulating tape is obtained after curing. The thickness of the substrate is 6 μm, the thickness of the adhesive layer is 1 μm, the viscosity of the adhesive layer is 100 N/m, the coating thickness is 19 μm, and the mass percentage of ceramic particles in the coating is 95%.

Example 12

The preparation method is consistent with the preparation method of Example 11. The difference is that in Example 12, PET is used as the substrate. The adhesive layer has a viscosity of 20N/m, the thickness of the coating is 3μm, and the mass percentage of ceramic particles in the coating is 85. %.

Example 13

The preparation method is consistent with the preparation method of Example 11, except that the thickness of the glue layer in Example 13 is 4 μm, the thickness of the coating is 3 μm, and the mass percentage of ceramic particles in the coating is 85%.

Example 14

The preparation method is consistent with the preparation method of Example 11, except that in Example 14, a PET film is used as the substrate, the thickness of the adhesive layer is 4 μm, and the viscosity of the adhesive layer is 20 N/m.

Example 15

The preparation method is consistent with the preparation method of Example 11, except that the thickness of the substrate in Example 15 is 30 μm, the viscosity of the adhesive layer is 20 N/m, and the thickness of the coating layer is 3 μm.

Example 16

The preparation method is consistent with the preparation method of Example 15, except that in Example 16, a PET film is used as the substrate, the thickness of the adhesive layer is 4 μm, and the viscosity of the adhesive layer is 100 N/m.

Example 17

The preparation method is the same as in Example 15, except that in Example 17, PET film is used as the substrate. The adhesive layer has a viscosity of 100N/m, the thickness of the coating is 19μm, and the mass percentage of ceramic particles in the coating is 85%. .

Example 18

The preparation method is consistent with the preparation method of Example 15, except that the thickness of the glue layer in Example 17 is 1 μm, the thickness of the coating is 19 μm, and the mass percentage of ceramic particles in the coating is 85%.

Example 19

The preparation method is consistent with the preparation method of Example 13, except that the mass percentage of the ceramic particles in the coating of Example 19 is 30%.

Example 20

The preparation method is consistent with the preparation method of Example 19, except that the mass percentage of the ceramic particles in the coating of Example 20 is 99%.

Examples 21-23

The preparation method is consistent with the preparation method of Example 19, except that the thickness of the coating layer, the thickness of the glue layer and the mass percentage of the ceramic particles are different in Examples 21-23.

Comparative example 1

The preparation method is consistent with the preparation method of Example 12, except that the thickness of the coating of Comparative Example 1 is 19 μm, and the mass percentage of ceramic particles in the coating is 0%.

Comparative example 2

It is consistent with the preparation method of Comparative Example 1, except that the adhesive layer of Comparative Example 2 has a viscosity of 100 N/m.

Comparative example 3-6

The preparation method is consistent with the preparation method of Comparative Example 1, except that the thickness of the coating layer, the thickness of the adhesive layer and the mass percentage of ceramic particles of Comparative Examples 3-6 are different.

The nail penetration test was performed on the lithium ion batteries of Examples 1-23 and Comparative Examples 1-6. The nail penetration test method is: fully charge the lithium-ion battery at 25°C, and then carry out the nail penetration test on the lithium ion battery. The nail penetration rate is 100mm/s, the diameter of the steel nail is 3mm, and the nail penetration test is If the lithium-ion battery does not explode or does not catch fire, it will pass. Each group of 10 lithium-ion batteries is tested, and the pass rate of the lithium-ion battery nail penetration test is calculated. The experimental parameters and measurement results of Examples 1-23 and Comparative Examples 1-6 are shown in Table 1 below.

Table 1

From the test results in Table 1, it can be seen that the nail penetration results of lithium-ion batteries are closely related to the mass percentage of ceramic particles. It can be seen from Examples 1-8 and 11-18 that when the mass percentage of ceramic particles is greater than 85%, the nail penetration rate reaches 100%. It can be seen from Examples 7-10 and Comparative Examples 1-2 that when the mass percentage of ceramic particles is less than 85%, as the mass percentage of ceramic particles decreases, the nail penetration rate will also decrease.

What has been disclosed above is only the preferred embodiments of this application, which of course cannot be used to limit this application. Therefore, equivalent changes made in accordance with this application still fall within the scope of this application.

Claims

An insulating tape, characterized in that it comprises:

The substrate includes a first surface and a second surface that are arranged oppositely;

The coating layer is arranged on the first surface, the coating layer includes hard particles and a binder, and the weight of the hard particles accounts for 30% to 99% of the total weight of the coating. Hardness ≥ 3 Mohs hardness.
8. The insulating tape of claim 1, wherein the insulating tape further comprises an adhesive layer, and the adhesive layer is disposed on the second surface or the side of the coating away from the substrate.
3. The insulating tape of claim 2, wherein the adhesive layer has a thickness of 1 μm to 10 μm.
The insulating tape of claim 1, wherein the weight of the hard particles accounts for 85% to 99% of the total weight of the coating.
The insulating tape of claim 1, wherein the hard particles include ceramic particles, and the ceramic particles include at least one of alumina, boehmite, magnesium hydroxide, barium sulfate, calcium silicate, or titanium dioxide. A sort of.
The insulating tape of claim 1, wherein the thickness of the coating is 3 μm to 19 μm.
The insulating tape according to claim 1, wherein the thickness of the base material is 6 μm to 30 μm.
The insulating tape of claim 1, wherein the adhesive comprises carboxymethyl cellulose, styrene butadiene rubber, polyvinylidene fluoride, polytetrafluoroethylene, fluorinated rubber, polyurethane, polyacryl alcohol, At least one of sodium polyacrylate, polyether amide sub or acrylate.
A pole piece, characterized in that it comprises:

Current collector

The active material layer is provided on at least one surface of the current collector; and

The insulating tape according to any one of claims 1 to 8, which is provided on the current collector and connected to at least one end of the active material layer.
An electrochemical device includes a battery cell, the battery cell includes a first pole piece, a second pole piece, and a diaphragm arranged between the first pole piece and the second pole piece, and is characterized in that: At least one of the first pole piece and the second pole piece is the pole piece of claim 9.