COMPOSITION COMPRISING A COMB COPOLYMER

Abstract

The invention relates to a composition comprising a) a polymer a) comprising polymerized units of a N-vinyl lactam, b) a comb copolymer b) having a polymer backbone based on a vinyl aromatic compound and an ethylenically unsaturated polymerizable carboxylic anhydride, and having at least two polyalkylene oxide side chains, and c) a carbon-based material.

Claims

1. A composition comprising a) a polymer a) comprising polymerized units of a N-vinyl lactam, b) a comb copolymer b) having a polymer backbone based on a vinyl aromatic compound and an ethylenically unsaturated polymerizable carboxylic anhydride, and having at least two polyalkylene oxide side chains, and c) a carbon-based material.

2. The composition according to claim 1, wherein polymer a) comprises polymerized units of N-vinylpyrrolidone.

3. The composition according to claim 1, wherein the weight average molecular weight of polymer a) is in the range of 2.000 to 500.000 g/mol, preferably 5.000 to 100.000 g/mol.

4. The composition according to claim 1, wherein the polyalkylene oxide side chains of comb polymer b) are linked to the polymer backbone via an amide group or an imide group.

5. The composition according to claim 1, wherein the comb copolymer b) comprises further functional groups comprising at least one of hydroxyl, carboxylic acid, salt of carboxylic acid, tertiary amine, salt of tertiary amine, and quaternary ammonium.

6. The composition according to claim 1, wherein the weight average molecular weight of comb polymer b) is in the range of 4.000 to 100.000 g/mol.

7. The composition according to claim 1, wherein the weight ratio of polymer a) to comb copolymer b) is in the range of 10:90 to 90:10.

8. The composition according to claim 1, wherein the composition comprises at least one organic solvent.

9. The composition according to claim 8, wherein the organic solvent comprises N-methyl pyrrolidone.

10. The composition according to claim 1, wherein the water content of the composition is in the range of 0.0 to 5.0% by weight, calculated on the total weight of the composition.

11. The composition according to claim 1, wherein the carbon-based material is electrically conductive and comprises at least one of carbon black, carbon nano tubes, graphite, carbon fibers, graphene, and fullerenes.

12-13. (canceled)

14. A process of preparing a carbon-based material dispersion comprising the steps of i) providing a composition comprising a) a polymer a) comprising polymerized units of a N-vinyl lactam, and b) a comb copolymer b) having a polymer backbone based on a vinyl aromatic compound and an ethylenically unsaturated polymerizable carboxylic anhydride, and having at least two polyalkylene oxide side chains, ii) providing a carbon-based material, iii) mixing the components provided in steps i) and ii) and exerting shear force to prepare a carbon-based material dispersion.

15. A rechargeable electrical battery having an electrode comprising the composition according to claim 1.

16. The rechargeable electrical battery according to claim 15, wherein polymer a) comprises polymerized units of N-vinylpyrrolidone.

17. The rechargeable electrical battery according to claim 15, wherein the comb copolymer b) comprises further functional groups comprising at least one of hydroxyl, carboxylic acid, salt of carboxylic acid, tertiary amine, salt of tertiary amine, and quaternary ammonium.

18. The rechargeable electrical battery according to claim 15, wherein the weight ratio of polymer a) to comb copolymer b) is in the range of 10:90 to 90:10.

19. The rechargeable electrical battery according to claim 15, wherein polymer a) comprises polymerized units of N-vinylpyrrolidone, and wherein the comb copolymer b) comprises further functional groups comprising at least one of hydroxyl, carboxylic acid, salt of carboxylic acid, tertiary amine, salt of tertiary amine, and quaternary ammonium.

20. The composition according to claim 1, wherein polymer a) comprises polymerized units of N-vinylpyrrolidone, and wherein the comb copolymer b) comprises further functional groups comprising at least one of hydroxyl, carboxylic acid, salt of carboxylic acid, tertiary amine, salt of tertiary amine, and quaternary ammonium.

Description

EXAMPLES

[0062] Raw materials:

[0063] Potassium carbonate: (Sigma-Aldrich)

[0064] (Dowanol) PMA: 1-methoxy-2-propyl acetate (DOW Chemicals)

[0065] SMA 2000: Styrene-maleic anhydride copolymer (molar ratio of styrene/maleic anhydride=2/1) (Cray Valley)

[0066] Jeffamine M 2070: Amine-terminated EO/PO polyether (Huntsman)

[0067] Lutensol AO11: Fatty alcohol (number of carbon: 13-15) ethoxylate (repeating unit of polyethylene glycol=11) (BASF)

[0068] DMAPA: N,N-Dimethylaminopropylamine (Huntsman)

[0069] Grilonit RV 1814: Alkyl (number of carbon: 13-15) glycidyl ether (EMS-GRILTECH)

[0070] Benzoic acid: (Sigma-Aldrich)

[0071] AMP: 95% of Aminomethyl propanol and 5% of water, (Sigma-Aldrich)

[0072] NMP: N-Methylpyrrolidone (BASF)

[0073] DISPERBYK-111: Acidic polymer, acid value=129 mg KOH/g (BYK-Chemie)

[0074] Measurement of Non-Volatile Content (Solids Content)

[0075] The sample (2.0±0.2 g of the tested substance) was weighed accurately into a previously dried aluminum dish and dried for 20 minutes at 150° C. in the varnish drying cabinet, cooled in a desiccator and then reweighed. The residue corresponds to the solids content in the sample (ISO 3251).

[0076] Measurement of the Amine Value

[0077] 1.5 to 3.0 g of a dispersant was precisely weighed out into a 80 mL beaker and dissolved with 50 mL of acetic acid. Using an automatic titration device provided with a pH electrode, this solution was neutralization-titrated with a 0.1 mol/L HClO.sub.4 acetic acid solution. A flexion point of a titration pH curve was used as a titration endpoint, and an amine value was obtained by the following equation (DIN 16945).

Amine value[mg KOH/g]=(561×0.1×f×V)/(W×S)

[0078] (wherein f: factor of titration agent, V: titration amount at titration endpoint [mL], W: weighed amount of dispersant sample [g], S: solid matter concentration of dispersant sample [wt %])

[0079] Measurement of the Acid Value

[0080] 1.5 to 3.0 g of a dispersant was precisely weighed out into a 80 mL beaker and dissolved with 50 mL of ethanol. Using an automatic titration device provided with a pH electrode, this solution was neutralization-titrated with a 0.1 mol/L ethanolic KOH solution. A flexion point of a titration pH curve was used as a titration endpoint, and an amine value was obtained by the following equation (DIN EN ISO 2114).

Acid value[mg KOH/g]=(561×0.1×f×V)/(W×S)

[0081] (wherein f: factor of titration agent, V: titration amount at titration endpoint [mL], W: weighed amount of dispersant sample [g], S: solid matter concentration of dispersant sample [wt %])

[0082] Gel Permeation Chromatography (GPC)

[0083] Weight-average molecular weight Mw was determined according to DIN 55672-1:2007-08 at 40° C. using a high-pressure liquid chromatography pump (WATERS 600 HPLC pump) and a refractive index detector (Waters 410). As separating columns, a combination was used of 3 Styragel columns from WATERS with a size of 300 mm×7.8 mm ID/column, a particle size of 5 μm, and pore sizes HR4, HR2 and HR1. The eluent used was tetrahydrofuran with 1% by volume of dibutylamine, with an elution rate of 1 ml/min. The conventional calibration was carried out using polystyrene standards.

[0084] Synthesis of Comb Copolymer C-1

[0085] 85 g PMA was added into a reactor. 21 g SMA 2000 was added during stirring, while the mixture was heated up to 70° C. Then, 64 g of Jeffamine M 2070 and 4 g of DMAPA were added dropwise to the reactor. The reaction was carried at 170° C. for 4 hours. PMA was distilled off during the reaction. Mw of the polymer was 30210 g/mol.

[0086] In a next step, the reactor was cooled down to 120° C. Then, 9 g of Grilonit RV 1814 and 4 g of benzoic acid were added to the reactor. The reaction was carried out at 120° C. for 4 hours. After that, a comb copolymer C-1 was obtained.

[0087] The comb copolymer C-1 has a 100% solid content, an amine value of 18 mg KOH/g and an acid value of 8 mg KOH/g.

[0088] Synthesis of Comb Copolymer C-2

[0089] 85 g PMA was added into a reactor. 21 g SMA 2000 was added during stirring, while the mixture was heated up to 70° C. Then, 79 g of Jeffamine M 2070 was added dropwise to the reactor. The reaction was carried at 170° C. for 4 hours. After solvent-removal at reduced pressure, a comb copolymer C-2 was obtained.

[0090] The comb copolymer C-2 has a 100% solid content and an acid value of 27 mg-KOH/g. Mw of the comb copolymer C-2 was 31220 g/mol.

[0091] Synthesis of Comb Copolymer C-3

[0092] 85 g PMA is added into a reactor. 21 g SMA 2000 was added during stirring, while the mixture was heated up to 70° C. After addition of 0.4 g potassium carbonate, 43 g Lutensol AO11 was added dropwise and the reactor was heated up to 140° C. for 4 hours.

[0093] In a next step, PMA was distilled off at 150° C. at reduced pressure. After cooling down to 80° C., 30 g NMP was added to the reactor. After adding 6 g AMP, followed by homogenization, comb copolymer C-3 was obtained.

[0094] The comb copolymer C-3 has a 70% theoretical solid content (solvent: NMP), an amine value of 37 mg KOH/g and an acid value of 27 mg KOH/g. Mw of the comb copolymer C-3 was 9600 g/mol.

[0095] Synthesis of Comb Copolymer C-4

[0096] 50 g PMA was added into a reactor. 13 g SMA 2000 was added during stirring, while the mixture was heated up to 70° C. Then, 24 g of Jeffamin M 2070 was added dropwise to the reactor and the reaction was carried at 170° C. for 4 hours. PMA was distilled off during the reaction. Mw of the comb copolymer was 23590 g/mol.

[0097] In a next step, 50 g NMP was added to the reactor, followed by, 11 g of DISPERBYK-111. The salinization reaction is carried out at 80° C. for 1 hour to obtain the comb copolymer C-4.

[0098] The comb copolymer C-4 has a 50% solid content (solvent: NMP), an amine value of 15 mg KOH/g and an acid value of 18 mg KOH/g.

[0099] Production of Carbon Black Dispersion

[0100] Carbon black: Denka Black (granular) (Denka)

[0101] PVP K30: Polyvinyl pyrrolidone Sokalan K30P (BASF), Mw 40.000 g/mol

[0102] The dispersions were prepared using a paint shaker Disperser DAS 200 (LAU GmbH) and 150 g of 2 mm Zirconia beads. Dispersing time was 3 hours at 30° C.

[0103] General Procedure for Preparing the Carbon Black Dispersions D-1 to D-8

[0104] A comb copolymer (C-1, C-3 and C-4) and PVP K30 stored in a sealed box were dissolved in NMP in a 140 ml glass bottle. Then, carbon black was added and the mixture was dispersed for 3 hours at 30° C. to obtain the respective carbon black dispersion D-1 to D-8 (Details are described in Table 1).

[0105] General Procedure for Preparing Comparative Carbon Black Dispersions CD-1 to CD-3

[0106] Carbon black dispersions CD-1 to CD-3 were prepared using the same procedure as used for carbon black dispersions D-1 to D-8, except that they did not contain PVP K30. (Details are described in Table 1).

[0107] Procedure for Preparing Comparative Carbon Black Dispersion CD-4

[0108] Carbon black dispersion CD-4 was prepared using the same procedure as used for carbon black dispersions D-1 to D-8, except that it did not contain the comb copolymer. (Details are described in Table 1).

TABLE-US-00001 TABLE 1 Recipes of carbon black dispersions D-1 to D-8, and CD-1 to CD-4 Weight ratios between Name of Dispersant comb carbon Comb copolymer PVP copolymer black Carbon Product K30 and PVP Solvent dispersion black (g) name Amount (g) (g) K30 NMP (g) D-1 10.00 C-1 0.75 0.25 75/25 39.00 D-2 10.00 C-1 0.50 0.50 50/50 39.00 D-3 10.00 C-1 0.25 0.75 25/75 39.00 D-4 10.00 C-3 1.07 0.25 75/25 38.68 D-5 10.00 C-3 0.71 0.50 50/50 38.79 D-6 10.00 C-3 0.36 0.75 25/75 38.89 D-7 10.00 C-4 1.00 0.50 50/50 38.50 D-8 10.00 C-4 0.50 0.75 25/75 38.75 CD-1 10.00 C-1 1.00 100/0  39.00 CD-2 10.00 C-3 1.43 100/0  38.57 CD-3 10.00 C-4 2.00 100/0  38.00 CD-4 10.00 1.00  0/100 39.00

[0109] Preparation of Carbon Nano Tube (CNT) Dispersion

[0110] CNT: FT7320 (C-nano)

[0111] The dispersions were prepared using a Paint shaker Disperser DAS 200 (LAU GmbH) and 50 g of 1 mm glass beads. Dispersing time was 12 hours at 30° C.

[0112] General Procedure for Preparing CNT Dispersions D-9 to D-11

[0113] A comb copolymer C-1 to C-3 and PVP K30 stored in sealed box were dissolved in NMP in a 100 ml glass bottle. Then, CNT was added and the mixture was dispersed for 12 hours at 30° C. to obtain the respective CNT dispersion D-9 to D-11 (Details are described in Table 2).

[0114] General Procedure for Preparing Comparative CNT Dispersions CD-5 to CD-7

[0115] CNT dispersions CD-5 to CD-7 were prepared using the same procedure as used for CNT dispersions D-9 to D-11, except that they did not contain PVP K30. (Details are described in Table 2).

[0116] General Procedure for Preparing CNT Dispersion CD-8

[0117] CNT dispersion CD-8 was prepared using the same procedure as used for CNT dispersions D-9 to D-11, except that it did not contain the comb copolymer. (Details are described in Table 2).

TABLE-US-00002 TABLE 2 Recipes of CNT dispersions Weight ratios between Dispersant comb Name of Comb copolymer PVP copolymer CNT Product K30 and PVP Solvent dispersion CNT (g) name Amount (g) (g) K30 NMP (g) D-9 0.50 C-1 0.13 0.13 50/50 49.24 D-10 0.50 C-3 0.18 0.13 50/50 49.19 D-11 0.50 C-2 0.13 0.13 50/50 49.24 CD-5 0.50 C-1 0.25 100/0  49.25 CD-6 0.50 C-3 0.36 100/0  49.14 CD-7 0.50 C-2 0.25 100/0  49.25 CD-8 0.50 0.25  0/100 49.25

[0118] Application Test Results

[0119] Viscosity of Carbon Black Dispersion and CNT Dispersion

[0120] Viscosity of carbon black dispersion was measured by using BROOKFIELD VISCOMETER DV-II+ (BROOKFIELD, upper limitation of viscosity: 1000 mPa.Math.s).

[0121] Particle Size of Carbon Black Dispersion

[0122] Particle size (median diameter: D50) of carbon black dispersion was measured by using Particle Size Analyzer ELSZ-1000 (Otsuka Electronics).

Example 1-6 Viscosity and Particle Size of Carbon Black Dispersion D-2, D-3, and D-5 to D-8

[0123] Viscosity (at 20° C., rotation: 60 rpm) and particle size (D50) of carbon black dispersions D-2, D-3 and D-5 to D-8 are described in Table 3.

TABLE-US-00003 TABLE 3 Viscosity and particle size of carbon black dispersion Name of carbon Viscosity (mPa .Math. s) Particle size Example black dispersion (at 20° C., 60 rpm) (D50, nm) 1 D-2 24 199 2 D-3 28 155 3 D-5 28 183 4 D-6 17 149 5 D-7 62 176 6 D-8 24 145

Comparison Example 1-4: Viscosity and Particle Size of Carbon Black Dispersion CD-1-CD-4

[0124] Viscosity (at 20° C., rotation: 60 rpm) and particle size (D50) of carbon black dispersions CD-1-CD-4 are described in Table 4.

TABLE-US-00004 TABLE 4 Viscosity and particle size of carbon black dispersion CD-1 - CD-4 Comparison Name of carbon Viscosity (mPa .Math. s) Particle size example black dispersion (at 20° C., 60 rpm) (D50, nm) 1 CD-1 Not measured* >1000 2 CD-2 Not measured* >1000 3 CD-3 Not measured* >1000 4 CD-4 65 162 *Viscosity is more than 1000 mPa .Math. s

[0125] According to the results in Table 3 and 4, the carbon black dispersions including the mixture of comb copolymer and PVP (Example 1-6) showed lower viscosity and smaller particle size (D50) compared with those of the carbon black dispersions including comb copolymer only or PVP only (Comparison example 1-4).

Example 7-9: Viscosity of CNT Dispersion D-9-D-11

[0126] Viscosity (at 20° C., rotation: 1 rpm and 100 rpm) is described in Table 5.

TABLE-US-00005 TABLE 5 Viscosity of CNT dispersion D-9 - D-11 Name of CNT Viscosity (mPa .Math. s) Viscosity (mPa .Math. s) Example dispersion (at 20° C., 1 rpm) (at 20° C., 100 rpm) 7 D-9  52 25 8 D-10 42 20 9 D-11 35 20

Comparison Example 5-8: Viscosity of CNT Dispersion CD-5-CD-8

[0127] Viscosity (at 20° C., rotation: 1 rpm and 100 rpm) is described in Table 6.

TABLE-US-00006 TABLE 6 Viscosity of CNT dispersion CD-5 - CD-8 Comparison Name of CNT Viscosity (mPa .Math. s) Viscosity (mPa .Math. s) example dispersion (at 20° C., 1 rpm) (at 20° C., 100 rpm) 5 CD-5 Not measured* Not measured* 6 CD-6 Not measured* Not measured* 7 CD-7 Not measured* Not measured* 8 CD-8 60 26 *Viscosity is more than 1000 mPa .Math. s

[0128] According to the results in Table 5 and 6, the CNT dispersions including the mixture of comb copolymer and PVP (Example 7-9) showed lower viscosity at different shear rates compared with that of the CNT dispersions including comb copolymer only or PVP only (Comparison example 5-8).

[0129] Evaluation of Volume Resistivity

[0130] Volume Resistivity

[0131] The electrode material Li.sub.1+x(Ni.sub.0.5Co.sub.0.2Mn.sub.0.3).sub.1−xO.sub.2(NCM), polyvinylidene difluoride (PVDF) as a binding agent, and a carbon black (CB) dispersion as a conductive auxiliary agent were added to N-methyl-2-pyrrolidone. The mass ratio, based on non volatile material, in a paste of electrode material was NCM:CB:PVDF=93:5:2, and the components were mixed together, thereby preparing the paste of an electrode material.

[0132] The paste of an electrode material was applied to a surface of 180 μm-thick PET sheet so as to form a coating, and the coating was dried, thereby forming a cathode layer on the surface of the PET sheet. After that, this PET sheet with cathode layer was cut to 3 cm width to measure the volume resistivity of the cathode layer.

[0133] In addition, the volume resistivity of the electrode coating was measured by means of a four point measurement using a low resistivity meter (Mitsubishi Chemical Corporation product, model No.:Loresta-AX) at 25° C.

Examples 10-12: Volume Resistivity of Electrode Coatings Prepared with the Carbon Black Dispersions D-4-D-6

[0134] Volume resistivity of the electrode coatings prepared with carbon black dispersion D-4-D-6 is described in Table 7.

TABLE-US-00007 TABLE 7 Volume resistivity of the carbon black dispersion D-4 - D-6 Name of carbon black Volume resistivity Example dispersion (Ω .Math. cm) 10 D-4 29 11 D-5 28 12 D-6 35

Comparison Example 9: Volume Resistivity of the Electrode Coating Prepared with the Carbon Black Dispersion CD-4

[0135] Volume resistivity of the electrode coating prepared with the carbon black dispersion CD-4 is described in Table 8.

TABLE-US-00008 TABLE 8 Volume resistivity of the electrode coating prepared with the carbon black dispersion CD-4 Name of carbon black Volume resistivity Comparison example dispersion (Ω .Math. cm) 9 CD-4 37

[0136] According to the results in Table 7 and 8, the electrode coatings prepared with the carbon black dispersions including the mixture of comb copolymer and PVP (Example 10-12) showed lower volume resistivity compared with that of the carbon black dispersion including PVP only (Comparison example 9).

[0137] Battery Assembly

[0138] 90 wt % of Li.sub.1+x(Ni.sub.0.5Co.sub.0.2Mn.sub.0.3).sub.1−xO.sub.2(NCM), as cathode active material, 5.5 wt % of carbon black (CB) which was supplied as dispersion, and 4.5 wt % of PVDF were combined and mixed in a mixer Dispermat CV (VMA Getzmann GmbH) to prepare a cathode mixture. Subsequently, the cathode mixture was coated, dried, and rolled over aluminum foil having 21 μm-thickness. The cathode mixture was applied in an amount of 15.4 mg/cm.sup.2.

[0139] 96 wt % of graphite, as a electrode active material, 2.0 wt % of carboxymethyl cellulose (CMC), and 2.0 wt % of styrene-butadiene-rubber (SBR) were combined and mixed in a mixer to prepare an anode mixture. Subsequently, the anode mixture was coated and dried and rolled over copper foil having a 17 μm-thickness. The anode mixture was applied in an amount of 8.4 mg/cm.sup.2.

[0140] As the separator, a microporous film made of polypropylene with a thickness of 16 μm was used. The battery structure had the following configuration: cathode/separator/anode. It was assembled in the form of a laminated cell which was impregnated with a carbonate electrolytic solution which contained 1 mol of LiPF.sub.6 dissolved therein and in which a volumetric ratio of ethylene carbonate (EC):propylene carbonate (PC) was 1:1 as an electrolyte to manufacture a battery.

[0141] C-Rate Discharge Performance

[0142] For a battery with a maximum capacity Q, of 22 mAh, a “1 C current would be 22 mA, where the unit C or C-rate is a capacity expressed current in units of 1/h to be multiplied by Q, to get the current in amps.

[0143] C-rate discharge was increased from 0.2 C to 2 C. Then, C-rate discharge capacity was measured as the discharge capacity from 4.3 V to 3.0 V.

[0144] In all these tests, charging was done under constant current of 0.067 C to a voltage limit of 4.3 V and constant voltage to a current limit of 0.03 C while the discharging rate was progressively increased. C-rate performance tests were done at a temperature condition of 25° C.

Example 13-15: C-Rate Discharge Performance of Battery Including the Carbon Black Dispersion D-4-D-6

[0145] C-rate discharge performance of battery including the carbon black dispersion D-4-D-6 is described in Table 9.

TABLE-US-00009 TABLE 9 C-rate discharge performance of battery including the carbon black dispersion D-4 - D-6 C-rate discharge performance Name of carbon Capacity (%) Example black dispersion 0.5 of C-rate 1.0 of C-rate 2.0 of C-rate 13 D-4 100 95 84 14 D-5 100 95 85 15 D-6 100 93 77

Comparison Example 10: C-Rate Discharge Performance of Battery Including the Carbon Black Dispersion CD-4

[0146] C-rate discharge performance of battery including the carbon black dispersion CD-4 is described in Table 10.

TABLE-US-00010 TABLE 10 C-rate discharge performance of battery including the carbon black dispersion CD-4 C-rate discharge performance Comparison Name of carbon Capacity (%) example black dispersion 0.5 of C-rate 1.0 of C-rate 2.0 of C-rate 10 CD-4 100 92 76

[0147] According to the results in Table 9 and 10, the battery including the carbon black dispersions which contain the mixture of comb copolymer and PVP (Example 13-15) showed better C-rate discharge performance compared to the battery including the carbon black dispersion which contains PVP only (Comparison example 10).

[0148] Cycle Test

[0149] For cycle life evaluation of the cell, the cell was repeatedly charged and discharged 0, 50, 100, 200, 400 and 500 times under a temperature condition of 25° C.,

[0150] Charging was done under constant current of 0.067 C to a voltage limit of 4.3 V and constant voltage to a current limit of 0.03 C. Discharge was done under a constant current of 1 C to a voltage limit of 3.0 V.

[0151] The discharge capacity of the 1.sup.st cycle was set as 100%.

Example 16-17: Cycle Test of Battery Including the Carbon Black Dispersion D-5-D-6

[0152] Cycle test of battery including the carbon black dispersion D-5-D-6 is described in Table 11.

TABLE-US-00011 TABLE 11 Cycle test of battery including of the carbon black dispersion D-5-D-6 Name of carbon Cycle test black Cycle (times) Example dispersion 0 50 100 200 400 500 16 D-5 100 98.3 95.1 89.8 81.1 76.4 17 D-6 100 97.5 94.5 89.9 82.8 79.2

Comparison Example 11 Cycle Test of Battery Including the Carbon Black Dispersion CD-4

[0153] Cycle test of battery including the carbon black dispersion CD-4 is described in Table 12.

TABLE-US-00012 TABLE 12 Cycle test of battery including of the carbon black dispersion CD-4 Name of carbon Cycle test Comparison black Cycle (times) example dispersion 0 50 100 200 400 500 11 CD-4 100 96.3 91.9 85.2 71.3 64.4

[0154] According to the results in Table 11 and 12, it is evident that the battery including the carbon black dispersions which contain the mixture of comb copolymer and PVP (Example 16-17) showed better cycle test performance compared to the battery including the carbon black dispersion which contains PVP only (Comparison example 11).