TW472413B - Graphite electrode binder including polyethylene oxide additive - Google Patents

Abstract

An electrochemical cell according to the present invention includes positive and negative electrodes and an electrolyte, wherein at least one of the electrodes includes a carbonaceous active material and polyethylene oxide (PEO). The carbonaceous active material is preferably graphite. The electrode also preferably includes styrene-butadiene (SB) latex, which is mixed with the graphite and PEO prior to being applied to a current collector. By utilizing PEO with a latex binder, a suitable binder for a graphite electrode may be provided that does not utilize any organic solvents. Further, the use of PEO surprisingly reduces the irreversible capacity of an electrode made with KS44 graphite.

Description

472413 A7 B7 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the invention (Background of the invention: The invention is about the electrode binding material used in the pool. The 2i of the invention is about the preparation of carbonaceous active material The binding material of the electrode. It is well known to use the binding material in the battery electrode prepared with a special active material. It has been commercially used and disclosed in many patents a large number of different polymers and copolymers and combinations thereof. The selection depends on the type of battery to be used in the battery design, the production and combination method to be used, and the expected battery performance type. Effective binding materials must provide good cohesion of the active electrode material and active electrode material on the conductive electrode. Good adhesion of the electrode current collector. These features are of great importance in order to minimize internal resistance in terms of good high-speed performance and maximize the use of active materials during battery discharge and charging. At the electrode Must be maintained during winding processing and during electrode expansion and contraction during discharge / charge Cohesion and adhesion. The choice of the combination must also be compatible with the method of coating the anode and cathode mixtures to their respective current collectors and the method of removing those solvents necessary for coating. The resulting electrode must be sufficient Allows the flexibility of the winding without damage. The combination used must also be compatible with the electrode. The final electrode's good electrical conductivity and ion conductivity also have the importance of good capacitance and high-speed performance. Often Many combinations used in non-aqueous battery electrodes, such as ethylene-propylene copolymers, ethylene-propylene-diene terpolymers (EPDM), and polyvinylidene fluoride (PVDF) are only soluble in organic solvents. Use these combinations The organic-organic solvent system will avoid environmental problems related to the handling and disposal of these solvents-^ The paper size applies the Chinese National Standard (CNS) A4 specification (; 2iOX 297 mm) — III—— —! — — —— — ^; III l · I-^ «— —— — — — II II (Please read the notes on the back before filling this page) 472413 A7 B7 V. Explanation of the invention (2). Therefore, No need to use Organic solvents are used to prepare conjugate solutions. Some known conjugates, such as carboxymethyl cellulose (cmc) and polyacrylic acid (PAA), are water-soluble, and these have been found to be unsuitable for use in rechargeable batteries. . Has used carboxylated styrene-butadiene (SB) or styrene-associated acid (SA) copolymer as a latex conjugate. Because of its excellent properties, it is desirable to use SB as a second non-aqueous The combination of battery electrodes is expected to be SB latex, because it avoids the user's health and environmental issues related to the organic solvents used in the electrode manufacturing method. However, not all graphite, common anode materials and s The latex mixture was satisfactorily handled. One method of making an anode involves coating a thin coating of graphite and latex conjugate released in a slurry on a metal foil substrate, such as a steel foil. However, these muds are not stable enough for some production areas. The previous plan of roller-coated latex-bonded graphite electrodes was unsuccessful 'mainly due to two problems, namely the unstable mixture and insufficient wetting ability. Regarding the problem of instability of the mixture, it should be noted that graphite will rapidly deposit in the latex mixture due to its large particle size and low liquid (water) viscosity. The larger the particles, the denser the particles. The less dense the liquid phase and the lower the viscosity of the liquid, the faster the deposition. Because latex is mainly water, the density of the liquid phase is basically the density of water. The polymer in the latex does not increase the viscosity of the liquid phase because the polymer is not in the dissolved state. As a result, a water or water / latex layer quickly forms on the top of the mixture tank. With regard to this water-rich top layer, the paint roller has made it difficult to remove the mixture and transfer it to the copper mesh. Regarding the problem of wetting ability, the graphite mixture combined with latex is not enough. -5- This paper size applies to the national standard of China (CNS) A4 (210 X 297). (Please read the precautions on the back before filling this page. ) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs

ϋ in n n I n-*-T-nJI n n n n n i I I n I I I n n n n I -1 n n n I n n n n n n n n I 472413 A7 B7 V. Description of the invention (3) Wet or copper carrier or roller coated roller. If the agitation of the slurry is stopped, the water / latex phase will immediately separate from the graphite 'and the slurry will not be sufficient to wet the metal foil substrate. Assuming continuous mixing to avoid deposition of the mixture, the negative electrode has an uneven coating ' with bare spots, lumps, and a high degree of surface roughness. Graphite / S B latex also has the consistency of wet sand, so it will not flow smoothly. In order to make the anode 'by the wiping method, the slurry must have a uniform consistency, smooth flow, and completely wet the coating roller. Therefore, it is desirable to use thickeners to obtain the necessary viscosity and wetting characteristics. In many applications' latex compounds include thickeners to achieve the viscosity required for processing. Some examples of thickeners include sulfonyl cellulose, sodium carboxymethyl cellulose, sodium polyacrylate, alginates, sycamore gum, casein, starch, locust wood gum, bentonite clay, and crushed acid fish, although they can be used Many of the above-mentioned thickeners achieve a viscosity suitable for processing and improve the stability and wetting characteristics of the mixture required for use in an electrode having a carbonaceous active material. For example, methylcellulose will provide the necessary effects on the stability and coating performance of the mixture, but it is unlikely to be suitable for lithium ion (Li-lithium) batteries because of the large number of hydroxyl groups and their potential to interact with Li. Therefore, there is a need to improve the ability to use graphite / SB latex mud in the roll coating method. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a binder used in an electrode prepared from a carbonaceous active material such as graphite, which does not require the use of an organic solvent. Another object of the present invention is to provide a combination of carbonaceous electrodes that exhibits good cohesion and adhesion characteristics. Another object of the present invention is to provide a uniform electrode coating that can be easily mixed with a carbonaceous active material and coated with a roll coating method. 6- This paper is sized to Chinese National Standard (CNS) A4 (210 X 297) (Mm) (Please read the notes on the back before filling out this page) Order --------- Line 丨 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 472413 A7 B7 V. Description of Invention (4). Still another object of the present invention is to provide an electrode which can be formed using a graphite / Sb latex slurry. To achieve these and other objects and advantages, the electrochemical cell of the present invention includes positive and negative electrodes and an electrolyte, at least one of which includes a carbonaceous active material, latex, and polyethylene oxide. The carbonaceous active material is preferably graphite. The latex is preferably SB latex, which is mixed with graphite and polyethylene oxide before being coated on a conductive current collector strip. Adding a small amount of polyethylene oxide (PEO) to the S B latex will effectively overcome the problems described above. Graphite and SB latex each have a wet sand consistency and are not easy to process. However, PEO, which improves the wettability of graphite powder, will be dispersed in graphite in the liquid phase, resulting in a smooth mixture with applicable viscosity. PEO has the effect of acting as a reticulum agent to increase continuous liquid viscosity, thereby reducing the number of collisions between particles and reducing the amount of deposition. PEO also improves the wettability of metal surfaces. It allows the use of latex mixtures and improved metal electrode current collector mixing ranges and adhesion to them on roller coating equipment with metal coated rollers. Immediately after stopping the stirring of the mixture, the water / latex phase was separated from the graphite without PEO additives. When PEO is used, there is no separation of graphite or latex for several hours to several days (it depends on the amount of PEO added). From an optimal processing point of view, a small amount of PEO is required, and the stability of the mixture increases with an increase in the amount of PEO. It produces a smooth mixture with a processable viscosity, which provides a very smooth and uniform coating. In addition to the advantages of its improved electrode manufacturing method, PEO also has a significant beneficial effect on the electrochemical performance of rechargeable Li-ion batteries. Impossible -7- This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm). Rit read the back, notes before filling in this page} Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs on consumer cooperation Du-nnnnn- * -T-0J nnn I · IIII n I nnnnnnnni I-472413 Α7 Β7 V. Description of the invention (5) Reverse capacitance is a common problem for batteries containing a negative electrode containing a carbonaceous active material. The irreversible capacitance is defined as the difference in capacitance between the initial power cycle and the first discharge cycle. It has been unexpectedly found that the use of at least a minimum amount of PEO in a mixture can greatly reduce the irreversible capacitance below the intrinsic intrinsic reversible capacitance of the active material. The theoretical amount of PEO required to minimize the irreversible capacitance is related to the molecular weight of PEO and the surface area of the carbonaceous material. Performance considerations can also set an upper limit on the amount of PEO actually used. If too much PEO is used, it may adversely affect the internal resistance and subsequent high-speed performance (performance under heavy discharge conditions). Those skilled in the art can further understand and recognize these and other features, advantages, and objectives of the present invention by referring to the following application, patent application scope, and accompanying drawings. A brief description of the figure is shown in the figure: Fig. 1 is a mixture diagram illustrating various mixture formulations of PEO, latex and graphite in a favorable range; Fig. 2 is a performance map showing an experimental formula that passes a coating ability test; Performance chart of the experimental formula of the stability test of the mixture; Figure 4 shows the performance chart of the first cycle discharge capacity measured with the active mixture of milliamps / gram according to the formula of each mixture; Figure 5 shows the formula of the various mixtures Performance chart of the measured masking data; Figure 6 is a performance chart showing the irreversible capacitance data of the first cycle measured for each mixture formula; -8-

¥ Paper size Guzhong @ 0 house standard (CNS) A4 specification (210 X 297 male H (Please read the precautions on the back before filling out this page) Printed by the Employee Consumption Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs

-nn 1 nn ^ -OJI nnnnnnn II n < 1 nnn I nnnnnnt— nnnnn I 472413 A7 B7 Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention (6) Figure 7 shows the measured formula for each mixture Performance graph of tensile adhesive strength; Figure 8 is a graph showing the performance of the first cycle discharge capacitance measured with a mixture of milliamps per gram of each mixture formulation; Figure 9 is a graph showing the formulation for each mixture Measure the performance chart of the first cycle discharge capacitance measured with the electrode coating of milliamps per milliliter; Figure 10 is a performance chart showing a better mixture formula; Figure 11 is a display showing the next best mixture formula Performance chart; Figure 12 is a statistically generated compression profile to show the effect of mixture variation on tensile adhesive strength; Figure 13 is a statistically generated compression profile to show the effect of mixture formulation variation on fading; 14 is a statistically generated profile chart to show the effect of mixture formula variation on irreversible capacitance; Figures 15A-15C are examples of three experimental mixture formulas Figures of irreversible capacitance; Figures 16A-16E are statistically generated compression profiles that achieve perfect masking, irreversible capacitance, and tensile strength at various feed rates designated as fade, irreversible capacitance, and tensile strength. Mixture formula. Detailed description of the preferred embodiment. The electrochemical cell according to the present invention includes positive and negative electrodes and an electrolyte. At least one of the electrodes (preferably a negative electrode (anode) is preferred) is configured as a current collector, and it is coated with a mixture including a carbonaceous active material, SB latex, and pp〇. The current collector is preferably in the form of a conductive mesh, such as a box, sieve, and expansion. -9-This paper size applies to China National Standard (CNS) A4 specifications (210: (Please read the note on the back? Matters before filling out this page)

II-l · n I- Iir ° J nnn I nnn I-III nn 1 III n II n I-n I- n--I-I 472413 A7 k 〇Foil made of steel or aluminum Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs

5. Description of the invention (7) Sheet metal or metal foam is preferred. The carbonaceous active material is preferably graphite. The electrode combination structure of the spiral winding according to the present invention is preferably used to form positive and negative electrodes on an elongated conductive box strip, so that the electrodes are spirally formed by a separator layer disposed between the electrodes. The windings around the shaft < are inserted into the box with the electrode assembly holding the helical winding, and the liquid electrolyte is dispersed in the box. The electrode group of the green group ^ may have a circular shape for use in a circular battery or may be an oval shape for use in an edge-opening cell. The electrode combination may be replaced by a flat positive and negative electrode with a dividing layer ^ Alternating layers of electrodes. Alternative non-aqueous polyelectrolyte can be placed between the negative and positive electrodes. Utilizing the material structure that produces Li-ion batteries, the electrochemical cell of the present invention is better. In order to produce ^ i-ion battery chemistry It is better to coat the positive electrode with U deintercalable active material (LiMn204, LiC02 or UNi02) and the negative electrode with u intercalaM active material (such as graphite or other carbonaceous materials). Mixture of latex, PEO and graphite The preliminary evaluation of these examples demonstrates that these formulations can be applied on a roll coater and properly wet the current collector and maintain sufficient stability for large-scale manufacturing processes. In order to achieve a mixture formulation that not only achieves perfect wetting ability and stability of the mixture It can also achieve perfect electrochemical performance, so experiments are performed to make the mixture formula in the mixture characteristics, mixture processing ability, electrode adhesion And electrochemical performance characterization. Prepare 20 mixtures (including 7 replicates and 13 single formulas). In these mixtures, the amount of milk in the mixture can vary from 0 to 8% by volume. The amount of PE in the mixture can be changed from 0 to 8% by volume and within -10- This paper size applies Yin National Standard (CNS) A4 specifications (Magic ο X 297 mm) {Please read the precautions on the back before filling (This page) --- Order --------- line! 472413 A7 B7 V. Description of the invention (8) The amount of graphite in the mixture can be changed from 8 4 to 9 2 volume. The mixture formula is shown graphically in the mixture diagram, and the volume percentage of each component is shown in the following figure. Formula No. Batch No. Latex PEO Graphite 1 3 0.0800 0.0800 0.8400 2 2 0.0000 — | 0.0800 0.9200 3 2 0.0400 0.0800 0.8800 4 2 0.0579 0.0221 0.9200 5 2 0.0800 0.0221 0.8979 6 1 0.0579 0.0800 0.8621 7 1 0.0800 0.0579 0.8621 8 1 0.0221 0.0800 0.8979 9 1 0.0221 0.0579 0.9200 10 1 0.0400 0.0400 0.9200 11 2 0.0533 0.0533 0.8933 12 1 0.0800 0.000 0 0.920 13 1 0.0800 0.0400 0.8800 (Please read the notes on the back before filling out this page) Printed and analyzed by the Consumers' Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs about the coating ability (success / failure), stability (rough estimation in latex / water) The time elapsed before separation and / or graphite deposition) and the percentage of air volume in the mixture (estimated by comparing a solid gram / ml mixture to a calculated gram / ml mixture). Each mixture consists of 25 grams of water supply and 56.3 milliliters of water. The reported latex volume percentage is considered to be the solid volume of the latex, excluding the liquid portion of the latex fluid. The latex used was SB latex, Rovene 4076 (from Unocal / Rohm & Haas) 'which is 50% by weight solids. Use pE〇 is 600 〇 〇〇〇 -11- This paper size applies Chinese National Standard (CNS) A4 specifications (210

-nn I n one OJ I nn I n I n II (I a ^ fn I-^ 1 nnnn 1 n I- I 297 mm) Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 472413 A7 •-B7 V. Description of the invention (9) Polyox 205 'PEO (from Union Carbide Chemicals) with a molecular weight. The graphite used is a KS44 synthetic graphite (from Lonza) with a special BET surface area of 9 square meters per gram. The total water content can vary slightly with the mixture because it is derived from latex (50% solids by weight) component Contribution. Prior to adding the remaining mixture components, the latex was mixed with water with a 2-gas mixer at low speed for 5 minutes. The mixture was processed in a 250 ml stainless steel beaker. Graphite was slowly added to the water / latex mixture and stirred in an air-started mixer at 900-1000 rpm for 5 minutes. PE0 was then slowly added to the mixture 'and the mixture was stirred with a mixer at 90,000 rpm for 4 5 minutes before coating. Handle and analyze the electrode load, filling 'adhesion (axial winding and tension test) and electrochemical performance. For the adhesion test, a 3M Scotch Mount high-density open-cell polyurethane roll with a 1 / 8-inch thick adhesive on both sides was punched out with a diameter of 15 inches. Adhesive tape tray. Remove the protective cover on one side of the adhesive tape tray, and adhere it to the ACCuForCe500 force plate, paying attention to ensure that they are aligned with each other. Then, remove the protective cover of the tape tray, and place a piece of electrode material with the coating side up on the backing sheet of the double-sided tape to make sure to cover the entire adhesive layer. Close the gap between the tape reels until the force gauge reads 0.5 kg. Then zero the table. The force will be increased until the watch reads 30 kg. The purpose is to ensure that the sample is evenly attached to the adhesive tape and the test board. Set the meter to record the peak force, and manually separate the pressure plate, applying tension in an attempt to break the adhesive tape. Assume that it is recorded on the coating peeling foil substrate (Please read the precautions on the back before filling this page) -----: ---- Order --------- Line! i

472413 A7

V. Description of the invention (10) When printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, the load is printed to indicate the adhesion strength of the coating. Assume that when the peak load of the coating is separated from the tape or the tape is separated from the platen, the adhesive strength of the coating is greater than the adhesiveness of the tape to the electrode or platen. Dividing the kilogram reading by the tape area converts the kilogram reading into kilograms per square inch or kilograms per square centimeter. The measurement shows the adhesive strength of the coating. The first cycle charge utilizes a voltage swing from 30 volts to 5 volts at 1 millivolt / second, and a voltage swing from 15 volts to 0.0005 volts at a swing speed of 1 millivolt / second. The 00 second potential static pressure was maintained at 0.0005 volts to Ll. Discharge is included! The voltage swing from millivolts per second from 0.0005 volts to 1 ^ to .5 volts to Ll. The number of seconds after four cycles is similar to the first, except that the charging voltage is not repeated from 30 volts to 15 volts. Electrochemical tests were performed on a 1-cm-cm single-sided electrode in a reference test cell and a reference electrode with a lithium metal counter. Using a ^ gram molecular weight UPFS EC / DMC (67/33 weight) electrode and a borosilicate slope fiber filter (from GF / D grade of Whatman International Ltd., Mddstone, UK), before using it Dry at 25 ^ τ. The average electrode filling range for each batch at the time of coating was from 308 to% (average 32.87%). The average final filling of the batch after compaction was from 52.29% (average 47.52%). Use the instructions above to evaluate the spreading ability and stability of the mixture based on success / failure. If the coating completely wets the surface of the foil and does not "，", then the mixture can be considered coatable. "匍匐" is defined as dehydration of a coating applied on a large area or edge of a board or component. The coating ability was found to be related to the volume percentage of PEO in the mixture. Observed to have at least 2 ^ body --------------------- order --------- line! (Please read the notes on the back before filling in this page} -13- 472413 A7 B7 V. Description of the invention (h) t / kPECH compound is coatable. No, it is mixed with ㈣. 〇vol% PEO, 8.0% by volume latex) does not wet the copper surface and is therefore not coatable. Due to the lack of coating ability, the mixture of Formula 12 was excluded for further study. The mixture is considered stable if it is observed for 10-15 minutes after the mixing has stopped without any evidence of latex or graphite separation or deposition. Mixtures that begin to separate within 10-15 minutes after the mixing is stopped are not considered to be stable enough for roller coating purposes. It was observed that only 2.2% by volume of the peo mixture started to separate within 10 to 15 minutes after the mixing was stopped. When the mixing has been stopped 5 to 5 minutes or longer, no separation was observed with a larger amount of PEO. The average response data for each response variation is shown in Figure 2-9 with the formula as a function. In particular, Figure 2 shows the coating ability as a function of the formulation, Figure 3 shows the stability of the mixture, Figure 4 shows the measured first-cycle discharge capacitance (milliampere / gram of active material), and Figure 5 shows discoloration (milliseconds). Ampere / gram of active material per cycle), Figure 6 shows the irreversible capacitance of the first cycle (milliampere / gram of active material), Figure 7 shows the tensile viscosity strength, and Figure 8 shows the discharge capacity of the first cycle (Milliampere / mixture gram volume) and Figure 9 shows the first cycle discharge capacity (milliampere / electrode coating milliliter volume) at 50% fill. Response mapping provides a stable comparison of performance as a function of recipe. The first cycle discharge capacity is listed in terms of milliamps per gram of active substance (Figure 4), milliamps per gram of mixture (Figure 8), and milliamps per liter of paint (Figure 9). However, only milliamps / milliliter of coating is used for the performance levels shown below. Confirm each variation -14- This paper size applies to Chinese National Standards (CNS> A4 size (210 X 297 mm) (Please read the notes on the back before filling this page) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs

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Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 472413 A7 B7 V. Description of the Invention (13) The total levels are shown in Figures 10 and 11. Intersecting lines in Figure 10 indicate those better formulations because of acceptable performance in the 6 response areas. Good formulations that meet 5 acceptable criteria in 6 performance areas are indicated in Figure 11. It was observed that all response variations of the following three formulations reached an acceptable range: 4.0 vol% 2PE0 and 4.0 vol% latex; 5 33 vol% PEO and 5.33 vol% latex and 4.0 vol% pE0 and 800 vol% Of latex. Recipes are further graded in each response category. The best performance in the classification is +1, the medium performance is 0, and the worst performance is _j. Variations in coating ability and stability were excluded in the second grade because it was a success / failure variation. Although these three special formulas have achieved acceptable performance, the second grade recommendation of 5,33 / 5 33 PE〇 / latex formula is the best, followed by 4.0 / 8.0 PEO / latex formula and then 4.0 / 4.0 PEO / latex formula. To better evaluate the best formula, use the

HCHessin City, 724 Yorklyn Road, 350, 19707-8703 ECHIP statistical analysis and experimental design software for statistical analysis. Statistical analysis was performed using a quadratic private formula. Use this program to estimate the continuously changing imaginary response surface. The quadratic equation was chosen because it includes the meaning of line shapes, interactions, and quadratic elements, and it demonstrates the best correction between measured and suitable 値. However, the coating capability and mixture stability are not analyzed by Echip's response surface program, because none of the variations and measurements are continuous. Use the ECHIP response surface program to analyze the following continuous response variations: ⑴axis adhesion (weight% remaining after winding); (ii) tensile adhesion (kg n 5 inch diameter sample); (Hi) in milliseconds ( (Please read the notes on the back before filling out this page)

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472413 A7 B7 V. Description of the invention (14) Capacitance of the first cycle discharge expressed in ampere / gram of active substance; (iv) Discoloration (milliampere / gram of active substance in each cycle after 4 cycles) (v) irreversible Capacitance (capacitance of the first cycle discharge minus the capacity of the second cycle discharge) (milliampere / gram of active material); (vi) Capacitance of the first cycle discharge expressed in milliamps / gram of mixture; vii) Capacitance of the first cycle discharge expressed in milliamps / milliliter of paint; and percentage of air volume in the mixture. No significant change in axial adhesion was observed for any of the mixture changes. Axial adhesion data range from 99.6 to 100% favorable full mixture. As a result, it can be considered to exclude cardiac tackiness in achieving the best mixture formulation. However, many mixture changes have a significant effect on tensile adhesive strength. It was found that the graphite volume percentage had the most obvious effect. With an effective amount of 0.1%, it was found that the tensile adhesive strength would increase with the increase in the amount of graphite. The amount of graphite in the test effect was ~ 9.85 kg. Both latex and PEO were found to have no significant effect. At an effective amount of 1%, it is found that the tensile adhesive strength increases with the amount of PEO and latex. All the latexes and PEOs tested were 3.58 kg of PEO and 3.41 kg of latex. The interactions between latex and PEO, latex and graphite, and peO and graphite were observed at an efficiency of 5%. It was also found that the amount of PEO had a secondary effect of an effective amount of 5%. Figure 12 shows the tensile adhesive strength profile. The "㊉" symbol represents the formulation of the maximum tensile adhesive strength within the limits of the mixture variation used in this experiment. The optimal adhesive strength of 16.25 kg is predicted to occur in a mixture formulation containing 8.0% by volume of latex and 7.59% by volume of 2PEO. -17- This paper size is in accordance with China National Standard (CNS) A4 (210 X 297 Gongchu) (Please read the precautions on the back before filling this page) Order --------- line 丨 Ministry of Economy Wisdom Printed by the Consumer Cooperative of the Property Bureau 472413 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention (15) No observable mixture variation was measured first in milliamps per gram of active substance. The discharge capacity of the secondary cycle has a significant effect. Also, no change in the mixture was observed for the first cycle discharge capacity measured in milliamps / mixed gram units or milliamps / paint milliliter units. Figure 13 shows the outline of the stem color. There is no obvious gradation or coexisting effect on nude colors. However, there is a secondary effect on each mixture variation. These are effective amounts to 5%. The nature of the secondary effect can be seen in the faded outline drawing in Figure 1 3, which shows that the composition represented by the π㊉ "mark has a bowling ball-shaped response surface with the least discoloration. The mark represents 4.34% by volume of latex and 4.91 Mixture of 混合物 0% by volume. Changing the volume percentage of any of the three mixture components from this optimal formula will increase the rate of fading. To observe the secondary effect, it is suggested that the perfection of the formula is important because it is too much or Too few combinations can cause high fading rates. Many variations have been found to significantly affect the irreversible capacitance of the first cycle. Figure 14 shows the outline of the irreversible capacitance of the first cycle. Suggestions based on the real data shown in Figure 6 The step function in the irreversible capacitance, when the ratio of PE 0 to graphite increases, the irreversible capacitance will be significantly reduced. The irreversible capacitance data is discussed in the following two stages: (1) Also known as the step function response and variation will The irreversible capacitance of the active material at a high graphite and low PEO content of 14.7 mAh / g is reduced to a large amount at low graphite and high P The amount of 45.4¾ amperes / gram of active material in EO, and (2) the second discussion of the irreversible capacitance changes from a relatively small amount of about 4 6-6 5 amperes / gram of active material. About the step function response, self-profile Drawing (Figure 14) and -18- This paper size applies to Chinese national standard (CNS> A4 specification (210 X 297 mm) --- I -------- k .------- Order ------ I--line IC, please read the precautions on the back before filling out this page: > Printed by the Employee Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 472413 A7 B7 V. Description of the invention (16) Irreversible capacity data The graph (Figure 6) shows that when the content of PEO increases, the irreversible capacitance will be significantly reduced. The maximum irreversible capacitance is observed under the combination of low PEO content and high graphite content, and it is observed under the combination of high PEO content and low graphite content. To the smallest irreversible capacitance. When the electrode's PEO content increases from 2.2 to 4.0 vol%, the irreversible capacitance will increase significantly: PEO vol% and graphite vol% are effective variations. The first-order effects of PEO and graphite and PEO Interactions with graphite all have an effective amount of up to 0.1%. About These first-order interactions have observed that the irreversible capacitance will increase with the increase of the amount of PEO and will decrease the amount of graphite. The interaction between PEO and graphite will even impact the irreversible capacitance of the first cycle of these variations Greater than the first order effect. If the PEO content is increased while reducing the graphite content (compared with 2.2 vol% PEO and 92 vol% graphite with 8.0 vol% PEO and 84 vol% graphite), the first The irreversible capacitance will decrease significantly in one cycle. The interaction effect containing latex is less important (5% amount). Of course, the effect of changing the latex content can be expressed by the amount of graphite in PEO. Increasing both PEO and latex at the same time will reduce the irreversible capacitance more than any one of them, because when PEO and latex increase, the graphite content must decrease. Increasing both graphite and latex at the same time will increase the irreversible capacitance more than any one of them alone, because when graphite and latex are increased at the same time, the PEO content will decrease. When PEO volume. /. Since 2.2 volumes. /. When it is increased to a larger amount, the cyclic voltammetry data of the irreversible capacitance can be adjusted, as shown in the diagrams in Figure 15A-15C. The three graphic comparisons shown in Figures 15A-15C contain 2.2 volumes each. -19- This paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) ------------- 14. ·· ---- r --- Order · -------- Line (Please read the precautions on the back before filling this page) 472413 A7 ~ " " -------- — B7__ 5. Description of the invention The first and second cycle charge curves of (17)%, 4.0% by volume and 8.0% by volume electrodes. There is another peak (identified by # 2) on the first cycle charge curve 'which is only present in cells containing 2.2 vol% PEO. This peak did not appear in electrodes containing more than 2.2% by volume < PEO. This peak was also observed for the non-combined KS44 electrode and is believed to be an intrinsic property of KS44 graphite. This peak above the PEO vol% limit meets the use pH. The mechanism of the nomadic compound coated on the graphite active material to avoid the occurrence of peak # 2 in the electrochemical reaction. PEO is soluble in the liquid phase of the latex_pE0_graphite mixture and enables it to coat the surface of graphite particles. It is expected that the amount of PEQ required to eliminate the second irreversible capacitance peak is related to the volume percentage of graphite in the mixture and the surface of the graphite particles (ie, the total graphite surface area in the mixture). ECHIP analysis data clearly exemplifies the interaction between PEO volume percentage and graphite volume percentage, and shows statistical significance. The primary effect of PEO and graphite and the interaction between pE〇 and graphite are due to the PE 0 coating on the surface of graphite particles and the elimination of two peaks of irreversible capacitance. Eliminating this second peak will significantly reduce the irreversible capacitance of the graphite electrode. Similar effects can be expected to have a high solubility in the coating solution (water in this example) and other binders that adhere perfectly to the graphite particles. Latex conjugates do not have the same effect as PE0 because latex particles are not soluble in coating solvents' and therefore do not effectively coat graphite particles. It is not easy to understand the secondary effect of PE0 (0.01% effective amount) and graphite (5% effective amount) and the first-order effect of latex (0.01% effective amount) by step function response and PEO coating mode. The data shown in Figure 6 and the outline shown in Figure 14 _ -20- This paper size applies to China National Standard (CNS) A4 (210 X 297 cm) (Please read the precautions on the back before filling out this page) Line-Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economics Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economics Printed by the Consumer Cooperatives of the Ministry of Economic Affairs 472413 A7 B7 V. Description of the Invention (18) The drawing can be seen that the irreversible electrode contains electrodes greater than 2.2% by volume? £ 0 There are some variations in capacitance. None of these electrodes includes the additional irreversible capacitance peaks discussed above, and there is no significant pattern difference in the battery's cyclic voltammetry curve. The secondary effect of PEO is very important and is evidenced by the irreversible capacitance that changes when the PEO content increases from 2.2 vol% to 8.0 vol% at a graphite content fixed at 92.0 vol%. When PEO is increased from a very low amount (2.2% by volume) to a medium amount (4.0-5.8% by volume), the irreversible capacitance will decrease, and when the PEO content increases to 8.0% by volume, the irreversible capacitance will increase. When the PEO content increased from 4.0% by volume to 8.0% by volume, it was 89.8% by volume. / 〇 the same effect will occur under graphite. This data suggests that factors other than the PEO coating of individual graphite particles are affecting the irreversible capacity of the first cycle. The secondary effect of the percentage of graphite body has an effective amount of up to 5%, and it is relatively difficult to observe from the data. A first-order effect with irreversible capacitance to an effective amount of 0.1% was also observed for latex volume percentage. Statistical analysis suggests that as the latex content increases, the irreversible capacitance will increase. This is the most likely PEO and graphite-effect product, because the low PEO / high graphite mixture also includes a large amount of latex conjugates, because of the irreversible high capacitance at high latex content. Electrodes with high latex and high PEO content will not exhibit irreversible high capacitance. In fact, when the PEO content > 2.2% by volume of PEO, as the latex volume percentage increases (and the graphite volume percentage decreases), the irreversible capacitance increases. There is no change in the mixture. The percentage of air volume in the mixture is clear. -21-This paper size applies the Chinese National Standard (CNS) A4 (210 X 297 mm) ------------- "- ----: ---- Order --------- line (please read the notes on the back before filling this page) 472413 A7 B7 V. Description of the invention (19 (Please read the notes on the back first (Fill on this page again). The effect is observed. The mixture is included in the air from 37_49% by volume of air. The percentage of air volume in the mixture can be required to be reduced from the observed 値 to zero to increase the packing density after coating. Therefore, the decimal fraction compared to the predicted maximum effect does not guarantee perfect variation of the optimal formulation. Anti-foaming agents or air mixing are two alternative methods of reducing the air volume percentage in the mixture. It is possible to get air volume percentages that are significantly lower than those predicted by the best formula. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs because the volume percentage in the mixture and the first cycle discharge capacity will not be significantly affected by the mixture The effects of variations in the formulation are excluded from the optimal formulation. Therefore, 'only those variations that are found to be significantly affected by the mixture formulation (that is, tensile adhesive strength, fading, and irreversible capacitance for the first cycle) are covered. In the best formula, the first attempt to achieve the best of all three variations is to weight the average of all three variations. To maximize the tension and adhesion, minimize the fading and reduce the irreversible capacitance of the first cycle The lowest. The results of the best formula are shown in Figure 16A. It can be predicted that the electrode prepared with this formula has a tensile adhesive strength of 5.29 kg '3.98 milliamps per gram and the fade rate of the active substance and 29.70 milliamps per gram. The irreversible capacitance of the active substance. Because the predicted rate of fading is greater than a better amount of 3.0 milliamperes per gram of active substance per cycle and the predicted stickiness is generally greater than the minimum of 5.0 kg, a series of The best formula of the formula is to change the tensile adhesive strength from 1 (shown in Figure 16A) to 0 (shown in Figure 16E). In Figures 16A-16E The contours of these best formulas are shown. All five best formulas suggest a PEO amount of 5.7-5.8% by volume. To -22- this paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 472413 A7 _—.___ B7 V. Description of the Invention (20) The recommended formula based on ECHIP analysis includes latex from 4.9 to 6.4% by volume, which is based on The weight of the tensile adhesive strength provided by the one-time irreversible capacitance depends on the weight of the PEO and latex, and the preferred amount of graphite is between about 87.8 to 89.4% by volume of the electrode mixture. Although the above experiments were performed using KS44 graphite as an active material, the PEO-latex conjugate can be used with other carbonaceous active materials. For example, other shapes of amorphous carbon or graphite can also be used, such as mesophase graphite, natural graphite, or other synthetic graphite. However, it should be noted that the irreversible capacitance effect cannot be as effective as in the KS44 example, as these other carbon and graphite may not include the inherent second peak exhibited by KS44. Those graphites that are expected to show additional peaks in the charge curve can benefit from using the PEO-latex conjugate formulation of the present invention. Moreover, although the S B latex is described, it is expected that other compatible combinations (such as SA) may be used in place of the S B latex used in the above experiments. The above description is to be regarded as merely a preferred embodiment. Modifications of the invention will occur to those skilled in the art and to those skilled in the art or skilled in the art. Therefore, of course, the specific embodiments illustrated in the figures and described above are for illustrative purposes only, and are not intended to limit the scope of the present invention defined by the scope of the following patent applications, which are described in accordance with patent principles (including Doctrine of Equivalents). -23- This paper size applies to Chinese National Standard (CNS) A4 (210 X 297 meals) n n n n n n n n I ^ n n n I-i-f-- ° JI n n n n I (Please read the precautions on the back before filling this page)

Claims (1)

472413 6. .7. 8. This paper is printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. 9. An electrochemical cell containing positive and negative electrodes and electrolytes, at least one of which includes carbonaceous active material, latex, and polyepoxide. Ethane. The electrochemical cell according to item 1 of the patent application scope, wherein the carbonaceous biomass is graphite. The electrochemical cell ' according to item 1 of the patent claim, wherein the latex is styrene-butadiene. The electrochemical cell according to item 3 of the application, wherein at least one of the electrodes further comprises a current collector coated with a mixture containing between 4.9-6.4% by volume of a styrene-butadiene latex. The electrochemical cell according to item 1 of the patent application scope, wherein at least one of the electrodes further comprises a volume comprised between about 2.2-8.0. / 〇 的 Polyethylene oxide fired mixture coated current collector. The electrochemical cell according to item 1 of the application, wherein at least one of the electrodes further includes a metal foil current collector coated thereon with a mixture of the carbonaceous active material, latex, and ethylene oxide. The electrochemical cell according to item 6 of the application, wherein the metal foil current collector is a copper foil. The electrochemical cell according to item 1 of the patent application scope, wherein at least one of the electrodes further comprises a current collector coated with a mixture containing polycyclofluorene in an amount of about 5.7 to 5.8% by volume. The electrochemical cell according to item 1 of the patent application scope, wherein at least one of the electrodes further comprises a mixture containing at least about 87.8% by volume of graphite, at least about 4.9% by volume of latex, and at least about 5.7% by volume of polyethylene oxide. Coated current collector. -24 National Standard (CNS) A'l Specification (210 X 297 mm) -------------- Xiang ------- Order -------- -Line (please read the precautions on the back before filling this page) ^^ 413 Patent application scope 10. The electrochemical cell according to item 1 of the patent application scope, wherein at least one of the electrodes further includes a current collector coated with graphite of about 87.8 to 89.4% by volume with a winter man. Among them, the electrochemical cell 11, the electrochemical cell according to item 1 of the applied patent garden, is a secondary Li-ion battery. Wherein the positive and the positive and the negative electrode windings of the electrochemical cell according to item 1 of the scope of patent application are combined into an electrode. 13. According to the scope of the patent application, the negative electrode of the electrochemical cell is combined into a stack of alternating positive and negative electrodes. H: a kind of secondary electrode with a negative electrode and an electrolyte. Latex and polymer: 15. The electrochemical cell according to item (2) of the patent claim, wherein the electrode further includes a latex containing at least about 87.8% by volume of stone ◎ 1% by volume of latex and about 5.7% by volume of polymer. Ethylene oxide-coated current collector. 's% line 16. The electrochemical cell according to item 14 of the patent scope, wherein to the heart ~ the electrode further includes an electric current coated with a mixture containing ^ = Oki of about 2.2.8.0% by volume collector. Wu Π. The electrochemical cell according to item 14 of the scope of the patent application, wherein the electrode further includes a current collector coated with a mixture containing about 57-58% by volume of ethane. Oxygen 18. The electrochemical cell according to item 4 of the scope of the patent application, wherein the electrical connection further includes a stupid solid with a content of between about 4.9-6.4% by volume. -25- This paper applies the national standard (CNS) / V1 specification (2ί0Γ_297mm) 472413 _—J88 VI. Patent application scope Butadiene mixture coated current collector. 19. An electrochemical cell according to item 14 of the scope of patent application, wherein at least one of the electrodes further comprises a current collector coated with a mixture containing approximately 88.8-89 4% by volume of graphite. 20. The electrochemical cell according to item 14 of the scope of patent application, wherein the negative electrode includes a current collector coated with a mixture consisting of graphite, styrene-butadiene latex, and an amount sufficient to stabilize the mixture. 21.-An electrode for use in an electrochemical cell, comprising a current collector coated with a mixture of carbonaceous active material rhenium, latex, and polycycloe. 22. The electrode according to item 21 of the application, wherein the electro-hydraulic collector is a metal box. 23. The electrode according to item 22 of the patent application park, wherein the metal box is copper foil. (Please read the precautions on the back before filling in this page) Packing-line _ Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 26- This paper size applies to China National Standard (CNS) A. 丨 Specifications (210 X 297 mm)