KR20080000902A - Lithium battery using solvent-soluble modified polyimide - Google Patents

Abstract

A lithium battery using a soluble modified polyimide is provided to minimize the self-discharge ratio, to improve the discharge time by at least 50% as compared with conventional batteries, and to realize excellent stability at high and low temperatures. A lithium battery using a soluble modified polyimide comprises an anode whose surface(1) is coated with a soluble polyimide(2) including polyether imide(PEI), polyamide imide(PAI) or polyether imide ester(PEIE), or a copolymer containing at least two of the polyimide compounds. The anode is coated with the soluble polyimide through a spraying or dipping process. The lithium battery comprises an electrolyte containing a lithium salt in combination with an aluminum salt.

Description

Lithium battery using soluble modified polyimide {LITHIUM BATTERY USING SOLVENT-SOLUBLE MODIFIED POLYIMIDE}

1 is a schematic diagram of a negative electrode of a lithium battery according to the present invention;

* Description of the major symbols in the drawings *

1: lithium foil 2: soluble polyimide coating

3: conductive carbon layer

The present invention relates to a lithium battery (Li / SOCl ₂ ) using a soluble modified polyimide, dilute PEI, PAI, PEIEs showing high insulation on the surface of the negative electrode foil of a lithium battery with a solvent and apply it to a lithium surface and dry it The present invention relates to a lithium battery which is manufactured by forming a film to maximize the storage performance of a lithium battery (Li / SOCl ₂ ) and solves the shortcomings of a voltage delay phenomenon when used after long-term storage under extreme conditions.

In general, lithium batteries are small in size, light in weight, high in energy density, small in size, have a larger capacity than general manganese batteries or nickel cadmium batteries, and are widely used as power sources for various electronic devices.

Disadvantages are the lithium salt film formed by reaction of thionyl chloride (SOCl ₂ ) and lithium (Li) on the cathode surface of Li / SOCl _2. This passivation film is used when the battery is left unattended for a long time. This is to suppress the self-discharge phenomenon, which is naturally consumed. It is essential for enhancing the performance of lithium batteries. However, if the battery is used for a long time and the battery is reused, the battery can be discharged for a certain period of time. It is accompanied by a disadvantage of this delayed voltage delay phenomenon.

Many efforts have been made to reduce or eliminate this phenomenon because voltage delays that fail to achieve the required voltage at the start of operation can interfere with the smooth operation of electronic devices.

Conventionally, a lithium battery was manufactured using a slurry electrolyte by adding an electrically conductive filler to a polymer material (usually Teflon-based) or polyimide in a lithium ion battery, and adding an inactive organic solvent. In non-rechargeable Li / SOCl ₂ batteries, the life span of the battery is reached at the end of the reaction between lithium and SOCl ₂ , so that the lithium used as the negative electrode to increase the use time is coated with alkyl cyanoacrylate. After the reaction to form a polymer film, in a more advanced method, by using the aryl cyanoacrylate in the linear reaction method of the general alkyl cyano acrylate secondary crosslinking by aryl occurs to increase the heat resistance and adhesion To increase the solvent resistance to thionyl chloride. Lithium battery prepared by this method was somewhat improved, but the pressure inside the battery was very dangerous when the capacity discharge at that temperature after storage for 40 days at 60 ± 2 ℃ was dangerous.

This confirmed that the hydrolysis proceeds faster as the carbon number of the alkyl group in the cyanoacryl is small, and in the presence of the aryl group in which crosslinking occurs, the decomposition rate is delayed, thereby improving performance of the battery. It is prepared by methyl, ethyl, n-propyl, n-butyl, 2-ethylhexyl, n-octylcyanoacrylate on the glass surface, surface coating, curing, and then obtaining a film to obtain a 0.5% NaOH aqueous solution. Hydrolysis of 7 days, 15 days, and 30 days at 40 ° C. was confirmed by analysis using mass spectrometry (MS) and high pressure liquid chromatography (HPLC). Based on these results, it is thought that the ester bond of the functional group attached to the side chain is accelerated at high temperature. In addition, although the reasons are unknown, the battery operated at minus 20 degrees showed the disadvantage that the battery does not play at minus 32 ℃. This is not yet accurate, but it is thought that the crystallinity of the film is close to amorphous up to minus 20 ℃ and then decreases to minus 32 ℃, which increases the crystallinity of the film and blocks the passage of ions.

Accordingly, the present invention is to improve the above problems, by applying PAI, PEI, PEIEs, which are insulators on the surface of Li / SOCl ₂ anode lithium foil to minimize the self-discharge rate and the discharge time is improved by more than 50% And a stable Li / SOCl ₂ battery at low and high temperatures.

The negative electrode of the lithium battery was manufactured using a lithium foil having a thickness of 0.3 to 1.5 mm, and a lithium thickness of 0.4 to 0.8 mm was appropriate. In order to form a polyimide film on the surface of the lithium foil, a solution was prepared from a solid content of 8% to 40% with a solvent and coated on the surface of the lithium foil by spraying, followed by hot air drying at 70 ° C. or lower for 4 hours and then at 70 ° C. or lower. Vacuum drying for more than 12 hours to produce a cathode. The coating thickness of 5 ~ 50㎛ was the most suitable, the effect was less than 1㎛ and more than 100㎛.

The positive electrode was prepared by mixing, drying and pulverizing acetylene black and capzen black in a PTFE binder with 2-propanol to produce a conductive carbon powder, and then using the same.

The mixing ratio of fluororesin, acetylene black and capzen black in the conductive carbon powder was suitable for mixing 1: (1 ~ 4) :( 3 ~ 10), and 1: 1: (2 ~ 3): (4 ~ 8) The dose increased most.

The battery was completed by incorporating the prepared negative electrode, the positive electrode and the separator into a battery case and injecting an electrolyte solution. The thickness of the anode was about 0.3-1.5 mm. Especially 0.5 ~ 0.8mm is suitable.

The mixing ratio of solvent is azeotropic solvents such as DMF, DMAc, NMP, DMSO that can dissolve modified polyimide (PAI, PEI, PEIEs) and organic solvents such as m-Cresol, Dioxane, THF, MC, Chloroform, Acetone, Acetonitrile, Hexane, etc., which can be removed quickly and do not oxidize lithium, were used in 10 ~ 200% of high boiling point solvents. In addition, imides having excellent solubility have often used MC or chlorophore alone or other low boiling point solvents. However, when only the low boiling point solvent was used alone, errors were severely produced in preparing the coating film. This is caused by too fast drying time, it is suitable to use a mixture of high boiling point solvent to maintain physical properties. All solvents were used after adjusting the water to 30 ppm or less before use, and the experiment was performed under an inert atmosphere.

1 is a schematic view of a negative electrode of a lithium battery according to the present invention, the lithium foil (1) is used as a negative electrode as an intermediate layer, composed of 0.3 ~ 1.2mm, PAI or PEI film (2) is used as an insulating layer, It consists of 5-50 micrometers, and the conductive carbon layer 3 is used as an anode by the most bar part of both sides, and is comprised by 0.3-1.5 mm.

The terminal is taken out of the lithium metal 1 to be a cathode, and the terminal is taken out of the conductive carbon layer 3 to be an anode. Put this membrane on top of it, roll it in a circle, insert a stainless steel can, connect both terminals to the outside, and then operate it to complete the battery by sealing and adding electrolyte.

Example 1

Solvents in oxyphenylenediamine in Trimelliric anhydride chloride or Trimelliric anhydride prepared polyamic acid using NMP and heated again to synthesize PAI. After purification, drying, and grinding, it was first dissolved in DMAc under an inert atmosphere, and THF alone or its additives were added to rapidly remove DMAc. Drying was carried out at 70 ° C or lower. When the drying temperature is higher than 70 ℃ even under inert atmosphere, it was found that the physical properties of the battery is significantly reduced. After coating, hot air drying was performed for 4 hours at 70 ° C. or lower, followed by vacuum drying at 70 ° C. or lower for 12 hours or more. As for the coating method, the physical properties of the manufactured battery were consistent with those produced by the spray method rather than those prepared by the precipitation method. After mixing, drying and pulverizing PTFE 30J, Schengen black, and acetylene black under IPA in a ratio of 1: 6: 2, a conductive carbon powder prepared after the 0.5 to 4 mm layer on the lithium metal prepared above was subjected to a pressing process. After rolling the cylinder into a cylindrical cylinder, the negative electrode terminal was removed, and the electrolyte containing 3 M or less of electrolyte was added to SOCl ₂ so that the aluminum salt and the lithium salt were 1.2M concentration, and then sealed with a spring susball. . After stabilization for about one week after the production was evaluated by the Department of Defense quality standards DKS 6135-4003 and US defense quality standards BA-6813, 6818, 6821AK.

Example 2

Trimeric acid anhydride and dioxytetrahydrofuran-3-methylcyclohexane-1,2-dicarboxylic dianhydride are added 9: 1, and oxydiphenylamine is quantitatively added to prepare a polyamic acid. By heating, alicyclic PAI was added. After the purification, drying, and grinding processes, the remaining processes are performed in the same manner as in Example 1.

Example 3

4-chlorophthalic anhydride and bicyclo [2,2,2] octa-7-ene-2,3,5,6-tetracarboxylic diacid anhydride are mixed in a ratio of 9: 1 and metaphenylenediamine Was added quantitatively to form a precursor, and then substituted with OH groups on both sides of bisphenol A to Na and reacted to synthesize PEI, followed by purification, drying, and grinding. . However, the solvent used MC.

Example 4

Precursor was prepared using 4-chlorophthalic anhydride and oxyphenylenediamine, and then substituted OH group of bisphenol A with Na, followed by reaction to synthesize PEI, followed by purification, drying and grinding. It carried out similarly to Example 1.

Example 5

After reacting with 10 equivalents of trimellitic anhydride, 7 equivalents of oxyphenylenediamine was first reacted. Then, 3 equivalents of bisphenol A was added to react to form a precursor, and a catalyst and heat were added thereto to synthesize polyetherimide. After the grinding process, the rest of the process is carried out in the same manner as in Example 1.

Example 6

After reacting with 10 equivalents of trimellitic anhydride, 7 equivalents of bisaminophenylmethane was first reacted, and 3 equivalents of bisphenol A were added thereto to react to form a precursor, followed by the addition of a catalyst and heat to synthesize polyetherimide. After the grinding process, the rest of the process is carried out in the same manner as in Example 1.

Comparative Example 1

After dilution with ethyl acetate and toluene mixed solution (1: 1) in ethyl cyano acrylate, the coating was cured to prepare a film, and then the process was performed in the same manner as in Example 1.

Comparative Example 2

After diluting with arylcyano acrylate with a mixture of ethyl acetate and toluene (1: 1), coating and curing to prepare a film, the process is carried out in the same manner as in Example 1.

Examples 1, 2, 3, 4, 5, and 6 of the present invention are represented by cells 1, 2, 3, 4, 5, and 6, and Comparative Examples 1 and 2 prepared according to a conventional method are batteries. (cell) 7,8.

[Table 1] shows that when the soluble polyimide is coated on the surface of the lithium foil that forms the negative electrode of the lithium battery, the voltage retardation phenomenon is significantly reduced at room temperature, low temperature, and high temperature than the conventional products manufactured by coating arylcyanoacrylate. It also shows that the discharge time is more than 60% more.

[Table 1] Property comparison table

Cell No. Compound Delay (sec) Discharge Capacity (%) Room temperature High temperature Low temperature Conduct1 Soluble polyamideimide 1 1 or less 180 160 210 Conduct2 Soluble polyamideimide 2 1 or less 170 160 220 Conduct 3 Soluble Polyetherimide 1 1 or less 180 160 280 Conduct4 Soluble Polyetherimide 2 1 or less 190 170 260 Conduct 5 Soluble Polyetherimide Ester1 1 or less 170 160 260 Conduct6 Soluble Polyetherimide Ester1 1 or less 175 165 220 Comparison 1 Ethylcyanoacrylate over 10 40 - - Comparison 2 Arylcyanoacrylate 3 ~ 5 100 100 100

(The coating thickness is the same at 20㎛ (deviation within 10%)

Delay time is 0.5A, measured under discharge condition, stored for 4 weeks at high temperature (54 ± 3 ℃), then cooled to room temperature for 2 hours

High temperature capacity measurement is carried out after 40 days storage at 60 ± 2 ℃

Low temperature capacity measurement is carried out after 12 hours storage at minus 32 ± 2 ℃ and forced discharge at that temperature

At the high temperature of Comparative 1, all 10 manufactured samples leak electrolyte due to internal pressure, but no discharge at low temperature

Capacity evaluation measures effective voltage of 0.5A, 2.5V or more according to Ministry of Defense quality standard.)

Table 1 shows the voltage delay time at the time of forced discharge after storing the prepared battery for 45 days at 72 ± 2 ℃ and left at room temperature for 24 hours. This shows that the voltage delay phenomenon is greatly improved when PAI, PEI, and PEIEs are used compared to the conventional comparison 2, and the voltage delay disappears within 1 second. It is believed that this is due to the decomposition of the ester, which is a disadvantage of cyanoacryl due to the good solvent resistance of the polyimide, and the reaction with SOCl ₂ at an early stage, thereby preventing the formation of a passivation film of lithium salt. It has an ester or amide structure inside, which is likely to be in an amorphous form and is considered to be an effect on it. X-ray analysis shows that the better the crystallinity, the better the physical properties. The reason for the current flow due to the breakdown of the polyimide film having excellent insulation during voltage driving is still unknown at this time.

In addition, the performance of the manufactured batteries at room temperature (forced discharge test at storage temperature after storage for 2 days at 21 ± 2 ℃) shows a performance improvement of more than 70% compared to Cell 8.

And it shows the change of performance of cryogenic temperature (discharge test at storage temperature after 12 hours storage at -32 ± 2 ℃) depending on the presence or absence of polyimide of lithium anode. In the case of conventional ethyl cyano acrylate treatment, Cell 7 is not discharged, and compared with Cell 8 treated with arylcyano acrylate, it shows about 110% improvement in performance compared to existing products at low temperature. This capacity increase phenomenon is judged as a result of the advantage of the polyimide.

Finally, it shows the change of the battery's ultra-high temperature (forced discharge at that temperature after 40 days storage at 60 ± 2 ℃) depending on the presence or absence of polyimide on the lithium anode. This shows about 60% improvement in performance compared to the conventional arylcyano acrylate treatment.

Preferably the PEI used is represented by Formula 1,

Wherein diamine is polyoxyalkylenediamine (molecular weight 4000 or less), polypropylenediamine (molecular weight 1000 or less), poly (tetra menyleneether) diamine, copoly (propyleneether-ethyleneether) diamine or mixtures thereof, Alkyl group diamines, such as bisamino alkyl ketrahydrofuran, and aromatic diamine shown by General formula (2) are included,

The aliphatic compounds used in R 'represented by the formula (3) include low molecular weight diols (butanediol, hexanediol, butenediol, cyclohexanedimethanol, etc.) and high molecular weight diols (polyethylene glycol, polypropylene glycol molecular weight 4). Transition) or dicarboxylic acid ester-forming derivatives, alicyclic diols, high molecular weight unsaturated diols (molecular weight 4,000 or less), derivatives with tricarboxylic acids or anhydrides and aromatic diols represented by R 'are represented by Formula 3, The aromatic acid anhydrides are represented by Formula 4, and include at least one aromatic acid anhydride and at least one aromatic diamine, and at least one compound of the foregoing.

[Formula 1]

Where x + y = 1, 0≤y <0.6

[Formula 2]

= -알콕시, -CN, -폴리에테르류, -알칸류, -시클로알칸류, -아마이드결합에 의한 알칸류등과의 결합, -에스테르 결합에 의한 알칸류등과의 결합,

= -Alkoxy, -CN, -polyethers, -alkanes, -cycloalkanes, -alkanes by amide bonds, alkanes by ester bonds, etc.,

[Formula 3]

[Formula 4]

In addition, the PAI used is represented by the formula (5),

Wherein diamine is polyoxyalkylenediamine (molecular weight 4000 or less), polypropylenediamine (molecular weight 1000 or less), poly (tetramethylene ether) diamine, copoly (propyleneether-ethyleneether) diamine or mixtures thereof, bis Alkyl group diamines such as amino alkylkentrahydrofuran and at least one aromatic diamine in R, R 'and R "shown in formula (6), and the acid anhydride is represented by R" " As described above, an alicyclic diacid anhydride and an aromatic acid anhydride are included, and the polyhydric acid anhydride of the above and the following formulas, the amine and the diamine of the following formulas each include at least one, and at least one of the compounds.

[Formula 5]

Where n + m = 1, 0≤ m <0.6

[Formula 6]

[Formula 7]

The last PEIEs used are represented by Formula 8,

Wherein diamine is polyoxyalkylenediamine (molecular weight 4000 or less), polypropylenediamine (molecular weight 1000 or less), poly (tetra menyleneether) diamine, copoly (propyleneether-ethyleneether) diamine or mixtures thereof, Alkyl group diamines, such as bisamino alkyl trihydrofuran, and aromatic diamine shown by General formula (9) are included,

Aliphatic compounds used in R 'represented by Formula 8 include low molecular weight diols (butanediol, hexanediol, butenediol, cyclohexanedimethanol, etc.) and high molecular weight diols (polyethylene glycol, polypropylene glycol molecular weight of 4,000 or less). Or dicarboxylic acid ester-forming derivatives, alicyclic diols, high molecular weight unsaturated diols (molecular weight 4,000 or less), tricarboxylic acids or derivatives with anhydrides, and aromatic diols represented by R ' Here, the aromatic diacid anhydride used in claims 6 and 7 can be removed if the heat resistance is not a problem, it is preferable to include at least one aromatic diamine represented by the formula (9).

[Formula 8]

Where x + y = 1, 0.3≤ y <0.7

[Formula 9]

= -알콕시, -CN, -폴리에테르류, -알칸류, -시클로알칸류, -아마이드결합에 의한 알칸류등과의 결합, -에스테르 결합에 의한 알칸류등과의 결합,

= -Alkoxy, -CN, -polyethers, -alkanes, -cycloalkanes, -alkanes by amide bonds, alkanes by ester bonds, etc.,

[Formula 10]

As described above, the present invention can reduce the self-discharge rate to 0.2% or less by increasing the capacity of the negative electrode by increasing the discharge time by at least 30% than the existing product by coating the surface of the negative electrode with modified polyimide. It is the invention which produced the remarkable effect which can be maintained in less than 1 second.

Claims (16)

In a lithium battery, Lithium battery using a soluble modified polyimide, characterized in that the coating on the surface of the cathode electrode using a soluble polyimide-based polyetherimide, polyamideimide, polyetherimide ester or two or more copolymers According to claim 1, Lithium battery using soluble modified polyimide, characterized in that the PEI, PAI, PEIEs or two or more copolymers are applied by spraying or precipitation in applying to the cathode According to claim 1, Lithium battery using soluble modified polyimide, characterized by mixing lithium salt (LiClO4, LiAsF ₆ , LiBF ₆ , LiPF ₄ , LiCF ₃ SO ₃ , LiF, etc.) and aluminum salt (AlCl _3, etc.) in the electrolyte According to claim 1, Lithium battery using soluble modified polyimide, characterized in that liquid and gaseous phases such as SOCl ₂ , SO ₂ , SO ₂ Cl _2, etc. are contained so that the concentration of lithium salt and aluminum salt of claim ₃ is 0.5 to 2M as electrolyte. According to claim 1, Lithium battery using soluble modified polyimide, characterized in that the thickness of the lithium metal thin film is 0.3 ~ 1.5mm constituting the negative electrode According to claim 1, PEI used is represented by the formula (1), Wherein diamine is polyoxyalkylenediamine (molecular weight 4000 or less), polypropylenediamine (molecular weight 1000 or less), poly (tetra menyleneether) diamine, copoly (propyleneether-ethyleneether) diamine or mixtures thereof, Alkyl group diamines, such as bisamino alkyl ketrahydrofuran, and aromatic diamine shown by General formula (2) are included, The aliphatic compounds used in R 'represented by the formula (3) include low molecular weight diols (butanediol, hexanediol, butenediol, cyclohexanedimethanol, etc.) and high molecular weight diols (polyethylene glycol, polypropylene glycol molecular weight 4). Transition) or dicarboxylic acid ester-forming derivatives, alicyclic diols, high molecular weight unsaturated diols (molecular weight 4,000 or less), derivatives with tricarboxylic acids or anhydrides and aromatic diols represented by R 'are represented by Formula 3, Aromatic acid anhydrides are represented by Formula 4, Lithium battery using soluble modified polyimide containing at least one aromatic acid anhydride and at least one aromatic diamine, and at least one compound [Formula 1]

Where x + y = 1, 0≤y <0.6 [Formula 2]

= -Alkoxy, -CN, -polyethers, -alkanes, -cycloalkanes, -alkanes by amide bonds, alkanes by ester bonds, etc., [Formula 3]

[Formula 4]

According to claim 1, PAI used is represented by the formula (5), Wherein diamine is polyoxyalkylenediamine (molecular weight 4000 or less), polypropylenediamine (molecular weight 1000 or less), poly (tetramethylene ether) diamine, copoly (propyleneether-ethyleneether) diamine or mixtures thereof, bis Alkyl group diamines such as amino alkylkentrahydrofuran and at least one aromatic diamine in R, R 'and R "shown in formula (6), and the acid anhydride is represented by R" " As described above, the alicyclic diacid anhydride and the aromatic acid anhydride are included, and the polyhydric acid anhydride of the above and the following formulas, and the amine and the diamine of the following formulas, respectively, each of which contains at least one or more. Lithium Battery Using Soluble Modified Polyimide [Formula 5]

Where n + m = 1, 0≤ m <0.6 [Formula 6]

[Formula 7]

According to claim 1, The PEIEs used are represented by Formula 8, Wherein diamine is polyoxyalkylenediamine (molecular weight 4000 or less), polypropylenediamine (molecular weight 1000 or less), poly (tetra menyleneether) diamine, copoly (propyleneether-ethyleneether) diamine or mixtures thereof, Alkyl group diamines, such as bisamino alkyl trihydrofuran, and aromatic diamine shown by General formula (9) are included, Aliphatic compounds used in R 'represented by Formula 8 include low molecular weight diols (butanediol, hexanediol, butenediol, cyclohexanedimethanol, etc.) and high molecular weight diols (polyethylene glycol, polypropylene glycol molecular weight of 4,000 or less). Or dicarboxylic acid ester-forming derivatives, alicyclic diols, high molecular weight unsaturated diols (molecular weight 4,000 or less), tricarboxylic acids or derivatives with anhydrides, and aromatic diols represented by R ' , Here, the aromatic diacid anhydride used in claims 6 and 7 can be removed as long as it does not have a problem in heat resistance, and a lithium battery using a soluble modified polyimide containing at least one aromatic diamine represented by Formula 9 [Formula 8]

Where x + y = 1, 0.3≤ y <0.7 [Formula 9]

= -Alkoxy, -CN, -polyethers, -alkanes, -cycloalkanes, -alkanes by amide bonds, alkanes by ester bonds, etc., [Formula 10]

According to claim 1, Lithium battery using soluble modified polyimide, characterized in that it contains 0 to 10% of monoamine or monoacid anhydride as the molecular weight regulator for the properties of the polyimide used According to claim 1, Polyimide is a lithium battery using a soluble modified polyimide comprising the copolymer of claim 6, 7, and 8 According to claim 1, The polyimide used is aprotic solvents such as DMF, DMAc, NMP, DMSO, high boiling point organic solvents such as gamma butyrolactone and m-Cresol, and Dioxane, THF, MC, Chloroform, Acetone, Acetonitrile, Hexane, EA, Toluene Lithium battery using a soluble modified polyimide, characterized in that it is dissolved at room temperature alone or in two or more mixed solutions in a solvent such as  The method of claim 2, Polyimide coating solvents can easily remove high boiling point solvents by azeotropic effects on aprotic solvents such as DMF, DMAc, NMP, DMSO and high boiling point organic solvents such as gamma butyrolactone and m-Cresol. Dioxane, THF, MC , Chloroform, Acetone, Acetonitrile, Hexane, EA, Toluene, etc. Lithium battery using soluble modified polyimide, characterized in that 0 to 300% using a high boiling point solvent The method of claim 2, The solvent used is a lithium battery using soluble modified polyimide, which is coated with a single or mixed solution of Dioxane, THF, MC, Chloroform, Acetone, Acetonitrile, Hexane, EA, Toluene which can be dissolved at room temperature. According to claim 1, The amount of the solvent used is a lithium battery using a soluble modified polyimide, characterized in that the solid content is prepared at 5 to 60%. According to claim 1, The composition of the carbon layer used as the anode layer is a soluble modified polyimide comprising 200 to 1,000% of conductive carbon based on a fluororesin emulsion (Dupont PTFE 30J, 60% solids and a fluorinated emulsion having a similar function). Used Lithium Battery The method of claim 15, Conductive carbon is a lithium battery using a soluble modified polyimide, characterized by using a ratio of 100 to 500% of the black black based on acetylene black.

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