KR20230150583A - Binder for secondary battery, electrode for secondary battery comprising the same and secondary battery comprising the same - Google Patents

Abstract

The binder composition for secondary batteries according to one aspect of the present invention includes a copolymer containing a repeating unit represented by the following formula (1):
[Formula 1]

In Formula 1, n is a natural number from 1 to 100,000, and L ₁ is an alkylene group with 1 to 6 carbon atoms, an alkenylene group with 2 to 6 carbon atoms, or an ether with the sum of carbon numbers and oxygen numbers of 3 to 12. group, L ₂ is an alkylene group having 1 to 6 carbon atoms, an alkenylene group having 2 to 6 carbon atoms, or an ether group having a sum of carbon numbers and oxygen numbers of 3 to 12, and M is hydrogen or an alkali metal ion. and R ₁ is hydrogen or a methyl group.

Description

Binder for secondary batteries, electrodes for secondary batteries containing the same, and secondary batteries {BINDER FOR SECONDARY BATTERY, ELECTRODE FOR SECONDARY BATTERY COMPRISING THE SAME AND SECONDARY BATTERY COMPRISING THE SAME}

The present invention relates to a binder for secondary batteries, electrodes for secondary batteries containing the same, and secondary batteries. More specifically, it relates to a binder for secondary batteries containing a polymer compound, a negative electrode for secondary batteries containing the same, and a secondary battery.

Secondary batteries are batteries that can be repeatedly charged and discharged, and have been widely applied to portable electronic communication devices such as camcorders, mobile phones, and laptop PCs with the development of the information and communication and display industries. Examples of secondary batteries include lithium secondary batteries, nickel-cadmium batteries, and nickel-hydrogen batteries. Among these, lithium secondary batteries have high operating voltage and energy density per unit weight, and are advantageous for charging speed and weight reduction. It has been actively developed and applied in this regard.

A lithium secondary battery may include, for example, an electrode assembly including a positive electrode, a negative electrode, and a separator, and an electrolyte impregnating the electrode assembly. The lithium secondary battery may further include an exterior material, for example in the form of a pouch, that accommodates the electrode assembly and the electrolyte.

For example, the negative electrode may use carbon-based or silicon-based active material particles as the negative electrode active material. When the active material particles are repeatedly charged/discharged, side reactions may occur due to contact with the electrolyte, and mechanical or chemical damage such as cracks may occur in the particles.

For example, commonly known anode binders, such as styrene-butadiene-based polymers and styrene-acrylate-based polymers, lack high-temperature stability and adhesion, and may cause side reactions with the electrolyte solution.

For example, Republic of Korea Publication No. 10-2013-0094738 A discloses a secondary battery comprising CMC and SBR satisfying predetermined physical property conditions as a negative aqueous binder, but fails to overcome the above-mentioned limitations.

Republic of Korea Publication No. 10-2013-0094738 A

One object of the present invention is to provide a binder for secondary batteries with excellent stability.

One object of the present invention is to provide a binder for secondary batteries that can contribute to improving the discharge characteristics of secondary batteries.

One object of the present invention is to provide an electrode for a secondary battery, especially a cathode, with improved stability and discharge characteristics.

One object of the present invention is to provide a secondary battery with improved stability and discharge characteristics.

A binder composition for a secondary battery according to one aspect includes a copolymer containing a repeating unit represented by the following formula (1).

[Formula 1]

In Formula 1, n is a natural number from 1 to 100,000, and L ₁ is an alkylene group with 1 to 6 carbon atoms, an alkenylene group with 2 to 6 carbon atoms, or an ether with the sum of carbon numbers and oxygen numbers of 3 to 12. group, L ₂ is an alkylene group having 1 to 6 carbon atoms, an alkenylene group having 2 to 6 carbon atoms, or an ether group having a sum of carbon numbers and oxygen numbers of 3 to 12, and M is hydrogen or an alkali metal ion. and R ₁ is hydrogen or a methyl group.

A binder composition for a secondary battery according to one aspect may include a copolymer containing a repeating unit represented by the following Chemical Formula 1-1.

[Formula 1-1]

In Formula 1-1, n, M, and R ₁ are as defined in Formula 1.

A binder composition for a secondary battery according to one aspect may include at least one of a copolymer containing a repeating unit represented by the following Chemical Formula A to a copolymer containing a repeating unit represented by the following Chemical Formula E.

[Formula A]

[Formula B]

[Formula C]

[Formula D]

[Formula E]

In the formulas A to E, n, L ₁ , L ₂ , M and R ₁ are as defined in formula 1, n' is a natural number from 1 to 100,000, M' is hydrogen or an alkali metal ion, and R ₁ ' is hydrogen or a methyl group.

A binder composition for a secondary battery according to one aspect includes at least one of a copolymer containing a repeating unit represented by the following formula 1-1-A to a copolymer containing a repeating unit represented by the following formula 1-1-E: can do.

[Formula 1-1-A]

[Formula 1-1-B]

[Formula 1-1-C]

[Formula 1-1-D]

[Formula 1-1-E]

In Formulas 1-1-A to 1-1-E, n, L ₁ , L ₂ , M and R ₁ are as defined in Formula 1, n' is a natural number from 1 to 100,000, and M' is hydrogen Or it is an alkali metal ion, and R ₁ ' is hydrogen or a methyl group.

In one aspect, the weight average molecular weight of the copolymer may be 1,000 to 700,000 g/mol.

An electrode for a secondary battery according to one aspect includes an electrode active material and the binder composition for a secondary battery on an electrode current collector.

In one aspect, the electrode is a negative electrode, and the electrode active material may include a carbon-based active material as the negative electrode active material.

In one aspect, the electrode is a negative electrode, and the electrode active material may include a silicon-based active material as a negative electrode active material.

A secondary battery according to one aspect includes the electrode.

As an effect, the binder for a secondary battery according to the above-described aspect is included, so that discharge characteristics such as initial discharge maintenance rate and discharge capacity of the secondary battery can be improved.

As an effect, the binder for a secondary battery according to the above-described aspect is included to suppress volume expansion of the electrode active material and delay detachment of the electrode active material, thereby improving life characteristics such as discharge capacity retention rate of the secondary battery.

As an effect, the binder for secondary batteries according to the above-mentioned aspect is included, so that the structure of the electrode active material can be stabilized and the mechanical stability of the electrode can be improved.

Expressions such as “comprising” used herein should be understood as open-ended terms that imply the possibility of including other elements.

As used herein, “preferred” and “preferably” refer to embodiments of the invention that may provide certain advantages under certain circumstances. However, other embodiments may also be preferred, under the same or different circumstances, and are not intended to exclude other embodiments from the scope of the present invention.

The binder composition for secondary batteries according to one aspect of the present invention relates to a copolymer prepared from a single monomer or a mixed monomer, and includes a copolymer containing a repeating unit represented by the following formula (1).

[Formula 1]

In Formula 1, n may be a natural number from 1 to 100,000, more preferably from 10 to 10,000.

L ₁ may be an alkylene group having 1 to 6 carbon atoms, an alkenylene group having 2 to 6 carbon atoms, or an ether group having a total of 3 to 12 carbon atoms and oxygen numbers.

As an example, the following case can be assumed for L ₁ .

L ₂ may be an alkylene group having 1 to 6 carbon atoms, an alkenylene group having 2 to 6 carbon atoms, or an ether group having a total of 3 to 12 carbon atoms and oxygen numbers.

As an example, L ₂ may be assumed to be as follows.

M is hydrogen or an alkali metal ion. When M is hydrogen, a covalent bond is possible with an adjacent oxygen atom, and when M is an alkali metal ion, an ionic bond is possible with an adjacent oxygen atom.

R ₁ is hydrogen or a methyl group.

In this specification, “copolymerization” may mean block copolymerization, random copolymerization, graft copolymerization, or alternating copolymerization, and “copolymer” may mean block copolymer, random copolymer, graft copolymer, or alternating copolymer.

The binder composition for secondary batteries according to the above embodiment includes a carboxylic acid or carboxylate functional group, thereby increasing bonding strength such as hydrogen bonding between polymers, thereby improving interactions between polymers.

The binder composition for a secondary battery according to the above embodiment includes a carboxylic acid or carboxylate functional group, thereby increasing the bonding force between the electrode active material and the substrate, and improving the interaction with the electrode active material and the substrate.

In the binder composition for secondary batteries according to the above aspect, the bond length from the main polymer skeleton to the carboxylic acid or carboxylate functional group is adjusted to be long, so that it is easy to develop adhesion to the electrode active material, substrate, and conductive material that interacts with the binder. Separation from the substrate can be further suppressed.

The binder composition for secondary batteries according to the above embodiment adjusts the bond length from the main polymer skeleton to the carboxylic acid or carboxylate functional group to be long, thereby increasing the glass transition temperature (Tg) of a resin such as poly-acrylic acid (PAA). ), the glass transition temperature (Tg) can be adjusted to be lower than that of the electrode, and the electrode, especially the cathode, can expand when expanded, improving the flexibility of the electrode.

The binder composition for secondary batteries according to the above aspect allows carboxylic acid or carboxylate functional groups to extend outwards from the main polymer skeleton, thereby further strengthening the interaction between polymers, the interaction with the active material surface, and the interaction with the substrate. By doing so, the mechanical stability of the electrode can be improved and the discharge characteristics and life characteristics of the secondary battery can be improved.

The binder composition for secondary batteries according to the above embodiment includes both an ester group and a carboxylic acid (or carboxylate) functional group, so that an attractive force acts between the ester group and the carboxylic acid (or carboxylate) group, thereby creating an interaction between the polymers. This can be improved.

The binder composition for secondary batteries may be as follows.

A binder composition for a secondary battery according to a more preferred embodiment that achieves the above-described effect may include a copolymer containing a repeating unit represented by the following formula 1-1-A.

[Formula 1-1-A]

In Formula 1-1-A, n, M and R ₁ are as described above.

A binder composition for a secondary battery according to a more preferable embodiment that achieves the above-mentioned effect is poly-acryloyloxyethyl succinate (copolymer prepared from the following acryloyloxyethyl succinate (AOES) monomer): It may be poly-acryloyloxyethyl succinate (PAOES) resin.

A binder composition for a secondary battery according to one aspect may include a copolymer containing a repeating unit represented by the following formula (A).

[Formula A]

In the copolymer, acrylic acid increases the glass transition temperature (Tg), thereby improving cohesion of the copolymer and extending battery life.

A binder composition for a secondary battery according to one aspect may include a copolymer containing a repeating unit represented by the following formula (B).

[Formula B]

In the copolymer, methyl acrylate increases the glass transition temperature (Tg), thereby improving cohesion of the copolymer and extending battery life.

A binder composition for a secondary battery according to one aspect may include a copolymer containing a repeating unit represented by the following formula (C).

[Formula C]

In the copolymer, butylacrylate lowers the glass transition temperature (Tg), improves adhesion between the binder, electrode active material, conductive material, and substrate, and can extend battery life.

A binder composition for a secondary battery according to one aspect may include a copolymer containing a repeating unit represented by the following formula (D).

[Formula D]

In the copolymer, biphenylmethyl acrylate improves the cohesion of the copolymer through pi-phi interactions between the copolymers, thereby extending battery life.

A binder composition for a secondary battery according to one aspect may include a copolymer containing a repeating unit represented by the following formula (E).

[Formula E]

In the copolymer, styrene increases the glass transition temperature (Tg), thereby improving cohesion of the copolymer and extending battery life.

Therefore, by including a copolymer containing any one or more of the repeating units represented by the above formulas A to E in the binder composition for secondary batteries, it is possible to pursue a balanced relationship between polar interactions and non-polar interactions, and mixing the slurry for electrodes Uniformity can be further increased.

In the formulas A to E, n, L ₁ , L ₂ , M and R ₁ are as defined in formula 1, n' is a natural number from 1 to 100,000, M' is hydrogen or an alkali metal ion, and R ₁ ' is hydrogen or a methyl group.

In one embodiment, the repeating unit represented by Formula 1 may be included in an amount of 50% by weight or more, 60% by weight, or 70% by weight or more relative to the total content of the repeating units, but is not limited thereto.

The binder composition for secondary batteries according to one aspect may be a copolymer containing the following repeating units.

In one aspect, the weight average molecular weight of the copolymer may be 1,000 to 700,000 g/mol. By satisfying the weight average molecular weight in the above-mentioned range, it is possible to pursue a balanced pursuit of ease of mixing and adhesiveness of the binder composition for secondary batteries.

The binder composition for secondary batteries according to one embodiment includes, in addition to the above copolymer, styrene-butadiene rubber (SBR), polyvinyl alcohol (poly vinyl alcohol), polyacrylic acid (PAA), and carboxymethyl cellulose. , CMC), hydroxypropylcellulose, and diacetylcellulose may further be included, but are not limited thereto.

In one aspect, the copolymer may be included in an amount of 10% by weight or more, 20% by weight, or 30% by weight or more based on the total content of the binder composition for secondary batteries. By meeting the above-mentioned numerical range, the adhesiveness of the binder can be further improved and the lifespan characteristics of the electrode, such as discharge capacity maintenance rate, can be further improved.

An electrode for a secondary battery according to one aspect includes an electrode active material and the binder composition for a secondary battery on an electrode current collector.

In a more preferred embodiment, the electrode is a negative electrode, the electrode active material may be a negative electrode active material, and the negative electrode may include a negative electrode active material layer containing the above-described binder composition for a secondary battery and a negative electrode active material on a negative electrode current collector. there is.

For example, the negative electrode current collector may include gold, stainless steel, nickel, aluminum, titanium, copper, or an alloy thereof, and preferably includes copper or a copper alloy, but is not limited thereto.

In one embodiment, the binder composition for secondary batteries may be included in an amount of 0.001 to 2% by weight based on the total content of the negative electrode active material layer, but is not limited thereto.

In one aspect, the negative electrode active material may include a carbon-based active material and/or a silicon-based active material, but is not limited thereto.

In a more preferred embodiment, the negative electrode active material may include a silicon-based active material.

When using a silicon-based active material as a negative electrode active material, the reversible capacity of the secondary battery can be significantly increased compared to the case of using a conventional carbon-based active material, while electrode deterioration occurs due to volume expansion and contraction of the silicon-based active material during charging and discharging of the secondary battery. And there is a problem that battery life is reduced due to peeling.

The binder composition for secondary batteries according to one aspect of the present invention not only suppresses peeling due to volume expansion and contraction of the silicon-based active material, but also can achieve uniform electrode density, thereby solving the above problems and increasing the reversible capacity of the secondary battery. can be greatly increased.

As another aspect, the negative electrode active material may include a carbon-based active material.

For example, the carbon-based active material may include at least one of a crystalline carbon-based material and an amorphous carbon-based material. Additionally, the carbon-based active material may be derived from artificial graphite and/or natural graphite, but is not limited thereto.

For example, the carbon-based active material may include artificial graphite. Artificial graphite may have a smaller capacity than natural graphite, but can have relatively high chemical and thermal stability.

For example, the carbon-based active material may include an amorphous carbon-based material. Examples of amorphous carbon-based materials include glucose, fructose, galactose, maltose, lactose, sucrose, phenolic resin, naphthalene resin, polyvinyl alcohol resin, urethane resin, polyimide resin, furan resin, cellulose resin, epoxy resin, Carbon derived from any one selected from the group consisting of polystyrene resin, resorcinol-based resin, phloroglucinol-based resin, coal-based pitch, petroleum-based pitch, tar, and low molecular weight heavy oil, or a mixture of two or more of these. based compounds may be considered.

The electrode active material may further include a conductive material to provide conductivity to the electrode, and at least one selected from the group consisting of a graphite-based conductive material, a carbon black-based conductive material, and a metal or metal compound-based conductive material may be used. , but is not limited to this.

A secondary battery according to one aspect includes the electrode.

In one aspect, the secondary battery may be a lithium secondary battery, a nickel-cadmium battery, a nickel-hydrogen battery, etc., and may be a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, a lithium ion polymer secondary battery, a lithium sulfur secondary battery, or It may be an all-solid-state battery, but is not limited thereto.

The structure of the secondary battery, the materials of each component, the manufacturing method of the secondary battery, etc. are interpreted to include everything possible without limitation.

Manufacturing example

Manufacturing Example 1

Dissolve 100 g of acryloyloxyethyl succinate in 200 g of methyl ethyl ketone, add AIBN polymerization initiator, raise the temperature to 80°C, and stir for 6 hours to synthesize a homopolymer with a weight average molecular weight of 170,000, After cooling to room temperature, 500 g of hexane was added to the reactor and stirred for 10 minutes.

After confirming that the polymer had clumped together in the reactor, the solution was poured out.

The above operation was repeated three times to remove residual reaction solvent and residual monomer.

After completing the above work, a vacuum pump was connected to the reactor and a temperature environment of 80°C was created. All residual solvents were removed by vacuum drying at 80°C for 9 hours.

400 g of water was added to the reactor, and 50 mol% NaOH based on 100 g of acryloyloxyethylsuccinate was added and stirred to prepare a polymer aqueous solution with a solid content of 20%.

Production example 2

Instead of 100g of acryloyloxyethylsuccinate, proceed in the same manner using 80g of acryloyloxyethylsuccinate and 20g of acrylic acid, and proceed in the same manner using 50 mol% of KOH compared to the amount of acryloyloxyethylsuccinate added. Thus, a 20% solids polymer aqueous solution with a weight average molecular weight of 19.30,000 was prepared.

Production example 3

Instead of 100g of acryloyloxyethylsuccinate, proceed in the same manner using 80g of acryloyloxyethylsuccinate and 20g of methyl acrylate, and use 50 mol% of KOH compared to the amount of acryloyloxyethylsuccinate added. Proceeding as follows, a 20% solids polymer aqueous solution with a weight average molecular weight of 23.1 million was prepared.

Production example 4

Instead of 100g of acryloyloxyethylsuccinate, proceed in the same manner using 80g of acryloyloxyethylsuccinate and 20g of butylacrylate, and use 50 mol% of KOH compared to the amount of acryloyloxyethylsuccinate added. Proceeding as follows, a 20% solids polymer aqueous solution with a weight average molecular weight of 19.7 million was prepared.

Production example 5

Instead of 100g of acryloyloxyethylsuccinate, proceed in the same manner using 80g of acryloyloxyethylsuccinate and 20g of biphenylmethyl acrylate, and use 50 mol% of KOH compared to the amount of acryloyloxyethylsuccinate added. By proceeding in the same manner, a 20% solids polymer aqueous solution with a weight average molecular weight of 15.10,000 was prepared.

Production example 6

Instead of 100g of acryloyloxyethylsuccinate, proceed in the same manner using 80g of acryloyloxyethylsuccinate and 20g of styrene, and use 50 mol% of KOH compared to the amount of acryloyloxyethylsuccinate added. Proceeding, a 20% solids polymer aqueous solution with a weight average molecular weight of 128,000 was prepared.

Production example 7

Instead of 100 g of acryloyloxyethyl succinate, the same procedure was performed using 100 g of acrylic acid, and the same procedure was performed using 50 mol% KOH compared to the amount of acrylic acid added, to prepare a 20% solids polymer aqueous solution with a weight average molecular weight of 29.50,000. .

Examples and Comparative Examples

A total of 100 parts by weight slurry was prepared by mixing 98 parts by weight of artificial graphite and 2 parts by weight of the binder of the production example. The negative electrodes of Examples 1 to 6 contained the binders of Preparation Examples 1 to 6, respectively, and the negative electrode of Comparative Example 1 contained the binder of Preparation Example 7.

The slurry was applied and dried on copper foil and roll pressed to prepare negative electrodes of Examples and Comparative Examples to have the same loading level and charge density. The loading level of the negative electrode according to each Example and Comparative Example was 13 mg/cm ² and the charge density was 1.65 g/cc.

Experiment example

In order to evaluate the characteristics of the battery, a lithium secondary battery was manufactured as follows. A coin-type battery was manufactured by compressing the negative electrode according to each of the above-described examples and comparative examples, the lithium counter electrode, and a 20㎛ thick polyethylene separator Celgard 2500, and injecting an electrolyte solution therein.

As a solvent for the electrolyte solution, a mixed solvent of ethylene carbonate (EC) and diethyl carbonate (DEC) in a volume ratio of 30 to 70 (EC:DEC=30v%:70v%) was used, and 1.3M of electrolyte was added to the solvent. of LiPF ₆ was added. Additionally, 5 parts by weight of fluoroethylene carbonate (FEC) was used as an additive based on a total of 100 parts by weight of the electrolyte.

1. Evaluation of adhesion of cathode

The negative electrode active material layer formed on the copper foil was attached to the tape using a universal testing machine, and then the negative electrode was peeled off at a speed of 180° peel and 50 mm/min to evaluate the adhesion of the negative electrode according to each example and comparative example. The evaluation results are shown in Table 1 below.

2. Crack evaluation of cathode

After each cathode according to the Examples and Comparative Examples was folded back and forth once, the occurrence of cracks and the presence or absence of pinholes were observed. The evaluation results are shown in Table 1 below.

The specific evaluation criteria are as follows.

<Evaluation criteria>

◎: No cracks occurred and no active material fell off during slitting.

○: No cracks occurred

△: A pinhole occurred.

X: crack occurs

Example Comparative example One 2 3 4 5 6 One Adhesive strength
(gf/cm) 23 27 25 31 29 26 15 crack ◎ ◎ ○ ◎ ◎ ○ △

3. Evaluation of charging and discharging characteristics of secondary batteries

The secondary batteries including each negative electrode of the above Examples and Comparative Examples were charged and discharged once at 0.05C to measure the charge capacity, discharge capacity, and initial efficiency, respectively. The evaluation results are shown in Table 2 below.

4. Evaluation of lifespan characteristics of secondary batteries

For the secondary batteries including each negative electrode of the above Examples and Comparative Examples, life characteristics were evaluated by charging and discharging between 0.01V and 2V under the conditions of 0.1C↔0.1C (one charge and discharge).

Lifespan characteristics were evaluated based on the discharge capacity maintenance rate. The discharge capacity maintenance rate (30 ^th /1 ^st ) is an indicator expressing the discharge capacity of 30 cycles as a percentage compared to the initial discharge capacity. The evaluation results are shown in Table 2 below.

Example Comparative example One 2 3 4 5 6 One charging capacity
(mAh/g) 3455 3488 3476 3465 3459 3436 3473 Discharge capacity (mAh/g) 3083 3132 3130 3129 3099 3102 3091 I.C.E. (initial charge/discharge efficiency, %) 89.2 89.8 90.0 90.2 89.6 90.3 89.0 Discharge capacity maintenance rate (%) 83.4 87.2 85.4 86.1 88.0 84.9 81.5

Claims (9)

A binder composition for a secondary battery comprising a copolymer containing a repeating unit represented by the following formula (1):
[Formula 1]

In Formula 1, n is a natural number from 1 to 100,000,
L ₁ is an alkylene group with 1 to 6 carbon atoms, an alkenylene group with 2 to 6 carbon atoms, or an ether group with a total of 3 to 12 carbon atoms and oxygen numbers,
L ₂ is an alkylene group having 1 to 6 carbon atoms, an alkenylene group having 2 to 6 carbon atoms, or an ether group having a total of 3 to 12 carbon atoms,
M is hydrogen or an alkali metal ion,
R ₁ is hydrogen or a methyl group.
According to claim 1,
Containing a copolymer containing a repeating unit represented by the following formula 1-1,
Binder composition for secondary batteries:
[Formula 1-1]

In Formula 1-1, n, M, and R ₁ are as defined in Formula 1.
According to claim 1,
Containing at least one of a copolymer containing a repeating unit represented by the following formula (A) to a copolymer containing a repeating unit represented by the following formula (E),
Binder composition for secondary batteries:
[Formula A]

[Formula B]

[Formula C]

[Formula D]

[Formula E]

In the formulas A to E, n, L ₁ , L ₂ , M and R ₁ are as defined in formula 1, n' is a natural number from 1 to 100,000, M' is hydrogen or an alkali metal ion, and R ₁ ' is hydrogen or a methyl group.
According to claim 1,
Containing at least one of a copolymer containing a repeating unit represented by the following formula 1-1-A to a copolymer containing a repeating unit represented by the following formula 1-1-E,
Binder composition for secondary batteries:
[Formula 1-1-A]

[Formula 1-1-B]

[Formula 1-1-C]

[Formula 1-1-D]

[Formula 1-1-E]

In Formulas 1-1-A to 1-1-E, n, L ₁ , L ₂ , M and R ₁ are as defined in Formula 1, n' is a natural number from 1 to 100,000, and M' is hydrogen Or it is an alkali metal ion, and R ₁ ' is hydrogen or a methyl group.
According to claim 1,
The weight average molecular weight of the copolymer is 1,000 to 700,000 g/mol,
Binder composition for secondary batteries.
Containing an electrode active material and the binder composition for a secondary battery according to claim 1 on an electrode current collector,
Electrodes for secondary batteries.
According to claim 6,
The electrode is a negative electrode, and the electrode active material includes a carbon-based active material as a negative electrode active material.
Electrodes for secondary batteries.
According to claim 6,
The electrode is a negative electrode, and the electrode active material includes a silicon-based active material as a negative electrode active material.
Electrodes for secondary batteries.
Comprising the electrode according to claim 6,
Secondary battery.