KR102144944B1 - Functional polymer separator made from agar and lithium ion batteries based on the agar separator - Google Patents

Abstract

The present invention relates to a functional polymer separator using agar and a lithium ion battery including the same. The functional polymer separator using agar comprises agar, wherein the agar is modified with a silane compound. The agar-based functional polymer separator has effects of stabilizing a hydrofluoric acid precursor to suppress performance degradation of a lithium ion battery due to hydrofluoric acid, and maintaining high cycle performance even at high temperature and high voltage driving.

Description

Functional polymer separator made from agar and lithium ion batteries based on the agar separator

The present invention relates to a functional polymer separator using agar and a lithium ion battery including the same.

Lithium ion batteries are manufactured by using a material capable of intercalating and deintercalating lithium ions as a negative electrode and a positive electrode, or as an active material thereof, and by injecting a liquid electrolyte after installing a porous separator between the negative electrode and the positive electrode. It is an energy storage with high energy density that can be charged and discharged while electricity is generated or consumed by redox reactions caused by insertion and desorption of lithium ions.

Due to the high energy density of these lithium-ion batteries, they are widely used as power sources for small electronic equipment such as mobile phones and notebook computers. In recent years, hybrid electric vehicles are used in response to environmental issues, high oil prices, energy efficiency and storage. Applications to vehicles, HEVs), plug-in EVs, e-bikes, and energy storage systems (ESS) are rapidly expanding. In addition, as these devices become larger, higher capacity and higher weight of secondary batteries tend to proceed further, and thus securing durability and safety is becoming more important.

As cathode materials currently used in lithium-ion batteries, most of them are transition metal oxides, and are considered in terms of price, performance, and environmental friendliness, and have a spinel structure of lithium manganese oxide (LiMn ₂ O ₄ ; LMO), or Lithium nickel manganese oxide (LiNi _0.5 Mn _1.5 O ₄ ; LNMO) is mainly used.

Most of these cathode materials have excellent electrochemical properties, but in the long term, the stability between the surface of the material and the electrolyte is not sufficient, so there is a problem that a little deterioration proceeds from the surface of the material, thereby limiting the life characteristics. Specifically, the spinel structure lithium manganese oxide (LMO, LNMO) is advantageous compared to other materials in terms of cost due to its low manufacturing cost, and it has a high diffusion rate because lithium diffuses in three dimensions within the spinel structure, so it has excellent high rate discharge characteristics. Do. However, the spinel structure lithium manganese oxide is continuously eluted by PF ₅ , an unstable hydrofluoric acid precursor generated by the decomposition reaction of the electrolyte solution (LiPF ₆ ) at high temperature and high voltage operation, and the resulting hydrofluoric acid (HF). In addition to structurally destroying the surface, the eluted manganese ions form a thick solid electrolyte interface (SEI) layer on the surface of the negative electrode, thereby increasing the interface resistance of the positive electrode and the negative electrode, thereby significantly reducing the high-temperature cycle performance.

Therefore, there is a need for research on a separator material capable of stabilizing the hydrofluoric acid precursor generated in the electrolyte to suppress the degradation of the lithium ion battery due to hydrofluoric acid, and to maintain the cycle performance of the battery when driven at high temperatures.

1. Korean Patent Registration No. 10-1592185 (published on January 21, 2014)

It is an object of the present invention to provide a functional polymer membrane capable of stabilizing a hydrofluoric acid precursor that is generated from a reaction of an electrolyte solution and causes the generation of hydrofluoric acid, and a method for manufacturing the same.

In addition, another object of the present invention is to provide a lithium ion battery using the functional polymer membrane.

In order to achieve the above object, the present invention is agar; And it provides an agar-based functional polymer membrane, characterized in that the agar is modified with a silane compound represented by the following formula (1).

[Formula 1]

In the above formula, R ¹ to R ³ may each be the same or different, C1 to C4 alkyl or C1 to C4 alkoxy, and R ⁴ is glycidoxy (C1 to C10) alkyl, amino (C1 to C10) )Alkyl, (C1 to C10)alkyl isocyanate, amino group, vinyl group, epoxy group, methacryloxy group, acryloxy group, ureido group, chloropropyl group, mercapto group, sulfido group and isocyanato group One.

In addition, the present invention provides a lithium ion battery having the agar-based functional polymer separator.

In addition, the present invention comprises the steps of preparing an agar solution modified with a silane compound represented by the following formula (1); Casting the agar solution onto a substrate to prepare a polymer film; And placing the polymer membrane in a non-solvent to form pores by a phase transfer method. It provides a method of manufacturing an agar-based functional polymer membrane comprising a.

[Formula 1]

In the above formula, R ¹ to R ³ may each be the same or different, C1 to C4 alkyl or C1 to C4 alkoxy, and R ⁴ is glycidoxy (C1 to C10) alkyl, amino (C1 to C10) )Alkyl, (C1 to C10)alkyl isocyanate, amino group, vinyl group, epoxy group, methacryloxy group, acryloxy group, ureido group, chloropropyl group, mercapto group, sulfido group and isocyanato group One.

In addition, the present invention provides a lithium ion battery having a separator manufactured by the method of manufacturing the agar-based functional polymer separator.

In the present invention, a porous separator having a uniform pore structure by a non-solvent phase transfer method through chemical modification of agar can be manufactured in a large area through a simple process.

The porous separator prepared as described above stabilizes the hydrofluoric acid precursor to suppress the degradation of the lithium ion battery due to hydrofluoric acid, etc., and when agar is used as a binder in addition to the separator, it contributes to rapid lithium ion transfer within the positive electrode. Discharge characteristics and high temperature, high voltage driving, there is an effect of absorbing the eluted manganese to maintain the cycle performance of the battery.

Therefore, the chemically modified agar separator/agar binder manufactured according to the present invention can be used in a battery system in which various transition metals are eluted under high temperature and high voltage conditions.

1 is a diagram showing a polymerization reaction between agar and GPTMS.
2 is a view showing the change in viscosity of G-Agar according to the amount of GPTMS.
3 is a view showing a process of manufacturing a separator for a secondary battery of 0.5G-Agar through a non-solvent phase transfer method.
Figure 4 shows the change in the structure and surface properties of G-Agar according to the concentration of GPTMS, (a), (b): agar (agar), (c), (d): 0.2G-Agar, (e) , (f): The result of measuring the cross-section of 0.5G-agar and the porous structure of the upper part, and (g) a view showing the change in contact angle and porosity of G-agar.
Figure 5 shows the electrochemical characteristics according to the separator in the coin cell composed of LMO / separator / Li, (a) constant current charging and discharging characteristics, (b) high rate characteristics, (c) high temperature of the coin cell using various separators / binders. It is a diagram showing cycle characteristics, (d) surface resistance characteristics, and (e) stability characteristics of a PE separator and a HF precursor of 0.5G-Agar.
6 is a diagram showing surface element analysis of a separator in a coin cell after a high temperature cycle, (a) surface SEM structure analysis, (b) surface element amount measurement.
7 shows the electrochemical characteristics according to the separator in the coin cell composed of LNMO/separator/graphite, (a) the configuration of a coin cell and (b) constant current charge/discharge characteristics of a coin cell using various separators/binders, (c ) It is a diagram showing high temperature cycle characteristics.

Hereinafter, the present invention will be described in detail.

The present inventors chemically modified the agar surface using GPTMS (3-Glycidyloxypropyl) trimethoxysilane), and prepared a porous separator having a uniform pore structure through a non-solvent phase transfer method, which stabilizes the hydrofluoric acid precursor by hydrofluoric acid. It suppresses the performance degradation of lithium-ion batteries, and when agar is used as a binder in addition to the separator, it contributes to rapid lithium ion transfer within the anode, thereby absorbing the high rate discharge characteristics and manganese that is eluted when driving at high temperature and high voltage. The present invention was completed by finding that it can be used as a separator for a battery system in which various transition metals are eluted because the cycle performance of can be maintained.

The present invention is agar; And it provides an agar-based functional polymer membrane, characterized in that the agar is modified with a silane compound represented by the following formula (1).

[Formula 1]

In the above formula, R ¹ to R ³ may each be the same or different, C1 to C4 alkyl or C1 to C4 alkoxy, and R ⁴ is glycidoxy (C1 to C10) alkyl, amino (C1 to C10) )Alkyl, (C1 to C10)alkyl isocyanate, amino group, vinyl group, epoxy group, methacryloxy group, acryloxy group, ureido group, chloropropyl group, mercapto group, sulfido group and isocyanato group One.

In this case, the silane compound may be represented by Formula 1 below, and 3-(glycidoxypropyl)trimethoxysilane (3-(glycidoxypropyl)trimethoxysilane; GPTMS), 3-(glycidoxypropyl)triethoxy Silane (3- (glycidoxypropyl) triethoxysilane; GPTES), 3- (isocyanatopropyl) triethoxysilane (3- (isocyanatopropyl) triethoxysilane; ICPTES), 3- (aminopropyl) triethoxysilane (3- ( aminopropyl) triethoxysilane; APTES), 3- (aminopropyl) trimethoxysilane (3- (aminopropyl) trimethoxysilane; APTMS) may be any one or more selected from the group consisting of, but preferably 3- (glycidoxypropyl) It may be trimethoxysilane (3-(glycidoxypropyl)trimethoxysilane; GPTMS).

[Formula 1]

In the above formula, R ¹ to R ³ may each be the same or different, and either methoxy or ethoxy, and R ⁴ is an epoxy group, a vinyl group, an amino group, a methacryloxy group, an acryloxy group, a ureido group, and a chloropropyl It is any one of the group consisting of a group, a mercapto group, a sulfido group, and an isocyanato group.

In addition, the silane compound and the agar may be included in a mass ratio of 0.1 to 1:1, and preferably may be included in a mass ratio of 0.5:1, but is not limited thereto.

In addition, the agar-based functional polymer membrane may contain 40 to 80% of pores, preferably 60% of pores.

In addition, the present invention provides a lithium ion battery having the agar-based functional polymer separator.

At this time, the lithium ion battery includes a positive electrode, a negative electrode, a separator, and an electrolyte, and the positive or negative electrode may contain 5 to 20 wt% of an agar binder based on the total weight of the positive or negative electrode, but preferably 5 wt% It can be included in the content of.

In addition, the positive electrode or negative electrode includes an active material, a conductive material, a solvent, etc. that are commonly used when manufacturing a lithium ion battery in addition to a binder, and the positive electrode active material includes lithium cobalt oxide (LiCoO ₂ ; LCO), lithium nickel manganese oxide (LiNi _0.5). Mn _1.5 O ₄ ; LNMO), lithium manganese oxide (LiMn ₂ O ₄ ; LMO), lithium iron phosphate oxide (LiFePO ₄ ), etc. may be used, but the lithium ion battery according to the present invention is lithium nickel manganese oxide (LiNi _0.5 Mn _1.5 O ₄ ; LNMO) or lithium manganese oxide (LiMn2O4; LMO) may be used.

In addition, the present invention comprises the steps of preparing an agar solution modified with a silane compound represented by the following formula (1); Casting the agar solution onto a substrate to prepare a polymer film; And placing the polymer membrane in a non-solvent to form pores by a phase transfer method. It provides a method of manufacturing an agar-based functional polymer membrane comprising a.

[Formula 1]

In the above formula, R ¹ to R ³ may each be the same or different, C1 to C4 alkyl or C1 to C4 alkoxy, and R ⁴ is glycidoxy (C1 to C10) alkyl, amino (C1 to C10) )Alkyl, (C1 to C10)alkyl isocyanate, amino group, vinyl group, epoxy group, methacryloxy group, acryloxy group, ureido group, chloropropyl group, mercapto group, sulfido group and isocyanato group One.

In this case, the silane compound and the agar may be included in a mass ratio of 0.1 to 1: 1, and may preferably be included in a mass ratio of 0.5:1, but is not limited thereto.

The non-solvent induced phase separation (NIPS) is a method of forming microporous pores while an exchange between a solvent and a non-solvent is made while a solution of a composition consisting of a polymer and a solvent is immersed in a non-solvent system. In the agar, the exchange rate between the solvent and the non-solvent was too fast to form uniform pores, but a polymer membrane having uniform pores could be prepared by the non-solvent phase transfer method by modifying the silane compound.

At this time, the present invention is characterized in that the polymer membrane made of agar is reacted with a non-solvent for 5 to 15 hours, preferably for 6 hours.

In this case, if the reaction conditions are out of the above, the uniformity of the pores may decrease, or a polymer membrane having a desired pore size may not be formed, thereby causing a problem that cannot be effectively used as a separator for a lithium ion battery.

In addition, the present invention provides a lithium ion battery having a separator manufactured by the method of manufacturing the agar-based functional polymer separator.

At this time, the lithium ion battery includes a positive electrode, a negative electrode, a separator, and an electrolyte, and the positive or negative electrode may contain 5 to 20 wt% of an agar binder based on the total weight of the positive or negative electrode, but preferably 5 wt% It can be included in the content of.

In addition, the positive electrode or negative electrode includes an active material, a conductive material, a solvent, etc. that are commonly used when manufacturing a lithium ion battery in addition to a binder, and the positive electrode active material includes lithium cobalt oxide (LiCoO ₂ ; LCO), lithium nickel manganese oxide (LiNi _0.5). Mn _1.5 O ₄ ; LNMO), lithium manganese oxide (LiMn ₂ O ₄ ; LMO), lithium iron phosphate oxide (LiFePO ₄ ), etc. may be used, but the lithium ion battery according to the present invention is lithium nickel manganese oxide (LiNi _0.5 Mn _1.5 O ₄ ; LNMO) or lithium manganese oxide (LiMn ₂ O ₄ ; LMO) may be used.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for describing the present invention in more detail, and that the scope of the present invention is not limited by these examples according to the gist of the present invention, to those of ordinary skill in the art. It will be self-evident.

< Manufacturing example 1> Preparation of membrane using agar

1-1. GPTMS -Agar(G-Agar) solution synthesis

As shown in FIG. 1, agar extracted from seaweed was reacted with a sol-gel method with various concentrations of GPTMS (3-Glycidyloxypropyl)trimethoxysilane) to prepare a separator for a secondary battery using a non-solvent phase transfer method.

Specifically, 0.8 g of Agar was dissolved in a 10 mL solvent in which dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) were 4:1 (V:V) at 90°C for 5 hours. After that, GPTMS 0.33mmol (0.1G-Agar(GPTMS/agar=1/10w/w)) ~ 3.3mmol (1.0G-agar(GPTMS/agar=1/1w/w)) was added and sol at 120℃ for 90 minutes. -The gel reaction was carried out to introduce the organic silicon (R-Si-O-Si-R) of GPTMS into the hydroxy group (-OH) of the agar during polymerization (hereinafter referred to as'G-Agar'). ).

As shown in Fig. 2, when the reacting GPTMS concentration increases, the viscosity increases due to polymerization of many organosilicon systems, and eventually solidifies, so that a separator cannot be manufactured by a non-solvent phase transfer method as shown in <Preparation Example 1-2>. The optimized conditions were selected as a solution obtained by reacting GPTMS with a concentration of 1.6 mmol (0.5G-Agar).

1-2. Separation membrane manufacturing using G-Agar

The 0.5G-Agar solution prepared in <Preparation Example 1-1> was prepared as a porous polymer through a non-solvent phase transfer method as shown in FIG. 3 (FIG. 3).

Specifically, a 0.5G-Agar solution was applied to a flat glass substrate with a thickness of 300 μm using a doctor blade, and this was immersed in anhydrous ethanol as a non-solvent. At this time, the exchange between the solvent and the non-solvent was made, and after reacting for 6 hours, it was taken out and dried in a vacuum oven at 70° C. for 20 minutes to prepare a porous separator.

For comparison, a porous separator was prepared in the same manner as described above using the following <Comparative Example 1>, 0.2G-Agar and 0.7G-Agar solutions.

< Comparative example 1> Preparation of membrane using agar

In <Preparation Example 1-1>, a porous separator was manufactured according to <Preparation Example 1-2> using only an agar solution without including GPTMS.

< Experimental example 1> Structure analysis

As shown in Figs. 4(a), (b) and (g), agar has a hydrophilic property with a low contact angle and has a high affinity with anhydrous ethanol, which is a non-solvent. On the other hand, as the concentration of GPTMS introduced into the agar increases as shown in FIGS. 4(c) to (g), the hydrophilicity decreases as the contact angle increases. It was confirmed that pores of were formed.

From the above results, 0.5G-Agar, which showed the most uniform pore structure and ideal porosity, was selected as the final sample.

< Experimental Example 2> Electrochemical properties of a coin cell composed of LMO / separator / Li

LMO and LNMO cathode materials have high driving voltage characteristics, but there is a problem that manganese is eluted by hydrofluoric acid (HF) in the electrolyte at high temperatures, and a film is formed on the cathode surface to increase the resistance of the cell, greatly reducing the high temperature cycle performance. come. Accordingly, if the generation of hydrofluoric acid is suppressed and the eluted manganese is captured, the cell performance may be improved.

In order to solve the above problems, the porous separator made of agar prepared in <Preparation Example 1> was used as a separator for lithium ion batteries including LMO and LNMO cathode materials.

The binder of the LMO cathode material included commercially available polyvinylidene fluoride (PVDF) or agar at 5% by weight based on the total weight of the cathode material, and the separator was introduced with a commercially available polyolefin-based polyethylene (PE) separator and GPTMS. Using three types of non-Agar separator (Comparative Example 1) and 0.5G-agar separator (Preparation Example 1), LMO/separator/Li metal and commercially available electrolyte (1M LiPF ₆ , EC(ethylene carbonate)/DEC( The test was conducted with a coin cell consisting of diethyl carbonate)=1/1(v/v)).

As a result, the constant current charging and discharging results of the separators/binders (PE/PVDF binder, PE/Agar binder, Agar/Agar binder, 0.5G-Agar/Agar binder) under various conditions as shown in FIG. 5(a) show a similar tendency. Although shown, the Agar/Agar binder and 0.5G-Agar/Agar binder maintained higher discharge capacity than the PE/PVDF binder and PE/Agar binder at various discharge rates from 0.5C to 10C (Fig. 5(b)). ), this is because the Agar binder contributes to the rapid transfer of lithium ions within the positive electrode.

In addition, the capacities of the PE/PVDF binder and PE/Agar binder steadily decreased as the cycle progressed due to the elution of manganese generated by hydrofluoric acid generated in the LiPF ₆ electrolyte at a high temperature cycle of 60°C as shown in FIG. 5(c). The Agar/Agar binder and 0.5G-Agar/Agar binder showed 91% and 96% capacity retention, respectively, and the R _SEI value in the cell resistance measurement result was PE/PVDF binder, PE/Agar binder, Agar/Agar binder. And 0.5G-Agar/Agar binders were 215, 127, 50, and 7Ω, respectively, and it was confirmed that the 0.5G-Agar/Agar binder according to the present invention showed very low resistance (FIG. 5(d)). In addition, in the SEM image of the separator measured after 100 cycles as shown in FIG. 6, a large amount of by-products were observed on the surface of the 0.5G-Agar membrane compared to the PE membrane and the Agar membrane, and it was confirmed that high amounts of Mn and F elements were included. , This large amount of MnF ₂ is generated from the reaction of the eluted Mn ²⁺ and HF derived from the electrolyte. Thus, it was confirmed that the 0.5G-Agar/Agar binder separator according to the present invention could well capture manganese eluted from the high temperature reaction.

In addition, the main cause of the manganese elution reaction is HF generated by hydrolysis of PF ₅ generated in the decomposition reaction of the electrolyte solution (LiPF ₆ ). To confirm the stability of the 0.5G-Agar membrane against PF ₅ After immersing in LiPF ₆ electrolyte with 200 ppm of water for 24 hours, the surface composition of the separator was measured.

As a result, it was confirmed that the intensity of F ^- and PO ₂ F ₂ ^- was significantly reduced in the 0.5G-Agar membrane, unlike the PE membrane, as shown in FIG. 5(e). This 0.5G-Agar membrane sikimyeo effectively stabilize the PF _5, F by hydrolysis of PF ₅ ^- it was confirmed that by inhibiting the formation of hydrofluoric acid can be reduced to produce ^- and PO ₂ F _2.

Therefore, the porous separator manufactured using GPTMS-modified agar not only suppresses the generation of hydrofluoric acid by stabilizing PF ₅ derived from the electrolyte, but also shows excellent capacity retention by effectively adsorbing manganese eluted by hydrofluoric acid when driven at high temperatures. gave.

< Experimental example 3> LNMO /Separator/ graphite furnace Composed Coin cell Electrochemical properties

In order to check the effect of the G-Agar separator according to high temperature and high voltage operation in the full cell of LNMO/separator/graphite, LNMO/separator/graphite and commercialized electrolyte (1M LiPF ₆ , EC (ethylene carbonate) as shown in FIG. 7(a)) )/DEC(diethyl carbonate)=1/1(v/v)) to prepare a coin cell.

In the LNMO cathode material, commercially available polyvinylidene fluoride (PVDF) or agar binder was included in an amount of 5% by weight based on the total weight of the cathode material.

As a result, in the constant current charging/discharging analysis as shown in FIG. 7(b), the overvoltage of the coin cell including the 0.5G-Agar separator was the lowest compared to the PE separator and the Agar separator, which means that the resistance inside the cell is small. do. In addition, it was confirmed that the coin cell including the 0.5G-agar separator and the agar binder exhibited the most stable performance in the cycle characteristics at 55°C high temperature (Fig. 7(c)), which prevents manganese from which the 0.5G-agar separator is eluted. It is because it can absorb and stabilize a hydrofluoric acid precursor.

Claims (14)

Agar; And
Agar-based functional polymer separator, characterized in that the agar is modified with a silane compound represented by the following formula (1).
[Formula 1]

In the above formula, R ¹ to R ³ may each be the same or different, C1 to C4 alkyl or C1 to C4 alkoxy, and R ⁴ is glycidoxy (C1 to C10) alkyl, amino (C1 to C10) )Alkyl, (C1 to C10)alkyl isocyanate, amino group, vinyl group, epoxy group, methacryloxy group, acryloxy group, ureido group, chloropropyl group, mercapto group, sulfido group and isocyanato group One. The method of claim 1,
The silane compound is an agar-based functional polymer membrane, characterized in that represented by the following formula (1).
[Formula 1]

In the above formula, R ¹ to R ³ may each be the same or different, and either methoxy or ethoxy, and R ⁴ is an epoxy group, a vinyl group, an amino group, a methacryloxy group, an acryloxy group, a ureido group, and a chloropropyl It is any one of the group consisting of a group, a mercapto group, a sulfido group, and an isocyanato group. The method of claim 1,
Silane compounds include 3-(glycidoxypropyl)trimethoxysilane (3-(glycidoxypropyl)trimethoxysilane; GPTMS), 3-(glycidoxypropyl)triethoxysilane (3-(glycidoxypropyl)triethoxysilane; GPTES), 3 -(Isocyanatopropyl)triethoxysilane (3-(isocyanatopropyl)triethoxysilane; ICPTES), 3-(aminopropyl)triethoxysilane (3-(aminopropyl)triethoxysilane; APTES), 3-(aminopropyl) Agar-based functional polymer separator, characterized in that at least one selected from the group consisting of trimethoxysilane (3-(aminopropyl)trimethoxysilane; APTMS). The method of claim 1,
Agar-based functional polymer separator, characterized in that the silane compound and agar are contained in a mass ratio of 0.1 to 1: 1. The method of claim 1,
The separator is an agar-based functional polymer separator, characterized in that it contains 40 to 80% of pores. A lithium-ion battery comprising the agar-based functional polymer separator according to any one of claims 1 to 5. The method of claim 6,
Lithium ion batteries include a positive electrode, a negative electrode, a separator, and an electrolyte,
Lithium ion battery, characterized in that it comprises an agar binder (binder) in the positive electrode or negative electrode. The method of claim 7,
Lithium ion battery, characterized in that the agar binder (binder) comprises 5 to 20wt% based on the total weight of the positive electrode or negative electrode. Preparing an agar solution modified with a silane compound represented by the following Chemical Formula 1;
Casting the agar solution onto a substrate to prepare a polymer film; And
Placing the polymer membrane in a non-solvent to form pores by a phase transfer method; A method for producing a functional agar-based polymer membrane comprising a.
[Formula 1]

In the above formula, R ¹ to R ³ may each be the same or different, C1 to C4 alkyl or C1 to C4 alkoxy, and R ⁴ is glycidoxy (C1 to C10) alkyl, amino (C1 to C10) )Alkyl, (C1 to C10)alkyl isocyanate, amino group, vinyl group, epoxy group, methacryloxy group, acryloxy group, ureido group, chloropropyl group, mercapto group, sulfido group and isocyanato group One. The method of claim 9,
A method for producing a functional polymer membrane based on an agar, characterized in that the silane compound and agar are included in a mass ratio of 0.1 to 1: 1. The method of claim 9,
A method for producing a functional polymer membrane based on an agar, characterized in that the polymer membrane is reacted with a non-solvent for 1 to 10 hours. A lithium ion battery comprising a separator manufactured by the method of manufacturing an agar-based functional polymer separator according to any one of claims 9 to 11. The method of claim 12,
Lithium ion batteries include a positive electrode, a negative electrode, a separator, and an electrolyte,
Lithium ion battery, characterized in that it comprises an agar binder (binder) in the positive electrode or negative electrode. The method of claim 13,
Lithium ion battery, characterized in that the agar binder (binder) comprises 5 to 20wt% based on the total weight of the positive electrode or negative electrode.

Images