TW202106757A - Polymer and lithium battery - Google Patents

Abstract

A polymer and a lithium battery are provided. The polymer is obtained by a polymerization reaction of a compound containing at least one ethylenically unsaturated group, a polyetheramine compound and a nucleophile compound. The compound containing at least one ethylenically unsaturated group is a maleimide-based compound. The nucleophile compound is selected from a group consisting of monomaleimide, barbituric acid, barbituric acid derivative, thiobarbituric acid, thiobarbituric acid derivative, cyanuric acid, trithiocyanuric acid, uracil, thiouracil and a combination thereof.

Description

Polymer and Lithium Battery

The present invention relates to a polymer and a battery, and particularly relates to a polymer and a lithium battery used in a lithium battery.

Because primary batteries do not meet environmental requirements, the market demand for secondary lithium batteries that can be repeatedly charged and discharged with the characteristics of light weight, high voltage value, and high energy density has increased rapidly in recent years. Therefore, the requirements for the performance of secondary lithium batteries, such as light weight, durability, high voltage, high energy density, and high safety, are becoming higher and higher. The application and expansion potential of secondary lithium batteries, especially in light electric vehicles, electric vehicles, and large-scale power storage industries, is quite high.

However, in general commercialized secondary lithium batteries, due to the use of lithium transition metal oxide as the cathode, in high-temperature applications, the cathode is likely to react with the electrolyte and be damaged, causing the oxygen in the lithium metal oxide to release and cause damage. Participate in the combustion reaction. This is one of the main reasons for the explosion, swelling and performance degradation of secondary lithium batteries. Therefore, how to maintain the structural stability and high performance of the cathode material under high temperature applications is one of the goals that those skilled in the art want to achieve.

The invention provides a polymer, which can be applied to the cathode material of a lithium battery, so that the lithium battery has good performance.

The present invention provides a lithium battery having the above-mentioned polymer.

The polymer of the present invention is obtained by polymerizing a compound containing at least one ethylenically unsaturated group, a polyetheramine compound, and a nucleophilic compound, wherein the polymer contains at least one ethylenically unsaturated group. The base compound is a maleimide-based compound, and the nucleophilic compound is selected from monomaleimide (MI), barbituric acid (BTA), and barbituric acid (BTA). Bituric acid derivatives, thiobarbituric acid (TBTA), thiobarbituric acid derivatives, cyanuric acid (CA), trithiocyanuric acid (TCA) , Uracil (uracil, UR), thiouracil (thiouracil, TUR), and their combinations.

In an embodiment of the polymer of the present invention, the molar ratio of the compound containing at least one ethylenically unsaturated group, the polyetheramine compound and the nucleophilic compound is, for example, 1:1:5 To 5:1:1.

In an embodiment of the polymer of the present invention, the maleimide compound is, for example, monomaleimide or bismaleimide (BMI).

In an embodiment of the polymer of the present invention, the polyetheramine compound includes monoamine, diamine or triamine.

In an embodiment of the present invention, the reaction temperature of the polymerization reaction is, for example, between 25°C and 200°C.

In an embodiment of the present invention, the reaction time of the polymerization reaction is, for example, between 0.5 hours and 8 hours.

The lithium battery of the present invention includes an anode, a cathode, a separator, an electrolyte, and a packaging structure. The cathode and the anode are arranged separately, and the cathode includes the above-mentioned polymer. The isolation film is arranged between the anode and the cathode, and the isolation film, the anode and the cathode define a containing area. The electrolyte is arranged in the containing area. The package structure covers the anode, the cathode and the electrolyte.

In an embodiment of the lithium battery of the present invention, the electrolyte includes an organic solvent, a lithium salt, and additives, where the additives are, for example, monomaleimide, polymaleimide, and dimaleimide. Leximine, polybismaleimide (polybismaleimide), copolymer of bismaleimide and monomaleimide, vinylene carbonate (vinylene carbonate) or mixtures thereof.

Based on the above, by using the above-mentioned compound containing at least one ethylenically unsaturated group, polyetheramine compound and nucleophilic compound to prepare, the polymer of the present invention can be applied to the cathode material of lithium battery, and make the lithium battery even It still has good electric capacity, battery efficiency and charge-discharge cycle life under high temperature operation.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

In this text, the range represented by "a value to another value" is a summary expression way to avoid listing all the values in the range one by one in the specification. Therefore, the record of a specific numerical range covers any numerical value within the numerical range, as well as a smaller numerical range defined by any numerical value within the numerical range.

In this article, sometimes the structure of a compound is represented by a skeleton formula. This notation can omit carbon atoms, hydrogen atoms, and carbon-hydrogen bonds. Of course, when a functional group is clearly drawn in the structural formula, the drawn one shall prevail.

In order to prepare a polymer that can be applied to a cathode material of a lithium battery so that the lithium battery still has good performance in a high temperature environment, the present invention proposes a polymer that can achieve the above advantages. Hereinafter, the specific embodiments are cited as examples on which the present invention can be implemented.

The embodiment of the present invention proposes a polymer, which is obtained by the polymerization reaction of a compound containing at least one ethylenically unsaturated group, a polyetheramine compound, and a nucleophilic compound.

In the present invention, the compound containing at least one ethylenically unsaturated group is a maleimide compound. The maleimide-based compound is, for example, monomaleimide or bismaleimide.

In the present invention, the polyetheramine compound is, for example, Jeffamine-M-1000, Jeffamine-D-400, or Jeffamine-T-400 manufactured by Huntsman Corporation.

In the present invention, the nucleophilic compound is selected from monomaleimide, barbituric acid, barbituric acid derivatives, thiobarbituric acid, thiobarbituric acid derivatives, cyanuric acid , Trimer thiocyanate, uracil, thiouracil, and combinations thereof. The above-mentioned monomaleimines can also be referred to as 2,5-pyrrolidone (2,5-pyrrolidone).

In the embodiment of the present invention, the polymer is obtained by reacting a compound containing at least one ethylenically unsaturated group, a polyetheramine compound, and a nucleophilic compound in a solvent. Furthermore, in this embodiment, the Michael addition reaction can be used to dissolve at least one ethylenically unsaturated group compound and polyetheramine compound in a solvent for polymerization to form a prepolymer. ), and then use the Michael addition reaction or free radical copolymerization reaction to dissolve the prepolymer and the nucleophilic compound in a solvent for polymerization to form the polymer of the present invention. However, the present invention is not limited to this. In other embodiments, the at least one ethylenically unsaturated group compound, polyetheramine compound, and nucleophilic compound are dissolved in a solvent to carry out polymerization by using Michael addition reaction or free radical copolymerization reaction to form the present invention Of polymers.

In the embodiment of the present invention, the molar ratio of the compound containing at least one ethylenically unsaturated group, the polyetheramine compound and the nucleophilic compound used is, for example, between 1:1:5 and 5:1:1. between. If the molar ratio of the compound containing at least one ethylenically unsaturated group, the polyetheramine compound and the nucleophilic compound is less than 1:1:5, the reactivity is poor. If the molar ratio of the compound containing at least one ethylenically unsaturated group, the polyetheramine compound and the nucleophilic compound is higher than 5:1:1, electrochemical side reactions are likely to occur. The temperature of the aforementioned polymerization reaction is, for example, between 25°C and 200°C, and the reaction time is, for example, between 0.5 hour and 8 hours.

In the present invention, the above-mentioned solvent may be an organic solvent, and examples thereof include N-methyl pyrrolidone (NMP), dimethylformamide (DMF), dimethyl sulfoxide (dimethyl sulfoxide) , DMSO) or dimethylacetamide (DMAC). The above-mentioned solvents can be used alone or in combination.

In addition, the above-mentioned Michael addition polymerization reaction can also be carried out in the presence of a catalyst. That is, the above-mentioned reactants and catalysts are dissolved in a solvent to carry out the reaction. At this time, the reaction temperature is, for example, between 25°C and 80°C, and the reaction time is, for example, between 0.5 hour and 2 hours. The above-mentioned catalyst is, for example, triethylamine (triethylamine) or triphenylphosphine (TPP), and the addition amount of the catalyst is, for example, 1 part by weight to 10 parts by weight.

The polymerization reaction for preparing the polymer of the present invention will be exemplified below, and these examples are not intended to limit the present invention.

Preparation of prepolymer of compound containing at least one ethylenically unsaturated group and polyetheramine compound

Bismaleimide (BMI) was used as the compound containing at least one ethylenically unsaturated group, Jeffamine-M-1000 was used as the polyetheramine compound, and N-methylpyrrolidone (NMP) was used as the solvent. Bismaleimide and polyetheramine (PE-NH ₂ ) can undergo Michael addition reaction to form prepolymer (PE-N-BMI).

（R為-(CH₂ )₂ -、-(CH₂ )₆ -、-(CH₂ )₈ -、聚醚基（polyether group）、

、

、

、

、

或

，x = 19，y = 3，R'為-CH₃ ，n為聚合度（degree of polymerization））Michael addition reaction:

(R is -(CH ₂ ) ₂ -, -(CH ₂ ) ₆ -, -(CH ₂ ) ₈ -, polyether group,

,

,

,

,

or

, X = 19, y = 3, R'is -CH ₃ , n is the degree of polymerization)

>Example 1>

（X為O或S，n為聚合度） 麥可加成反應：

（X為O或S）Barbituric acid (BTA) and thiobarbituric acid (TBTA) are used as nucleophilic compounds, respectively. Barbituric acid (or thiobarbituric acid) and the above-mentioned prepolymer (PE-N-BMI) can undergo Michael addition reaction and free radical copolymerization to form the polymer of the present invention. Free radical polymerization:

(X is O or S, n is the degree of polymerization) Michael addition reaction:

(X is O or S)

>Example 2>

（X為O或S）Cyanuric acid (CA) and thiocyanuric acid (TCA) are respectively used as nucleophilic compounds. Cyanuric acid (or thiocyanuric acid) and the aforementioned prepolymer (PE-N-BMI) can undergo a Michael addition reaction to form the polymer of the present invention. Michael addition reaction:

(X is O or S)

>Example 3>

（n為聚合度） 自由基聚合反應：

（n為聚合度）Monomaleimide (MI) is used as the nucleophilic compound. Monomaleimide and the above-mentioned prepolymer (PE-N-BMI) can undergo Michael addition reaction and free radical copolymerization to form the polymer of the present invention. Michael addition reaction:

(N is the degree of polymerization) Free radical polymerization:

(N is the degree of polymerization)

>Example 4>

（X為O或S） 自由基聚合反應：

（X為O或S，n為聚合度）Ureacil (UR) and thiouracil (TUR) are used as nucleophilic compounds, respectively. Ureacil (or thiouracil) and the above-mentioned prepolymer (PE-N-BMI) can undergo Macho addition reaction and free radical copolymerization to form the polymer of the present invention. Michael addition reaction:

(X is O or S) Free radical polymerization reaction:

(X is O or S, n is the degree of polymerization)

The polymer of the present invention can be applied to cathode materials of lithium batteries. Furthermore, the polymer of the present invention can form a protective layer on the surface of the cathode material, and because the polymer of the present invention has high thermal reactivity, high thermal stability and a rigid chemical structure, it can effectively block the high temperature environment from affecting the cathode. Structural destruction. As a result, in a high-temperature environment, a lithium battery with a cathode material including the polymer of the present invention can have good electrical capacity, battery efficiency, and safety, and have an excellent battery cycle life.

Hereinafter, a lithium battery including the polymer of the present invention will be described.

FIG. 1 is a schematic cross-sectional view of a lithium battery according to an embodiment of the present invention. Please refer to FIG. 1, the lithium battery 100 includes an anode 102, a cathode 104, a separator 106, an electrolyte 108 and a packaging structure 112.

The anode 102 includes an anode metal foil 102a and an anode material 102b, wherein the anode material 102b is disposed on the anode metal foil 102a through coating or sputtering. The anode metal foil 102a is, for example, copper foil, aluminum foil, nickel foil, or highly conductive stainless steel foil. The anode material 102b is, for example, carbide or metallic lithium. The aforementioned carbide is, for example, carbon powder, graphite, carbon fiber, carbon nanotube, graphene or a mixture thereof. However, in other embodiments, the anode 102 may only include the anode material 102b.

The cathode 104 and the anode 102 are arranged separately. The cathode 104 includes a cathode metal foil 104a and a cathode material 104b, wherein the cathode material 104b is disposed on the cathode metal foil 104a through coating. The cathode metal foil 104a is, for example, copper foil, aluminum foil, nickel foil, or highly conductive stainless steel foil. The cathode material 104b includes the polymer of the present invention and a lithium mixed transition metal oxide (lithium mixed transition metal oxide). The mixed oxide of lithium and transition metal is, for example, LiMnO ₂ , LiMn ₂ O ₄ , LiCoO ₂ , Li ₂ Cr ₂ O ₇ , Li ₂ CrO ₄ , LiNiO ₂ , LiFeO ₂ , LiNi _x Co _1-x O ₂ , LiFePO ₄ , LiMn _0.5 Ni _0.5 O ₂ , LiMn _1/3 Co _1/3 Ni _1/3 O ₂ , LiMc _0.5 Mn _1.5 O ₄ or a combination thereof, where 0>x>1, Mc is a divalent metal.

Based on the total weight of the cathode material 104b being 100 parts by weight, the content of the polymer is, for example, 0.5 to 5 parts by weight (preferably 1 to 3 parts by weight), and the content of the mixed oxide of lithium and transition metal is, for example It is 80 parts by weight to 95 parts by weight. If the content of the polymer is less than 0.5 parts by weight, battery safety characteristics are not obvious. If the content of the polymer is higher than 5 parts by weight, the cycle life of the battery is poor.

In addition, the lithium battery 100 may further include a polymer binder. The polymer adhesive reacts with the anode 102 and/or the cathode 104 to increase the mechanical properties of the electrode. In detail, the anode material 102b can be adhered to the anode metal foil 102a by a polymer adhesive, and the cathode material 104b can be adhered to the cathode metal foil 104a by a polymer adhesive. The polymer adhesive is, for example, polyvinylidene fluoride (PVDF), styrene butadiene rubber (SBR), polyamide, melamine resin, or a combination thereof.

The isolation film 106 is disposed between the anode 102 and the cathode 104, and the isolation film 106, the anode 102 and the cathode 104 define a containing area 110. The material of the isolation film 106 is an insulating material, such as polyethylene (PE), polypropylene (PP), or a composite structure composed of the foregoing materials (for example, PE/PP/PE).

The electrolyte 108 is disposed in the containing area 110. The electrolyte 108 includes an organic solvent, a lithium salt, and additives. The amount of organic solvent added is, for example, 55 wt% to 90 wt% of electrolyte 108, the amount of lithium salt added is, for example, 10 wt% to 35 wt% of electrolyte 108, and the amount of additives added is, for example, 0.05 wt% of electrolyte 108. % To 10 wt%. However, in other embodiments, the electrolyte 108 may not contain additives.

Organic solvents are, for example, γ-butyl lactone, ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), propyl acetate (PA ), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), or a combination thereof.

The lithium salt is, for example, LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiSbF ₆ , LiClO ₄ , LiAlCl ₄ , LiGaCl ₄ , LiNO ₃ , LiC(SO ₂ CF ₃ ) ₃ , LiN(SO ₂ CF ₃ ) ₂ , LiSCN, LiO ₃ SCF ₂ CF ₃ , LiC ₆ F ₅ SO ₃ , LiO ₂ CCF ₃ , LiSO ₃ F, LiB(C ₆ H ₅ ) ₄ , LiCF ₃ SO ₃ or a combination thereof.

Additives are, for example, monomaleimines, polymaleimines, bismaleimines, polybismaleimines, copolymers of bismaleimines and monomaleimines, carbonic acid Vinylene carbonate (VC) or its mixture. Monomaleimines are, for example, selected from unsubstituted maleimines, N-phenylmaleimines, N-(o-methylphenyl)-maleimines, N-(between (Methylphenyl)-maleimide, N-(p-methylphenyl)-maleimide, N-cyclohexylmaleimide, maleiminophenol, maleic acid Aminobenzocyclobutene, phosphorus-containing maleimines, phosphate maleimines, oxysilyl maleimines, N-(tetrahydropyranyl-oxyphenyl) horses Leximine and 2,6-xylylmaleimide constitute the ethnic group.

The packaging structure 112 covers the anode 102, the cathode 104 and the electrolyte 108. The material of the packaging structure 112 is, for example, aluminum foil.

In particular, the cathode 104 can be formed by adding the polymer of the present invention to the cathode material in the existing battery manufacturing process. Therefore, it can be effectively formed without changing any battery design, electrode material and electrolyte. Maintain the capacity, battery efficiency, and charge-discharge cycle life of the lithium battery 100 at high temperatures, and make the lithium battery 100 have higher safety.

Hereinafter, the effects of the polymer of the present invention will be described with experimental examples and comparative examples.

>Experimental example 1>

Preparation of anode

The metal lithium is cut to an appropriate shape and directly inserted to form the anode.

Preparation of the cathode

Add 1 part by weight (1 g) of bismaleimide (BMI) and polyetheramine compound (Jeffamine-M-1000, manufactured by Huntsman Corporation) (molar ratio 2:1) In a reactor containing 19 parts by weight of N-methylpyrrolidone (NMP) solvent, the reaction was carried out at a temperature of 70 °C for 8 hours to prepare a prepolymer (PE-N-BMI). Then, with a molar ratio of 1:2, barbituric acid (BTA) was added to the solution containing prepolymer (PE-N-BMI) and reacted at 130 °C for 8 hours to prepare The polymer of Experimental Example 1 was used as a cathode material additive. (The mol ratio is BMI: Jeffamine-M-1000: BTA = 2: 1: 1)

Next, 89 parts by weight of LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , 5 parts by weight of polyvinylidene fluoride (PVDF) and 5 parts by weight of acetylene black (conductive powder) were uniformly mixed in the N-methylpyrrolidone (NMP) solvent in. Then, 1 part by weight of the polymer of Example 1 was added to the above-mentioned mixed solution to form a cathode material. After that, after the cathode material is coated on the aluminum foil, it is dried, compressed and cut to form the cathode.

Preparation of electrolyte

LiPF _{6 is} dissolved in a mixture of propylene carbonate (PC), ethylene carbonate (EC) and diethyl carbonate (DEC) (the volume ratio is PC:EC:DEC = 2:3:5) to prepare the concentration It is a 1 M electrolyte, where the mixed solution is used as the organic solvent in the electrolyte, and LiPF _{6 is} used as the lithium salt in the electrolyte.

Lithium battery production

Polypropylene is used as a separator to separate the anode and the cathode, and define the accommodating area. Then, the above-mentioned electrolyte is added to the containing area between the anode and the cathode. After that, the above structure was sealed with an encapsulation structure to complete the production of the lithium battery of Experimental Example 1.

>Experimental example 2>

Preparation of anode

The anode of Experimental Example 2 was prepared according to the same preparation method as Experimental Example 1.

Preparation of the cathode

Add 1 part by weight (1 g) of bismaleimide (BMI) and polyetheramine compound (Jeffamine-M-1000) (molar ratio of 2:1) to 19 parts by weight of N-methyl In a reactor with pyrrolidone (NMP) solvent, react at 70 °C for 8 hours to prepare a prepolymer (PE-N-BMI). Then, with a molar ratio of 1:2, thiobarbituric acid (TBTA) was added to the solution containing the prepolymer (PE-N-BMI) and reacted at 130 °C for 8 hours. The polymer of Preparation Experimental Example 2 was used as the cathode material additive. (The mol ratio is BMI: Jeffamine-M-1000: TBTA = 2: 1: 1).

Next, 89 parts by weight of LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , 5 parts by weight of polyvinylidene fluoride (PVDF) and 5 parts by weight of acetylene black (conductive powder) were uniformly mixed in N-methylpyrrolidone (NMP ) In the solvent. Then, 1 part by weight of the polymer of Experimental Example 2 was added to the above-mentioned mixed solution to form a cathode material. After that, after the cathode material is coated on the aluminum foil, it is dried, compressed and cut to form the cathode.

Preparation of electrolyte

The electrolyte of Experimental Example 2 was prepared according to the same preparation method as Experimental Example 1.

Lithium battery production

The lithium battery of Experimental Example 2 was prepared according to the same preparation method as Experimental Example 1.

>Experimental example 3>

Preparation of anode

The anode of Experimental Example 3 was prepared according to the same preparation method as Experimental Example 1.

Preparation of the cathode

Add 1 part by weight (1 g) of bismaleimide (BMI) and polyetheramine compound (Jeffamine-M-1000) (molar ratio of 2:1) to 19 parts by weight of N-methyl In a reactor with pyrrolidone (NMP) solvent, react at 70 °C for 8 hours to prepare a prepolymer (PE-N-BMI). Then, add cyanuric acid (CA) to the solution containing prepolymer (PE-N-BMI) at a molar ratio of 2:3, and react at 130 °C for 8 hours to prepare The polymer of Experimental Example 3 was used as a cathode material additive. (The mol ratio is BMI: Jeffamine-M-1000: CA = 3: 1.5: 2)

Next, 89 parts by weight of LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , 5 parts by weight of polyvinylidene fluoride (PVDF) and 5 parts by weight of acetylene black (conductive powder) were uniformly mixed in the N-methylpyrrolidone (NMP) solvent in. Then, 1 part by weight of the polymer of Experimental Example 3 was added to the above-mentioned mixed solution to form a cathode material. After that, after the cathode material is coated on the aluminum foil, it is dried, compressed and cut to form the cathode.

Preparation of electrolyte

The electrolyte solution of Experimental Example 3 was prepared according to the same preparation method as Experimental Example 1.

Lithium battery production

The lithium battery of Experimental Example 3 was prepared according to the same preparation method as Experimental Example 1.

>Experimental example 4>

Preparation of anode

The anode of Experimental Example 4 was prepared according to the same preparation method as Experimental Example 1.

Preparation of the cathode

Add 1 part by weight (1 g) of bismaleimide (BMI) and polyetheramine compound (Jeffamine-M-1000) (molar ratio of 2:1) to 19 parts by weight of N-methyl In a reactor with pyrrolidone (NMP) solvent, react at 70 °C for 8 hours to prepare a prepolymer (PE-N-BMI). Then, in a molar ratio of 2:3, thiocyanuric acid (TCA) was added to the solution containing prepolymer (PE-N-BMI) and reacted at a temperature of 130 °C for 8 hours. The polymer of Experimental Example 4 was prepared as a cathode material additive. (The mol ratio is BMI: Jeffamine-M-1000: TCA = 3: 1.5: 2)

Next, 89 parts by weight of LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , 5 parts by weight of polyvinylidene fluoride (PVDF) and 5 parts by weight of acetylene black (conductive powder) were uniformly mixed in the N-methylpyrrolidone (NMP) solvent in. Then, 1 part by weight of the polymer of Experimental Example 4 was added to the above-mentioned mixed solution to form a cathode material. After that, after the cathode material is coated on the aluminum foil, it is dried, compressed and cut to form the cathode.

Preparation of electrolyte

The electrolyte of Experimental Example 4 was prepared according to the same preparation method as Experimental Example 1.

Lithium battery production

The lithium battery of Experimental Example 4 was prepared according to the same preparation method as Experimental Example 1.

>Experimental example 5>

Preparation of anode

The anode of Experimental Example 5 was prepared according to the same preparation method as Experimental Example 1.

Preparation of the cathode

Add 1 part by weight (1 g) of bismaleimide (BMI) and polyetheramine compound (Jeffamine-M-1000) (molar ratio of 2:1) to 19 parts by weight of N-methyl In a reactor with pyrrolidone (NMP) solvent, react at 70 °C for 8 hours to prepare a prepolymer (PE-N-BMI). Then, with a molar ratio of 1:2, monomaleimide (MI) was added to the solution containing the prepolymer (PE-N-BMI) and reacted at 130 °C for 8 hours. The polymer of Preparation Experimental Example 5 was used as the cathode material additive. (The mol ratio is BMI: Jeffamine-M-1000: MI = 2: 1: 1)

Next, 89 parts by weight of LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , 5 parts by weight of polyvinylidene fluoride (PVDF) and 5 parts by weight of acetylene black (conductive powder) were uniformly mixed in the N-methylpyrrolidone (NMP) solvent in. Then, 1 part by weight of the polymer of Experimental Example 5 was added to the above-mentioned mixed solution to form a cathode material. After that, after the cathode material is coated on the aluminum foil, it is dried, compressed and cut to form the cathode.

Preparation of electrolyte

The electrolyte solution of Experimental Example 5 was prepared according to the same preparation method as Experimental Example 1.

Lithium battery production

The lithium battery of Experimental Example 5 was prepared according to the same preparation method as Experimental Example 1.

>Experimental Example 6>

Preparation of anode

The anode of Experimental Example 6 was prepared according to the same preparation method as Experimental Example 1.

Preparation of the cathode

Add 1 part by weight (1 g) of bismaleimide (BMI) and polyetheramine compound (Jeffamine-M-1000) (molar ratio of 2:1) to 19 parts by weight of N-methyl In a reactor with pyrrolidone (NMP) solvent, react at 70 °C for 8 hours to prepare a prepolymer (PE-N-BMI). Then, with a molar ratio of 1:2, uracil (UR) was added to the solution containing the prepolymer (PE-N-BMI) and reacted at 130 °C for 8 hours to prepare the experimental example The polymer of 6 is used as a cathode material additive. (The mol ratio is BMI: Jeffamine-M-1000: UR = 2: 1: 1)

Next, 89 parts by weight of LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , 5 parts by weight of polyvinylidene fluoride (PVDF) and 5 parts by weight of acetylene black (conductive powder) were uniformly mixed in the N-methylpyrrolidone (NMP) solvent in. Then, 1 part by weight of the polymer of Experimental Example 6 was added to the above-mentioned mixed solution to form a cathode material. After that, after the cathode material is coated on the aluminum foil, it is dried, compressed and cut to form the cathode.

Preparation of electrolyte

The electrolyte solution of Experimental Example 6 was prepared according to the same preparation method as Experimental Example 1.

Lithium battery production

The lithium battery of Experimental Example 6 was prepared according to the same preparation method as Experimental Example 1.

>Experimental Example 7>

Preparation of anode

The anode of Experimental Example 7 was prepared according to the same preparation method as Experimental Example 1.

Preparation of the cathode

Add 1 part by weight (1 g) of bismaleimide (BMI) and polyetheramine compound (Jeffamine-M-1000) (molar ratio of 2:1) to 19 parts by weight of N-methyl In a reactor with pyrrolidone (NMP) solvent, react at 70 °C for 8 hours to prepare a prepolymer (PE-N-BMI). Then, with a molar ratio of 1:2, thiouracil (TUR) was added to the solution containing the prepolymer (PE-N-BMI) and reacted at 130 °C for 8 hours to prepare the experiment The polymer of Example 7 was used as a cathode material additive. (The mol ratio is BMI: Jeffamine-M-1000: TUR = 2: 1: 1)

Next, 89 parts by weight of LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , 5 parts by weight of polyvinylidene fluoride (PVDF) and 5 parts by weight of acetylene black (conductive powder) were uniformly mixed in the N-methylpyrrolidone (NMP) solvent in. Then, 1 part by weight of the polymer of Experimental Example 7 was added to the above-mentioned mixed solution to form a cathode material. After that, after the cathode material is coated on the aluminum foil, it is dried, compressed and cut to form the cathode.

Preparation of electrolyte

The electrolyte of Experimental Example 7 was prepared according to the same preparation method as Experimental Example 1.

Lithium battery production

The lithium battery of Experimental Example 7 was prepared according to the same preparation method as that of Experimental Example 1.

>Comparative example 1>

Preparation of anode

The anode of Comparative Example 1 was prepared according to the same preparation method as Experimental Example 1.

Preparation of the cathode

Add bismaleimide (BMI) and barbituric acid (BTA) (molar ratio of 2:1) into a reactor filled with N-methylpyrrolidone (NMP) solvent, at a temperature of 130 °C The reaction was continued for 8 hours to prepare the polymer of Comparative Example 1.

Next, 89 parts by weight of LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , 5 parts by weight of polyvinylidene fluoride (PVDF) and 5 parts by weight of acetylene black (conductive powder) were uniformly mixed in the N-methylpyrrolidone (NMP) solvent in. Then, 1 part by weight of the polymer of Comparative Example 1 was added to the above-mentioned mixed solution to form a cathode material. After that, after the cathode material is coated on the aluminum foil, it is dried, compressed and cut to form the cathode.

Preparation of electrolyte

The electrolytic solution of Comparative Example 1 was prepared according to the same preparation method as that of Experimental Example 1.

Lithium battery production

The lithium battery of Comparative Example 1 was prepared according to the same preparation method as Experimental Example 1.

>Comparative Example 2>

Preparation of anode

The anode of Comparative Example 2 was prepared according to the same preparation method as Experimental Example 1.

Preparation of the cathode

The cathode of Comparative Example 2 was prepared according to the same preparation method as Experimental Example 1, except that the cathode material of Comparative Example 2 did not contain cathode material additives.

Preparation of electrolyte

The electrolyte of Comparative Example 2 was prepared according to the same preparation method as Experimental Example 1.

Lithium battery production

The lithium battery of Comparative Example 2 was prepared according to the same preparation method as Experimental Example 1.

Charge and discharge cycle test

A potentiostat (model VMP3) was used to conduct a charge-discharge cycle test on the lithium batteries of the experimental example and the comparative example at a fixed current/voltage at room temperature. The measurement results are shown in Figure 2. It can be seen from FIG. 2 that the cycle life of the lithium batteries of Experimental Example 1 to Experimental Example 7 with the polymer of the present invention is significantly higher than that of the lithium batteries of Comparative Example 1 and Comparative Example 2. It can be seen that the polymer of the present invention can effectively improve the performance of lithium batteries. In addition, this result also confirms that the polymer of the present invention can indeed be accepted by existing lithium batteries and can improve the safety properties of lithium batteries.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be determined by the scope of the attached patent application.

100: Lithium battery 102: anode 102a: Anode metal foil 102b: anode material 104: cathode 104a: Cathode metal foil 104b: Cathode material 106: Isolation film 108: Electrolyte 110: containment area 112: Package structure

FIG. 1 is a schematic cross-sectional view of a lithium battery according to an embodiment of the present invention. 2 is a graph of the relationship between the number of charge and discharge cycles and the discharge capacity of the lithium batteries of the experimental example and the comparative example of the present invention at room temperature.

Claims (8)

A polymer obtained by polymerizing a compound containing at least one ethylenically unsaturated group, a polyetheramine compound and a nucleophilic compound, wherein the compound containing at least one ethylenically unsaturated group is maleimide Is a compound, and the nucleophilic compound is selected from monomaleimide, barbituric acid, barbituric acid derivatives, thiobarbituric acid, thiobarbituric acid derivatives, melamine A group of acids, thiocyanuric acid, uracil, thiouracil, and combinations thereof. The polymer according to item 1 of the scope of patent application, wherein the molar ratio of the compound containing at least one ethylenically unsaturated group, the polyetheramine compound and the nucleophilic compound is 1:1: Between 5 and 5:1:1. The polymer according to item 1 of the scope of patent application, wherein the maleimide-based compound includes monomaleimide or bismaleimide. The polymer according to item 1 of the scope of patent application, wherein the polyetheramine compound includes monoamine, diamine or triamine. The polymer described in item 1 of the scope of patent application, wherein the reaction temperature of the polymerization reaction is between 25 °C and 200 °C. The polymer according to item 1 of the scope of patent application, wherein the reaction time of the polymerization reaction is between 0.5 hour and 8 hours. A lithium battery, including: anode; A cathode, which is arranged separately from the anode, and the cathode includes the polymer according to any one of items 1 to 6 in the scope of the patent application; An isolation membrane, arranged between the anode and the cathode, and the isolation membrane, the anode and the cathode define a containing area; The electrolyte is arranged in the containing area; and The packaging structure covers the anode, the cathode and the electrolyte. The lithium battery according to item 7 of the scope of patent application, wherein the electrolyte includes an organic solvent, a lithium salt, and an additive, and the additive includes monomaleimide, polymaleimide, and bismaleimide Imines, polybismaleimines, copolymers of bismaleimines and monomaleimines, vinylene carbonate or mixtures thereof.

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