Polymer electrolyte and preparation method and application thereof

Abstract

The invention discloses a polymer electrolyte and a preparation method and application thereof. The polymer electrolyte comprises a polymer matrix, the polymer matrix is a polymer formed by self-polymerization of a polymeric monomer composed of three building blocks of acryloyl, carbamate and phosphate, or a polymer formed by copolymerizing a polymeric monomer and other monomers, wherein the polymeric monomer is composed of three building blocks, namely acryloyl, carbamate and phosphate. The polymer electrolyte can be used in a battery, the polymer matrix can be subjected to a self-crosslinking reaction at a high temperature of 130-190 DEG C to generate a compact thermosetting polymer which can cut off ion transmission and prevent thermal runaway of the battery; the self-crosslinking reaction is an endothermic reaction, so that the temperature of the battery can be quickly reduced, and the thermal runaway of the battery can be prevented; the polymer electrolyte can capture free radicals and has intrinsic flame retardance; and the characteristics of the polymer matrix are synergistic, so that the thermal runaway of the battery can be effectively prevented.

Description

technical field

[0001] The invention relates to the technical field of battery electrolytes, in particular to a polymer electrolyte and its preparation method and application. Background technique

[0002] Secondary lithium-ion batteries have the advantages of high energy density, long cycle life, and no memory effect, and have been widely used in 3C electronic products, electric vehicles and other fields. However, currently commercialized lithium batteries often use volatile and flammable organic carbonate-based liquid electrolytes, which can easily lead to safety hazards such as fire and explosion. In order to improve the safety of batteries, researchers have proposed a series of optimization measures, including changing the electrolyte solvent, designing high-concentration salt electrolytes, and using inorganic solid electrolytes or polymer electrolytes. Among them, the use of polymer electrolytes instead of liquid electrolytes is an effective method. Compared with the ...

Examples

Embodiment 1

[0064] The raw material ratio used to prepare the polymer electrolyte is shown in Table 1, and the LiTFSI / EMC solution was prepared in a glove box filled with argon. Will Add acrylonitrile and acrylonitrile to the above solution, and add the initiator AIBN. After it is completely dissolved, inject the solution into a lithium-ion battery containing positive and negative electrode materials, and place it at 60°C for in-situ polymerization. After 8 hours, the required polymer electrolyte battery.

[0065] Table 1:

[0066]

[0067] The electrolyte obtained from the above Example 1 has high ionic conductivity, wide electrochemical window and high tensile strength (Table 1). The NCM622 / Li metal full battery was assembled with the electrolyte obtained above, and the capacity retention rates were 90% and 87% after cycling at room temperature and 50°C for 100 cycles at operating voltages of 2.5-4.4V and 0.1C, respectively (such as figure 1 Shown), it can be seen that the obtain...

Embodiment 2

[0070] The ratio of raw materials used to prepare the polymer electrolyte is shown in Table 2. The urethane acrylate prepared in advance according to the monomer ratio shown in Table 2 was dissolved in NMP, mixed uniformly, scraped and coated on PET, and dried to obtain a polymer film. After the polymer film was punched, the Fully swell in the solution to obtain a polymer electrolyte membrane. The electrolyte membrane is combined with corresponding positive and negative electrode materials to assemble a lithium battery.

[0071] Table 2:

[0072]

[0073] The electrolyte obtained from the above Example 2 has high ionic conductivity, wide electrochemical window and high tensile strength (Table 2). The above-mentioned electrolytes were assembled into NCM811 / lithium metal full batteries, and the capacity retention rate was 89% after 100 cycles at an operating voltage of 2.5-4.3V and 2.0C (such as image 3 Shown), it can be seen that the obtained polymer electrolyte has ex...

Embodiment 3

[0076] The ratio of raw materials used to prepare the polymer electrolyte is shown in Table 3. In a glove box filled with argon, the Vinylene carbonate and LiDFOB were mixed together to make a solution, and the initiator BPO was added. After it was completely dissolved, the solution was injected into a lithium-ion battery containing positive and negative materials, and placed at 80°C for in-situ polymerization. After 6 hours Obtain the required polymer electrolyte battery.

[0077] table 3:

[0078]

[0079]

[0080] The electrolyte obtained from the above Example 3 has high ionic conductivity, wide electrochemical window and high tensile strength (Table 3). The lithium cobaltate / graphite full battery was assembled with the above electrolyte, and the capacity retention rate was 91% after 200 cycles at 50°C at an operating voltage of 2.5-4.4V and 0.5C (such as Figure 5 Shown), it can be seen that the obtained polymer electrolyte has excellent electrochemical performan...

technical field

[0001] The invention relates to the technical field of battery electrolytes, in particular to a polymer electrolyte and its preparation method and application. Background technique

[0002] Secondary lithium-ion batteries have the advantages of high energy density, long cycle life, and no memory effect, and have been widely used in 3C electronic products, electric vehicles and other fields. However, currently commercialized lithium batteries often use volatile and flammable organic carbonate-based liquid electrolytes, which can easily lead to safety hazards such as fire and explosion. In order to improve the safety of batteries, researchers have proposed a series of optimization measures, including changing the electrolyte solvent, designing high-concentration salt electrolytes, and using inorganic solid electrolytes or polymer electrolytes. Among them, the use of polymer electrolytes instead of liquid electrolytes is an effective method. Compared with the ...

Examples

Embodiment 1

[0064] The raw material ratio used to prepare the polymer electrolyte is shown in Table 1, and the LiTFSI / EMC solution was prepared in a glove box filled with argon. Will Add acrylonitrile and acrylonitrile to the above solution, and add the initiator AIBN. After it is completely dissolved, inject the solution into a lithium-ion battery containing positive and negative electrode materials, and place it at 60°C for in-situ polymerization. After 8 hours, the required polymer electrolyte battery.

[0065] Table 1:

[0066]

[0067] The electrolyte obtained from the above Example 1 has high ionic conductivity, wide electrochemical window and high tensile strength (Table 1). The NCM622 / Li metal full battery was assembled with the electrolyte obtained above, and the capacity retention rates were 90% and 87% after cycling at room temperature and 50°C for 100 cycles at operating voltages of 2.5-4.4V and 0.1C, respectively (such as figure 1 Shown), it can be seen that the obtain...

Embodiment 2

[0070] The ratio of raw materials used to prepare the polymer electrolyte is shown in Table 2. The urethane acrylate prepared in advance according to the monomer ratio shown in Table 2 was dissolved in NMP, mixed uniformly, scraped and coated on PET, and dried to obtain a polymer film. After the polymer film was punched, the Fully swell in the solution to obtain a polymer electrolyte membrane. The electrolyte membrane is combined with corresponding positive and negative electrode materials to assemble a lithium battery.

[0071] Table 2:

[0072]

[0073] The electrolyte obtained from the above Example 2 has high ionic conductivity, wide electrochemical window and high tensile strength (Table 2). The above-mentioned electrolytes were assembled into NCM811 / lithium metal full batteries, and the capacity retention rate was 89% after 100 cycles at an operating voltage of 2.5-4.3V and 2.0C (such as image 3 Shown), it can be seen that the obtained polymer electrolyte has ex...

Embodiment 3

[0076] The ratio of raw materials used to prepare the polymer electrolyte is shown in Table 3. In a glove box filled with argon, the Vinylene carbonate and LiDFOB were mixed together to make a solution, and the initiator BPO was added. After it was completely dissolved, the solution was injected into a lithium-ion battery containing positive and negative materials, and placed at 80°C for in-situ polymerization. After 6 hours Obtain the required polymer electrolyte battery.

[0077] table 3:

[0078]

[0079]

[0080] The electrolyte obtained from the above Example 3 has high ionic conductivity, wide electrochemical window and high tensile strength (Table 3). The lithium cobaltate / graphite full battery was assembled with the above electrolyte, and the capacity retention rate was 91% after 200 cycles at 50°C at an operating voltage of 2.5-4.4V and 0.5C (such as Figure 5 Shown), it can be seen that the obtained polymer electrolyte has excellent electrochemical performan...

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