Electrolyte composition, polymer electrolyte membrane, polymer electrolyte and preparation method thereof, all-solid-state battery and preparation method thereof

Abstract

The invention relates to the field of all-solid-state batteries, in particular to an electrolyte composition, a polymer electrolyte membrane, a polymer electrolyte and a preparation method thereof, anall-solid-state battery and a preparation method thereof, wherein the electrolyte composition contains a polymer, a lithium salt, an ionic liquid and a cross-linking agent, and the polymer is a copolymer composed of a structural unit represented by a formula (1) and a structural unit represented by a formula (2). The battery positive electrode and the electrolyte layer provided by the invention have relatively high peeling strength and proper compaction density, so that the battery has better specific capacity, cycle life and the like; formula (1); and formula (2).

Description

technical field [0001] The invention relates to the field of all-solid-state batteries, in particular to an electrolyte composition, a polymer electrolyte membrane, a polymer electrolyte and a preparation method thereof, and an all-solid-state battery and a preparation method thereof. Background technique [0002] At present, most lithium-ion batteries on the market use liquid electrolyte as the conductive substance, but during use, the liquid electrolyte is volatile, flammable and explosive, causing many safety problems; moreover, it is easy to grow lithium dendrites, which limits the Application of lithium as negative electrode in batteries. Therefore, solid polymer electrolytes (SPEs) have been proposed to replace liquid electrolytes. The solid polymer electrolyte membrane not only plays the role of ion conduction, but also prevents the contact of positive and negative electrodes. And because of its strong plasticity, it can be made into films of different shapes accord...

AI Technical Summary

Problems solved by technology

This technical solution has the following disadvantages: 1. The preparation process of the negative pole piece is complicated, because lithium powder has high requirements on the environment, and it needs to be operated in an anhydrous and oxygen-free environment, which makes it difficult to mix, filter, coat, dry, and tablet. operate

2. The negative electrode needs to mix lithium powder with superionic conductors and polymers, which is difficult to mix evenly, resulting in poor uniformity of the pole piece and poor consistency of the battery

3. Positive and negative pole pieces need to be soaked in the polymer electrolyte to make the battery. After soaking, the polymer electrolyte in the gel state is bonded to the pole piece, which increases the complexity of the lamination process and the difficulty of correct lamination.

4. The ionic conductivity of polymer electrolyte is low, which is far from the requirements of commercial application

This technical solution has the following disadvantages: 1. The particles of the positive electrode material are large, and the method of inkjet printing is easy to block the delivery pipe and nozzle, which affects the continuity of the manufacturing process

2. The positive electrode particles are easy to settle, which leads to the unevenness of the prepared positive electrode film layer and affects the uniformity of the battery

3. Conventional cathode slurry is relatively viscous, so inkjet printing is more difficult. In order to adapt to the inkjet process, the solid content of the slurry can only be reduced at the expense of battery capacity

4. Physical vapor deposition equipment and manufacturing costs are high, the process is complex, and there are high requirements for water and oxygen content, and the daily environment cannot meet the manufacturing requirements of this technology

5. The ionic conductivity of the polymer electrolyte is low, which is far from the requirements of commercial applications

There is following shortcoming in this technical scheme: 1. preparation process is complicated, and this method at first is that initiator (dibenzoyl peroxide BPO) and monomer MMA are mixed and stirred evenly, then crosslinking agent (ethylene glycol dimethacrylate DEMA), polymer PUA and ionic liquid (DEFYTFSI or Py 13 TFSI) heated and stirred evenly, and finally mixed the two liquids and added solvent N,N-dimethylformamide (DMF), stirred evenly, then cast, and cured by ultraviolet radiation to form a film

②Because the ionic conductivity of the polymer PUA and PMMA used in this method is not high, the ionic conductivity of the polymer electrolyte membrane is mainly improved by adding ionic liquid, and the cost of ionic liquid is higher

③ Dibenzoyl peroxide, the initiator used in ultraviolet crosslinking, is extremely unstable in nature, and it may cause fire and explosion when exposed to bright light, high temperature, and reducing agents, so the danger in the operation process is relatively high

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