A kind of polysiloxane based on aromatic disulfide bond and its application

Abstract

The invention discloses a polysiloxane based on an aromatic disulfide bond, which is composed of an amino-terminated polysiloxane and a substituted or unsubstituted 4,4'-diaminodiphenyl disulfide reacted with a crosslinking agent Formation of amide bonds, polycondensation. The polysiloxane of the present invention not only has good flexibility, but also has a large number of reversible dynamic bonds, abundant hydrogen bonds and disulfide bonds, and can spontaneously repair damage at room temperature or under heating conditions, and is more capable of The repair material adapts to the physical environment of the positive electrode material of the lithium battery, has good bonding performance and stability, and can alleviate the specific capacitance attenuation caused by the expansion of the battery during charging and discharging, thereby repairing the micro-cracks of the battery, increasing the cycle times of the battery, and prolonging the life of the battery. The service life of the battery can be used as a self-healing binder to prepare positive electrode materials in lithium batteries.

Description

technical field [0001] The invention relates to the technical field of organosilicon and the field of lithium batteries, in particular to an aromatic disulfide bond-based polysiloxane and its application as a self-repairing binder in the preparation of positive electrode materials for lithium batteries. Background technique [0002] With the rapid development of social economy, the traditional fossil energy is becoming exhausted, and the development of renewable energy has become a hot spot in human research. Lithium-ion batteries are currently a relatively mature energy storage material. Due to its advantages of environmental protection, high capacity density, and good cycle stability, it has been widely used in many fields such as wearable devices, smart phones, and new energy vehicles, and is closely related to our daily life. As an efficient and convenient energy storage technology, lithium batteries not only satisfy consumer electronics products, especially in the use ...

AI Technical Summary

Problems solved by technology

However, Ibon Odriozola et al. found that only disulfide bonds containing alkyl chains are dynamic at high temperatures, and aromatic disulfide bonds can only be broken at room temperature. Therefore, self-healing adhesives with disulfide bonds are very repairable. Poor (Materials Horizons, 2014, 1(2): 237-240.)

Chinese patent document CN109836566A discloses that UPy-PEG-UPy, a self-healing adhesive containing hydrogen bonds, can be used in lithium-sulfur batteries, but because the raw materials are easy to absorb water and deteriorate, and the obtained material also contains polyethylene glycol, the hydrophobicity of the material is very poor.

Many literatures have reported that self-healing materials prepared by imine bonds rely on the dynamics of imine bonds. Although they have good self-healing properties, imine bonds are unstable and easy to react with electrolytes, and they are used in lithium-sulfur batteries. In the process, the imine bond is easily damaged and cannot improve the stability of the battery (Advanced Materials, 2016, 28 (15): 2904-2909; Advanced materials, 2014, 26 (23): 3938-3942; Polymer, 2016, 85 :106-113.)

[0007] Under the existing technology, there is still no ideal binder for lithium-sulfur battery cathode materials that can meet the requirements of strong self-healing and good stability in the electrolyte environment.

Images