Organic-inorganic composite all-solid electrolyte, a preparation method and application thereof

Abstract

The invention discloses an organic-inorganic composite all-solid electrolyte, 40.0 to 80.0 wt% of polyethylene oxide, 15.0 to 30.0 wt% of polypropylene carbonate, 1.0 to 10.0 wt% of pseudo-one-dimensional inorganic fast ionic conductor and 4.0 to 20.0 wt% of lithium salt, which are mainly compose of polyethylene oxide, polypropylene carbonate, lithium salt and pseudo-one-dimensional inorganic fastionic conductor. The preparation method of the invention comprises the following steps: (1) adding a quasi-one-dimensional inorganic fast ionic conductor into a lithium salt solution, stirring, and uniformly dispersing; (2) sequentially adding polyethylene oxide and polypropylene carbonate into the solution after the step (1), stirring, and uniformly dispersing; (3) coating the mixed solution after the step (2) on the film-forming substrate and drying to obtain the composite electrolyte. The quasi-one-dimensional inorganic fast ionic conductor is introduced into the organic-inorganic composite all-solid electrolyte of the invention, which can effectively reduce the crystallinity, has high ionic conductivity and excellent mechanical properties, and can largely avoid the situation that a lithium dendrite punctures the separator and causes a short circuit inside the battery.

Description

technical field [0001] The invention belongs to the field of battery materials, and in particular relates to an organic-inorganic composite all-solid electrolyte and a preparation method and application thereof. Background technique [0002] Most of the current commercial lithium-ion secondary batteries have the following disadvantages: 1. The electrolyte used is mainly an organic electrolyte, and the lithium-ion battery using an organic electrolyte is easy to leak from the battery when it is in use, and there is a potential safety hazard; at the same time , batteries using liquid electrolytes also have potential safety hazards at high temperatures, and because the electrolyte is in a liquid state, it is difficult to process this type of lithium battery into a thin shape, which limits its application range; 2. The mechanical properties of gel polymer electrolytes It is poor and difficult to process and shape, which also limits its development and application. [0003] In or...

AI Technical Summary

Problems solved by technology

[0002] Most of the current commercial lithium-ion secondary batteries have the following disadvantages: 1. The electrolyte used is mainly an organic electrolyte, and the lithium-ion battery using an organic electrolyte is easy to leak from the battery when it is in use, and there is a potential safety hazard; at the same time , batteries using liquid electrolytes also have potential safety hazards at high temperatures, and because the electrolyte is in a liquid state, it is difficult to process this type of lithium battery into a thin shape, which limits its application range; 2. The mechanical properties of gel polymer electrolytes Poor and difficult to process and shape, which also limits its development and application

The solid-state electrolyte in the all-solid-state lithium-ion secondary battery is a key component of the lithium-ion battery, in which polyethylene oxide (PEO) as the matrix of the solid-state electrolyte is an earlier polymer electrolyte material, but the formation of PEO and lithium salt The conductivity of the polymer film at room temperature is low, and the electrochemical window is low, which is far from meeting the commercial requirements. Therefore, the purpose of improving the conductivity of the composite polymer film is achieved by adding other materials.

[0004] However, the current technical means are basically PEO electrolyte membranes obtained simply by adding other polymers or ionic conductors. The conductivity at room temperature is still low, the crystallinity is still relatively high, and the electrochemical window is also relatively small. The mechanical properties are also poor, so it is not suitable for direct use in batteries

Images