High-safety high-volume-energy-density quasi-solid-state lithium-ion battery and manufacturing method thereof

Abstract

The invention provides a high-safety high-volume-energy-density quasi-solid-state lithium-ion battery and a manufacturing method thereof. The manufacturing method comprises three steps of preparing isotropic polyphenylene sulfide solid electrolyte by adopting a solvent-independent method, manufacturing a high-load battery pole piece and assembling the quasi-solid-state lithium-ion battery. The volume ratio of the active substance load is increased to 30%-50%; the polyphenylene sulfide solid electrolyte has good flame retardant property and good thermal stability, the electrolyte injection amount is reduced, the electrolyte dosage is greatly reduced, combustibles in the battery are also reduced, and the safety performance of the battery is improved. The solid electrolyte contains lithium, and the content of toxic fluorine-containing lithium salt in the electrolyte is also greatly reduced. The battery pole piece and the solid electrolyte are bonded into a whole after hot pressing, are not easy to shift under repeated bending, can be used as an ultrathin flexible quasi-solid battery, and are used in wearable electronic equipment.

Description

technical field [0001] The invention relates to a quasi-solid-state lithium-ion battery with high safety and high volume energy density and a manufacturing method thereof, belonging to the technical field of new energy materials and device manufacturing. Background technique [0002] First, solid-state lithium-ion batteries have attracted increasing attention from both industry and academia due to their excellent safety performance and potential high energy density. However, the power density of solid-state lithium-ion batteries is very low, which greatly limits their commercial promotion and application. The key issue that urgently needs to be broken through is to develop new solid-state electrolyte materials with high electrical conductivity and excellent processability. Current inorganic ceramic / glass electrolytes such as Li 5 La 3 Zr 2 o 12 , Li 3x La 2 / 3-x TiO 3 , and sulfide electrolytes due to their Li-ion conductivity up to 10 -4 ~10 -2 S cm -1 , has recei...

AI Technical Summary

Problems solved by technology

Current inorganic ceramic / glass electrolytes such as Li 5 La 3 Zr 2 o 12 , Li 3x La 2 / 3-x TiO 3 , and sulfide electrolytes due to their Li-ion conductivity up to 10 -4 ~10 -2 S cm -1 , has received extensive attention, but this type of material has poor mechanical processing performance and difficult film formation, especially the extremely harsh processing environment requirements for sulfide electrolytes, and there is still a long way to go for engineering and commercialization

The other is organic electrolytes, such as PEO, PVDF, etc., which are easy to process into films and can be processed and produced roll-to-roll, but the conductivity of this type of organic electrolyte is low, only 10 -8 ~10 -5 S cm -1 , cannot be used normally at room temperature, which also limits the further large-scale promotion of this type of material

[0003] Secondly, the current traditional pole piece manufacturing process uses a solvent-containing wet coating process. This method has congenital defects such as high porosity, low electrical conductivity, and low loading capacity, and cannot realize the manufacture of thick pole pieces.

Limits the further improvement of the energy density of lithium batteries

[0004] Thirdly, in the current manufacturing process of stacked lithium batteries, in order to achieve high volume utilization, a thin sheet design is adopted, the area of ​​the electrode sheet is increased, and the thickness is thinned. The infiltration process of the liquid is difficult, and it is easy to cause uneven distribution of the electrolyte and lithium salt, which will affect the performance of the battery

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