Hypervolume stable lithium battery and preparation method thereof

Abstract

The invention discloses a hypervolume stable lithium battery, the hypervolume stable lithium battery comprises a positive electrode, a negative electrode, a composite membrane and a nonaqueous electrolyte; the nonaqueous electrolyte comprises a lithium salt, a room temperature ionic liquid electrolyte and a composite additive, wherein the room temperature ionic liquid electrolyte comprises a quaternary ammonium salt cationic liquid and a cosolvent at the mass ratio of 1:(0.1-0.5); and the composite membrane comprises a multi-arc hole fiber based membrane and an inorganic nanometer coating on the surface of the multi-arc hole fiber based membrane. Compared with the prior art, in the provided hypervolume stable lithium battery and a preparation method of the hypervolume stable lithium battery, the nonaqueous electrolyte uses an ionic liquid to replace the traditional organic solvent, the range of the working temperature of the battery is expanded, the stability on the metal lithium is good, the safety of the battery at the high-power density is further improved, the potential safety hazard of the battery is eliminated; the composite membrane guarantees the better mechanical propertyand the electric conductivity of the composite membrane, and meanwhile, the thermal stability of the membrane is improved. Therefore, the hypervolume stable lithium battery is higher in ionic conductivity and excellent in thermal stability, chemical stability and electrochemical stability.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a super-capacity stable lithium battery and a preparation method thereof. Background technique [0002] Since the concept of rechargeable lithium battery was put forward in the early 1970s, since lithium ion battery was born and commercialized, due to its superior performance, it has rapidly become a multidisciplinary research hotspot in advanced energy, materials, and electrochemistry. , And is widely used in notebook computers, mobile phones, digital cameras, mp3 players and other small electronic equipment and medical equipment, as a driving power supply. [0003] Non-aqueous electrolyte is one of the key materials of lithium batteries, and its comprehensive properties (such as chemical and electrochemical stability, high and low temperature performance, etc.) directly affect the use of secondary lithium batteries. The non-aqueous electrolyte solution applied to rec...

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Problems solved by technology

[0004] Under overcharge / overdischarge or other extreme conditions of incorrect use, the internal temperature of lithium-ion batteries will rise rapidly, resulting in diaphragm damage, battery fire or explosion

Commonly used lithium battery separators are mainly polyolefin polymer materials such as polypropylene (PP) and polyethylene (PE). These materials have high tensile strength and electrolyte wettability, but due to the need for pore formation in the preparation process There is a stretching hole expansion process, even at a higher temperature that does not reach the glass transition temperature, there is a tendency to rebound, causing heat shrinkage or diaphragm fusing, resulting in thermal safety issues; or coating the surface of the diaphragm with an inert polymer binder Bonded nano-inorganic oxide particle coating, but the inorganic particles in the existing inorganic coating slurry are mostly dense particles, which do not have lithium ion conductivity

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