Preparation method of bacterial cellulose-based aqueous zinc ion battery diaphragm material

Abstract

The invention discloses a preparation method of a bacterial cellulose-based aqueous zinc ion battery diaphragm material, and the method comprises the following steps of 1, adding montmorillonite into deionized water, and mechanically stirring and uniformly dispersing; adding a small molecule substance into the mixture solution, stirring at room temperature, and stripping the montmorillonite to obtain a suspension containing the sliced montmorillonite; 2, carrying out centrifugal separation on the suspension, washing with deionized water for multiple times, and centrifuging to obtain a sliced montmorillonite solid precipitate; 3, carrying out freeze drying on the sliced montmorillonite solid precipitate to obtain the sliced montmorillonite powder; 4, uniformly dispersing the sliced montmorillonite powder and the bacterial cellulose homogenate in the deionized water to obtain a homogeneous suspension; and 5, filtering the homogeneous suspension to obtain a wet diaphragm, and carrying out vacuum drying to obtain an MMT / BC diaphragm. The prepared MMT / BC diaphragm has the properties of high porosity, excellent mechanical strength, high liquid retention capacity and the like, and the electrochemical performance of a zinc negative electrode in an aqueous zinc ion battery can be improved.

Description

technical field [0001] The invention belongs to the field of new energy materials and electrochemistry, and relates to a preparation method of a zinc-ion battery diaphragm material, in particular to a preparation method of a bacterial cellulose-based aqueous zinc-ion battery diaphragm material. Background technique [0002] Lithium-ion batteries occupy a dominant position in the fields of portable mobile electronic devices and electric vehicles, but due to the scarcity of lithium resources, the safety problems caused by the use of toxic and flammable organic electrolytes hinder the further large-scale application of lithium-ion batteries. The aqueous zinc-ion battery uses metal zinc as the negative electrode, because zinc has high abundance, high water environment tolerance, and high theoretical mass specific capacity (820 mAh g -1 ), low redox potential (-0.76 V vs. SHE) and other advantages, it is considered as an alternative battery system for lithium-ion batteries. [0...

AI Technical Summary

Problems solved by technology

Due to the defects on the surface of the metal zinc negative electrode, the dislocation position is more conducive to the nucleation and deposition of Zn2+ in thermodynamics, and the uneven nucleation and growth will lead to the formation of zinc dendrites, resulting in battery capacity decay

In addition, the commonly used separator material in aqueous Zn-ion batteries is glass fiber, which has poor mechanical strength and is insufficient to maintain its structural integrity during battery assembly and cycling.

And the rigid zinc dendrite has a high modulus, which can easily pierce the glass fiber separator and directly contact the positive electrode, causing an internal short circuit in the battery.

[0004]Currently, researches on zinc-ion battery diaphragm materials are mainly aimed at modifying the properties of glass fiber and commercial Nafion membranes, but the cost is high and the modification process is complicated. To a certain extent, the cost of separator materials is increased, which damages the low-cost advantages of zinc-ion batteries

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