Mofs/pmma/pvdf three-phase composite battery diaphragm and preparation method thereof

Abstract

The invention discloses a preparation method of a MOFs / PMMA / PVDF three-phase composite battery diaphragm, comprising the following steps: step 1: preparing a metal-organic framework MOFs nanoparticle solution; step 2 preparing a PVDF solution; step 3: preparing the PVDF solution in step 1 The obtained solution is slowly added dropwise to the solution in Step 2; Step 4: Add the methyl methacrylate MMA solution to the mixed solution obtained in Step 3, Step 5: Electrospin the electrospinning stock solution prepared in Step 4 silk, thereby obtaining a porous diaphragm; Step 6: Prepare the initiator solution; Step 7: Evenly cover the initiator solution prepared in Step 6 on the porous diaphragm in Step 5; Step 8: Make the porous diaphragm at 120 ° C ~ 150 ° C Under hot pressing for 1-4 hours, at the same time, the methyl methacrylate MMA in the porous separator is polymerized under the action of the initiator to form polymethyl methacrylate PMMA, and finally the MOFs / PMMA / PVDF three-phase composite battery separator is obtained. The invention can reduce the thickness without reducing the tensile strength and low porosity.

Description

technical field [0001] The invention belongs to the field of materials, and in particular relates to a MOFs / PMMA / PVDF three-phase composite battery diaphragm and a preparation method thereof. Background technique [0002] Lithium-ion batteries have the advantages of high specific energy, long cycle life, no memory effect, safety, reliability, and fast charging and discharging, and have become a research hotspot in new power supply technologies in recent years. The composition of a lithium-ion battery includes a positive electrode, a negative electrode, a separator and an electrolyte. As a barrier between the positive and negative electrodes, the separator plays a vital role in the performance of the lithium-ion battery, and its performance directly affects the capacity and cycle of the battery, especially It is an important factor affecting the safety performance of the battery. At present, polyolefin separators commonly used in the market generally have disadvantages such ...

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Problems solved by technology

The relevant research that has been done so far is a nanocomposite fiber-reinforced gel polymer electrolyte and its preparation method with the patent publication number CN 104393336 B, but the patent does not clearly point out the mechanical properties and thermal stability of the prepared fiber membrane. And the thickness is generally above 50 μm (larger thickness can meet the strength requirements), which does not meet the thickness requirements of commercial lithium battery separators (generally less than 25 μm)

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