Research On Synthesis And Performance Of Core-shell Emulsion Adhesive For Lithium Battery Anode

The environmental pollution caused by the burning of fossil fuels is becoming more and more serious,and environmental protection has become the theme of development in the context of the new era.Therefore,the development of clean energy is imperative,and lithium-ion batteries are the mainstream of new energy sources.Adhesives for commercial batteries are mainly styrene butadiene rubber and polyvinylidene fluoride,but neither of them can be environmentally friendly and achieve high-efficiency bonding.The improvement of the adhesive is mainly to modify the styrene-butadiene rubber to improve the bonding performance.This paper introduces a core-shell emulsion synthesis method,and synthesizes an adhesive with high bonding performance.The core-shell emulsion is synthesized based on emulsion polymerization,with styrene(ST)and isooctyl acrylate(2-EHA)as the main monomers,and hydroxyethyl methacrylate(HEMA),acrylic acid(AA),2,2,3,4,4,4-hexafluorobutyl acrylate(F6BA)are functional monomers,with divinylbenzene,1,4-cyclohexanedimethanol divinyl ether,and aziridine as crosslinking agents.The hard core structure makes the emulsion stable under the action of strong external force,and the soft shell structure makes the emulsion have certain cohesiveness.A variety of hard-core and soft-shell emulsions were synthesized by changing the ratio of core-shell monomers and the amount of crosslinking agent added.During the experiment,the optimal reaction conditions for emulsion polymerization were discussed,including time,temperature,the ratio of core-shell and so on.Thermogravimetric analysis(TGA)was used to test the heat resistance of the emulsion.The morphology and structure of the emulsion were characterized by Scanning electron microscopy(SEM),transmission electron microscopy(TEM),and Fourier infrared spectroscopy(FT-IR),and finally the peel strength of the emulsion was tested by the peel test machine.The adhesive,graphite and carboxymethylcellulose sodium(CMC)were thoroughly mixed to prepare graphite slurry for peel strength test.The test results show that post-crosslinking with aziridine as the cross-linking agent is the best cross-linking method,and the adhesive was prepared at 60 ℃ for curing time of 16 h.The addition of crosslinking agent at 5 wt% has the same effect as styrene butadiene rubber.