| dc.description.abstract | In the preparation of traditional lithium batteries, Poly (vinylidene difluoride) (PVDF) is often used as binder to fix active materials and conductive substances. And N-Methyl-2-pyrrolidone (NMP) is used as a solvent, mixed with active material and conductive particles, and the slurry is coated on the aluminum foil. The battery plate that containing NMP is baked at high temperature for a long time (10-24 hours) in an oven to remove solvent. However, NMP is toxic, the recycling process must have an additional solvent recovery system, and a large number of baking equipment is required, and the baking process consumes a lot of electricity and time costs, which does not correspond to the environmental protection concept of environmental friendliness and energy saving and carbon reduction.
In view of this, this thesis mainly uses photo-curing polymer and thermal-curing polymer to replace the traditional electrode binder (PVDF) to solve the problem of traditional lithium battery manufacturing.
First of all, in terms of adhesives, it is divided into photo-curing binder and thermal-curing binder. In the photo-curing binder, the DE monomer and the G3E monomer are subjected to photopolymerization reaction. In the thermal-curing binder, the DP monomer and the G3E monomer are subjected to thermalpolymerization reaction. Composition Li[Ni1/3Mn1/3Co1/3]O2/Li half-cell test using scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) discuss. The experimental data confirm that the two binders are indeed involved in the formation of SEI and can reduce the consumption and decomposition of electrolyte and lithium salts. Compared with traditional binder, photopolymerized binder and thermally polymerized binder have a battery capacity of 104.6(mAh/g), 120.1(mAh/g), 107.9(mAh/g) after 100 cycles of charge and discharge, respectively. ), the capacitance retention is 76.6%, 81.9%, 64.3%, photopolymerized and thermally polymerized binder have enough performance to match or even surpass traditional lithium batteries.
Finally, we also used XPS, CV, and EIS to confirm that these two binder can tightly coat the electrodes to prevent the positive electrode from continuously reacting with the electrolyte, so that the battery can continue to maintain a good power after a long cycle. | en_US |