Aluminum Electrolytic Capacitor With The Preparation Of High Purity Silicon Sol

Working electrolyte electrolytic capacitors is the actual cathode, playing a repair anodealuminum foil oxidation film role. Additives in the working electrolyte content are less, but havevery big effect for the performance of the capacitor. Along with the further research on thesynthetic material, the new additive for working electrolyte of aluminum electrolytic capacitorappears constantly. Because of its small size, non-toxic, load charge, high temperaturecharacteristics, colloidal silica has a wide range of applications in the chemical field. In thispaper, the synthesis of organic colloidal silica and the application in the aluminum electrolyticcapacitors were studied.Firstly, the high purity, uniform and large particle size, stability colloidal silica was gotthrough uniform seed particle growth, where the seeds were prepared from sodium silicate(water-glass) using cation-exchange resins, grew by controlled hydrolysis of elemental silicon.Then the organic colloidal silica of low moisture content was made via Reduced pressuredistillation. At last, through the electrochemical experiments, examine the applicationperformance of in the of aluminum electrolytic capacitors.In this project, we systematically investigated the effects of factors such as feeding methods,reaction temperature, system pH, and initial sol concentration on the seed particle growth process;the effects of factors such as reaction temperature and system pH on the preparation of organiccolloidal silica; the test method of trace impurities in colloidal silica; the influence between addvolume of colloidal silica and flash fire voltage and the conductivity of working electrolyte. Theresults show that: the optimal production conditions of seed particle growth process is80℃,pH≈9~10,10%of the initial sol; the optimal production conditions of the preparation of organiccolloidal silica is110℃, the negative pressure gradually reduced to zero; the content of Iron ions,sulfate ion, chlorine ion in colloidal silica meet the electronic level requirement; As the addationvolume of nano SiO2to improve, the spark voltage of electrolyte increases a lot and the most isabout50V, and the conductivity of electrolyte raises about60×10-6S/cm; Life tests show thatthe capacitor containing homemade product is less attenuationin in electric capacity, leakagecurrent and loss tangent, which is better than similar foreign products.Using TEM; Zetasizer90DLS; TGA-DSC; FT-IR etc., we found that our final products hadcharacteristics including uniform and large size particle sizes, few secondary particles, narrow particle size distribution and good stability. The Aluminum foil of aluminum electrolyticcapacitors were examined by SEM, The result obtained showed that organic silicon Sol can beadsorbed on the surface of aluminum foil in the reaction process, effectively improving the fightwear of aluminum foil, so as to improve the Flash fire-voltage aluminum electrolytic capacitors.