Ultrafine Alumina Preparation And Research Of Its Modification On Li-ion Battery Separator

With the development of productivity and science and technology, chemical power source as dual- use technology showing a more important role. Due to their high energy density, long cycle life and green environmental protection and other excellent performance, the lithium ion battery is widely used. The diaphra gm, which can prevent short circuit, ensure lithium ion battery safety, and make the lithium ions pass, is an important part in lithium ion battery. Most current lithium ion battery using the diaphragm is micro-porous polyolefin film such as polyethylene(PE), polypropylene(PP) or between two or three different polyolefin composite. However, because affinity of electrolyte of PP or PE membrane is poorer and thermal stability is not high, these drawbacks limit its application. However, after the inorganic ceramic modification of li- ion battery diaphragm, it can improve its affinity and thermal stability of electrolyte, and keep good mechanical properties, which greatly improve safety performance of the battery. Among all inorganic ceramics materials, the alumina powder has the optimum properties. Alumina with high temperature resistant properties and good chemical stability, can be used to achieve the goal of improving membrane performance.In this paper, through the method of hydrolysis isopropanol aluminum preparation of ultrafine aluminum oxide which is used to make about 100 nm sized alpha Al2O3 particle. And by scanning electron microscope(sem), X-ray diffraction, I determined the synthetic alumina powders microscopic structure and crystallinity, and determined the live- fire alumina density and bulk density. This paper further put the alumina powders used for lithium battery PE modified diaphragm, and it was made for inorganic ceramic diaphragm modified lithium electricity. And the modified diaphragm, greatly improves wettability of the electrolyte. The transverse and longitudinal shrinkage than PE membrane can reduce about 3% and 11%. Longitudinal tensile strength is about 80%. Next, by button cell assembly, measurement of the modified lithium electric battery has good electrochemical properties of the diap hragm assembly. In this paper, we made industrial design for the preparation of alumina hydrolysis process. Through choosing production,the process flow and equipment model, and also the material balance and heat balance are used to select the appropriate heat exchanger, container equipment, such as reactor. At the same time, according to the scheduled production and manufacturing process selection of filter press, grinder and other equipment, it will provide reasonable basis for the industrialization production of the alcohol aluminum hydrolysis used in preparation of alumina.