Research Of Lithium Polymer Battery Swollen

Lithium Polymer Battery (LPB) is the most advanced secondary battery in the world, as the substitute of Lithium Ion Battery, it has been applied widely into the fields of mobile phone, laptop, MP3, PDA, DV and other electronic devices, acts the vital role among all life. Safety is the most important characteristic which effect the application of LPB, and swollen is the other most important affect within all safeties. Otherwise, the lithium polymer battery is packaged by the aluminum foil which can not burden higher gas pressure inside. So, swollen phenomenon is the vital case about the safety of LPB. There has little reports about the LPB swollen in the world, however, as result this report is so important for the method about swollen of LPB.In this paper, the based mechanism and development history are referred, and based on the Bell-core license and industrial production circumstance, test cells are manufactured. Used the CC-CV formation rules, gas chromatography-mass spectrum and other analysis methods, inner gas content, engender mechanism and other affects are researched.Test results appeared: upon the same formation rules, different gas content with different formation voltage; swollen grade differently with different formation rules; LiCoO2 and LiMn2O4 were selected as the anode materials which generate the same gas species and different content, so inner gas engender has little relation with cathode material, however, with anode; within the shelf, the electrolyte decomposed reduced the gas engendered which based on the free radical mechanism. In this report, the chain reactions of free radical are investigated, approved the mechanism of LPB gas engendered. the free radical capture dose is induced which has olefin and the same chemical bonds with electrolyte, VC (1,2-divinylene carbonate), to remove the initial free radical.; DBP,CH3OH and other impurity were input to increase the grade of cell self-discharge. When the voltage of cell decreased into some level, the SEI of anode active material was destroyed, and electrolyte was decomposed. H2O, as the...