Analyses the cause of the fire explosion lithium-ion batteries

Source: 2020 - 04 - 11 caused hits: the cause of the first lithium battery fire explosion when the lithium battery, when the voltage rise, the positive and negative REDOX state will become very strong, so the material is easy to instability. ( 1) Overcharge. Charging time is known as' the overcharge, because the battery may heat, electrolyte can produce flammable gas. In general, in a rechargeable battery, the first reduction reaction between electrolyte and cathode, and then the electrolyte 'between the electrolyte and the anode thermal decomposition of figure 7. Polymer lithium battery overview of figure 8 polymer lithium battery structure diagram of oxidation decomposition 'thermal decomposition' negative 'thermal decomposition' is' thermal decomposition 'eventually led to the isolation plate internal melt flow short circuit. The positive: as a result of the electrolytic oxidation 'crystal structures' destruction and fever. Cathode: lithium metal precipitation. ( 2) In the discharge. Over discharge called 'over discharge,' the overcharge get hot. The positive: the fusion of cobalt. Cathode: the collector melting ( Copper) 。 In short, in any case, the electrode, electrolyte and isolation plate by heating and melting, lead to internal short circuit. Joule heat will spread everywhere, until contact with combustible liquid electrolyte ( Combustible gas) Catch fire. When the battery from external heated by fire, the anode material, electrolyte and cathode materials react respectively. Isolation plate melt, electrode short circuit, joule heat began to spread. In addition, due to external shocks, insulation and isolation of each electrode plate is damaged, although there is no fire, but when charging internal short-circuit and sometimes catch fire. Due to their high energy density, short circuit when a sharp rise in the temperature, the electrolyte into organic solvent, easy to catch fire.