Thermal decomposition of ε-hexanitrohexaazaisowurtzitane (HNIW) was studied by thermogravimetrydifferential scanning calorimetry-mass spectrometry-Fourier transform infrared spectroscopy (TG-DSC-MS-FTIR) simultaneous analysis. It has been shown that there is a crystal transition point for ε-HNIW, and only a single decomposition process has been observed for HNIW. The kinetic parameters of thermal decomposition of HNIW were obtained by Kissinger and Flynn-Wall-Ozawa methods, indicating that HNIW has the higher reactivity compared to the other nitramines. The HNIW decomposition mechanism demonstrated by the non-isothermal kinetics conformed to Avrami-Erofeev equation with the factor of nucleus growth of n=1/3 and the conversion degree of α from 0.1 to 0.7. The MS and FTIR analyses indicated that the thermal decomposition of HNIW favors N-N bond cleavage over C-N bond cleavage as the rate determining step.

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Abstract:The thermal decomposition kinetics of hexanitrohexaazaisowurtzitane/ ammonium perchlorate (HNIW/AP) have been investigated by thermogravimetrydifferential scanning calorimetry-mass spectrometry (TG-DSC-MS) simultaneous analysis. TG showed that there were three weight loss processes for the thermal decomposition of the HNIW/AP mixture. The first was ascribed mainly to the thermal decomposition of HNIW, while the second and third were assigned to that of AP. The presence of AP has little effect on the thermal decomposition process of the HNIW component. The apparent activation energy of the thermal decomposition of the HNIW component, calculated by the Kissinger method, was little changed compared to that of neat HNIW. The addition of HNIW to AP caused the onset and end temperatures of the thermal decomposition to be decreased and the decomposition process to be shortened. The high-temperature and lowtemperature decomposition processes of AP became blurred in the presence of HNIW, and this was supported by the MS results.

Abstract:The power battery is composed of a plurality of batteries, and a single battery plays an important role in the safety of the whole battery pack. In this paper, the lithium-ion batteries with LiCo1/3Ni1/3Mn1/3O2 as cathode material was stimulated by overcharge, and analyzes apparent regularity of battery explosion from explosion combustion temperature, explosion pressure and battery deformation. Test results show that thermal runaway duration of lithium ion battery pack is longer than that of all single cells combined; firstly, the lithium ion battery going through thermal runaway will deformation; secondly, the pressure wave of a single cell's explosion is not enough to cause the explosion of the battery pack.