Green-light emitting illuminant and green pearls that are currently being used for pyrotechnics are mainly composed of barium carbonate and polyvinyl chloride (PVC), which lead inevitably to the substantial generation of abundant harmful products for environmental pollution. There is thus considerable scope for the development of a novel emitting illuminant with an improved "green" composition instead of compositions incorporating barium based oxidants and polyvinyl chloride for environmental protection. For this purpose, a new composition composed of boron carbide, potassium perchlorate, and guanidine nitrate with a suitable burning rate of 5~15 mm/s required for fireworks, the high luminous intensity of 34665 Cd and spectral purity of 67.1 % at a primary wavelength of 562 nm was developed. Notably, PM10 data demonstrated that the new composition generated less than half the amount of the smoke relative to the original one. More importantly, all of the safety parameters of this new formulation meet well with the standards' requirements, i. e., a remarkable low sensitivity to friction (0 %) and impact (8 %), relative stability to electric discharge (374.4 mJ), flame (14.0 cm) and heating (unburned, unexploded at 75°C for 48 h), as well as a high ignition temperature of 504.0°C and a low moisture absorption rate (0.66 %). Taken together, the new emitting illuminant developed herein showed great potential to be used for fireworks and signal flare in both military and civilian applications.
The energy density of lithium cobalt oxide (LiCoO 2 )-based cells can be increased by charging at voltages above 4.2 V. However, the poor interface stability of the cathode/electrolyte deriving from the continuous severe decomposition of the electrolyte on the cathode/electrolyte surface and the instability of the structure of the cathode at high-voltage operation limits their wider commercial application. Herein, a new fluoro-functionalized electrolyte additive, tetrafluoroethane beta-sultone (TFBS), is used for promoting the electrochemical performance of LiCoO 2 -based cells. Upon cycling between 3.0 and 4.5 V (vs. Li/ Li + ) with 0.5 C (1 C = 274.4 mAh/g), it is shown that the capacity retention of the LiCoO 2 /graphite pouch-cell with TFBS-controlled electrolyte reaches 96.8 % (183.9 mAh g À 1 ), yet it is 66.5 % (126.3 mAh g À 1 ) for the pouch-cell without TFBS in baseline electrolyte at the 100 th cycle. All the results indicate that TFBS can be decomposed prior to the solvents in the electrolyte and can then form low-resistance, high-conductivity interface layers on the surfaces of the cathode-electrolyte and the anode-electrolyte, respectively, thus improving the cycling stability of the cells at a high charging cutoff voltage (4.5 V).
In recent years, metal-organic frameworks (MOFs) have been widely used in various fields, especially electrochemical energy storage and conversion area, because of their excellent properties. It is reported that the...
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