In order to provide support for the early warning model of thermal runaway of lithium-ion battery, the thermal runaway behavior of power lithium battery is studied by analyzing the charging current, voltage and other parameters of lithium-ion power battery under overcharge condition. In addition, the morphological changes of battery before and after thermal runaway are compared. It is found that under the conditions of this study, overcharging for 58 minutes will lead to thermal runaway of full load lithium-ion battery. In the early stage of thermal runaway, the leakage gas in the battery box will continue to increase, which is 1339 ppm in the First Level early warning, 3405 ppm in the Second Level early warning and 8292 ppm in the Third Level early warning.

The influence mechanism of lignite thermal upgrading on moisture re-adsorption was investigated using analytical techniques such as differential thermal analysis–thermogravimetry, Fourier transform infrared spectroscopy and scanning electron microscopy. The results showed that the moisture content of lignite decreased from 44.78 to 25.07% through the drying process. After the moisture in the lignite and the air had reached a dynamic equilibrium, the moisture content of the lignite was 25.75 wt.%. The characteristic functional groups of lignite include hydroxyl, methylene, methyl, carbonyl, carboxyl and ether oxygen. The adsorption distances of the five adsorption sites of carboxyl, phenolic hydroxyl, alcoholic hydroxyl, carbonyl and ether bond to water molecules were 2.081, 2.933, 1.905, 1.860 and 1.881 Å, respectively. The order of the adsorption strength of water molecules on the characteristic functional groups was carbonyl > phenolic hydroxyl > ether oxygen > alcoholic hydroxyl > carboxyl. During the upgrading by drying process, the characteristic functional groups that were prone to hydrogen bonds of water molecules partially decomposed. The reduction of pores and the partial decomposition of hydrophilic functional groups after upgrading in the lignite structure weakened the adsorption capacity of lignite to water molecules. Therefore, the re-absorption of water molecules by lignite was reduced.

In this article, gradient-distributed VCp-ZTAp/Fe45 composites were prepared by vacuum sintering, and three-body abrasive wear experiments were carried out to investigate its anti-wear performance. The composite casting of VCp-ZTAp/Fe45 was investigated by using the finite element method and experiments, and the bonding between the Fe45 substrate and 35SiMnCrMoNi steel was fully investigated. Results show the in situ formation of VCp in the VCp-ZTAp/Fe45 composite matrix during vacuum sintering. The anti-wear property of the VCp-ZTAp/Fe45 composite is ca. 7 times that of Hardox450 and NM450 and ca. 8 times of 30SiMn. There forms a solid metallurgical bonding between the Fe45 matrix of VCp-ZTAp/Fe45 and 35SiMnCrMoNi steel, with a ca. 80 μ m thickness of the bonding area during the composite casting.

Nickel–aluminum bronze is a key structural material for marine propellers, yet its corrosion behavior under dynamic seawater erosion remains inadequately elucidated. To clarify the corrosion kinetics under high-speed dynamic seawater erosion of the ZCuAl10-4-4-2 marine copper alloy, erosion–corrosion tests and multi-method characterizations were conducted. The results illustrate that the α phase exhibited a higher corrosion susceptibility, driving micro-damage evolution: κ/α interface crack initiation at 4 h, significant crack propagation with a dense κ_II phase at 24 h, and pit formation (≈100 μm) at 48 h. Dynamic erosion induced critical electrochemical changes at 4 h and 24 h, with reduced charge transfer resistance, lower corrosion potential (E_corr) and elevated current density; the 24 h stage showed the peak corrosion rate due to unstable, spallable corrosion product films. Prolonged erosion–corrosion promoted the formation of a stable protective corrosion product layer, which enhanced the alloy’s corrosion resistance and reduced its corrosion rate.