This study investigated the low-temperature fracture behavior of an 80-mm-thick low-carbon steel plate welded by submerged arc. The relationship between impact absorbed energy and ductility–brittle transition temperature (DBTT) based on the microstructures was evaluated through quantitative analysis on grain size and complex constituent phases using advanced EBSD technique. The microstructure formed differently depending on the heat affections, which determined fracture properties in a low-temperature environment. Among the various microstructures of the heat-affected zone (HAZ), acicular ferrite has the greatest resistance to low-temperature impact due to its fine interlocking formation and its high-angle grain boundaries.

Many approaches to recycle lithium nickel – cobalt–manganese oxide (NCM) cathodes from degraded lithium‐ion batteries (LIBs) have been reported, but they remain challenging due to environmental issues such as pollution or toxic waste. In this study, a sustainable and green approach for lithium recovery and reuse via mechanochemical method based on high‐energy ball milling is employed to extract lithium from spent NCM without high temperature or toxic solution. The recycling process is as follows: planetary ball milling with spent NCM523 cathodes, lithium extraction as a carbonate through subsequent reaction in deionized water. Then the recovered lithium is used to synthesize a high‐nickel NCM cathode material with a freshly prepared NCM precursor. Structural and chemical analyses revealed that the extracted lithium has 11.06% fluorine impurities in an agglomerated form. Consequently, the resynthesized NCM with recycled lithium (RNCM) has relatively low electrochemical performance compared to NCM with reagent lithium (HNCM), achieved a specific capacity of 80.63 mAh g ⁻¹ at 0.5 C and retains 36.7% capacity after 300 cycles. These findings suggest the feasibility of green recycling of commercial spent LIBs. Subsequent research to eliminate fluorine impurities may mitigate the environmental limitations associated with the current recycling process.

The clean energy, namely hydrogen, has been spotted lighted as a promising means for tackling down the problem of climate change. Alkaline Water Electrolysis (AWE) is identified as the representative method for obtaining hydrogen through sustainable way, because it needs only water and electricity (supplied from renewable energy sources such as solar light and wind). Especially, cheaper electrode materials like transition metal (Nickel) could be employed for both cathode and anode, whereas the other method (PEM-WE) should use only more expensive Pt-group materials. Herein, we explored the possibility of stainless steel (SS) for anode under alkaline environment. SS based electrodes showed steady performance over the versatile range of current densities (from 10 mA/cm² to 100 mA/cm²). These novel results would provide subsequent research with how to design for alternative electrode materials. Figure 1