Electrochemical cells using LiFePO₄ cathode material are considered one of the safest and most resistant to overcharging among Li-ion batteries. However, if LiFePO₄-based electrodes are exposed to high potentials, surface and structural changes may occur in the electrode material. In this study Li/LiFePO₄ half-cells were overcharged under different modes with variable cut-off voltages and charge currents. The change in voltage profile, discharge capacity, surface layers composition, and crystalline structure were characterized after overcharge cycles. It was demonstrated that the cathode material is resistant to short-term overcharging up to 5 V, but undergoes irreversible changes with increasing overcharge time or potential. Thus, despite the well-known tolerance of LiFePO₄-based batteries to overcharge, a long overcharge time or high cut-off voltage leads to destructive changes in the cathode and should be avoided.

Polymers with embedded metal–organic frameworks (MOFs) have been of interest in research for advanced applications in gas separation, catalysis and sensing due to their high porosity and chemical selectivity. In this study, we utilize specific MOFs with high thermal stability and non-centrosymmetric crystal structures (zeolitic imidazolate framework, ZIF-8) in order to give an example of MOF–polymer composite applications in nonlinear optics. The synthesized MOF-based polymethyl methacrylate (PMMA) composite (ZIF-8–PMMA) demonstrates the possibility of the visualization of near-infrared laser beams in the research lab. The resulting ZIF-8–PMMA composite is exposed to a laser under extreme conditions and exhibits enhanced operating limits, much higher than that of the widely used inorganic materials in optics. Overall, our findings support the utilization of MOFs for synthesis of functional composites for optical application.

We report the first full synthesis of novel spiroether derivatives via reaction of 4-oxobut-2-enoates and alloxan. Our synthesis features the single-step assembly, mild reaction conditions, good yields, high diastereoselectivity, operational simplicity, and the absence of tedious separation procedures. Most of the prepared compounds possessed moderate growth inhibitory effects on human alveolar adenocarcinoma (A549), malignant melanoma (A375), ovarian adenocarcinoma (SK-OV-3), and fibrosarcoma (HT-1080) cell lines. Graphical Abstract

Reaction of N-arylacetoacetamides with aromatic aldehydes in the presence of piperidine in ethanol afforded N,N′,2-triaryl-6-hydroxy-6-methyl-4-oxocyclohexane-1,3-dicarboxamides. The latter reacted with p-toluidine leading to the formation of dehydration products. Reactions of N,N′,2-triaryl-6-hydroxy-6-methyl-4-oxocyclohexane-1,3-dicarboxamides with hydrazine hydrate and cyanoacetic acid hydrazide gave rise to tetrahydroindazoles. Some of the obtained compounds showed antimicrobial activity.