RESUMEN
The low mechanical reliability and integration failure are key challenges hindering the commercialization of geometrically flexible batteries. This work proposes that the failure of directly integrating flexible batteries using traditional rigid adhesives is primarily due to the mismatch between the generated stress at the adhesive/substrate interface, and the maximum allowable stress. Accordingly, a stress redistribution adhesive layer (SRAL) strategy is conceived by using elastic adhesive to redistribute the generated stress. The function mechanism of the SRAL strategy is confirmed by theoretical finite element analysis. Experimentally, a polyurethane (PU) type elastic adhesive (with maximum strain of 1425%) is synthesized and used as the SRAL to integrate rigid cells on different flexible substrates to fabricate directly integrated flexible battery with robust output under various harsh environments, such as stretching, twisting, and even bending in water. The SRAL strategy is expected to be generally applicable in various flexible devices that involve the integration of rigid components onto flexible substrates.
RESUMEN
Li-rich Mn-based layered oxides (LLOs) are one of the most promising cathode materials, which have exceptional anionic redox activity and a capacity that surpasses 250 mA h/g. However, the change from a layered structure to a spinel structure and unstable anionic redox are accompanied by voltage attenuation, poor rate performance, and problematic capacity. The technique of stabilizing the crystal structure and reducing the surface oxygen activity is proposed in this paper. A coating layer and highly concentrated oxygen vacancies are developed on the material's surface, according to scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. In situ EIS shows that structural transformation and oxygen release are inhibited during the first charge and discharge. Optimized 3@LRMA has an average attenuation voltage of 0.55 mV per cycle (vs 1.7 mV) and a capacity retention rate of 93.4% after 200 cycles (vs 52.8%). Postmortem analysis indicates that the successful doping of Al ions into the crystal structure effectively inhibits the structural alteration of the cycling process. The addition of oxygen vacancies reduces the surface lattice's redox activity. Additionally, surface structure deterioration is successfully halted by N- and Cl-doped carbon coating. This finding highlights the significance of lowering the surface lattice oxygen activity and preventing structural alteration, and it offers a workable solution to increase the LLO stability.
RESUMEN
In order to increase the loading of rare earth- and molybdenum-rich high-level waste in the waste forms, zirconolite- and powellite-based multi-phase borosilicate glass-ceramics were synthesized via an in-situ heat treatment method. The effects of the CTZ (CaO, TiO2 and ZrO2) content on the crystallization, microstructure and aqueous durability of the multi-phase borosilicate glass-ceramics were studied. The results indicate that the increase of CTZ content can promote crystallization. The glass-ceramics presented even structures when the CTZ content was ≥ 40 wt%. For the glass-ceramic with 40 wt% CTZ, only zirconolite and powellite crystals were detected and powellite crystals were mainly distributed around zirconolite, whereas for the glass-ceramics with 50 wt% CTZ, perovskite was detected. Furthermore, the leaching rates of Na, Ca, Mo and Nd were in the ×10-3, ×10-4, ×10-3 and ×10-5 g·m-2·d·-1 orders of magnitude on the 28th leaching day, respectively.
RESUMEN
As the raw material for the production of basalt continuous fibers in Sichuan, basalt glass (BG) and modified basalt glass (MBG) were prepared by the melt quenching method with the basalt and chemically modified basalt, respectively. The crystallization kinetics of BG and MBG were investigated by differential scanning calorimetry (DSC) according to Kissinger methods. The results revealed that it is difficult for both glasses to crystallize at a high temperature. In addition, the crystallization activation energy of MBG is much higher than that of BG, which indicates that MBG is more difficult to crystallize than BG. The crystalline phases seemed to be formed from the surface of the two glasses. The morphologies and crystal structure of the crystalline phases in the heat-treated BG and MBG were analyzed by scanning electron microscope (SEM/EDX) and XRD. It was found that only a small amount of crystalline phase can be observed in the MBG, which indicates that the crystallization ability of the MBG was greatly suppressed. Results of this initial investigation indicate that chemical modification can effectively suppress the crystallization tendency of basalt glass and improve its thermal stability, which opens up an effective way for the industrial scale and stable production of basalt fiber.