RESUMEN
Electrolyte additive engineering is a crucial method for enhancing the performance of aqueous zinc-ion batteries (AZIBs). Recently, most research predominantly focuses on the role of functional groups in regulating electrolytes, often overlooking the impact of molecule stereoscopic configuration. Herein, two isomeric sugar alcohols, mannitol and sorbitol, are employed as electrolyte additives to investigate the impact of the stereoscopic configuration of additives on the ZnSO4 electrolyte. Experimental analysis and theoretical calculations reveal that the primary factor for improving Zn anode performance is the regulation of the solvation sheath by these additives. Among the isomers, mannitol exhibits stronger binding energies with Zn2+ ions and water molecules due to its more suitable stereoscopic configuration. These enhanced bindings allow mannitol to coordinate with Zn2+, contributing to solvation structure formation and reducing the active H2O molecules in the bulk electrolyte, resulting in suppressed parasitic reactions and inhibited dendritic growth. As a result, the zinc electrodes in mannitol-modified electrolyte exhibit excellent cycling stability of 1600 h at 1 mA cm-2 and 900 h at 10 mA cm-2, respectively. Hence, this study provides novel insights into the importance of suitable stereoscopic molecule configurations in the design of electrolyte additives for highly reversible and high-rate Zn anodes.
RESUMEN
The effects of Sn content on the corrosion behavior and mechanical properties of Mg-5Gd-3Y-0.5Zr alloy were studied by SEM, EDS, XRD and electrochemical testing. Results show that Sn can refine the grain size and promote the precipitation of Mg5(Gd,Y) phase. When the Sn content is 1.5-2 wt%, a needle-like Mg2Sn phase will be precipitated in the alloy. Mg-5Gd-3Y-1Sn-0.5Zr alloy had the lowest corrosion rate, which is attributed to the barrier effect of the grain boundary and dispersed Mg5(Gd,Y) phase on corrosion. However, the Mg2Sn phase formed by excessive Sn addition will accelerate galvanic corrosion. At the same time, Mg-5Gd-3Y-1Sn-0.5Zr alloy had best mechanical properties. In 1.5Sn and 2Sn alloys, the cleavage effect of the needle-like Mg2Sn phase on the matrix reduced mechanical properties.
RESUMEN
The effects of different heat treatment processes on the microstructure and corrosion behavior of Mg-5Gd-3Y-0.5Zr (GW53K) magnesium alloy were studied by means of microanalysis, weight loss test and electrochemical test. The results show that appropriate heat treatment can improve the corrosion resistance of the alloy. Among the tested alloys, the T6-12 h alloy has the best corrosion resistance, which is mainly attributed to the morphology and distribution of the Mg-RE phase. The corrosion rate of the T4 alloy is similar to that of the T6-12 h alloy. The corrosion resistance of the T4 alloy may be reduced under long-term corrosion due to the existence of surface corrosion microcracks.
RESUMEN
Dynamic precipitation of Mgâ»8.08Gdâ»2.41Smâ»0.30Zr (wt %) alloy during hot compression was studied in the present work. The effects of temperature and strain rate on dynamic precipitation, and the effects of dynamic precipitation on dynamic recrystallization (DRX) and microhardness, were systematically analyzed. For this purpose, hot compression tests were conducted at the strain rates of 0.002~1 s-1 and temperatures of 350~500 °C, with the compaction strain of 70% (εmax = 0.7). The obtained results revealed that dynamic precipitation occurred during hot compression at 350~400 °C, but did not occur for T ≥ 450 °C. The precipitates were demonstrated to be ß-Mg5Gd with a size of 200~400 nm, and they were distributed in the DRXed region. Dynamic precipitation occurred at strain rates in the 0.002~0.01 s-1 range, but did not occur when the strain rates were in the 0.1~1 s-1 range for the hot compression temperature of 350 °C. The relationships between the hot compression temperature (T) and DRXed grain size (lnd), microhardness (Hv), and DRXed grain size (d-1/2) of Mgâ»8.08Gdâ»2.41Smâ»0.30Zr alloy were obtained.