and Li-O 2 batteries toward the post Li-ion battery era. [3] Howbeit, owing to the tough problems of dendritic Li growth and huge dimension fluctuation during cycling, metallic Li is still like a "hot potato" when used as anode in rechargeable batteries. The uncontrolled growth of Li dendrites can destroy the solid electrolyte interphase (SEI) layer, inducing the further side reactions between the electrolyte and fresh Li. Even worse, once Li dendrites penetrate the separator, the cell internal short circuit will occur and cause inestimable safety hazards. [4] As a consequence, rechargeable Li-metal batteries usually possess an undesirable cycling lifespan and low safety, which has severely impeded its practical applications over the past 40 years. [5] Until now, considerable progress has been made in stabilizing Li metal anode via various strategies. [6] Surface modification is a commonly used method to mitigate the risk of dendrite growth. The sacrificial electrolyte additives, such as fluoroethylene carbonate (FEC), [7] vinylene carbonate (VC)-LiNO 3 , [8] and trace amounts of H 2 O, [9] can promote a relatively stable SEI in the short-term cycle. In spite of this, additives still undergo constant consumption owing to the high reaction activity of Li metal, leading to SEI inefficacy and accumulation after the long-term cycling. Besides, utilizing chemical reactions between Li metal and active substances (e.g., N 2 , [10] P 2 S 5 /S, [11] C 2 Cl 4 , [12] CuF 2 , [13] sulfur vapor, [14] Zn 3 (PO 4 ) 2 [15] ) or physical/chemical technologies (e.g., atomic layer deposition, [16] molecular layer deposition, [17] magnetron sputtering, [18] and slurry coating [19] ) can also construct an artificial SEI or buffer layer. However, these protective layers may only regulate the surficial Li deposition and partially suppress the Li dendrites. Once the bulk Li participates in cycling, the SEI will not work well and even be ruptured because of accumulative "dead Li." [20] In general, the problem of dendritic growth keeps unsolved only via single SEI construction.The growth of Li dendrites origins from the inhomogeneous ion distribution and diffusion that are commonly induced by electric driving force as shown in Figure 1b. [21] Chazalviel's model also makes clear that a higher local current density can cause a sharper concentration gradient near electrodes. [22] Therefore, in order to avoid the dendritic Li formation essentially, it is very crucial to make Li + concentration incline to a relatively steady state. Some external technologies, such as pulse current charging [23] and external magnetic field, [24] can stabilize Li-metal batteries by realizing the above The introduction of 3D wettable current collectors is one of the practical strategies toward realizing high reversibility of lithium (Li) metal anodes, yet its effect is usually insufficient owing to single electron-conductive skeleton. Here, homogeneous Li deposition behavior and enhanced Coulombic efficiency is reported for electrochemically lithiated Cu 3 P na...
Hard carbons (HCs) as an anode material in sodium ion batteries present enhanced electrochemical performances in ether-based electrolytes, giving them potential for use in practical applications. However, the underlying mechanism behind the excellent performances is still in question. Here, ex situ nuclear magnetic resonance, gas chromatography–mass spectrometry, and high-resolution transmission electron microscopy were used to clarify the insightful chemistry of ether- and ester-based electrolytes in terms of the solid–electrolyte interphase (SEI) on hard carbons. The results confirm the marked electrolyte decomposition and the formation of a SEI film in EC/DEC but no SEI film in the case of diglyme. In situ electrochemical quartz crystal microbalance and molecular dynamics support that ether molecules have likely been co-intercalated into hard carbons. To our knowledge, these results are reported for the first time. It might be very useful for the rational design of advanced electrode materials based on HCs in the future.
Metal halide perovskites have excited tremendous research interests due to their extraordinary photovoltaic and optoelectronic performance. Cs2SnI6 has emerged as a promising lead-free perovskite in advanced optoelectronics due to its high stability, appropriate bandgap, and high absorption coefficient. The performance of two-dimensional (2D) Cs2SnI6-based photodetectors is limited as compared to lead-based perovskites. Here, we report a simple strategy for incorporating aliovalent metal ions (nickel and zinc) for doping or passivation of perovskites to improve their performance. Aliovalent metal ions are employed to break the inherent dark transition of the 2D Cs2SnI6, greatly increasing photoluminescence by two orders of magnitude than pristine Cs2SnI6. Density function calculation reveals the n-type doping of nickel ions without introducing any deep trap states. We further demonstrate that the surface passivation of 2D Cs2SnI6 by zinc ions can greatly reduce surface trap/defect density. Aliovalent metal ion-incorporated Cs2SnI6 perovskites exhibit broadband detection, high responsivity (1.6 × 103 A W–1, for Ni-incorporated Cs2SnI6) and high detectivity (1.56 × 1013 Jones, for Zn-incorporated Cs2SnI6). These results will prompt research on the influence of metal ions in perovskite materials that may afford novel properties for next-generation optoelectronics.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.