RESUMO
Fast-charging technology is set to revolutionize the field of lithium-ion batteries (LIBs), driving the creation of next-generation devices with the ability to get charged within a short span of time. From the anode perspective, it is of paramount importance to design materials that can withstand continuous Li+ insertion/deinsertion at high charging rates and still remain unaffected by factors such as mechanical fractures, electrolyte side reactions, polarisation, lithium plating and heat generation. Herein, the recent advancements in the design of amorphous materials as anodes for fast-charging LIBs have been discussed. While the development of this particular class of materials for application in high-rate anodes has been paid limited attention in recent literature, it holds immense promise for improving the fast-charging capabilities. This concept summarizes the recent strides made in this emerging field, outlining the strategies employed in the design of amorphous anodes and emphasizing the crucial role played by the amorphous nature in achieving fast-charging performance. Further, the successive initiatives that can be undertaken to drive the progress of amorphous materials for fast charging LIBs have also been detailed, which could potentially improve their commercial viability.
RESUMO
Ternary metal sulfides having layered morphology are considered as potential active materials for various applications. Herein, Nb3VS6 is synthesized topochemically for the first time using a Nb-V-HDA complex having a lamellar structure by employing H2S gas as the sulfidation agent. Nb3VS6, as an anode for SIBs, exhibited a specific capacity of 101.15 mA h g-1 at 0.5 A g-1, along with excellent cycling stability with 100% capacity retention after 2500 cycles.
RESUMO
Anode materials for advanced sodium-ion batteries (SIBs) require major improvements with regard to their cycling stability, which is a crucial parameter for long-term battery operation. Herein, we report 3R-NbS2, synthesised by a simple solid-state annealing route, as an anode for SIBs with remarkable cycling stability for 2500 cycles at 0.5 A g-1. The stable nature of the NbS2 anode was attributed to its dominant capacitive behaviour.
RESUMO
Herein, we report a low-temperature synthesis of crystalline pyrite-FeS2 through a solid-state annealing route, which was achieved using FeOOH, a metastable precursor, in the presence of H2S gas. The as-synthesized pyrite FeS2 was employed as an electrode for fabricating high energy density supercapacitors. The device delivered a high specific capacitance of 51 mF cm-2 at 20 mV s-1 and showed a superior energy density of 30 µW h cm-2 at a power density of 1.5 mW cm-2.
RESUMO
Electrocatalysis is key to the development of several important energy and biosensing applications. In this regard, the crystalline phase-dependent electrocatalytic activity of materials has been extensively studied for reactions such as hydrogen evolution, oxygen reduction, etc. But such comprehensive studies for evaluating the phase-dependence of electrochemical biosensing have not been undertaken. Herein, three crystalline phases (α-, ß-, and γ-) of iron oxyhydroxide (FeOOH) have been synthesized and characterized by spectroscopic and microscopy techniques. Electrochemical studies revealed their high sensitivity and selectivity towards dopamine (DA) detection. Amongst the three electrocatalysts, ß-FeOOH shows the highest sensitivity (337.15 µA mM-1 cm-2) and the lowest detection limit (0.56 µM). The enhanced electrocatalytic activity of ß-FeOOH, as compared to that of α- and γ-FeOOH, was attributed to its higher active site percentage and facile electrode kinetics. Furthermore, theoretical studies probed into the DA-FeOOH interactions by evaluating the charge transfer characteristics and hydrogen adsorption energies of the three phases to support the experimental findings.