RESUMO
Improving the layered-structure stability and suppressing vanadium (V) dissolution during repeated Zn2+ insertion/extraction processes are key to promoting the electrochemical stability of V-based cathodes for aqueous zinc (Zn)-ion batteries (AZIBs). In this study, barium vanadate (Ba2 V2 O7 , BVO) nanostructures (NSs) are synthesized using a facile hydrothermal method. The formation process of the BVO NSs is controlled by adjusting the concentration of hydrogen peroxide (H2 O2 ), and these NSs are employed as potential cathode materials for AZIBs. As the H2 O2 content increases, the corresponding electrochemical properties demonstrate a discernible parabolic trend, with an initial increase, followed by a subsequent decrease. Benefiting from the effect of H2 O2 concentration, the optimized BVO electrode with 20 mL H2 O2 delivers a specific capacity of 180.15 mA h g-1 at 1 A g-1 with good rate capability and a long-term cyclability of 158.34 mA h g-1 at 3 A g-1 over 2000 cycles. Thus, this study provides a method for designing cathode materials with robust structures to boost the electrochemical performance of AZIBs.
RESUMO
In order to achieve a sustainable future, researchers must continue to research improved electrode materials. Considering the high electronic conductivity, versatile redox activity, and enhanced energy storage performance, nanostructures have been employed as a novel electrode material for high-performance lithium-ion batteries (LIBs) and supercapacitors. Herein, carbon-coated selenium-rich trimetallic selenide (Cu2 NiSnSe4 @C) nanoparticles (NPs) as an efficient electrode material in energy storage devices are prepared. The prepared core-shell Cu2 NiSnSe4 @C NPs electrode is employed as an anode material for LIBs, which demonstrated a high reversible specific capacity of 988.46 mA h g-1 over 100 cycles at 0.1 A g-1 with good rate capability. Additionally, the core-shell Cu2 NiSnSe4 @C NPs electrode exhibited an outstanding capacity of 202.5 mA h g-1 at 5 A g-1 even after 10 000 cycles. Exploiting the synergistic characteristics, the core-shell Cu2 NiSnSe4 @C NPs material is also investigated as a battery-type electrode for hybrid supercapacitors. The assembled hybrid supercapacitor with Cu2 NiSnSe4 @C NPs and activated carbon showed excellent rate capability including high power (5597.77 W kg-1 ) and energy (64.26 Wh kg-1 ) densities. Considering the simple synthesis and enhanced energy storage properties, carbon-coated selenium-rich trimetallic selenide can be used as a durable electrode material for practical energy storage devices.
RESUMO
Rational architecture design of the artificial protective layer on the zinc (Zn) anode surface is a promising strategy to achieve uniform Zn deposition and inhibit the uncontrolled growth of Zn dendrites. Herein, a red phosphorous-derived artificial protective layer combined with a conductive N-doped carbon framework is designed to achieve dendrite-free Zn deposition. The Zn-phosphorus (ZnP) solid solution alloy artificial protective layer is formed during Zn plating. Meanwhile, the dynamic evolution mechanism of the ZnP on the Zn anode is successfully revealed. The concentration gradient of the electrolyte on the electrode surface can be redistributed by this protective layer, thereby achieving a uniform Zn-ion flux. The fabricated Zn symmetrical battery delivers a dendrite-free plating/stripping for 1100 h at the current density of 2.0 mA cm-2 . Furthermore, aqueous Zn//MnO2 full cell exhibits a reversible capacity of 200 mAh g-1 after 350 cycles at 1.0 A g-1 . This study suggests an effective solution for the suppression of Zn dendrites in Zn metal batteries, which is expected to provide a deep insight into the design of high-performance rechargeable aqueous Zn-ion batteries.