Rechargeable aqueous zinc-ion batteries (AZIBs) are considered for emerging cutting-edge energy storage technologies as an alternative to the existing nonaqueous lithium-ion batteries (LIBs) owing to their inimitable advantages of low-cost materials, high safety, high abundance, and environmental friendliness. Nevertheless, the key challenges of the AZIBs are mainly due to the development of cathode (positive electrode) materials. Here, we report the synthesis of vanadium-based oxides on twodimensional (2D) vanadium carbide MXene (V 2 O x @V 2 CT x ) that can serve as an efficient cathode material for AZIBs. The vanadium-based oxides could be formed during the high-temperature etching method and by the electrochemical cyclic process. The prepared V 2 O x @V 2 CT x electrodes can deliver an ideal rate performance with an average reversible capacity of about 304 to 84 mAh g −1 at current densities ranging from 0.05 to 2 A g −1 , respectively. The obtained results can be comparable to the well-known cathode materials reported for the ZIBs. Advancing from the characteristic, stable 2D layered structures, V 2 O x @V 2 CT x electrodes could exhibit an improved cycling life with the capacity retention of 81.6% at a rate of 1 A g −1 for about 200 cycles in 1 M ZnSO 4 electrolyte. The prepared MXene as cathode materials could further pave the way for the development of the advanced zinc ion storage systems.

Additive manufacturing, the so-called three-dimensional (3D) printing, is a revolutionary emerging technology. Fused filament fabrication (FFF) is the most used 3D printing technology in which the melted filament is extruded through the nozzle and builds up layer by layer onto the build platform. The layers are then fused together and solidified into final parts. Graphene-based materials have been positively incorporated into polymers for innovative applications, such as for the mechanical, thermal, and electrical enhancement. However, to reach optimum properties, the graphene fillers are necessary to be well dispersed in polymers matrix. This study aims to emphasise the interest of producing ABS/graphene oxide (GO) composites for 3D printing application. The ABS/GO composite filaments were produced using dry mixing and solvent mixing methods before further melt extruded to investigate the proper way to disperse GO into ABS matrix. The ABS/GO composite filament with 2 wt.% of GO, prepared from the solvent mixing method, was successfully printed into a 3D model. By adding GO, the tensile strength and Young’s modulus of ABS can be enhanced. However, the ABS/GO composite filament that was prepared via the dry mixing method failed to print. This could be attributed to the aggregation of GO, leading to the die clogging and failure of the printing process.

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Due to their cost effectiveness, high safety, and eco-friendliness, zinc-ion batteries (ZIBs) are receiving much attention nowadays. In the production of rechargeable ZIBs, the cathode plays an important role. Manganese oxide (MnO2) is considered the most promising and widely investigated intercalation cathode material. Nonetheless, MnO2 cathodes are subjected to challenging issues viz. limited capacity, low rate capability and poor cycling stability. It is seen that the MnO2 heterostructure can enable long-term cycling stability in different types of energy devices. Herein, a versatile chemical method for the preparation of MnO2 heterostructure on multi-walled carbon nanotubes (MNH-CNT) is reported. Besides, the synthesized MNH-CNT is composed of δ-MnO2 and γ-MnO2. A ZIB using the MNH-CNT cathode delivers a high initial discharge capacity of 236 mAh g−1 at 400 mA g−1, 108 mAh g−1 at 1600 mA g−1 and excellent cycling stability. A pseudocapacitive behavior investigation demonstrates fast zinc ion diffusion via a diffusion-controlled process with low capacitive contribution. Overall, the MNH-CNT cathode is seen to exhibit superior electrochemical performance. This work presents new opportunities for improving the discharge capacity and cycling stability of aqueous ZIBs.

Metallic zinc (Zn) anode has been received a great promise for aqueous rechargeable zinc-ion batteries (ZIBs) due to its intrinsic safety, low cost, and high volumetric capacity. However, the dendrite formation regarding the surface corrosion is the critical problems to achieve the high performance and the long lifespans of ZIBs. Here, we purpose the facile cyclic voltammetry deposition of polypyrrole/reduced graphene oxide (PPy/rGO) composites coated onto Zn 3D surface as Zn anode for ZIBs. As results, the deposited PPy/rGO layer demonstrates the homogeneous distribution covering onto Zn surface, effectively suppressing the formation of dendrite. Additionally, a symmetric cell of the PPy/rGO coated Zn remarkably enhances an electrochemical cycling with a low voltage hysteresis for zinc plating/stripping, which is superior to the pristine Zn cell. In addition, the deposited layer of PPy/rGO on Zn effectively improves the reactivity of electrochemically active surface area and the intrinsic electronic configurations, participating in extraction/intercalation of Zn2+ ions and leading to enhance ZIBs performance. The coin cell battery of Zn-PPy/rGO//MnO2 can deliver a high initial discharge capacity of 325 mAh/g at 0.5A/g with a good cycling stability up to 50% capacity retention after 300 cycles. Thus, these achieved results of Zn-PPy/rGO//MnO2 battery with dendrite-free feature effectively enhance the life-performance of ZIBs and open the way of the designed coating composite materials to suppress dendrite issues.

To overcome the limitations of both LDHs and MXenes, we develop a self-sacrifice template strategy by using Zeolite imidazolate framework-67 (ZIF-67) to derive Co-LDH anchored on MXene conductive substrate (Co-LDH/MXene)....

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Nickel–cobalt carbonate hydroxide with a three-dimensional (3D) sea-urchin-like structure was successfully developed by the hydrothermal process. The obtained structure enables the enhancement of charge/ion diffusion for the high-performance supercapacitor electrodes. The mole ratio of nickel to cobalt plays a vital role in the densely packed sea-urchin-like structure formation and electrochemical properties. At optimized nickel/cobalt mole ratio (1:2), the highest specific capacitance of 950.2 F g–1 at 1 A g–1 and the excellent cycling stability of 178.3% after 3000 charging/discharging cycles at 40 mV s–1 are achieved. This nickel–cobalt carbonate hydroxide electrode yields an energy density in the range of 42.9–15.8 Wh kg–1, with power density in the range of 285.0–2849.9 W kg–1. The charge/discharge mechanism at the atomic level as monitored by time-resolved X-ray absorption spectroscopy (TR-XAS) indicates that the high capacitance behavior in a nickel–cobalt carbonate hydroxide is mainly dominated by cobalt carbonate hydroxide.