Sodium (Na) metal batteries (SMBs) have emerged as promising alternatives to lithium metal batteries for large-scale energy storage applications, owing to their cost-effectiveness, abundance, and favorable redox potential. However, the practical implementation of SMBs faces several challenges associated with the Na metal anode, including the formation of dendrites, low Coulombic efficiency, and capacity fading. Here, we propose a novel approach to enhance the electrochemical performance of Na metal anodes through a porous Al-Cu alloy host (PAC) fabricated by a local eutectic melting engineering. The local eutectic melting facilitates the development of a conductive network, offering mechanical support, and the porous structure provides abundant channels for the diffusion of Na ions and accommodates volume fluctuations in the Na metal during charge–discharge cycling. Moreover, the PAC exhibits a high average Coulombic efficiency of 99.8% at 1 mA·cm⁻² for 1 mAh·cm⁻² and a low voltage polarization of 19 mV during 500 cycles. This study provides valuable insight into the design and fabrication of high-performance Na metal anodes, which hold significant promise for the advancements of next-generation energy storage systems.

Vanadium oxides have attracted extensive interest as electrode materials for many electrochemical energy storage devices owing to the features of abundant reserves, low cost, and variable valence. Based on the in-depth understanding of the energy storage mechanisms and reasonable design strategies, the performances of vanadium oxides as electrodes for batteries have been significantly optimized. Compared to crystalline vanadium oxides, amorphous vanadium oxides (AVOs) show many unique properties, including large specific surface area, excellent electrochemical stability, lots of defects and active sites, fast ion kinetics, and high elasticity. This review gives a comprehensive overview of the recent progress on AVOs for different energy storage systems, such as alkali metal ion batteries, multivalent ion batteries, and supercapacitors with a special focus on the preparation strategies. The basic mechanisms for energy storage performance improvements of AVOs as compared to their crystalline counterparts are also introduced. Finally, challenges faced by AVOs are discussed and future development prospects are also proposed. This review aims to provide a comprehensive knowledge of AVOs and is expected to promote the development of high-performance electrodes for batteries.