Phase Separation Induced Binary Core–Shell Alloy Nanoparticles Embedded in Carbon Sheets for Magnesium Storage

Abstract

Magnesium-ion batteries (MIBs) have aroused widespread interest in large-scale applications due to their low cost, high volumetric capacity, and safety. However, magnesium (Mg) metals are incompatible with conventional electrolytes, making it difficult to plate and strip reversibly. Therefore, developing novel Mg 2+ host anodes remains a huge challenge. Herein, we present a rational design and fabrication of binary Bi@Sn alloy nanoparticles embedded in carbon sheets (Bi@Sn−C) as a superior anode for MIBs employing phase separation during the annealing of bimetallic MOFs. The Bi@Sn−C simultaneously integrates the nanostructure design and multi-element coordination strategies which is favorable to improve the overall structural stability and Mg 2+ diffusion kinetics. Benefiting from the aforementioned features, the Bi@Sn−C electrodes deliver good cycling stability of 214 mA h g −1 at 100 mA g −1 after 100 cycles and rate capability with 200 mA h g −1 at 500 mA g −1 . And when using all-phenyl complex with lithium chloride (LiCl−APC) dual-salt electrolyte, the electrochemical performance of Bi@Sn−C is further optimized and shows enhanced rate performance (238 mA h g −1 at 500 mA g −1 ) and reversible capacity (308 mA h g −1 at 100 mA g −1 after 100 cycles). This novel strategy holds great promise for designing efficient alloy electrode materials for MIBs.

Bismuth Nanoparticle-Embedded Carbon Microrod for High-Rate Electrochemical Magnesium Storage

“…This indicates that the construction of the Bi⊂CM structure benefits the achievement of fast magnesium storage kinetics. A comparison of the rate performance among the Bi-based anodes in this work and previous reports using Mg-ion or [Mg–Cl] + electrolytes demonstrates the competitive rate capability of the as-prepared Bi⊂CM-120 anode in a broad current density range of 0.05–3 A g –1 (Figure e). ,,,− Importantly, the as-prepared Bi⊂CM-120 material exhibits an enhanced compactability than other Bi-based materials listed in Figure e because of its microsized profile (Table S1), which is beneficial to high-density magnesium storage. The EIS measurement was performed to analyze the reaction kinetics of the Bi⊂CM and pure Bi anodes upon cycling.…”

Robust Hewettite HKV6O16·4H2O/CNT Nanosheets as High-Performance Cathodes for Sustainable Mg2+ Storage

“…The whole cycle maintains a stable Coulombic efficiency, and the capacity retention rate is 90% after 4500 cycles. Sufficient layer spacing provides ample space for Mg 2+ to be released/embedded, which makes HKVO/CNT possess sustainable magnesium-ion storage. − Figure shows the morphology of the HKVO/CNT electrodes after the cycle. In the progress of charging and discharging (Figure a), the original and regular near-rectangle slice gradually transformed into a multilayer architecture, which provides sufficient Mg 2+ storage space and ion diffusion channels , (detailed information in Figure S1f–j).…”