The high theoretical capacity of Sb-based intermetallic alloys makes them attractive potential anode materials for sodium-ion batteries (SIBs) with high energy density . However, their cycling stability is greatly restricted by the huge volumetric variations resulted from the intrinsic (de-)alloying mechanism. Herein, we demonstrate a unique lattice softening mechanism, which enables highly reversible sodium storage and stable cycling of the as-prepared Bi–Sb alloy/carbon nanofibers electrodes. Theoretical analyses show that the elastic modulus of Bi–Sb alloys is reduced whereas the toughness is enhanced by tuning the lattice chemistry of rhombohedral Bi–Sb alloys, which is of great importance in relieving the concentrated stress during the continuous (de-)sodiation processes. In-situ characterization and electrochemical evaluations demonstrate that the electrodes made of BiSb 3 /C nanofibers exhibit high anti-pulverization capability upon Na-cycling and extraordinary long-life cyclability. Specifically, a highly reversible capacity of 233.2 mAh g −1 at 2 A g −1 is achieved over 2500 cycles. Moreover, a full cell assembled with the pre-sodiated BiSb 3 /C anode and a Na 3 V 2 (PO 4 ) 3 /C cathode delivers a high reversible capacity of 333.2 mAh g −1 at 0.2 A g −1 over 200 cycles. This present work provides further understandings and new solution for developing high-performance alloying-based anodes for SIBs.
Lithium metal is one of the most promising anode candidates for next-generation high-energy batteries. Nevertheless, lithium pulverization and associated loss of electrical contact remain significant challenges. Here, an antipulverization and high-continuity lithium metal anode comprising a small number of solid-state electrolyte (SSE) nanoparticles as conformal/sacrificial fillers and a copper (Cu) foil as the supporting current collector is reported. Guiding by the SSE, this new anode facilitates lithium nucleation, contributing to form a roundly shaped, micro-sized, and dendrite-free electrode during cycling, which effectively mitigates the lithium dendrite growth. The embedded Cu current collector in the hybrid anode not only reinforces the mechanical strength but also improves the efficient charge transfer among active lithium filaments, affording good electrode structural integrity and electrical continuity. As a result, this antipulverization and high-continuity lithium anode delivers a high average Coulombic efficiency of ≈99.6% for 300 cycles under a current density of 1 mA cm −2 . Lithium–sulfur batteries (elemental sulfur or sulfurized polyacrylonitrile cathodes) equipped with this anode show high-capacity retentions in their corresponding ether-based or carbonate-based electrolytes, respectively. This new electrode provides important insight into the design of electrodes that may experience large volume variation during operations.
危险品化学品经营许可证（带存储）