Fast capture and stabilization of Li‐ions via physicochemical dual effects for an ultra‐stable self‐supporting Li metal anode

Abstract Lithium (Li) metal is regarded as one of the most promising anode candidates for next‐generation batteries due to its extremely high specific capacity and low redox potential. However, its application is still hindered by the uncontrolled growth of dendritic Li and huge volume fluctuation during cycles. To address these issues, flexible and self‐supporting three‐dimensional (3D) interlaced N‐doped carbon nanofibers (NCNFs) coated with uniformly distributed 2D ultrathin NiCo2S4 nanosheets (denoted CNCS) were designed to eliminate the intrinsic hotspots for Li deposition. Physicochemical dual effects of CNCS arise from limited surface Li diffusivity with a higher Li affinity, leading to uniform Li nucleation and less random accumulation of Li, as confirmed by ab initio molecular dynamics simulations. Due to the unique structure, exchange current density is reduced significantly and metallic Li is further contained within the interspace between the NCNF and NiCo2S4 nanosheets, preventing the formation of dendritic Li. The symmetric cell with a Li/CNCS composite anode shows a long‐running lifespan for almost 1200 h, with an exceptionally low and stable overpotential under 1 mA cm−2/1 mAh cm−2. A full cell coupled with a LiFePO4 cathode at a low N/P ratio of 2.45 shows typical voltage profiles but more significantly enhanced performance than that of a LiFePO4 cathode coupled with a bare Li anode

Flexible Freestanding Carbon Nanofiber-Embedded TiO2 Nanoparticles as Anode Material for Sodium-Ion Batteries

Sodium-ion batteries (SIBs), owning to the low cost, abundant resources, and similar physicochemical properties with lithium-ion batteries (LIBs), have earned much attention for large-scale energy storage systems. In this article, we successfully synthesize flexible freestanding carbon nanofiber-embedded TiO2 nanoparticles (CNF-TiO2) and then apply it directly as anode in SIBs without binder or current collector. Taking the advantage of flexible CNF and high structural stability, this anode exhibits high reversible capacity of 614 mAh.g(-1) (0.27 mAh.cm(-2)) after almost 400 cycles and excellent capacity retention ability of similar to 100

Synthesis and Investigation of CuGeO3 Nanowires as Anode Materials for Advanced Sodium-Ion Batteries

Abstract Germanium is considered as a potential anode material for sodium-ion batteries due to its fascinating theoretical specific capacity. However, its poor cyclability resulted from the sluggish kinetics and large volume change during repeated charge/discharge poses major threats for its further development. One solution is using its ternary compound as an alternative to improve the cycling stability. Here, high-purity CuGeO3 nanowires were prepared via a facile hydrothermal method, and their sodium storage performances were firstly explored. The as-obtained CuGeO3 delivered an initial charge capacity of 306.7 mAh g−1 along with favorable cycling performance, displaying great promise as a potential anode material for sodium ion batteries

Flower-like Cu2SnS3 Nanostructure Materials with High Crystallinity for Sodium Storage

In this study, ternary Cu2SnS3 (CTS) nanostructure materials with high crystallinity were successfully prepared via a facile solvothermal method, which was followed by high-temperature treatment. The morphology of the as-synthesized samples is uniform flower-like spheres, with these spheres consisting of hierarchical nanosheets and possessing network features. Sodium storage measurements demonstrate that the annealed CTS electrodes have high initial reversible capacity (447.7 mAh·g−1 at a current density of 100 mA·g−1), good capacity retention (200.6 mAh·g−1 after 50 cycles at a current density of 100 mA·g−1) and considerable rate capability because of their high crystallinity and unique morphology. Such good performances indicate that the high crystallinity CTS is a promising anode material for sodium ion batteries