Ferrocene as a Novel Additive to Enhance the Lithium-Ion Storage Capability of SnO2/Graphene Composite

SnO2 Anchored in S and N Co-Doped Carbon as the Anode for Long-Life Lithium-Ion Batteries

Tin dioxide (SnO2) has been the focus of attention in recent years owing to its high theoretical capacity (1494 mAh g-1). However, the application of SnO2 has been greatly restricted because of the huge volume change during charge/discharge process and poor electrical conductivity. In this paper, a composite material composed of SnO2 and S, N co-doped carbon (SnO2@SNC) was prepared by a simple solid-state reaction. The as-prepared SnO2@SNC composite structures show enhanced lithium storage capacity as compared to pristine SnO2. Even after cycling for 1000 times, the as-synthesized SnO2@SNC can still deliver a discharge capacity of 600 mAh g-1 (current density: 2 A g-1). The improved electrochemical performance could be attributed to the enhanced electric conductivity of the electrode. The introduction of carbon could effectively improve the reversibility of the reaction, which will suppress the capacity fading resulting from the conversion process.

Synergistic effects of flake-like ZnO/SnFe2O4/nitrogen-doped carbon composites on structural stability and electrochemical behavior for lithium-ion batteries

In order to improve the electrochemical performance and relieve volume expansion of pure SnFe₂O₄ anode for lithium-ion batteries (LIBs), we synthesized a novel ZnO/SnFe₂O₄/nitrogen-doped carbon composites (ZSFO/NC) with flake-like polyhedron morphology by using ZIF-8 as a sacrificial template. Remarkably, it exhibited an initial charge/discharge capacities of 1078.3/1507.5 mAh g^-1 with a high initial coulombic efficiency (ICE) of 71.2%, and maintained a steady charge/discharge capacities of 1495.7/1511.8 mAh g^-1 at 0.2 A g^-1 after 300 cycles. The excellent rate performance of 435.6 mAh g^-1 at a higher current density of 10.0 A g^-1 and superior reversible capacity of 532.3/536.2 mAh g^-1 after 500 cycles at 2.0 A g^-1 were obtained. It revealed that the nitrogen-doped carbon matrix and peculiar structure of ZSFO/NC not only effectively buffered large volume expansion upon (de)lithiation through the synergistic interface action between ZnO, SnFe₂O₄ and NC, but also improved capacity of the composite by large contribution of surface pseudo-capacitance. The excellent charge-discharge performance showed that ZSFO/NC composite has a great potential for LIBs due to the synergistic effect of the multi-components.

Crystal structure of 1,1′-bis(diphenylphosphino)ferrocene-(1,1′-bis(diphenylphosphino)ferrocene-κ2 P,P′)-(O-isobutyl sulfurodithioito-κ2 S,S′)copper(I), C39H37CuFeOP2S2

C39H37CuFeOP2S2, triclinic, P1̄ (no. 2), a = 9.6132(10) Å, b = 11.5667(12) Å, c = 16.8739(18) Å, α = 99.732(2)°, β = 96.342(2)°, γ = 93.446(2)°, V = 1832.0(3) Å3, Z = 2, R gt(F) = 0.0455, wR ref(F 2) = 0.1212, T = 293.0 K.

Rational Design and Controllable Synthesis of Multishelled Fe2O3@SnO2@C Nanotubes as Advanced Anode Material for Lithium-/Sodium-Ion Batteries

Hierarchical Fe₂O₃ and SnO₂ nanostructures have shown great potential for applications in high-performance ion batteries because of their superiority, including wide resources, facile preparation, environmental friendliness, and high energy density. However, some severe challenges, such as rapid capacity decay due to volume expansion upon cycling and poor conductivity, limit their rate performance. To address this issue, multishelled Fe₂O₃@SnO₂@C (FSC) nanotubes were designed and synthesized by using a template method and Ostwald interaction. The as-prepared FSC nanotubes can deliver a high capacity of 1659 mA h g^-1 at a current density of 200 mA g^-1 and a high reversible capacity of 818 mA h g^-1 at 2000 mA g^-1 for lithium-ion batteries. Particularly, a high specific capacity of 1024 mA h g^-1 is still maintained after 100 charging/discharging cycles at 200 mA g^-1. Applied in sodium-ion batteries, the multishelled FSC nanotubes manifest a high specific capacity of 449 mA h g^-1 after 180 cycles at 50 mA g^-1. Such excellent performances of the as-fabricated FSC nanotubes may be due to the unique multishelled tubular structure, porous characteristics, and high specific surface area. Therefore, the present work provides an outstanding method to improve the energy storage performance of metal oxide composites and other types of nanocomposites.