Self-assembly of nano/micro-structured Fe3O4 microspheres among 3D rGO/CNTs hierarchical networks with superior lithium storage performances

MoP2/C@rGO synthesised by phosphating the molybdenum-based metal organic framework and GO coating with excellent lithium ion storage performance

With a high specific capacity, MoP₂ has been identified as an ideal electrode material for LIBs. However, the specific capacity is negatively affected due to its poor conductivity and severe volume expansion during insertion and extraction of Li⁺. In this paper, MoP₂-C synthesized by using a Mo-MOF as a precursor, with the generation of C, can effectively solve the agglomeration problem in the synthesis process and alleviate serious volume changes during cycling. Due to the lack of carbon sources provided by a Mo-MOF, the conductivity of MoP₂-C cannot be greatly improved. Therefore, rGO and PPy are added to improve the conductivity of MoP₂ and further increase the stability of the structure. Compared with MoP₂/C and MoP₂/C@PPy, MoP₂/C@rGO exhibits the highest initial discharge specific capacity of 1208 mA h g^-1 at a current density of 100 mA g^-1 and rate performances of 830, 750, 630, 550, and 430 mA h g^-1 with the current density increasing from 100 mA g^-1 to 2000 mA g^-1. Notably, the specific capacity remains at 640 mA h g^-1 at a current density of 100 mA g^-1 after 100 cycles. Followed by 200 cycles at a current density of 2000 mA h g^-1, the specific capacity remains at 395 mA h g^-1 with a capacity retention rate of 80%.

Top-down tailoring of nanostructured manganese molybdate enhances its lithium storage properties

Aggregated manganese molybdate micron-whiskers are tailored to nanospheres by a facile top-down strategy in the aqueous phase at room temperature.

Facile Synthesis of SiO2@C Nanoparticles Anchored on MWNT as High-Performance Anode Materials for Li-ion Batteries

Carbon-coated silica nanoparticles anchored on multi-walled carbon nanotubes (SiO₂@C/MWNT composite) were synthesized via a simple and facile sol-gel method followed by heat treatment. Scanning and transmission electron microscopy (SEM and TEM) studies confirmed densely anchoring the carbon-coated SiO₂ nanoparticles onto a flexible MWNT conductive network, which facilitated fast electron and lithium-ion transport and improved structural stability of the composite. As prepared, ternary composite anode showed superior cyclability and rate capability compared to a carbon-coated silica counterpart without MWNT (SiO₂@C). The SiO₂@C/MWNT composite exhibited a high reversible discharge capacity of 744 mAh g^-1 at the second discharge cycle conducted at a current density of 100 mA g^-1 as well as an excellent rate capability, delivering a capacity of 475 mAh g^-1 even at 1000 mA g^-1. This enhanced electrochemical performance of SiO₂@C/MWNT ternary composite anode was associated with its unique core-shell and networking structure and a strong mutual synergistic effect among the individual components.

Rational Design of Three-Dimensional Graphene Encapsulated with Hollow FeP@Carbon Nanocomposite as Outstanding Anode Material for Lithium Ion and Sodium Ion Batteries

Transition metal phosphides have been extensively investigated owing to their high theoretical capacities and relatively low intercalation potentials vs Li/Li⁺, but their practical applications have been hindered by low electrical conductivity and dramatic volume variation during cycling. In this work, an interesting strategy for the rational design of graphene (GR) encapsulated with a hollow FeP@carbon nanocomposite (H-FeP@C@GR) via a combination of a hydrothermal route, a carbon-coating process, phosphidation treatment, and carbothermic reaction is reported. The hollow FeP (H-FeP) nanospheres shelled with thin carbon layers are wonderfully incorporated into the GR matrix, interconnecting to form a three-dimensional (3D) hierarchical architecture. Such a design offers distinct advantages for FeP-based anode materials for both lithium ion batteries (LIBs) and sodium ion batteries (SIBs). For example, the 3D omnibearing conductive networks from the GR skeleton and outer coating carbon can provide an open freeway for electron/ion transport, promoting the electrode reaction kinetics. In addition, the wrapping of an H-FeP nanosphere in a thin carbon layer enables the formation of a solid electrolyte interphase (SEI) on the carbon layer surface instead of on the individual H-FeP surface, preventing the continual re-forming of the SEI. When used as anode materials for LIBs and SIBs, H-FeP@C@GR exhibited excellent electrochemistry performances.

Fe3O4 nanoparticle anchored layered graphene films for high performance lithium storage

Fe₃O₄ nanoparticles homogeneously decorated onto layered graphene nanosheets film exhibit excellent cyclic retention and good rate capability when used as anodes in lithium storage.