Shitong Wang

High-performance LiMnPO4 nanorods synthesized via a facile EG-assisted solvothermal approach

Novel LiMnPO4 nanorods have been successfully synthesized via a facile solvothermal approach in a mixed solvent of ethylene glycol (EG) and water (11:1, vol.). The as-prepared LiMnPO4 sample is of single crystalline and has a rod-like morphology with a small size especially a thin thickness of less than 50 nm along the [010] direction, which is expected to favour faster lithium-ion extraction/insertion reactions. Detailed investigations indicate that EG plays an important role in the formation of the LiMnPO4 nanorods by effectively regulating the morphology, size, and crystal orientation. Benefiting from the special rod-like morphology and the uniform thin carbon coating, the LiMnPO4/C composite nanorods exhibit a high reversible capacity of 168 mA h g−1 and 110 mA h g−1 at 0.05 C and 10 C, respectively, and a remarkable stable capacity retention of ∼94.5% after 100 cycles at 0.5 C.

A Universal Strategy for Intimately Coupled Carbon Nanosheets/MoM Nanocrystals (M = P, S, C, and O) Hierarchical Hollow Nanospheres for Hydrogen Evolution Catalysis and Sodium‐Ion Storage

Intimately coupled carbon/transition-metal-based hierarchical nanostructures are one of most interesting electrode materials for boosting energy conversion and storage applications owing to the strong synergistic effect between the two components and appealing structural stability. Herein, a universal method is reported for making hierarchical hollow carbon nanospheres (HCSs) with intimately coupled ultrathin carbon nanosheets and Mo-based nanocrystals. The in situ and confined reaction of the synthetic strategy can not only allow the aggregation of the nanocrystals to be impeded, but also endows extremely intimate coupled interaction between the conductive carbon nanosheets and the nanocrystals MoM (M = P, S, C and O). As a proof of concept, the as-prepared MoP/C HCSs exhibit extraordinary hydrogen evolution reaction electrocatalytic activity with small overpotential and robust durability in both acidic and alkaline solutions. In addition, the unique sheet-on-sheet MoS2 /C HCSs as an anode demonstrate high capacity, great rate capabilities, and long-term cycles for sodium-ion batteries (SIBs). The capacity can be maintained at 410 mA h g-1 even after 1000 cycles even at a high current density of 4 A g-1 , one of the best reported values for MoS2 -based electrode materials for SIBs. The present work highlights the importance of designing and fabricating functional strongly coupled hybrid materials for enhancing energy conversion and storage applications.

High-performance carbon-coated mesoporous LiMn2O4 cathode materials synthesized from a novel hydrated layered-spinel lithium manganate composite

Carbon-coated mesoporous spinel LiMn2O4 has been synthesized from a novel hydrated layered-spinel lithium manganate composite through a facile hydrothermal process and subsequent thermal treatment. Benefiting from the carbon coating and mesoporous structure, the LiMn2O4 material exhibits superior high-rate capability and long-life cycling stability, delivering the initial discharge capacity of 117.8 mA h g−1 at 30C with over 90% capacity retention after 1500 cycles. Moreover, the innovative employment of hydrated layered Li-deficient and spinel Li-rich intermediates might provide greater inspiration for other high-performance electrode materials with multiple layer architectures and optimized phase compositions.

Li4Ti5O12–TiO2/MoO2 nanoclusters-embedded into carbon nanosheets core/shell porous superstructures boost lithium ion storage

Ti-based materials are well-known to be good anode materials for lithium ion batteries because of their negligible volume change during the charge/discharge process. Nevertheless, poor electronic conductivity makes them exhibit relatively low capacity. Herein, we report our design of three-dimensional hierarchical Li4Ti5O12–TiO2/MoO2 nanoclusters embedded into carbon nanosheets core/shell porous superstructures for achieving more efficient lithium ion storage. The resulting hybrid makes full use of the advantage of high-capacity MoO2 nanoclusters and robust Li4Ti5O12–TiO2 substrate as well as high-conductivity carbon nanosheets. Such an assembly is highly particular for not only endowing enhanced ion diffusion and rapid electron transfer, but also preventing MoO2 nanoclusters from agglomeration and oxidation. Benefitting from the advantageous structural feature and synergistic effect of the components, the Li4Ti5O12–TiO2@MoO2/C exhibits a high reversible specific capacity of 413 mA g−1 at a current density of 1000 mA g−1 up to 500 cycles, indicating its high stability.

Thermal convection induced TiO2 microclews as superior electrode materials for lithium-ion batteries

One great challenge of lithium-ion battery (LIB) commercialization is to achieve high rate capacity at large mass loading density. Here, a thermal-convection hydrothermal method was newly designed and developed to synthesize TiO2 microclews (TiO2 MCs) for their use as LIB electrode materials. The unique MC architecture could be immobilized on a carbon cloth collector uniformly to form a 3D flexible conductive network (TiO2 MCs@CC), which facilitates fast Li-ion and electron transport and promotes continuous lithiation reaction during the charge–discharge process. With these merits, TiO2 MCs@CC with high loading density (up to 4 mg cm−2) exhibits ultra-high rate performance (75 mA h g−1 at an extremely high current density of 4000 mA g−1), outstanding long-cycling life (74 mA h g−1 over 1000 cycles at a specific current density of 2000 mA g−1) and a high initial coulombic efficiency (ICE) of 82%. The demonstrated advantages open up possibilities for fabricating ultrafast rechargeable LIBs with potential industrial applications.