Showing papers in "Advanced composites and hybrid materials in 2022"

Sandwich-like CoMoP2/MoP heterostructures coupling N, P co-doped carbon nanosheets as advanced anodes for high-performance lithium-ion batteries

Abstract: Transition metal phosphides as ideal anodes have been attracted a large number of interests due to their excellent performance for lithium-ion batteries. Nevertheless, CoMoP2 materials were rarely reported as lithium-ion battery anode materials. Thereupon, to excavate their ability in LIBs, a sandwich-like architecture was employed as anode material, in which heterostructured CoMoP2 and MoP nanoparticles were coated on N, P co-doped carbon matrix. Notably, doped micro-lamellated carbon sheets could not only allow boosted lithium ion and electron transport but also alleviate the volume changes of active material to sustain anode integrity during the discharge/charge processes. More importantly, the combination of CoMoP2 and MoP nanoparticles could synergically strengthen the electrochemical activities of the anodes, and their built-in heterojunction facilitated the reaction kinetics on their interfaces. This research may offer a rational design on both heterostructure and doping engineering of future anodes for lithium-ion batteries.

Improving thermal conductivity of polyethylene/polypropylene by styrene-ethylene-propylene-styrene wrapping hexagonal boron nitride at the phase interface

Abstract: In this work, the percentage of polyethylene (PE) and polypropylene (PP) blend is controlled at 50:50 to make the composite by forming a co-continuous structure with hexagonal boron nitride (h-BN). The h-BN is wrapped by thermoplastic elastomer styrene-ethylene-propylene-styrene (SEPS). This approach enables the localized distribution of h-BN at the interface of the co-continuous structure of PE/PP blend and SEPS phases, allowing the construction of a heat conduction path in the SEPS phase, thereby improving the thermal conductivity of PE/PP. Theoretical calculation predicted the localized distribution of SEPS at the interface of the PE/PP blend to form a co-continuous composite structure. The thermal conductivity of the composites can be improved by 57.7% by adding 10 wt% h-BN, presenting a commercial potential of such composites in certain heat dissipation applications.

Enhanced electromagnetic wave absorption of engineered epoxy nanocomposites with the assistance of polyaniline fillers

Abstract: Abstract In this work, the engineered polyaniline (PANI)/epoxy composites reinforced with PANI-M (physical mixture of PANI spheres and fibers) exhibit significantly enhanced electromagnetic wave absorption performance and mechanical property. Due to the synergistic effect of PANI fillers with different geometries, the reflection loss of 10.0 wt% PANI-M/epoxy could reach − 36.8 dB at 17.7 GHz. Meanwhile, the mechanical properties (including tensile strength, toughness, and flexural strength) of PANI/epoxy were systematically studied. Compared with pure epoxy, the tensile strength of epoxy with 2.0 wt% PANI-M was improved to 86.2 MPa. Moreover, the PANI spheres (PANI-S) and PANI fibers (PANI-F) were prepared by the chemical oxidation polymerization method and interface polymerization method, respectively. The characterizations including scanning electron microscope, Fourier transform infrared spectra, and X-ray diffraction were applied to analyze the morphology and chemical and crystal structures of PANI filler. This work could provide the guideline for the preparation of advanced engineered epoxy nanocomposites for electromagnetic wave pollution treatment. Graphical abstract