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Herein, oriented boron nitride (BN)/alumina (Al2O3)/polydimethylsiloxane (PDMS) composites were obtained by filler orientation due to the shear-inducing effect via 3-D printing. The oriented BN platelets acted as a rapid highway for heat transfer in the matrix and resulted in a significant increase in the thermal conductivity along the orientation direction. Extra addition of spherical Al2O3 enhanced the fillers networks and resulted in the dramatic growth of slurry viscosity. This, together with filler orientation induced the synergism and provided large increases in the thermal conductivity. A high orientation degree of 90.65% and in-plane thermal conductivity of 3.64 W/(m∙K) were realized in the composites with oriented 35 wt% BN and 30 wt% Al2O3 hybrid fillers. We attributed the influence of filler orientation and hybrid fillers on the thermal conductivity to the decrease of thermal interface resistance of composites and proposed possible theoretical models for the thermal conductivity enhancement mechanisms.

As a promising alternative anode material, silicon (Si) presents a larger capacity than the commercial anode to achieve large capacity lithium-ion batteries. However, the application of pure Si as anode is hampered by limitations such as volume expansion, low conductivity and unstable solid electrolyte interphase. To break through these limitations, the core-shell Si@Li4Ti5O12 nanocomposite, which was prepared via in-situ self-assembly reaction and decompressive boiling fast concentration method, was proposed in this work. This anode combines the advantages of nano-sized Si particle and pure Li4Ti5O12 (LTO) coating layer, improving the performance of the lithium-ion batteries. The Si@Li4Ti5O12 anode displays a high initial discharge/charge specific capacity of 1756/1383 mAh g−1 at 500 mA g−1 (representing high initial coulombic efficiency of 78.8%), a large rate capability (specific capacity of 620 mAh g−1 at 4000 mA g−1), an outstanding cycling stability (reversible specific capacity of 883 mAh g−1 after 150 cycles) and a low volume expansion rate (only 3.3% after 150 cycles). Moreover, the synthesis process shows the merits of efficiency, simplicity, and economy, providing a reliable method to fabricate large capacity Si@Li4Ti5O12 nanocomposite anode materials for practical lithium-ion batteries.

The combination of various fillers can improve the thermal conductivity of polymer composites, because an efficient heat conduction network synergistically formed in matrix. The synergistic effect of two fillers, carbon fiber and alumina particle, in polydimethylsiloxane (PDMS) is investigated in this work. A filler combination results in higher thermally conductive composite than any of the single filler. The volume ratio of 4:1 shows the greatest thermal conductivity. The thermal conductivity of PDMS composite filled with 24 vol% carbon fiber and 6 vol% alumina reaches 7.91 W m−1K−1, which was 34% higher than that of 30 vol% CF/PDMS. The combined filler composite also shown better process performance due to the lower viscosity. The synergy is attributed to the optimized heat transfer network and reduced interfacial thermal resistance. Therefore, a combined filler achieved better thermally conductive performance and better process performance with cost-effective source materials.