This study reports an efficient method for growing high-quality boron nitride nanotubes (BNNTs) via chemical vapor deposition of low-melting-point precursors—magnesium diboride (MgB₂), magnesium nitride (Mg₃N₂), and diboron trioxide (B₂O) at a growth temperature of 1000–1300 °C. The strong oxygen-capturing ability of Mg₃N₂ inhibits the formation of high-melting-point Mg₃B₂O₆, which helps MgB₂ to maintain an efficient and stable catalytic capacity, thereby enhancing its growth efficiency and utilization of the boron source. Moreover, polydimethylsiloxane (PDMS) composites formed from these BNNTs demonstrated much greater thermal conductivities than pure PDMS. Thus, this novel strategy for preparing BNNTs is efficient, and they have great potential for application as thermal interface materials.

Neutral aqueous rechargeable Co₃O₄//Zn batteries with high-output voltage and outstanding cycling stability have yielded new insights into wearable energy-storage devices. To meet the increasing demand for a means of powering wearable and portable devices, the development of a high-performance fiber-shaped Co//Zn battery would be highly desirable. However, the intrinsically poor conductivity of Co₃O₄ significantly restricts the application of these high-capacity and high-rate aqueous rechargeable battery. Encouragingly, density functional theory (DFT) calculations demonstrate that the substitution of Zn for Co³⁺ leads to an insulator-metal transition in the Zn-doped Co₃O₄ (Zn-Co₃O₄). In this study, we used metallic Zn-Co₃O₄ nanowire arrays (NWAs) as a novel binder-free cathode to successfully fabricate an all-solid-state fiber-shaped aqueous rechargeable (AFAR) Co//Zn battery. The resulting fiber-shaped Co//Zn battery takes advantage of the enhanced conductivity, increased capacity, and improved rate capability of Zn-Co₃O₄ NWAs to yield a remarkable capacity of 1.25 mAh·cm^-2 at a current density of 0.5 mA·cm^-2, extraordinary rate capability (60.8% capacity retention at a high current density of 20 mA·cm^-2) and an admirable energy density of 772.6 mWh·cm^-3. Thus, the successful construction of Zn-Co₃O₄ NWAs provides valuable insights into the design of high-capacity and high-rate cathode materials for aqueous rechargeable high-voltage batteries.