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Basalt fiber (BF) is deemed a new environmentally friendly and high-performance fiber material due to its high strength, electrical insulation, corrosion resistance and high temperature resistance. Yet, the surface inertness restricts its practical application. In this work, the BF was irradiated and activated by electron beam, followed by in situ growth of SiO2 using a hydrothermal method, then composites with polypropylene (PP) were prepared by microinjection molding. According to the results of scanning electron microscopy (SEM) and Fourier transform infrared (FTIR), more active sites can be formed after irradiation, thus more SiO2 nanoparticles were generated on the surface of BF. Consequently, the rough surface of modified BF could provide stronger shear force during melt processing and resulted in a higher orientation of the molecular chains, increasing the lamellar thickness and generating more highly ordered β crystals in the composites. I400BF-gSiO2 exhibited the highest content of β crystals with the crystallinity of 53.62% and orientation of β (300) crystal plane of 0.91, which were 8.66% and 0.04 higher than those of the composite with pristine BF. Furthermore, due to the perfection of crystals, increased interfaces and interfacial interlocking between PP molecules and modified BF, I400BF-gSiO2 showed good overall performance, with storage modulus of 8000 MPa at −100 °C, glass transition temperature of 23.03 °C and tensile strength of 62.2 MPa, which was 1900 MPa, 1.23 °C and 29.6 MPa higher than neat PP. Hence, the surface roughing strategy proposed in this work is expected to provide some insight and promote the application of BF reinforced thermoplastic composites. [ABSTRACT FROM AUTHOR]

Lithium cobalt oxide (LiCoO2), which has been successfully applied in commercial lithium-ion batteries for portable devices, possesses a theoretical specific capacity of 274 mAh g−1. However, its actual capacity is only half of the theoretical specific capacity, because the charging voltage is restricted below 4.2 V. If a higher charging voltage is applied, an irreversible phase transition of LiCoO2 during delithiation would occur, resulting in severe capacity fading. Therefore, it is essential to investigate the electrochemically driven phase transition of LiCoO2 cathode material to approach its theoretical capacity. In this work, it was observed that LiCoO2 partially degraded to Co3O4 after 150 charging-discharging cycles. From the perspective of crystallography, the conventional cell of LiCoO2 was rebuilt to an orthonormal coordinate, and the transition path from layered LiCoO2 to cubic Co3O4 proposed. The theoretical analysis indicated that the electrochemically driven phase transition from LiCoO2 to Co3O4 underwent several stages. Based on this, an experimental verification was made by doping LiCoO2 with Al, In, Mg, and Zr, respectively. The doped samples theoretically predicted behavior. The findings in this study provide insights into the electrochemically driven phase transition in LiCoO2, and the phase transition can be eliminated to improve the capacity of LiCoO2 to its theoretical value. [ABSTRACT FROM AUTHOR]