In this study, we utilized first-principles calculations to design a novel class of two-dimensional (2D) polycyclic materials composed of carbon and boron atoms, termed k-B₂C₃, which hold significant promise as high-capacity, fast-diffusing anode materials for Li/Na-ion batteries. We investigated the thermodynamic stability, mechanical properties, electronic structure, and energy storage characteristics of k-B₂C₃. The results reveal that k-B₂C₃ exhibits a density of states at the Fermi level of 0.18 states/eV, a Young’s modulus of \(274.43\text{ GPa}\cdot \text{mm}\), and a Poisson’s ratio of 0.43, indicating excellent metallic conductivity and mechanical ductility, which are crucial for stability during charge/discharge cycles. Furthermore, the Li/Na diffusion barriers for k-B₂C₃ are 0.55 eV and 0.17 eV, respectively, which are vital for efficient charge/discharge processes. Most notably, k-B₂C₃ demonstrates a high theoretical storage capacity of 930 mAhg⁻¹ for both Li and Na, coupled with low open-circuit voltages (1.30–0.54 V for Li and 1.17–0.34 V for Na). These findings suggest that 2D k-B₂C₃ is a promising candidate for use as an anode material in Li/Na-ion batteries and provides valuable insights for the development of advanced 2D electrode materials.

To improve the bio-tribological properties of the Ti6Al4V surface, the Ti6Al4V alloy was subjected to a shot-peening treatment and a subsequent Ni+ implantation process. The phase composition, phase content and grain size of the resulting Ni+ implantation layer formed on the surface were evaluated via X-ray diffraction. The nano-hardness of the modified layer was measured with a nano-micro mechanical probe. Moreover, after bio-tribological testing, the scratch morphology of the layer was observed with a scanning electron microscope. The results revealed that this layer was composed mainly of Ti2Ni. The shot-peening pretreatment yielded a significant increase in the Ti2Ni content and the nano-hardness of the layer, resulting in grain size refinement of the formation phase. When a Ni+ implantation energy of 45 keV was employed, the Ti2Ni phase content and the grain size of the shot-peened layer increased by 33.6% and decreased by 65.9%, respectively. The corresponding friction coefficients under artificial saliva and a sodium hyaluronate pure water solution decreased by 20.9% and 29.3%, respectively. In the case of samples implanted at an energy of 40 keV, the nano-hardness of the shot-peened layer was 50.8% higher than that of the non-peened layer. Therefore, a shot-peening pretreatment can yield a significant improvement in the properties of the single Ni+ implantation layer on the Ti6Al4V surface.

The current piston material, Al-12Si, lacks sufficient passivation in the acidic lubrication system of biodiesel engines, making it prone to corrosion in the presence of Cl⁻. Fe amorphous particles exhibit good compatibility with Al-12Si, possessing strong corrosion resistance, excellent passivation ability, and good high-temperature stability. They are a potential reinforcement for enhancing the Al-12Si piston material. Fe amorphous/Al-12Si core-shell structural composites (FACS) were synthesized through ball milling and hot extrusion. The composites’ composition, microstructure, and elemental distribution were characterized by X-ray diffraction, optical microscopy, and EDS spectroscopy. To accelerate the evaluation process, Potentiodynamic polarization and Electrochemical impedance spectroscopy were used to study the electrochemical corrosion behavior. By analyzing the self-corrosion current density (i_corr), self-corrosion potential (E_corr), polarization resistance, inductance, admittance absolute value (Y₀), and diffusion coefficient (n), the mechanism of Fe amorphous particle doping in enhancing the corrosion resistance of Al-12Si was discussed. The research results indicate that: The Fe amorphous particles, during ball milling and hot extrusion at 440 °C, do not recrystallize and maintain their good passivation ability. Spherical Fe amorphous particles act as “balls bearings” during hot extrusion, enhancing flowability and promoting the formation of a core-shell structure FACS with uniform composition distribution, high relative density, and low porosity when doping with 2–10% Fe amorphous particles. This prevents the formation of local potential differences, making the potential on the alloy surface more uniform, which helps reduce the risk of galvanic corrosion and improves corrosion resistance. However, when the doping content of Fe amorphous particles reaches 20%, excessive doping particles squeeze and rub against each other during hot extrusion, leading to amorphous agglomeration, low relative density, and high porosity defects in the resulting FACS, which causes uneven potential, increases local potential differences, and reduces corrosion resistance. Compared to Al-12Si, FACS doped with 2–10% Fe amorphous particles shows a decrease in i_corr from 254.66 µA/cm² to 114.98 µA/cm², and an increase in E_corr from 766.89 mV to 794.78 mV, indicating a reduced corrosion rate with the doping of an appropriate amount of Fe amorphous particles. As the doping content of Fe amorphous particles increases from 2 to 10%, the polarization resistance increases, indicating improved corrosion resistance; the inductance increases, suggesting that corrosion primarily occurs at the surface; Y₀ increases, and n decreases, indicating a reduction in the depth of the corrosion reaction, and the stability of the surface protective oxide film is improved. However, when the doping content of Fe amorphous particles reaches 20%, the opposite effect occurs, and the corrosion resistance of the FACS decreases. Notably, FACS with 10% Fe amorphous particles exhibited the strongest corrosion resistance, making it a potential candidate for biodiesel engine pistons.