• Korean Chemical Engineering Research
• /
• v.62 no.3
• /
• pp.262-268
• /
• 2024

In this study, the MXene/Si composite was prepared by electrostacic assembly with 2-dimensional structured titanium carbide (MXene) and nano silicon for anode material of high-performance lithium-ion battery. Ti₃C₂T_x MXene was synthesized by etching the Ti₃AlC₂ MAX with LiF/HCl, and the surface of nano silicon was charged to positively using CTAB (Cetyltrimethylammonium bromide). The MXene/Si anode composite was successfully manufactured by simple mixing process of synthesized MXene and charged silicon. The physical and electrochemical properties of prepared composite were investigated with MXene-silicon composition ratio, and the surface of electrode after cycles was analyzed to evaluate stability of the electrode. The MXene/Si composites demonstrated high initial discharge capacities of 1962.9, 2395.2 and 2504.3 mAh/g as the silicon composition ratio increased to 2, 3 and 4 compared to MXene, respectively. MXene/Si-4, which is MXene and silicon ratio with 1 : 4, exhibited 1387.5 mAh/g of reversible capacity, 74.5% of capacity retention at 100 cycles and high capacity of 700.5 mAh/g at high rate of 4.0 C. As the results, the MXene/Si composite prepared by electrostatic-assenbly could be applied to anode materials for high-performance LIBs.

• The Korean Journal of Ceramics
• /
• v.6 no.2
• /
• pp.91-95
• /
• 2000

Powder mixtures of $\beta$-SiC-TiC in a weight ratio of 2:1 containing 5-20 wt% additives ($Al_2O_3$-$Y_2O_3$) were liquid-phase sintered at $1830^{\circ}C$ for 1h by hot-pressing and subsequently annealed at $1950^{\circ}C$ for 6h to enhance grain growth. The annealed specimens revealed a microstructure of \"in situ-toughened composite\" as a result of the $\beta$longrightarrow$\alpha$ phase transformation of SiC during annealing. The increase of the content of additives accelerated the growth of elongated $\alpha$-SiC grains with higher aspect ratio and improved fracture toughness. The fracture toughness of SiC-TiC composite containing 20 wt% additive was 6.2 MPa.$m^{1/2}$.2}$.

• Journal of the Korean Ceramic Society
• /
• v.32 no.10
• /
• pp.1194-1202
• /
• 1995

The influences of TiC additions to the α-SiC on microstructural, mechanical, and electrical properties were investigated. Electrical discharge machinability of SiC-TiC composites was also studied. Samples were prepared by adding 30, 45, 60 wt.% TiC particles as a second phase to a SiC matrix. Sintering of SiC-TiC composites was done by hot pressing under a vacuum atmospehre from 1000 to 2000℃ with a pressure of 32 MPa and held for 90 minutes at 2000℃. Samples obtained by hot pressing were fully dense with the relative densities over 99% except 60wt.% TiC samples. Flexural strength and fracture toughness of the samples were increased with the TiC content. In case of SiC samples containing 45 wt.% TiC, the fracture toughness showed 90% increase compared to that of monolithic SiC sample. The crack propagation and crack deflection were observed with a SEM for etched samples after Vicker's indentation. The electrical resistivities of SiC-TiC composites were measured utilizing the four-point probe. The electrical dischage machining of composites was also conducted to evaluate the machinability.

• The Korean Journal of Ceramics
• /
• v.5 no.4
• /
• pp.317-323
• /
• 1999

Si3N4-TiC composites have been known as electrically conductive ceramics. $Si_3N_4-TiC$ composites with 2 wt% $Al_2O_3$ and 4 wt% $Y_2O_3$ were hot pressed in $N_2$ environment. The mechanical properties including hardness, fracture toughness, and flexural strength and tribological properties were investigated as a function of TiC content. $Si_3N_4-40$ vol% TiC composite was hot pressed at $1,750^{\circ}C$, $1,800^{\circ}C$, and $1,850^{\circ}C$ for 1, 3 and 5 hours in $N_2$ gas. Mechanical and tribolgical properties depended on microstructures, which were controlled by hte TiC content, hot press temperature, and hot press holding time. However, mechanical properties and tribological behaviors were degraded by the chemical reaction between TiC and N. The chemically reacted products such as TiCN, SiC, and $SiO_2$ were detered by the X-ray diffraction analysis.