개질된 Ti3C2Tx MXene@ZnO 복합체 제조 및 에너지 저장소자로의 응용

다국어 초록 (Multilingual Abstract)

The demand for high-performance energy storage systems has increased, highlighting the need to improve the pore structure and specific surface area of electrode materials for both supercapacitors and lithium-ion batteries. Supercapacitors offer high power density, but their energy density must be improved by enlarging the active surface area and optimizing ion transport pathways. Lithium-ion batteries provide high energy density however, their rate capability and cycling stability depend on reducing diffusion resistance and increasing the number of electrochemically active sites. Therefore, controlling porosity and surface area is a key strategy for enhancing the performance of both devices. In this study, we fabricated electrode materials based on the carbide derived two dimensional material Ti3C2Tx MXene. The Al layer of Ti3AlC2 MAX phase was etched using a LiF/HCl solution instead of conventional HF. The LiF/HCl method offers milder and more uniform etching, improving safety and providing higher reaction controllability. As a result, single-layer Ti3C2Tx MXene sheets with a thickness of about 1.6 nm were successfully obtained. To further improve the electrochemical performance, MXene was combined with zinc oxide (ZnO), which has a wurtzite structure and preferential c-axis growth, allowing ZnO nanostructures to grow uniformly on the MXene surface. The MXene@ZnO composite was synthesized using a precipitation process, which requires no additional equipment and allows easy control of particle size and growth time. Structural characterization using SEM and XRD confirmed that the layered MXene structure was preserved and that ZnO nanoparticles were uniformly formed on the MXene sheets. BET analysis showed that the composite synthesized for 2 hours exhibited the largest specific surface area of 43.639 cm3 g-1, indicating the most effective pore structure formation. In supercapacitor measurements, the 2 hour composite exhibited the highest performance, with a specific capacitance of 139.0 F g-1 and the longest discharge time of 172.6 s. These results are attributed to the expanded pore structure and the increased active surface area. For lithium-ion battery anode performance, the 3 hour composite showed a high initial capacity but poor rate capability, with a capacity retention below 70% at high scan rates. In contrast, the 2 hour composite showed better stability, achieving 38% rate retention and 52% charge–discharge capacity retention. Overall, the LiF/HCl-etched Ti3C2Tx MXene combined with ZnO effectively enhanced structural stability, ion transport pathways, and electrochemically active surface area. This study confirms that the Ti3C2Tx MXene@ZnO composite is a promising electrode material for high power and high stability energy storage applications.

목차 (Table of Contents)

• 제1장 서론 1
• 제2장 이론적 배경 4
• 2.1 슈퍼커패시터 4
• 2.1.1 슈퍼커패시터의 구성 및 작동 원리 4
• 2.1.2 슈퍼커패시터 물질 9
• 2.2 리튬이온 전지 11
• 2.2.1 리튬이온 전지의 구성 및 작동 원리 11
• 2.2.2 리튬이온 전지 물질 14
• 2.3 Ti3C2Tx MXene 16
• 2.4 산화 아연 20
• 제3장 연구 방법 23
• 3.1 Ti3C2Tx MXene 표면 개질 23
• 3.2 Ti3C2Tx MXene 물성 분석 24
• 3.3 Ti3C2Tx MXene 전기화학 분석 25
• 3.3.1 슈퍼커패시터 25
• 3.3.2 리튬이온 전지 26
• 3.4 Ti3C2Tx MXene@ZnO 복합체 제작 28
• 3.5 Ti3C2Tx MXene@ZnO 복합체 물성 분석 29
• 3.6 Ti3C2Tx MXene@ZnO 복합체 전기화학 분석 30
• 3.6.1 슈퍼커패시터 30
• 3.6.2 리튬이온 전지 31
• 제4장 연구결과 및 고찰 33
• 4.1 Ti3C2Tx MXene 물성 분석 결과 33
• 4.2 Ti3C2Tx MXene 전기화학 분석 결과 35
• 4.2.1 슈퍼커패시터 35
• 4.2.2 리튬이온 전지 39
• 4.3 Ti3C2Tx MXene@ZnO 복합체 물성 분석 결과 41
• 4.4 Ti3C2Tx MXene@ZnO 복합체 전기화학 분석 결과 46
• 4.4.1 슈퍼커패시터 46
• 4.4.2 리튬이온 전지 48
• 제5장 결론 52
• 참고 문헌 54
• Abstract 70
• 감사의 글 72