다기능성 탄소양자점을 이용한 전도성 고분자 슈퍼커패시터 응용 및 탄소 기반 전극 설계 = Application of multifunctional carbon quantum dots in conductive polymer supercapacitors and carbon-based electrode design

다국어 초록 (Multilingual Abstract)

Carbon quantum dots (CQDs) are nanoscale materials smaller than 10 nm that have attracted significant attention due to their excellent semiconductor properties and facile surface functionalization. In this work, poly(ethylene glycol)-modified CQDs(PEG-CQDs) were employed as multifunctional additives for electrodes in energy storage devices. PEG-CQDs play multiple roles within the electrodes based on their unique structural characteristics.First, in PEDOT:PSS-based supercapacitor electrodes, PEG-CQDs effectively induced phase separation between PEDOT and PSS, which significantly enhanced both electrical conductivity and capacitance. This improvement is attributed to hydrogen bonding between the PEG chains and PSS, which weakens the interaction between PEDOT and PSS, while the sp²-carbon core of CQDs forms π-π interactions with PEDOT to strengthen the conductive pathways.
Second, in CNT-based electrodes, PEG-CQDs improved the dispersion stability of CNTs, while simultaneously serving as a chemical linkers to the binder. The sp²-carbon core provieds stable adsorption onto CNT surfaces through π-π interactions, whereas hydrophilic PEG chains promote dispersion in solvent media. Additionally, the terminal –OH groups of PEG can interact with the binder, enhancing adhesion and structural stability. In this study, a silane-based binder system was introduced to establish a covalent bonding-driven attachment mechanism, enabling preservation of the porous electrode structure and efficient utilization of the overall electrode volume environmentally friendly and efficient electrode-coating process. These results highlight the potential of carbon quantum dots as highly effective multifunctional additives for next-generation energy storage applications.

목차 (Table of Contents)

• 1. PEG-기능화 탄소양자점을 이용한 슈퍼커패시터용 PEDOT:PSS 전극의 전도도 및 정전용량 향상 1
• 1.1 서론 1
• 1.2 이론적 배경 5
• 1.2.1 슈퍼커패시터 5
• 1.2.2 PEDOT:PSS 6
• 1.2.3 탄소양자점 7
• 1.3 실험 9
• 1.3.1 재료 및 시약 9
• 1.3.2 실험 방법 9
• 1.3.2.1 PEG-CQDs 합성 9
• 1.3.2.2 PEG-CQDs/PEDOT:PSS 전극 제조 10
• 1.3.2.3 슈퍼커패시터 소자 제작 10
• 1.3.3 특성 분석 11
• 1.3.3.1 UV-Vis 분광법 분석 (UV-Visible spectroscopy) 11
• 1.3.3.2 PL 분광법 분석 (photoluminescence spectroscopy) 11
• 1.3.3.3 푸리에 변환 적외선 분광법 분석 (FT-IR) 11
• 1.3.3.4 면저항 분석(Sheet resistance, 4-point probe method) 11
• 1.3.3.5 AFM 분석(atomic force microscopy) 12
• 1.3.3.6 순환 전류 전압법 분석(cyclic voltammetry) 12
• 1.3.3.7 정전류 충방전 분석(galvanostatic charge/discharge) 12
• 1.3.3.8 전기화학 임피던스 분광법(EIS) 12
• 1.4 결과 및 고찰 13
• 1.4.1 PEG-CQDs의 합성 13
• 1.4.2 PEG-CQDs/PH 전극 17
• 1.4.3 전기화학적 성능 평가 23
• 1.5 결론 32
• 2. PEG-기능화 탄소양자점을 이용한 탄소나노튜브/실란 복합 전극 설계 및 슈퍼커패시터 응용 33
• 2.1 서론 33
• 2.2 이론적 배경 38
• 2.2.1 CNT의 분산 안정성 38
• 2.2.2 바인더(Binder) 40
• 2.3 실험 41
• 2.3.1 재료 및 시약 41
• 2.3.2 실험 방법 41
• 2.3.2.1 PEG-CQDs 합성 41
• 2.3.2.2 PEG-CQDs/CNT 복합체 제조 42
• 2.3.2.3 PEG-CQDs/CNT/Silane 복합 전극 제조 42
• 2.3.2.4 슈퍼커패시터 소자 제작 43
• 2.3.3 특성 분석 43
• 2.3.3.1 접속이온빔-주사전자현미경(FIB-SEM) 43
• 2.3.3.2 에너지분산 분광기(EDS) 43
• 2.3.3.3 순환 전류 전압법 분석(CV) 43
• 2.3.3.4 정전류 충방전법 분석(GCD) 44
• 2.3.3.5 전기화학 임피던스 분광법(EIS) 44
• 2.4 결과 및 고찰 45
• 2.4.1 CNT/PEG-CQDs 45
• 2.4.2 CNT/PEG-CQDs/Silane 전극 47
• 2.4.3 전기화학적 성능 평가 52
• 2.5 결론 60
• 3. 결론 62
• 4. 참고문헌 63