FePO4∙2H2O 전구체를 이용한 LiFePO4 양극소재의 합성 및 전기화학적 특성에 관한 연구
- 주제(키워드) 리튬이온전지
- 발행기관 고려대학교 대학원
- 지도교수 변동진
- 발행년도 2014
- 학위수여년월 2014. 2
- 학위구분 석사
- 학과 일반대학원 신소재공학과
- 원문페이지 62 p
- 실제URI http://www.dcollection.net/handler/korea/000000049434
- 본문언어 한국어
- 제출원본 000045793444
초록/요약
During the past decade, lithium ion batteries have been investigated and widely used as the main rechargeable power sources and the needs of lithium-ion batteries have gained the most interests in emerging energy devices such as electric vehicles (EVs) and energy storage system (ESS). Among many cathode candidates for the automotive applications, LiFePO4 electrode materials are being studied intensively because of their advantages in safety, thermal stability, and high current rate capability. LiCoO2 is still commercialized cathode material of lithium ion batteries due to its excellent electrochemical properties. The high cost and inherent toxicity of this material, however, have led to the intensive investigations on the possible alternatives during the last decade. In the work, a novel process route to synthesize LiFePO4/C electrode materials is proposed. First, a new strategy to synthesize the LiFePO4/C cathode materials from a precursor of a crystalline FePO4∙2H2O, the solution precipitation route is adapted, where the reaction conditions such as temperature and pH are precisely controlled. Among various heat treatment temperatures to calcinate our prepared FePO4∙2H2O with the lithium sources, we find that the LiFePO4/C cathode materials synthesized at 700°C deliver a maximum discharge capacity of 168.51 mAh g-1 at 0.1 C (1 C rate = 170 mAh g-1), as well as with the capacity retention of 99.36 % after the 25th cycle at 1 C.
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목 차
제 1 장 서 론………………………………………………… 1
1.1 리튬이온전지의 특징 및 원리…………………… 1
1.2 양극 물질 (Cathode materials)………………… 9
1.3 음극 물질 (Anode Materials)………………… 16
1.4 전해질 (Electrolytes)……………………………20
1.5 분리막 (Separator)………………………………23
제 2 장 실험 방법……………………………………………… 24
2.1 합성 방법………………………………………… 24
2.1.1 공침 합성공정을 통한 FePO4·2H2O 합성…………………………………………………24
2.1.2 기계화학적 합성공정을 통한 LiFePO4/C 합성………………………………………………… 25
2.2 특성 분석……………………………………… 26
2.2.1 X-선 회절 분석…………………………………………………………………… 26
2.2.2 주사전자현미경 분석…………………………………………………………………… 26
2.2.3 투과전자현미경 분석…………………………………………………………………… 27
2.2.4 X-선 광전자 분광법 분석……………………………………………………………………27
2.2.5 뫼스바우어 분석……………………………………………………………………27
2.3 전기 화학 특성…………………………………… 27
제 3 장 결과 및 고찰…………………………………………… 29
3.1 합성공정을 통해 제조된 양극 물질의 구조 특성…………………………………………………………… 29
3.2 합성공정을 통해 제조된 양극 물질의 표면 특성……………………………………………………………… 33
3.3 합성공정을 통해 제조된 양극 물질의 화학적 특성……………………………………………………………………39
3.3 전기화학적 특성……………………………………………………………………43
제 4 장 결 론 ……………………………………………50
참고 문헌……………………………………………………… 51
