| 학회 | 한국재료학회 |
| 학술대회 | 2018년 가을 (11/07 ~ 11/09, 여수 디오션리조트) |
| 권호 | 24권 2호 |
| 발표분야 | C. 에너지 재료 분과 |
| 제목 | Observation of structural degradation for the solid electrolyte in the seawater battery system |
| 초록 | Aqueous rechargeable sodium-ion batteries so-called 'seawater batteries' can be operated in seawater, which serves as a catholyte in the system, likewise the hybrid characteristics of air-batteries. Among the components of the 'seawater batteries', the NASICON (Na Super Ionic CONductor) is the most important part as a role of the electrolyte to transfer Na+ ions and to separate sodium metal and seawater. Therefore, the NASICON should be chemically and physically stable during the electrochemical reaction when the battery is operating. Here, we have analyzed the degradation of the NASICON after the battery cycling in various conditions, such as high current density and low pH of seawater. When seawater batteries are charging or discharging, the by-products of HCl and NaOH are produced at the interface of the NASICON. These products are considered as the cause of degradation of the NASICON. In particular, we have found the phase transition and the minor phase dissolution by the change of the grain boundaries in the electrolyte at the seawater side after charge process. Na+ concentration at the interface changes slightly lower than the inner part after the electrochemical reaction. To confirm the durable mechanical properties of the solid electrolyte, the hardness test was measured to in the pristine and cycled samples. We have also characterized the ion concentration of the seawater after the cycling and XPS analysis to correlate with the structural and chemical data. |
| 저자 | 이찬희, 위태웅, 김영식, 이현욱 |
| 소속 | 울산과학기술원 에너지공학과 |
| 키워드 | <P>Seawater batteries; solid electrolyte; NASICON; structural degradation</P> |
