当前位置: X-MOL 学术ACS Appl. Energy Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Molten Sodium Penetration in NaSICON Electrolytes at 0.1 A cm–2
ACS Applied Energy Materials ( IF 5.4 ) Pub Date : 2023-02-13 , DOI: 10.1021/acsaem.2c03944
Ryan Hill 1 , Amanda Peretti 2 , Leo J. Small 2 , Erik D. Spoerke 2 , Yang-Tse Cheng 1
Affiliation  

High-conductivity solid electrolytes, such as the Na superionic conductor, NaSICON, are poised to play an increasingly important role in safe, reliable battery-based energy storage, enabling advanced sodium-based batteries. Coupled demands of increased current density (≥0.1 A cm–2) and low-temperature (<200 °C) operation, combined with increased discharge times for long-duration storage (>12 h), challenge the limitations of solid electrolytes. Here, we explore the penetration of molten sodium into NaSICON at high current densities. Previous studies of β″-alumina proposed that Poiseuille pressure-driven cracking (mode I) and recombination of ions and electrons within the solid electrolyte (mode II) are the two main mechanisms for Na penetration, but a comprehensive study of Na penetration in NaSICON is necessary, particularly at high current density. To further understand these modes, this work employs unidirectional galvanostatic testing of Na|NaSICON|Na symmetric cells at 0.1 A cm–2 over 23 h at 110 °C. While galvanostatic testing shows a relatively constant yet increasingly noisy voltage profile, electrochemical impedance spectroscopy (EIS) reveals a significant decrease in cell impedance correlated with significant sodium penetration, as observed in scanning electron microscopy (SEM). Further SEM analysis of sodium accumulation within NaSICON suggests that mode II failure may be far more prevalent than previously considered. Further, these findings suggest that total (dis)charge density (mAh cm–2), as opposed to current density (mA cm–2), may be a more critical parameter when examining solid electrolyte failure, highlighting the challenge of achieving long discharge times in batteries using solid electrolytes. Together, these results provide a better understanding of the limitations of NaSICON solid electrolytes under high current and emphasize the need for improved electrode–electrolyte interfaces.

中文翻译:

0.1 A cm–2 下 NaSICON 电解质中的熔融钠渗透

高电导率固体电解质,如钠超离子导体 NaSICON,有望在安全、可靠的电池储能中发挥越来越重要的作用,从而实现先进的钠基电池。增加电流密度的耦合需求 (≥0.1 A cm –2) 和低温 (<200 °C) 操作,再加上长时间储存​​ (>12 小时) 的放电时间增加,挑战了固体电解质的局限性。在这里,我们探讨了熔融钠在高电流密度下渗透到 NaSICON 中的情况。以往对β″-氧化铝的研究提出泊肃叶压力驱动的开裂(模式I)和固体电解质中离子和电子的复合(模式II)是Na渗透的两个主要机制,但综合研究Na在NaSICON中的渗透是必要的,特别是在高电流密度下。为了进一步了解这些模式,这项工作采用了 0.1 A cm –2下的 Na|NaSICON|Na 对称电池的单向恒电流测试在 110 °C 下超过 23 小时。虽然恒电流测试显示出相对恒定但噪声越来越大的电压曲线,但电化学阻抗谱 (EIS) 显示与显着钠渗透相关的电池阻抗显着降低,如扫描电子显微镜 (SEM) 中所观察到的那样。对 NaSICON 内钠积累的进一步 SEM 分析表明,模式 II 故障可能比以前认为的更为普遍。此外,这些发现表明总(放电)电荷密度(mAh cm –2)与电流密度(mA cm –2), 在检查固体电解质失效时可能是一个更关键的参数,突出了使用固体电解质的电池实现长放电时间的挑战。总之,这些结果使我们更好地理解了 NaSICON 固体电解质在高电流下的局限性,并强调了改进电极-电解质界面的必要性。
更新日期:2023-02-13
down
wechat
bug