TY - JOUR
T1 - In situ visualizing the interplay between the separator and potassium dendrite growth by synchrotron X-ray tomography
AU - Ni, Ling
AU - Osenberg, Markus
AU - Liu, Haijun
AU - Hilger, André
AU - Chen, Libao
AU - Zhou, Dong
AU - Dong, Kang
AU - Arlt, Tobias
AU - Yao, Xiayin
AU - Wang, Xiaogang
AU - Chen, Yanan
AU - Li, Yutao
AU - Zhao, Kangning
AU - Yang, Chao
AU - Manke, Ingo
AU - Sun, Fu
AU - Chen, Renjie
N1 - Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/5
Y1 - 2021/5
N2 - Rechargeable potassium (K) batteries are a promising next-generation technology for low-cost grid scale energy storage applications. Nevertheless, the undesirable interfacial instabilities originating from the interplay between the employed separators and electrodes largely compromise the battery's performance, and the underlying mechanism of which remains elusive. Herein, the interfacial stability between three types of commercial separators (Celgard 2325, Celgard 2400 and GF/D) and the K electrodeposits is investigated in K|K symmetric cells via in-situ Synchrotron X-ray tomography technique. It is demonstrated that the cell built with a Celgard 2400 separator can achieve a stable cycling performance due to its high mechanical strength and integrity along the thickness direction, thus alleviating the K dendrites growth. In contrast, a GF/D membrane of low mechanical cohesion and excessive porosity is found to be easily deformed and filled with deciduous potassium dendritic aggregates during battery cycling. Similarly, the tri-layer Celgard 2325 separators, which are weakly bonded by interlaminar forces, are found to be severely delaminated by the overgrowth of K dendrites. Furthermore, it is revealed that the delamination failure behaviors of Celgard 2325 is driven by the local stress induced by the spatially and heterogeneously formed “dead” K dendrites. Our work provides direct visualization of morphological evolvement of the separators in presence of potassium dendrites in K|K symmetric cells and highlights the significance of mechanical cohesion, porosity distribution and mechanical integrity of separators in dictating the battery's performance under realistic battery operation conditions. As a result, these discoveries provide an in-depth understanding that is needed to design next-generation high performance separators to mitigate the formation of potassium dendrite in KMBs.
AB - Rechargeable potassium (K) batteries are a promising next-generation technology for low-cost grid scale energy storage applications. Nevertheless, the undesirable interfacial instabilities originating from the interplay between the employed separators and electrodes largely compromise the battery's performance, and the underlying mechanism of which remains elusive. Herein, the interfacial stability between three types of commercial separators (Celgard 2325, Celgard 2400 and GF/D) and the K electrodeposits is investigated in K|K symmetric cells via in-situ Synchrotron X-ray tomography technique. It is demonstrated that the cell built with a Celgard 2400 separator can achieve a stable cycling performance due to its high mechanical strength and integrity along the thickness direction, thus alleviating the K dendrites growth. In contrast, a GF/D membrane of low mechanical cohesion and excessive porosity is found to be easily deformed and filled with deciduous potassium dendritic aggregates during battery cycling. Similarly, the tri-layer Celgard 2325 separators, which are weakly bonded by interlaminar forces, are found to be severely delaminated by the overgrowth of K dendrites. Furthermore, it is revealed that the delamination failure behaviors of Celgard 2325 is driven by the local stress induced by the spatially and heterogeneously formed “dead” K dendrites. Our work provides direct visualization of morphological evolvement of the separators in presence of potassium dendrites in K|K symmetric cells and highlights the significance of mechanical cohesion, porosity distribution and mechanical integrity of separators in dictating the battery's performance under realistic battery operation conditions. As a result, these discoveries provide an in-depth understanding that is needed to design next-generation high performance separators to mitigate the formation of potassium dendrite in KMBs.
KW - Bulky potassium deposition
KW - High mechanical separator
KW - Potassium metal anode
KW - Synchrotron X-ray Tomography
UR - http://www.scopus.com/inward/record.url?scp=85100218010&partnerID=8YFLogxK
U2 - 10.1016/j.nanoen.2021.105841
DO - 10.1016/j.nanoen.2021.105841
M3 - Article
AN - SCOPUS:85100218010
SN - 2211-2855
VL - 83
JO - Nano Energy
JF - Nano Energy
M1 - 105841
ER -