Speaker
Description
Alkali metal (Li/Na) batteries are strong candidates for next-generation high-capacity energy storage due to their high theoretical specific capacities (Li: 3860 mAh g⁻¹; Na: 1166 mAh g⁻¹) and low reduction potentials. However, uncontrolled dendrite propagation during cycling remains a key barrier to commercialization. The solid electrolyte interphase (SEI) — a 10-100 nm layer formed from electrolyte decomposition at the anode/electrolyte interface — regulates ion transport and dendrite suppression [1]. Conventional ex-situ techniques (e.g., TEM, XPS) reveal the SEI’s bilayer, mosaic-like structure (dense inorganic inner layer [MF, MxOy, M2CO3] and porous organic matrix) [2], but cannot capture SEI evolution dynamics during cell operation.
In this work, we aim to establish real-time correlations between interfacial nanoscale structural evolution and applied potential by coupling synchrotron grazing-incidence wide-angle/small-angle X-ray scattering (GIWAXS/GISAXS) with the electrochemical cycling of Li/Na battery cells. Several Li- and Na-based electrolytes with varying chemistries were tested to ensure a diverse range of studied SEI. For all analyzed samples, GIWAXS revealed no presence of crystalline phases in the formed SEI, while the evolution of amorphous components, correlated with electrochemical reactions, is evident. Simultaneously, the analysis of GISAXS patterns allowed us to gain further insight into the morphology of the as-formed thin layers.
This work establishes operando X-ray scattering as a useful tool for correlating electrochemical conditions with SEI formation processes, providing mechanistic insights into interfacial stabilization strategies for anode-less battery architectures.
References
[1] H. Adenusi, G.A. Chass, S. Passerini, K. V. Tian, G. Chen, Adv. Energy Mater. 13 (2023).
[2] J. Tan, L. Ma, Z. Li, Y. Wang, M. Ye, J. Shen, Mater. Today. 69 (2023) 287–332.
Acknowledgments
This work was partially supported by the Wallenberg Initiative Materials Science for Sustainability (WISE) funded by the Knut and Alice Wallenberg Foundation. Beamtime at the ESRF was granted within the European Battery Hub MA-6230.
