Engineering Interfaces for Stable Na Metal Solid-State Batteries

Abstract

Efficient and reversible cycling of alkali metal anodes is a key requirement for achieving high-energy density solid-state batteries [1,2]. While there has been significant interest and research on understanding plating and stripping mechanisms of lithium metal, there has been far less work to understand sodium metal electrode kinetics at solid electrolyte interfaces. Sodium metal is highly reactive with most solid electrolytes which leads to the formation of unstable interphases. These interphases lead to low cycle life and poor power performance. Herein, we study the electrochemical and transport properties of a novel hybrid polymer-Na3SbS4 solid electrolyte. Combining a polymer with a inorganic solid electrolytes provides a way to process thin sodium-ion conducting solid electrolytes at scale and provides a pathway toward tailoring the stability of the solid electrolyte against a alkali metal [3]. A cross-linking approached is utilized to control the structure of the inorganic ionic conductor within the polymer matrix and improve the electrolyte stability. The buried interface is characterized using a suite of in situ imaging techniques to track transformations at the Na-metal interface.[1]Shen, Fengyu, Marm B. Dixit, Xianghui Xiao, and Kelsey B. Hatzell. "Effect of pore connectivity on Li dendrite propagation within LLZO electrolytes observed with synchrotron X-ray tomography." ACS Energy Letters 3, no. 4 (2018): 1056-1061.[2]Zaman, Wahid, Nicholas M. Hortance, Marm B. Dixit, Vincent De Andrande, and Kelsey Bridget Hatzell. "Visualizing percolation and ion transport in hybrid solid electrolytes for Li-metal batteries." Journal of Materials Chemistry A (2019).[3]Dixit, Marm B., Wahid Zaman, Yousuf Bootwala, Yanjie Zheng, Marta C. Hatzell, and Kelsey B. Hatzell. "Scalable manufacturing of hybrid solid electrolytes with interface control." ACS applied materials & interfaces (2019).