Grant: Research Tools and Instruments

Li-ion batteries (LIBs) are one of the most popular and developed energy storage systems in the past years, particularly for portable electronic devices and even electrical vehicles (EVs). However, the current LIBs cannot meet the increasing demand for safety, lifespan, and high energy density. The solid-state batteries (SSBs) have recently emerged as a promising alternative energy storage system for next-generation EVs due to their ability to overcome the safety concerns presented by the flammable liquid electrolytes, which are used in traditional batteries. The SSBs are expected to achieve greater volumetric energy density and last longer without compromising safety or power. However, there are still big challenges for SSBs towards practical applications. One of the major challenges for the development of high-performance SSBs is the interface stability between the electrodes (cathode and anode) with SSEs. To reveal the chemical and electrochemical stability on the interface, various ex-situ and in-situ characterization methods have been demonstrated. However, there are huge limitations for the current characterization techniques when characterizing the interfacial changes in the SBBs. Most of the ex-situ characterization techniques are destructive and the batteries need to be disassembled for preparing the samples. In addition, most of the in-situ characterization techniques, such as Raman and synchrotron-based X-ray techniques, are carried out in specially designed cells, which cannot reflect the real situation in the batteries. In this proposed research, we request funds to purchase a newly developed ultrasonic battery scanner to carry out the in-situ experiments to study the interface stability for solid-state Li and Na batteries. It will graphically reveal side reactions and structural evolution at the interfaces by probing the trace amount of gas generation or contact loss that can be reflected on the ultrasonic transmission scanning image. The new knowledge will guide the design of stable interfaces for high-performance solid-state batteries.