In-situ and real time study of SEI formation on anode in a Lithium battery cell using atomic force micrscope

S. Xu
Keysight Technologies,
United States

Keywords: SEI, AFM, lithium battery

Summary:

Atomic force microscope is a very powerful tool to study electrochemistry reaction in-situ and in real time. This technology is capable of resolve high resolution topography changes on an electrode inside an electrochemistry cell while the cell is under potential control. Lithium battery research attracts great interest because of its performance and durability characteristics. Study lithium battery electrode using in-situ atomic force microscope, however, has its unique set of problems. The cathode material Lithium is a highly active metal and will oxidize when exposed to trace amount of oxygen and moisture. It is also a very soft metal and difficult to be shaped into an electrode. So here are the challenges: 1. An AFM need to be operated with its sample under environmental protection. 2. An electrochemistry cell need to be constructed inside a glove box where there is no small tools allowed. 3. AFM instrument need to be noise isolated inside a very confined space of glove box. In this lecture, we will discuss the solutions to all these problems and we will present the data obtained with an in-situ atomic force microscope with topography change and SEI formation on HOPG anode inside an Lithium battery cell. An interesting two layered structure was observed with the experimental set up, and we also discover a frequently ignored factor in most of the other in-situ AFM imaging of SEI formation in a charging / discharging circle of a lithium battery: the temperature. The last part of the presentation we will touch some of the basic concept of 3D desktop manufacturing and how these newly developed tools helped us to solve practical problems in the AFM modification for Lithium battery research. The latest desktop manufacturing tools and software bring new ideas and capabilities to research experiments.