Recent Progress on Advanced Imaging Techniques for Lithium‐Ion Batteries

Abstract

Lithium‐ion batteries are the most commercially successful electrochemical devices, extensively used in intelligent electronics, electric vehicles, grid energy storages, etc. However, there still needs to be further improvement of their performance such as in energy density, cyclability, rate capability, and safety. To do so, it is necessary to understand the detailed structural evolution progress inside the battery. Many advanced imaging techniques have been developed to directly monitor the status and get some key information inside the battery. For advanced imaging techniques, superhigh resolution, fully informative function, nondestruction of the sample, and in situ observation are required. This review introduces and discusses some recent important progress on a variety of advanced imaging techniques for battery research. These imaging techniques have enabled the visualization of sub‐micrometer level chemical valence distribution, evolution of solid‐electrolyte interface, Li dendrite growth, and trace amount of gassing, etc., which greatly promote the development of rechargeable batteries. Of particular note, a new ultrasonic imaging technique has been recently developed to monitor gas generation, the electrolyte wetting process, and the state of charge in the battery. Finally, a perspective is given on some future developments in the imaging techniques for Li‐ion batteries and other rechargeable batteries.

Polycationic Polymer Layer for Air‐Stable and Dendrite‐Free Li Metal Anodes in Carbonate Electrolytes

“…Gas generation as a result of parasitic reactions between electrolyte and Li anode is one of major issues of high‐energy LMBs. [ 25 ] To investigate the gassing behavior of LMBs, we carried out ultrasonic transmission mapping using the ultrasonic imaging technique developed by our group. [ 26 ] LFP/Li pouch cell was used for scanning since LFP cathode is usually very stable with no gas generation.…”

From Fundamental Understanding to Engineering Design of High‐Performance Thick Electrodes for Scalable Energy‐Storage Systems

“…Since the architecture of thick electrodes plays a critical role in determining the overall battery performance, characterizing the properties of charge‐transport networks and tracking the reactivity of AMs during cycling are vital to deepen the understanding of the intriguing battery science and to develop systematic approaches toward more predictable performance. [ 52,53 ] Nevertheless, due to the inhomogeneous nature of composite electrodes, normal imaging techniques by sampling at multiple regions inside the electrodes are neither reliable nor efficient to illustrate electrode architectures, and thus could be hardly convincing to correlate with the electrochemical performance. Advanced imaging techniques such as 3D Raman mapping have been used as a nondestructive approach to reveal the 3D spatial distribution of various components within charge‐transport systems.…”

Evaluating Interfacial Stability in Solid-State Pouch Cells Via Ultrasonic Imaging

“…2b and 2d). Such signi cant attenuation of the ultrasonic signal usually indicates the existence of gas 24 . When the ultrasonic wave passes through the interface of two different media, the transmission and re ection ratios can be calculated according to the following formulas 25 , respectively, where Z 1 and Z 2 are the acoustic impedances of the two different media.…”