Application of Nondestructive Testing Technology in Device‐Scale for Lithium‐Ion Batteries

Lithium‐ion batteries (LIBs), due to their high energy density and long cycling life have been widely applied in a variety of industries, including electric vehicles, small‐ and medium‐sized electronic devices, and intelligent medical care. Nevertheless, the security and real‐time state of LIBs is difficult to obtain accurately, improving the battery's service life and ensuring battery safety have become the focus of research. Nondestructive testing (NDT) technology has developed quickly to reach this purpose, requiring a thorough investigation of how batteries’ internal structures have evolved. The principles, contributing factors, and applications of various widely used NDT techniques are summarized and discussed in this review. These inspection techniques can be used to evaluate the battery condition, observe the internal structure of the battery, analyze the failure phenomenon and electrochemical performance of the battery operation, etc. Finally, a summary and outlook are given regarding the characteristics and prospects of NDT methods. This overview will show new light on the application of NDT technology for LIBs and will promote the development of next‐generation LIBs with high security

Recent Progress of Promising Cathode Candidates for Sodium‐Ion Batteries: Current Issues, Strategy, Challenge, and Prospects

Lithium‐ion batteries (LIBs) have dominated the secondary batteries market in the past few decades. However, their widespread application is seriously hampered by the limited lithium resource and high cost. Recently, sodium‐ion batteries (SIBs) have generated significant attention because of their characteristics of abundant raw sources, low cost, and similar “rocking chair” mechanism with LIBs, which hold great application potential in large‐scale energy storage. Cathode materials with excellent electrochemical performance are in urgent demand for next‐generation SIBs. Herein, this review provides a comprehensive overview of the recent advances of the most promising SIBs cathode candidates, including layered oxides, polyanionic materials, and Prussian blue analogues. The currently existing issues that need to be addressed for these cathodes are pointed out, such as insufficient energy density, low electron conductivity, air sensitivity, and so on. This review also details the structural characteristics of these three cathode candidates. Moreover, the recent optimization strategies for improving the electrochemical performance are summarized, including element doping, morphology modification, structure architecture, and so on. Finally, the current research status and proposed future developmental directions of these three cathode materials are concluded. This review aims to provide practical guidance for the development of cathode materials for next‐generation SIBs