Understanding the Electrochemical Window of Solid-State Electrolyte in Full Battery Application

In recent years, solid-state Li batteries (SSLBs) have emerged as a promising solution to address the safety concerns associated. However, the limited electrochemical window (ECW) of solid-state electrolytes (SEs) remains a critical constraint full battery application. Understanding the factors that influence the ECW is an essential step toward designing more robust and high-performance electrochemical systems. This review provides a detailed classification of the various "windows" of SEs and a comprehensive understanding of the associated interfacial stability of SEs in full battery application. The paper begins with a historical overview of SE development, followed by a detailed discussion of their structural characteristics. Next, examination of various methodologies used to calculate and measure the ECW is presented, culminating in the proposal of standardized testing procedures. Furthermore, a comprehensive analysis of the numerous parameters that influence the thermodynamic ECW of SEs is provided, along with a synthesis of strategies to address these challenges. At last, this review concludes with an in-depth exploration of the interfacial issues associated with SEs exhibiting narrow ECWs in full SSLBs.