Failure Mechanisms and Design Strategies for Low-Temperature Solid-State Metal Batteries

Abstract

Solid-state metal batteries (SSMBs), with their high theoretical energy density and inherent safety advantages, are considered to be the ultimate choice for next-generation energy storage systems. Extensive experimental and theoretical research has highlighted the remarkable electrochemical performance of SSMBs under moderate and high temperature conditions. Nevertheless, the transition towards practical implementation is significantly impeded by critical issues that arise specifically in low temperature environments. These include inadequate electrochemical stability, uncontrolled lithium dendrite formation, mechanical degradation of the solid electrolyte interface, and sluggish kinetic processes that limit the overall efficiency and durability of the battery system. In addressing these limitations, this review provides an in-depth analysis of the underlying failure mechanisms that affect SSMBs when operated at suboptimal temperatures. We scrutinize the root causes of these failures, including the impact of thermal contraction and expansion on the electrolyte-electrode contact, the exacerbation of localized stress leading to dendrite formation, and the reduction in ionic conductivity which hampers the overall performance of the battery. Additionally, we discuss the role of interfacial chemistry and the formation of stable solid electrolyte interphase (SEI) at low temperatures, which are pivotal for suppressing side reactions and improving cycle life. Based on these critical assessments, we propose and evaluate various design strategies aimed at enhancing the performance of SSMBs in cold conditions. These strategies encompass the development of novel electrolyte materials with enhanced thermal stability and ionic conductivity, the engineering of advanced electrode architectures to mitigate dendrite growth, and the exploration of alternative current collectors and additives to stabilize the SEI layer. The overarching goal of this review is to stimulate further research efforts dedicated to overcoming the low temperature limitations of SSMBs, thereby paving the way for their widespread adoption and integration into diverse technological applications, ranging from portable electronics to electric vehicles and grid-scale energy storage solutions.