Critical Current Densities for High-Performance All-Solid-State Li-Metal Batteries: Fundamentals, Mechanisms, Interfaces, Materials, and Applications

All-solid-state lithium batteries (ASSLBs) are considered promisingnext-generation energy storage devices due to their safety and high volumetricenergy densities. However, achieving the key U.S. DOE milestone of a powerdensity of 33 kW L-1appears to be a significant hurdle in current ASSLBs. One ofthe main reasons is that advancements in solid electrolyte (SE) conductivity havebeen prioritized over the critical current density (CCD) when employing anelemental Li anode. Several aspects of Li electrode- and SE interface-baseddifficulties must be resolved before commercialization. Here, we very deeplyanalyze some crucial parameters that effectively restrict Li dendrite formationwhile achieving high CCD. Mechanistic explanations are provided to comprehendthe critical relationship between a cell failure and development of Li dendrites.The latest progress is discussed in achieving higher CCD in emerging SEstructures, including Li-stuffed garnets, Na superionic conductors (NASICONs), Li sulfides, and lithium phosphorusoxynitride (LiPON). Furthermore, primary strategies for improving CCDs by tailoring SE design and stabilizing interfaces areproposed for advanced ASSLBs.

Automated summary

All-solid-state lithium batteries (ASSLBs) are promising energy storage devices with safety and high energy densities. Achieving the desired power density has proven to be difficult due to the prioritization of solid electrolyte conductivity over critical current density. Addressing the challenges related to lithium electrode and solid electrolyte interface is essential for commercialization. This study analyzes key parameters that restrict lithium dendrite formation and discusses recent advances in solid electrolyte structures to improve critical current density in ASSLBs.