December 2018 - High-energy rechargeable lithium metal batteries have been intensively revisited in recent years. As more researchers start to use pouch cell as the platform to study the fundamentals at relevant scales, safe testing and handling of high-energy lithium metal batteries becomes critical but has not been well discussed so far. Cautions and safety procedures need to be taken when handling cycled pouch cells with pulverized lithium particles inside. From cell design, electrode preparation, cell fabrication to testing procedure, this work discusses all possible root causes that may initiate cell internal shorting and raise safety concerns. Safe transfer and disposal of cycled pouch cells are also discussed. The insights provided in this article are also applicable for the research on high-energy lithium-ion batteries to inspire more safety strategies to accelerate research innovation by using large-format batteries as the testing vehicle and conduct the research safely.