A Mechanical Engineering Approach Toward Practical Calcium Metal Anodes with Improved Electrochemical Performance

Rechargeable calcium (Ca) metal batteries present an exciting opportunity for electrochemical systems offering high energy density at low costs. Although Ca possesses intrinsic advantages as a metal anode, the feasibility of fabricating thin Ca metal foils for use as practical electrodes remains unexplored. This represents a critical objective for the realization of Ca metal batteries, while it currently limits the research progress in this area. In this study, we introduce a straightforward and effective method for producing Ca foils with a thickness of approximately 100 µm from inexpensive Ca metal chunks. Additionally, we demonstrate that mechanical deformation of Ca can induce alterations in hardness, structural features, and electrochemical properties. The as‐prepared Ca foils exhibit enhanced electrochemical performance underscoring that mechanical processing is a key parameter controlling the electrochemical reliability of Ca metal anodes and provides a scalable pathway toward more practical Ca metal battery architectures. This processing method could significantly contribute to the advancement of the research and development of Ca batteries.