Stretchable Lithium Metal Anode with Improved Mechanical and Electrochemical Cycling Stability

Stretchable batteries are key components of stretchable/flexible electronic devices. However, they typically exhibit low energy density due to the low lithium storage capability. Lithium (Li) metal is the ideal anode material, but it is ductile and the unstable electrochemical performance further hinders its practical applications. Herein, for the first time, a stretchable Li metal anode with stable mechanical and electrochemical performance is fabricated. It consists of one-entity 3D-patterned Li metal microdomains connected by highly elastic polymer rubbers. Upon stretching, the rubber absorbs the mechanical energy while the electroactive Li domains are not mechanically strained. Moreover, the whole electrode is fabricated by simply winding one single Cu wire, which is facile and cost-effective. The stretchable Li metal anode is a key step in the development of novel stretchable “lithium batteries” rather than traditional stretchable “lithium-ion batteries” to boost the energy density of stretchable energy-storage devices.