Co-sputtering strategy to construct robust sodiophilic interfaces for anode-less sodium metal batteries.

A copper-bismuth composite coating was fabricated by a facile co-sputtering strategy to enhance the sodiophilicity and structural stability of the substrate. The composite coating with lower bismuth content can maintain the sodiophilicity and form a thin and dense SEI during cycling, thus improving the reversibility of the anode-less sodium metal batteries.