Robust silver nanowire membrane with high porosity to construct stable Li metal anodes

Abstract

Silver is a promising candidate component in the fabrication of Li metal anodes. While most efforts are focused on performance improvement via regulating the lithiophilicity of Ag-based electrodes, the detailed lithiation behavior of Ag nanoparticles is another key research topic for the rational design of Li–Ag anodes. In this work, we report the fabrication of Ag nanowire (AgNW) membranes to examine their electrochemical alloying process in Li cells. The robust and compact membranes show high porosity up to 90% with tunable thickness of 1–10 μm, thus facilitating lithiation reactions as well as accommodating the subsequently deposited Li. Electrochemical tests reveal compositions and phases of lithiated AgNWs can be varied depending on external current, and the electrochemically formed Li–Ag interfaces effectively guide uniform Li deposition from both experimental and theoretical analyses. Full cells composed with thin Li-AgNW composite anodes (10 mAh/cm2) and high-loading LiFePO4 cathodes (12 mg/cm2) also demonstrate stable life over 150 cycles. These findings provide insight into fundamental Ag electrochemistry in Li cells and meanwhile highlight the great potentials of Ag-based Li anodes for practical applications.