Large-scale synthesis of Ag–Si core–shell nanowall arrays as high-performance anode materials of Li-ion batteries

Abstract

We demonstrate the synthesis of Ag–Si core–shell nanowall arrays via a simple displacement reaction and subsequent RF-sputtering deposition. The displacement between the Cu substrate and Ag⁺ leads to Ag nanowall arrays with good substrate adhesion. The Ag nanowall arrays can function as a mechanical support and an efficient electron conducting pathway for Si anode materials. These Ag–Si core–shell nanowall arrays show a discharge capacity of >1500 mA h g⁻¹ at a current density of 2100 mA g⁻¹ after 400 cycles. The capacity fade from 2^nd to 400^th cycles is only 0.1% per cycle. Moreover, cycling performance can be retained when the thickness of the Si layer increases, clearly demonstrating the superior cycling performance of Ag–Si core–shell nanowall arrays. Considering the simple and large-scale synthesis of Ag–Si core–shell nanowall arrays, this work may facilitate the commercial application of Si anode materials for Li-ion batteries.