Pyramid-Patterned Germanium Composite Film Anode for Rechargeable Lithium-Ion Batteries Prepared Using a One-Step Physical Method

Abstract

Using a top-down magnetron sputtering technique with a high deposition-rate, a one-step method for preparing germanium (Ge) hybrid film is presented. At present, graphite film is used as a current collector because it is flexible, self lubricating, and possesses a stress–strain-relieving property. In order to further suppress the volume changes of the Ge, a multilayered electrically conductive nickel film is deposited between multilayered Ge films. The cells are cycled at a current density of 200 mA g−1. An initial discharge and charge capacity of 1180.7 and 949.3 mAh g−1 are achieved by the prepared integrated pyramid patterned Ge composite film anode, respectively. The average capacity was maintained at 580 mAh g−1 after 280 cycles. In the rate capability measurement, the Ge composite demonstrated a reversible capacity of 1163.1 mAh g−1. It is easily made using magnetron sputtering, which is widely accepted in the industry. A physical approach to increase pure Ge’s specific capacity and its cycle life for LIBs is demonstrated in this work.