Work

Prelithiation of silicon thin film anodes using ion implantation for lithium ion batteries

Year: 2025

Type: article

Abstract: Silicon is the most promising anode material for lithium ion batteries (LIBs) because of its high theoretical specific capacity of 3590 mAhg-1 in the Li3.73Si phase at room temperature. However, two important issues such as volume expansion after the lithiation and the growth of a solid electrolyte interface during the cycling on the anodic side hinder the full use of Si as a negative electrode in modern LIBs. Here, we prelithiate the Si thin film on Cu foil using Li+ ion implantation at room temperature with a fluence of 1016 ions/ cm2 and three implantation energies of 1, 2 and 3 keV in order to achieve different depth profiles. The ion implantation enables a high controllability and homogeneity of the Li ion profile in the near surface region of the Si anode. Using both a half and full cell configuration versus lithium nickel cobalt aluminum oxide (NCA) in combination with a liquid electrolyte (1 M LiPF6, EC:DMC 1:1 and 2 wt% of FEC), the implanted Si anodes were cycled and compared to pure amorphous Si. The morphology and the structure of the Si anodes are investigated using scanning electron microscopy (SEM) and x-ray diffraction (XRD). Depth profiles of the implanted Li+ in the Si anode obtained by elastic recoil detection analysis (ERDA) reveal that the distribution of the implanted Li+ extends from the surface to a depth of ca. 80 nm (deeper than predicted by simulations), which is caused by the roughness of the Cu foil.

Source: Electrochemistry Communications

DOI: 10.1016/j.elecom.2025.108089