Atomic Interface Engineering of Battery Current Collectors via Ion Implantation

TL;DR

This paper introduces a scalable ion implantation method to create a clean, oxidation-resistant copper interface for lithium metal batteries, improving performance and cycle life by controlling interfacial chemistry.

Contribution

It develops a novel ion implantation technique to engineer copper interfaces, removing native oxides and introducing vacancy clusters to enhance battery stability.

Findings

Achieved 99.0% Coulombic efficiency over 400 cycles

Suppressed reoxidation and parasitic reactions

Enabled uniform lithium deposition

Abstract

Atomic interface engineering (AIE) is critical for advancing technologies in energy storage, catalysis, and microelectronics. In anode-less lithium metal batteries (ALLMBs), AIE is essential for controlling interfacial chemistry governing lithium deposition and solid electrolyte interphase (SEI) formation on copper current collectors. However, native copper surfaces readily oxidize, forming electronically insulating oxides that degrade performance and obscure failure mechanisms. Here, we report a scalable ion implantation strategy to create an atomically clean and robust copper interface. By implanting copper ions into commercial foils, we simultaneously remove the native oxide and introduce subsurface vacancy clusters that act as oxygen traps, yielding an oxidation-resistant and conductive surface. Experimental characterization and multiscale simulations reveal that these engineered vacancies suppress reoxidation and guide the formation of an ultrathin Li2O-enriched solid electrolyte interphase. When applied in ALLMBs, the current collectors enable uniform lithium deposition, suppress parasitic reactions, and deliver a Coulombic efficiency of 99.0% over 400 cycles under lean electrolyte conditions. This work presents a generalizable and industry-compatible approach for stabilizing electrochemical interfaces.