Understanding the Electrochemical Behavior of Multi-Component Aluminum-Based Foils As Anodes for Lithium-Ion Batteries

Abstract

Alloy anodes are promising materials for next-generation lithium batteries. The intrinsic properties of aluminum, such as high capacity, light weight, earth abundance, and low cost, make it a competitive alloy anode candidate in lithium batteries. Furthermore, the ability to readily manufacture aluminum-based foils is an advantage for potentially simplifying battery manufacturing processes. However, utilization of Al anodes is not yet fully practical due to the capacity fading during charge and discharge. To improve cycling performance, here we fabricate aluminum alloys and composite foil structures and investigate their reversibility for Li storage in Li-ion batteries. Alloy foils including Al-Sn, Al-Zn, and Al-In were fabricated with contents ranging from 50 to 99 atomic % Al, and the electrochemical behavior of these materials as anodes for Li-ion batteries were investigated. With these materials, we studied the effects of composition, structure, and morphology on the cycling performance of the alloy foils using battery-relevant capacity metrics (areal capacity of > 2 mAh/cm2 with foil thickness < 50 microns). We show that the composition of the foils plays a significant role in determining the electrochemical cycling capability of these foils. Furthermore, the foil processing characteristics are also important in determining the achievable specific capacity, rate behavior, and cycle life of these foils anodes. This effort indicates the promise of foil-based alloy anodes and provides guidance toward engineering strategies to improve performance.