# Formation and Discharge of Zn Sponge Anodes, Followed by Synchrotron Hard X‑ray Imaging

## TL;DR

This paper studies how zinc sponge anodes are formed and discharged using advanced X-ray imaging to improve battery electrode performance.

## Contribution

The study introduces a method combining electrochemistry and synchrotron X-ray imaging to optimize formation of Zn sponge anodes.

## Key findings

- Formation conditions were optimized to prevent hydrogen-induced damage to the sponge structure.
- Time-lapse tomography revealed early structural evolution and Zn/ZnO phase distribution during formation and discharge.

## Abstract

The fabrication of engineered Zn anodes often relies
on different
forms of ZnO as the material in direct contact with the alkaline aqueous
electrolyte in the pristine assembled cell state. Of course, in this
case, the as-assembled cell is in the discharged state and requires
an initial charging step, or “formation”, to generate
active metallic Zn. The formation of ZnO-based anodes is a complex
process the control of which calls for an in-depth understanding of
electrochemical phase growth. In fact, formation gives rise to morphochemical
imprinting, profoundly impacting the electrode functional performance.
The present work contributes to the understanding of the formation
of Zn sponge electrodes, combining electrochemistry and synchrotron-based
X-ray imaging. Specifically, we employed dynamic in operando radiography to select the potentiostatic formation conditions that
exclude hydrogen-induced damaging of the sponge structure. Subsequently,
formation and the subsequent first discharge are followed by time-lapse in situ tomography, allowing to track the early structural
evolution of the sponge electrode and the Zn/ZnO phase distribution.