On the unsuspected role of multivalent metal ions on the charge storage of a metal oxide electrode in mild aqueous electrolytes.

ABSTRACT: Insertion mechanisms of multivalent ions in transition metal oxide cathodes are poorly understood and subject to controversy and debate, especially when performed in aqueous electrolytes. To address this issue, we have here investigated the reversible reduction of nanostructured amorphous TiO2 electrodes by spectroelectrochemistry in mild aqueous electrolytes containing either a multivalent metal salt as AlCl3 or a weak organic acid as acetic acid. Our results show that the reversible charge storage in TiO2 is thermodynamically and kinetically indistinguishable when carried out in either an Al3+- or acetic acid-based electrolyte, both leading under similar conditions of pH and concentrations to an almost identical maximal charge storage of ∼115 mA h g-1. These observations are in agreement

SUBMITTER: Kim YS 

PROVIDER: S-EPMC6849641 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature