Showing papers by "Dominique Larcher published in 2022"
TL;DR: In this paper , optical reflectometry is used to image and quantitatively monitor the MnO2 electrode's charge and discharge in situ and under operation, providing a comprehensive picture of the mechanism at play in aqueous Zn-MnO2 batteries.
Abstract: Energy storage provides flexibility to an energy system and is therefore key for the incorporation of renewable energy sources such as wind and solar into the grid. Aqueous Zn–MnO2 batteries are promising candidates for grid‐scale applications due to their high theoretical capacity (616 mAh g–1) and the abundance of their components in the Earth's crust. However, they suffer from low cyclability, which is probably linked to the dramatic pH variations induced by the electrochemical conversion of MnO2. These pH variations are known to trigger the precipitation/dissolution of zinc hydroxide sulfate (Zn4(OH)6SO4 . xH2O, (ZHS)), which might have an influence on the conversion of MnO2. Herein, optical reflectometry is used to image and quantitatively monitor the MnO2 electrode's charge and discharge in situ and under operation. It emphasizes how solid‐phase ZHS rules the dynamics of both charge and discharge, providing a comprehensive picture of the mechanism at play in aqueous Zn–MnO2 batteries. If the precipitation of ZHS might impede the MnO2 electrode's discharge, it is a crucial pH buffer delaying the occurrence of the competing oxidation of water on charge.
17 citations
TL;DR: In this article , the authors revisited the Zn-MnO2 chemistry by combining fundamental solution chemistry considerations and complementary analytical techniques (TEM, Raman spectroscopy and EQCM) together with the assembly of cells using either MnO2 or MnO 2-free initial positive electrodes.
8 citations
TL;DR: The charge storage at the MnO2 electrode remains a mystery, delaying real-life applications as mentioned in this paper , and Frédéric Kanoufi and co-workers shine light on its mechanism using optical microscopy.
Abstract: Zn–MnO2 Batteries With a high theoretical gravimetric capacity, intrinsic safety, and low cost, aqueous Zn–MnO2 batteries are promising candidates for grid-scale energy storage. However, the charge storage at the MnO2 electrode remains a mystery, delaying real-life applications. In article number 2200722, Frédéric Kanoufi and co-workers shine light on its mechanism using optical microscopy.