Work

A CaI2‐Based Electrolyte Enabled by Borate Ester Anion Receptors for Reversible Ca−Organic and Ca−Se Batteries

Year: 2024

Type: article

Abstract: Passivating solid electrolyte interphases (SEIs) in Ca metal anodes constitute a long‐standing challenge, as they block Ca2+ transport and inhibit reversible Ca deposition/stripping. Current solutions focus primarily on boron/aluminum‐based electrolytes to mitigate such interfacial issues by producing Ca2+‐conductive species, yet the complex synthetic procedure of these salts restricts the widespread application. Moreover, whether any inorganic phases possess decent Ca2+ conductivity within SEIs remains ambiguous. Herein, we report that a commercially available CaI2‐dimethoxyethane electrolyte supports reversible Ca/Ca2+ redox reactions via forming CaI2‐involved SEI, inspired by our density functional theory calculations where CaI2 species is predicted to possess the lowest Ca2+ diffusion barrier among a range of inorganic phases. We further materialize this finding by introducing a serial of borate ester anion receptors, resulting in the formation of CaI2/borides hybrid SEIs with an enhanced Ca2+ conductivity. Consequently, the resultant electrolytes realize a 7‐fold reduction in deposition/stripping overpotential compared to anion receptor‐free one, allowing for the construction of reversible Ca‐metal full cells with high‐capacity selenium and organic cathodes.

Source: Angewandte Chemie

DOI: 10.1002/ange.202413416

Authors: Zhen Hou, Rui Zhou, Kai Liu, Junwu Zhu, Biao Zhang

Institutions: Hong Kong Polytechnic University, Nanjing University of Science and Technology

Language: English

Topic: Advanced Battery Materials and Technologies

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $5,250