Next-Generation Mg-Ion Batteries Design: Do Cl- anions favour the Mg2+ deposition?

COLOMBO, ESTEFANIA; BELLETTI, GUSTAVO; NAZMUTDINOV, RENAT; SCHMICKLER, WOLFGANG; QUAINO, PAOLA

JOURNAL OF PHYSICS CONDENSED MATTER

IOP PUBLISHING LTD

Año: 2025

0953-8984

Understanding the behavior of Mg(II) complexes in chloride-containing environments is essential for advancing magnesium-based electrochemical systems. In this study, we propose a model to elucidate the fundamental behavior of Mg(II) complexes near a pristine Mg(0001) surface in tetrahydrofuran (THF), with a focus on the role of Cl− anions. We investigate the stability and deposition behavior of three representative coordination species: [Mg(THF)5 ]2+, [MgCl(THF)3]+, and [MgCl2(THF)2]. Our findings demonstrate that Cl− shifts deposition potentials without significantly affecting kinetics at high concentrations, while trace amounts of Cl− may slightly inhibit deposition. The proposed mechanism provides new insights into the speciation and electrochemical behavior of Mg(II) in chloride-containing THF, contributing to the development of more efficient Mg battery electrolytes.