In Situ Formed Magnesiophilic Sites Guiding Uniform Deposition for Stable Magnesium Metal Anodes

Abstract

Owing to its high volumetric capacity and natural abundance, magnesium (Mg) metal has attracted tremendous attention as an ideal anode material for rechargeable Mg batteries. Despite Mg deposition playing an integral role in determining the cycling lifespan, its exact behavior is not clearly understood yet. Herein, for the first time, we introduce a facile approach to build magnesiophilic In/MgIn sites in situ on a Mg metal surface using InCl3 electrolyte additive for rechargeable Mg batteries. These magnesiophilic sites can regulate Mg deposition behaviors by homogenizing the distributions of Mg-ion flux and electric field at the electrode–electrolyte interphase, allowing flat and compact Mg deposition to inhibit short-circuiting. The as-designed Mg metal batteries achieve a stable cycling lifespan of 340 h at 1.0 mA cm–2 and 1.0 mAh cm–2 using Celgard separators, while the full cell coupled with Mo6S8 cathode maintains a high capacity retention of 95.5% over 800 cycles at 1 C.

Hybrid Polymer-Alloy-Fluoride Interphase Enabling Fast Ion Transport Kinetics for Low-Temperature Lithium Metal Batteries

“…The advantages of the artificial PAF interphase over the electrolyte-derived Li 2 CO 3 -rich native SEI in regulating Li deposition behavior were further validated in a visualized clue by finite element simulation. − As depicted in Figure e and Figure S22, during galvanostatic deposition at a low temperature of −40 °C, a nonuniform Li + concentration can be observed above the vicinity of the pristine Li anode owing to the poor Li affinity and diffusivity of the native SEI. The intense concentration polarization is conducive to triggering the growth of Li dendrites (Figure S23a).…”

Revealing the Interfacial Chemistry of Fluoride Alkyl Magnesium Salts in Magnesium Metal Batteries

“…Compared with MACC electrolyte (Figure S10), they have a single deposition peak, which implies that the irreversible deposition of aluminum is inhibited. Nevertheless, the maximum current density of MTFE and MHFP electrolytes are significantly lower, suggesting that Mg redox kinetics in these electrolytes is slower than in MPFB electrolyte [27d] . In addition, linear sweep voltammetry (LSV) was carried out to check the highest voltage tolerance of these electrolytes (Figure 2d).…”

Realizing horizontal magnesium platelet deposition and suppressed surface passivation for high-performance magnesium metal batteries

“…Generally, the dynamic behaviours of Mg deposition are significantly influenced by the distributions of Mg 2+ flux and electrical field at the interphase between electrode and electrolyte, 49,52 which can be simulated and visualized using the finite element method (FEM) conducted in COMSOL. As shown in Fig.…”