Superior plating/stripping performance through constructing an artificial interphase layer on metallic Mg anode

Rechargeable magnesium batteries(RMBs)have attracted tremendous attention in energy storage ap-plications in term of high abundance,high specific capacity and remarkable safety of metallic magne-sium(Mg)anode.However,a serious passivation of Mg anode in the conventional electrolytes leads to extremely poor plating/stripping performance,further hindering its applications.Herein,we propose a convenient method to construct an artificial interphase layer on Mg anode by substitution and alloy-ing reactions between SbCl_(3) and Mg.This Sb-based artificial interphase layer containing mainly MgCl_(2) and Mg_(3) Sb_(2) endows the significantly improved interfacial kinetics and electrochemical performance of Mg anode.The overpotential of Mg plating/stripping in conventional Mg(TFSI)2/DME electrolytes is vastly reduced from over 2 V to 0.25-0.3 V.Combining experiments and calculations,we demonstrate that un-der the uniform distribution of MgCl_(2) and Mg_(3) Sb_(2),an electric field with a favorable potential gradient is formed on the anode surface,which enables swift Mg^(2+)migration.Meanwhile,this layer can inhibit the decomposition of electrolytes to protect anode.This work provides an in-depth exploration of the artificial solid-electrolyte interface(SEI)construction,and a more achievable and safe path to realize the application of metallic Mg anode in RMBs.

Magnesium alloys as anodes for neutral aqueous magnesium-air batteries

Magnesium(Mg)is abundant,green and low-cost element.Magnesium-air(Mg-air)battery has been used as disposable lighting power supply,emergency and reserve batteries.It is also one of the potential electrical energy storage devices for future electric vehicles(EVs)and portable electronic devices,because of its high theoretical energy density(6.8 k Wh·kg^(-1))and environmental-friendliness.However,the practical application of Mg-air batteries is limited due to the low anodic efficiency of Mg metal anode and sluggish oxygen reduction reaction of air cathode.Mg metal as an anode material is facing two main challenges:high self-corrosion rate and formation of a passivation layer Mg(OH)_(2)which reduces the active surface area.In last decades,a number of Mg alloys,including Mg-Ca,Mg-Zn,commercial Mg-Al-Zn,Mg-Al-Mn,and Mg-Al-Pb alloys,have been studied as anode materials for Mg-air batteries.This article reviews the effect of alloying elements on the battery discharge properties of Mg alloy anodes.The challenges of Mg-air batteries are also discussed,aiming to provide a depth understanding for the theoretical and practical development of high-performance Mg-air batteries.

On the bramble way to Mg metal anodes in secondary Mg ion batteries

As a prospective alternative to lithium-ion batteries,rechargeable magnesium metal batteries(RMBs)have many unparalleled advantages,including direct use of Mg metal as the electrode;large nature abundance;intrinsically safe merits;high theoretical volumetric capacity.Nonetheless,there exist a large number of challenges on electrodes for their applications.Among them,surface passivation,uneven deposition/dissolution,and corrosion are critical issues that severely hinder the development of Mg anodes in RMBs.This review gives a specific comprehensive,and in-depth summary of mechanisms relative to these problems.Subsequently,it displays the protection progresses of the Mg metal anode via three-dimensional host nanostructure fabrication,Mg alloys anode design,current collector modification,artificial solid-electrolyte interphase construction,and electrolyte optimization.Finally,future perspectives and outlooks in developing the other blossom of these strategies for rechargeable Mg batteries are also discussed.This overview provides significant guidance for designing and fabricating high-performance Mg metal anodes in secondary Mg batteries and boosting their commercial applications.