A Stable Solid Electrolyte Interphase for Magnesium Metal Anode Evolved from a Bulky Anion Lithium Salt.
Rechargeable magnesium (Mg) metal batteries are a promising candidate for "post-Li-ion batteries" due to their high capacity, high abundance, and most importantly, highly reversible and dendrite-free Mg metal anode. However, the formation of passivating surface film rather than Mg2+ -conducting solid electrolyte interphase (SEI) on Mg anode surface has always restricted the development of rechargeable Mg batteries. A stable SEI is constructed on the surface of Mg metal anode by the partial decomposition of a pristine Li electrolyte in the electrochemical process. This Li electrolyte is easily prepared by dissolving lithium tetrakis(hexafluoroisopropyloxy)borate (Li[B(hfip)4 ]) in dimethoxyethane. It is noteworthy that Mg2+ can be directly introduced into this Li electrolyte during the initial electrochemical cycles for in situ forming a hybrid Mg2+ /Li+ electrolyte, and then the cycled electrolyte can conduct Mg-ion smoothly. The existence of this as-formed SEI blocks the further parasitic reaction of Mg metal anode with electrolyte and enables this electrolyte enduring long-term electrochemical cycles stably. This approach of constructing superior SEI on Mg anode surface and exploiting novel Mg electrolyte provides a new avenue for practical application of high-performance rechargeable Mg batteries.
['Tang|Kun|K|', 'Du|Aobing|A|', 'Dong|Shanmu|S|', 'Cui|Zili|Z|', 'Liu|Xin|X|', 'Lu|Chenglong|C|', 'Zhao|Jingwen|J|', 'Zhou|Xinhong|X|', 'Cui|Guanglei|G|https://orcid.org/0000-0001-5987-7569']
solid electrolyte interphase magnesium metal anodes lithium tetrakis(hexafluoroisopropyloxy)borate rechargeable magnesium batteries