Uniform metal-ion flux through interface-modified membrane for highly stable metal batteries

Abstract

Lithium (Li) metal has received huge attention as a promising anode candidate due to its high theoretical capacity, the lowest negative potential, and its potential as next-generation energy storage devices (such as Li-S and Li-O2 batteries), where Li metal electrode is indispensable for the system. However, systemic issues, which are mainly associated with Li dendritic growth, result in poor electrochemical performances and safety problems (e.g. short-circuit). This article describes a unique design of multifunctional membrane, comprising of nanoporous inorganic (SiO2) nanosheet layer, in order to uniformly distribute metal-ion flux and delay the penetration of Li dendrites through the separator. When a designed membrane was employed, the propagation of Li dendrites against the separator was dramatically restrained and suppressed by structural and materialistic benefits of nanoporous inorganic (SiO2) nanosheets, thus leading to the significant enhancement of electrochemical performances of Li metal batteries. Similar to Li metal batteries, it showed analogous promising results and possibilities in achieving high electrochemical stabilities and cycle performances of Na metal batteries. Moreover, Li-S prototype cell coupled with a designed membrane delivered stable cycle retention (over 400 cycles) with high Coulombic efficiency by selectively allowing Li ions to pass through membrane but suppressing the migration of polysulfides.