The formation of LiAl5O8 nanowires from bulk Li-Al alloy enables dendrite-free Li metal batteries

Lithium metal has been regarded as an ideal anode to meet the rapidly growing requirements on high energy density batteries, owing to their highest gravimetric capacity and their lowest redox potential. However, lithium metal batteries persistently suffer from serious issues, such as the unstable solid electrolyte layer and uncontrolled dendrite growth during plating/stripping, especially under high current density. Herein, we developed an innovative method to prepare dense LiAl5O8 nanowires membrane and designed a LiAl5O8 nanowires membrane/poly (vinylidene fluoride-co-hexafluoropropylene)-based gel polymer composite electrolyte (LPH-GPE) to address these issues. On the interface of LPH-GPE and lithium anode, uniformly dispersed aluminum is in situ generated by reducing LiAl5O8 nanowires, which brings both superlithiophilic sites and uniform lithium ion flux, and thus enables the lithium ion depositing in plates rather than forming sharp lithium dendrites. The solid-state lithium/lithium symmetric cells with LPH-GPE exhibit significantly improved lifespan at 0.5 mA cm(-2) and short-circuit does not occur even at current density up to 4 mA cm(-2). (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study successfully improved the challenges faced by lithium metal batteries at high current densities using LiAl5O8 nanowires membrane and polymer composite electrolyte, which promotes uniform lithium ion deposition in plate form by generating uniformly dispersed aluminum, reducing the formation of lithium dendrites and enhancing battery lifespan.