Lithium deposition stability using TiO2/MWCNT as artificial solid-electrolyte interphases in gel polymer electrolytes based lithium metal batteries

Abstract

Many severe problems of lithium (Li) metal anode during cyclings, such as dendritic formation, dead Li, volume expansion, and safety issues, hinder practical applications of Li metal batteries (LMB). Ensuring performance stability by a gel polymer electrolyte (GPE), combined with strengthening the Li surface, is considered an effective strategy to solve the problems of the LMB. Herein, a composite of titanium dioxide (TiO2) with multiwall carbon nanotube (MWCNT) acted as artificial solid electrolyte interphase, effectively controlling the Li electrodeposition process and sustaining the structural integrity of the anode. The characteristics of the composite suspension elucidate the vital role of citric acid in the TiO2 surface functionalization, thereby creating effective adsorption with MWCNT, which directly built a new composite. The cycle performance of the TiO2/ MWCNT/Li anode in the GPE-based LMB is evaluated with a high energy density electrode that stably maintains over 200 cycles. The cross-sectional image of the advanced anode shows the ability to rebuild a strong and durable anode structure after many stripping/platting cycles. The advanced anode applied on a thin Li (70 & mu;m) and a medium capacity cathode shows efficiency based on over 580 cycles.