Synergism of Al-containing solid electrolyte interphase layer and Al-based colloidal particles for stable lithium anode

Abstract

Trace water in nonaqueous electrolytes has been supposed to be detrimental to Li metal, which may induce formation of HF and corrode battery materials. Herein, we propose that a controllable AlCl3 is an efficient electrolyte additive for dendrite-free Li deposition. The additive could react with trace water in the electrolyte to form a stable Al2O3-rich solid electrolyte interphase (SEI) layer on the surface of Li and Al-based positively charged colloidal particles (PCCPs) in the electrolyte. PCCPs could form a positively charged electrostatic shield around the protruding lithium during the deposition process and induce the subsequent deposition of Li to the adjacent regions of the protruding Li, enabling a uniform and dendrite-free Li morphology. The assembled Li|Se and Li|Li4Ti5O12 batteries benefit from the synergism of SEI layer and PCCPs, thereby demonstrating the impressive capability for dendrite suppression of Li anode and improved electrochemical performance.