Modulating Ionic Transport and Interface Chemistry via Surface‐Modified Silica Carrier in Nano Colloid Electrolyte for Stable Cycling of Li‐Metal Batteries

Abstract

Tailoring the Li+ microenvironment is crucial for achieving fast ionic transfer and a mechanically reinforced solid–electrolyte interphase (SEI), which administers the stable cycling of Li‐metal batteries (LMBs). Apart from traditional salt/solvent compositional tuning, this study presents the simultaneous modulation of Li+ transport and SEI chemistry using a citric acid (CA)‐modified silica‐based colloidal electrolyte (C‐SCE). CA‐tethered silica (CA‐SiO2) can render more active sites for attracting complex anions, leading to further dissociation of Li+ from the anions, resulting in a high Li+ transference number (≈0.75). Intermolecular hydrogen bonds between solvent molecules and CA‐SiO2 and their migration also act as nano‐carrier for delivering additives and anions toward the Li surface, reinforcing the SEI via the co‐implantation of SiO2 and fluorinated components. Notably, C‐SCE demonstrated Li dendrite suppression and improved cycling stability of LMBs compared with the CA‐free SiO2 colloidal electrolyte, hinting that the surface properties of the nanoparticles have a huge impact on the dendrite‐inhibiting role of nano colloidal electrolytes.