Achieving Stable Lithium Metal Anodes via the Synergistic of Electrostatic Shielding and High Li+ Flux Inorganic Interphase

Abstract

Uncontrolled dendrite growth and slow Li+ transport kinetics on the anode/electrolyte interface severely restricted the practical process of lithium metal batteries (LMBs). Here, a high-charge density cationic polymer, poly(octaallyltetraazacyclo-decane nitrate) (POTA-NO3), was developed as an anodic protective layer to moderate Li+ deposition and enhance Li+ transport efficiency. According to the Li+ deposition characteristics and simulation, POTA-NO3 with multiple positive charge sites furnished excellent electrostatic shielding and enhanced Li+ desolvation process for the anodes. Meanwhile, anions generated robust and high Li+ flux inorganic SEI to inhibit polymer cationic layer and electrolyte decomposition. With the POTA-NO3 protective layer, Li||Li symmetric batteries achieved stable cycling of 6300 h at high current density (5 mA cm-2) with a capacity of 5 mAh cm-2. Furthermore, the POTA-NO3 protected Li||LiCoO2 batteries exhibited over 80% capacity retention after 1400 long-term cycles at 1C. This work provides potential for the development of stable lithium anode.