Polymer-Templated Formation of Polydopamine-Coated SnO₂ Nanocrystals: Anodes for Cyclable Lithium-Ion Batteries

Well-controlled nanostructures and a high fraction of Sn/Li₂ O interface are critical to enhance the coulombic efficiency and cyclic performance of SnO₂ -based electrodes for lithium-ion batteries (LIBs). Polydopamine (PDA)-coated SnO₂ nanocrystals, composed of hundreds of PDA-coated "corn-like" SnO₂ nanoparticles (diameter ca. 5 nm) decorated along a "cob", addressed the irreversibility issue of SnO₂ -based electrodes. The PDA-coated SnO₂ were crafted by capitalizing on rationally designed bottlebrush-like hydroxypropyl cellulose-graft-poly (acrylic acid) (HPC-g-PAA) as a template and was coated with PDA to construct a passivating solid-electrolyte interphase (SEI) layer. In combination, the corn-like nanostructure and the protective PDA coating contributed to a PDA-coated SnO₂ electrode with excellent rate capability, superior long-term stability over 300 cycles, and high Sn→SnO₂ reversibility.