Polymer‐Templated Formation of Polydopamine‐Coated SnO 2 Nanocrystals: Anodes for Cyclable Lithium‐Ion Batteries

Well‐controlled nanostructures and a high fraction of Sn/Li 2 O interface are critical to enhance the coulombic efficiency and cyclic performance of SnO 2 ‐based electrodes for lithium‐ion batteries (LIBs). Polydopamine (PDA)‐coated SnO 2 nanocrystals, composed of hundreds of PDA‐coated “corn‐like” SnO 2 nanoparticles (diameter ca. 5 nm) decorated along a “cob”, addressed the irreversibility issue of SnO 2 ‐based electrodes. The PDA‐coated SnO 2 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 SnO 2 electrode with excellent rate capability, superior long‐term stability over 300 cycles, and high Sn→SnO 2 reversibility.