Plasma‐Induced Amorphous Shell and Deep Cation‐Site S Doping Endow TiO 2 with Extraordinary Sodium Storage Performance

Structural design and modification are effective approaches to regulate the physicochemical properties of TiO 2 , which play an important role in achieving advanced materials. Herein, a plasma‐assisted method is reported to synthesize a surface‐defect‐rich and deep‐cation‐site‐rich S doped rutile TiO 2 (R‐TiO 2– x ‐S) as an advanced anode for the Na ion battery. An amorphous shell (≈3 nm) is induced by the Ar/H 2 plasma, which brings about the subsequent high S doping concentration (≈4.68 at%) and deep doping depth. Experimental results and density functional theory calculations demonstrate greatly facilitated ion diffusion, improved electronic conductivity, and an increased mobility rate of holes for R‐TiO 2− x ‐S, which result in superior rate capability (264.8 and 128.5 mAh g −1 at 50 and 10 000 mA g −1 , respectively) and excellent cycling stability (almost 100% retention over 6500 cycles). Such improvements signify that plasma treatment offers an innovative and general approach toward designing advanced battery materials.