Plasma-Induced Amorphous Shell and Deep Cation-Site S Doping Endow TiO2 with Extraordinary Sodium Storage Performance

Hanna He; Dan Huang; Weikong Pang; Dan Sun; Qi Wang; Yougen Tang; Xiaobo Ji; Zaiping Guo; Haiyan Wang

doi:10.1002/adma.201801013

Plasma-Induced Amorphous Shell and Deep Cation-Site S Doping Endow TiO₂ with Extraordinary Sodium Storage Performance

Adv Mater. 2018 Jun;30(26):e1801013. doi: 10.1002/adma.201801013. Epub 2018 May 10.

Authors

Hanna He^{1

2}, Dan Huang³, Weikong Pang², Dan Sun¹, Qi Wang¹, Yougen Tang¹, Xiaobo Ji¹, Zaiping Guo^{2

4}, Haiyan Wang¹

Affiliations

¹ College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, P. R. China.
² Institute for Superconducting & Electronic Materials, University of Wollongong, Wollongong, New South Wales, 2522, Australia.
³ Guangxi Key Laboratory for Relativistic Astrophysics, Guangxi Colleges and Universities Key Laboratory of Novel Energy Materials and Related Technology, Guangxi Novel Battery Materials Research Center of Engineering Technology, School of Physical Science and Technology, Guangxi University, Nanning, 530004, P. R. China.
⁴ School of Mechanical, Materials, Mechatronics and Biomedical Engineering, University of Wollongong, Wollongong, New South Wales, 2500, Australia.

PMID: 29744949
DOI: 10.1002/adma.201801013

Abstract

Structural design and modification are effective approaches to regulate the physicochemical properties of TiO₂ , 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 TiO₂ (R-TiO_2-_x -S) as an advanced anode for the Na ion battery. An amorphous shell (≈3 nm) is induced by the Ar/H₂ 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.

Keywords: amorphous shell; deep cation-site S doping; rate performance; sodium ion battery; titanium dioxide.