Laser constructed bulk oxygen vacancy caused high P doping for boosting the sodium‐storage capability

Abstract

AbstractDefect‐assisted heteroatom doping can effectively enhance the intrinsic transfer characteristics of carriers in the crystal structure, which advantages over fast and efficient charge storage. In this work, a three‐dimensional self‐supporting titanium dioxide nanoparticle rich in bulk vacancies (L‐TiOx) on titanium substrate is synthesized by pulsed laser. Different from the surface vacancies, the bulk oxygen defects of L‐TiOx cause a uniform and bulk phosphorus (P) doping with a high concentration of ~5.71 at %, which endows the elevated electronic conductivity, and accelerates the transport of Na+. The obtained P‐doped L‐TiOx (LP‐TiOx) as an anode material in sodium‐ion batteries (SIBs) provides a reversible capacity of 400 mAh g−1 at 200 mA g−1, outstanding rate capability of 196 mAh g−1 at 10,000 mA g−1, and maintains stable performance over 1000 cycles. In situ X‐ray diffraction and ex situ high‐resolution transmission electron microscopy show that LP‐TiOx exhibits robust mechanical behavior with almost no lattice change under (de)sodiation. This work supplies a novel idea for high‐concentration bulk heteroatoms doping to enhance the electrochemical performance of SIBs.