Concomitant Mitigation of VO6 Octahedron Distortion and Band Broadening in V2O3 for High‐Performing Flexible Supercapacitors

Abstract

AbstractVanadium trioxide (V2O3) has emerged as one of the promising candidates for fiber‐shaped supercapacitors. However, irreversible redox behavior during prolonged cycling process has been commonly reported due to the intrinsically distorted VO6 octahedron in V2O3, which inevitably compromises its electrochemical capacitance. Herein, a strategy to simultaneously mitigate the distortion in VO6 octahedron and optimization of electronic structure in V2O3 is proposed by studying a Mo‐doped V2O3 modified stainless steel wire (Mo‐V2O3@SSW). The introduction of Mo dopants effectively tunes the V–O local environment, resulting in a substantial alleviation of the distortion in VO6 octahedron. The as‐prepared Mo‐V2O3 with a more regular VO6 octahedron exhibits highly reversible redox behavior, with negligible structural change after 10 000 cycles. Moreover, it is found that doping Mo into V2O3 leads to V 3d band broadening, which generates more electronic states around Fermi level, thereby significantly accelerating the electron transfer during redox processes. Consequently, Mo‐V2O3@SSW attains a capacitance of 774.4 mF cm−2 at 0.4 mA cm−2, with a capacitance retention of 85.49% after 10 000 cycles. And the integration of Mo‐V2O3@SSW supercapacitors, further showcases its strong applicability in wearable technologies. The comprehensive understanding of the structural–activity/stability relationship in this study offers a novel paradigm for developing flexible high‐performing supercapacitors.