Constructed TiO ₂/WO ₃ heterojunction with strengthened nano-trees structure for highly stable electrochromic energy storage device

Abstract

Tungsten trioxide (WO 3 ) has been widely regarded as a prospective bifunctional material due to its electrochromic and pseudocapacitive properties, while still facing the dilemma of inadequate cycle stability and trapping-induced degradation. Here, inspired by the trees-strengthening approach, a unique titanium dioxide (TiO 2 ) nanorod arrays strengthened WO 3 nano-trees (TWNTs) heterojunction was rationally designed and constructed. In sharp contrast to the transmittance modulation (ΔT) attenuation of primary WO 3 nano-trees during cycling, the TWNTs film showed not only excellent electrochromic performance but also fascinating cycle stability (77.35% retention of the initial ΔT after 10,000 cycles). Besides, the trapping-induced degradation could be easily rejuvenated by a potentiostatic de-trapping process. An electrochromic energy storage device (EESD) was further assembled based on the TWNTs film to deliver excellent ΔT (up to 79.5% at 633 nm), fast switching speed (t c /t b =1.9 s/14.8 s), extremely high coloration efficiency value (443.4 cm 2 •C −1 ), and long-term cycle stability (over 10,000 charge/discharge cycles). This innovative study provided in-depth insights into the electrochromism nature and a significant step in the realization of stable electrochromic-energy storage application, paving the way for multifunctional smart windows as well as next-generation optoelectronic devices.

Boosting bidirectional conversion of polysulfide driven by the built-in electric field of MoS 2/MoP Mott–Schottky heterostructures in lithium–sulfur batteries

“…Heterostructure engineering is identified to be a promising strategy to combine the merits of each component to achieve crucial synergistic effect and thus improve electrochemical performance [15][16][17][18][19]. For instance, Li et al [20] proposed a MoO 2 -Mo 3 N 2 heterojunction combining the merits of conductive Mo 3 N 2 and adsorptive MoO 2 to serve as jobsynergistic trapping-conversion sites for LiPSs.…”