Atomic Insights into Aluminium‐Ion Insertion in Defective Anatase for Batteries

Abstract

Aluminium batteries constitute as afe and sustainable high-energy-density electrochemical energy-storage solution. Viable Al-ion batteries require suitable electrode materials that can readily intercalate high-charge Al 3+ ions.H ere,w e investigate the Al 3+ intercalation chemistry of anatase TiO 2 and howc hemical modifications influence the accommodation of Al 3+ ions.W eu se fluoride-and hydroxide-doping to generate high concentrations of titanium vacancies.T he coexistence of these hetero-anions and titanium vacancies leads to acomplex insertion mechanism, attributed to three distinct types of host sites:n ative interstitial sites,s ingle vacancy sites,a nd paired vacancy sites.W edemonstrate that Al 3+ induces astrong local distortion within the modified TiO 2 structure,which affects the insertion properties of the neighbouring host sites.O verall, specific structural features induced by the intercalation of highly polarising Al 3+ ions should be considered when designing new electrode materials for polyvalent batteries.

Reversible Zn2+ Insertion in Tungsten Ion-Activated Titanium Dioxide Nanocrystals for Electrochromic Windows

“…The decrease in the Zn 2+ diffusion barrier in W-doped TiO 2 was also found at the doping level of 2.1% (Fig. S12), which may be due to the distortion of the TiO 6 octahedron caused by the introduction of W dopant ions [18,30,49]. In general, this small diffusion barrier is more conducive to the diffusion of Zn 2+ ions in the lattice, thus activating the Zn 2+ electrochemical reaction of TiO 2 .…”

Optimization Design and Application of Niobium‐Based Materials in Electrochemical Energy Storage

“…[148] 3) Doped ions can hinder grain growth, resulting in smaller average particle size than pure. [149] In previous reports, doping and vacancy has been studied in Nb-based materials.…”

“…Incorporating atomic-scale defects, such as oxygen ion vacancies, into electrode materials is an effective strategy to improve the electrochemical performance of materials. [149] Vacancies can significantly change the oxide electronic structure or the adsorption intermediate stability, thereby greatly enhance the electrochemical activity of oxide surface. [148] Meanwhile, the vacancy structure will greatly affect material properties, such as electronic structure, conductivity, and ion/electron diffusion rate.…”

Amorphous anion-rich titanium polysulfides for aluminum-ion batteries

“…The single-electron transfer of traditional cationic redox chemistry also delays the local charge compensation process, leading to a high reaction barrier and large polarization. Furthermore, upon massive electron injection, unstable lattice distortions and irreversible structural collapse often occur, reducing the storage sites and accelerating the potential failure ( 14 , 15 ). Therefore, the designs for the Al 3+ host should focus on an open and unrestricted structure, and special attention should be paid to the local chemical environment and the electron-compensation ability of the active sites, as well as the short ion diffusion paths.…”