Amorphous anion-rich titanium polysulfides for aluminum-ion batteries

Abstract

The strong electrostatic interaction between Al3+ and close-packed crystalline structures, and the single-electron transfer ability of traditional cationic redox cathodes, pose challenged for the development of high-performance rechargeable aluminum batteries. Here, to break the confinement of fixed lattice spacing on the diffusion and storage of Al-ion, we developed a previously unexplored family of amorphous anion-rich titanium polysulfides (a-TiSx, x = 2, 3, and 4) (AATPs) with a high concentration of defects and a large number of anionic redox centers. The AATP cathodes, especially a-TiS4, achieved a high reversible capacity of 206 mAh/g with a long duration of 1000 cycles. Further, the spectroscopy and molecular dynamics simulations revealed that sulfur anions in the AATP cathodes act as the main redox centers to reach local electroneutrality. Simultaneously, titanium cations serve as the supporting frameworks, undergoing the evolution of coordination numbers in the local structure.

Design Strategies of High‐Performance Positive Materials for Nonaqueous Rechargeable Aluminum Batteries: From Crystal Control to Battery Configuration

“…Reproduced with permission. [ 142 ] Copyright 2021, American Association for the Advancement of Science.…”

“…In addition, Lin et al. [ 142 ] introduced a special strategy of amorphization and anion enrichment in amorphous titanium polysulfides (a‐TiS x ) with a high concentration of defects and a large number of anionic redox centers (Figure 12g), in which amorphization could effectively break the confinement of ordered structures and generate high concentrations of defects, as well as anion‐rich structure could increase anionic redox centers and enhance the multielectron transfer efficiency. Through a facile top‐down high‐energy ball‐milling method, the raw crystalline TiS 2 (c‐TiS 2 ) particles were refined continuously and deformed to form a metastable state containing a large number of defects and dislocations, and further formed a series of a‐TiS x by continuous breaking and recombination, with a diameter of 50 to 200 nm (Figure 12h).…”

“…j) Rate performance and k) cycling stability of a-TiS 4 . Reproduced with permission [142]. Copyright 2021, American Association for the Advancement of Science.…”

Aqueous rocking-chair aluminum-ion capacitors enabled by a self-adaptive electrochemical pore-structure remolding approach

“…[10][11][12] As a result, the desolvation kinetics of the solvated Al 3+ ion on the electrode/electrolyte interface is greatly restricted, and the solidphase transport of the bare Al 3+ ion within electrode materials is also much hindered. 13 In light of these limitations, the key to constructing high-performance Al 3+ ion based EES devices is to screen the strong electrostatic field around the bare Al 3+ ion.…”

An Efficient Rechargeable Aluminium–Amine Battery Working Under Quaternization Chemistry

“…The high‐energy chalcogen cathodes (O 0 /O 2− and S 0 /S 2− ) interact strongly with Al 3+ , [3] making Al–O 2 batteries unrechargeable [4] and leading to poor kinetics and low stability of Al−S batteries [5] . Improved Al 3+ diffusion kinetics was achieved lately in amorphous TiS 4 under S − /S 2− conversion [6] . In contrast to Al 3+ , anionic Al complexes (Al 2 Cl 7 − and AlCl 4 − ) in ionic liquid show impressively high diffusion coefficients and smooth Al plating–stripping behavior, enabling Al‐graphite/graphene batteries based on anion intercalation chemistry of graphitic carbon (C n 0 /C n + ) [7] .…”