Combined Defect and Heterojunction Engineering in ZnTe/CoTe₂@NC Sulfur Hosts Toward Robust Lithium–Sulfur Batteries

Abstract

Lithium–sulfur batteries (LSBs) are feasible candidates for the next generation of energy storage devices, but the shuttle effect of lithium polysulfides (LiPSs) and the poor electrical conductivity of sulfur and lithium sulfides limit their application. Herein, a sulfur host based on nitrogen‐doped carbon (NC) coated with small amount of a transition metal telluride (TMT) catalyst is proposed to overcome these limitations. The properties of the sulfur redox catalyst are tuned by adjusting the anion vacancy concentration and engineering a ZnTe/CoTe2 heterostructures. Theoretical calculations and experimental data demonstrate that tellurium vacancies enhance the adsorption of LiPSs, while the formed TMT/TMT and TMT/C heterostructures as well as the overall architecture of the composite simultaneously provide high Li+ diffusion and fast electron transport. As a result, v‐ZnTe/CoTe2@NC/S sulfur cathodes show excellent initial capacities up to 1608 mA h g−1 at 0.1C and stable cycling with an average capacity decay rate of 0.022% per cycle at 1C during 500 cycles. Even at a high sulfur loading of 5.4 mg cm–2, a high capacity of 1273 mA h g−1 at 0.1C is retained, and when reducing the electrolyte to 7.5 µL mg−1, v‐ZnTe/CoTe2@NC/S still maintains a capacity of 890.8 mA h g−1 after 100 cycles at 0.1C.

A polyaniline-coated Ni–Co Prussian blue analogue nanocube-modified separator for high-performance lithium–sulfur batteries

“…9a, the characteristic absorbance of Li 2 S 6 at 410 nm after adding NCP@PANi was significantly reduced compared with the original and NCP adsorption solutions, reflecting the relatively low concentration of polysulfides remaining after adsorption. 44 To determine the interaction mechanism, we further utilized XPS to investigate the surface state of NCP@PANi after Li 2 S 6 adsorption. Fig.…”

Unveiling the Synergy of Architecture and Anion Vacancy on Bi2Te3–x@NPCNFs for Fast and Stable Potassium Ion Storage

“…35 Electron paramagnetic resonance (EPR) results show a distinct EPR signal around g = 2.003 (Figure ), corresponding to abundant Te vacancies. 34,36 It is worth noting that a small number of Te defects in Bi 2 Te 3−x @NCNFs are caused by the etching of Te atoms on the surface of the composites by a reducing atmosphere. Significantly, compared with Bi 2 Te 3−x @NCNFs, the porous structure of Bi 2 Te 3−x @ NPCNFs facilitates full contact with the reducing atmosphere during high-temperature annealing, thereby generating more Te vacancies.…”

Identifying the Role of the Cationic Geometric Configuration in Spinel Catalysts for Polysulfide Conversion in Sodium–Sulfur Batteries

“…The incorporation of transition-metal-based catalysts into the cathode of metal–sulfur batteries can significantly accelerate sulfur redox reactions, enhancing the capacity, cycling rate, and stability of the battery. − To rationally optimize the cathode additive material and maximize its catalytic activity, it is critical to understand the involved mechanisms and the contribution of each material parameter. Notwithstanding the significant role played by catalysts in the sulfur redox reaction, the precise mechanisms and structure–property correlations have been poorly investigated.…”