Oxygen‐Deficient Ferric Oxide as an Electrochemical Cathode Catalyst for High‐Energy Lithium–Sulfur Batteries

Abstract

Lithium–sulfur batteries, as one of promising next‐generation energy storage devices, hold great potential to meet the demands of electric vehicles and grids due to their high specific energy. However, the sluggish kinetics and the inevitable “shuttle effect” severely limit the practical application of this technology. Recently, design of composite cathode with effective catalysts has been reported as an essential way to overcome these issues. In this work, oxygen‐deficient ferric oxide (Fe2O3−x), prepared by lithiothermic reduction, is used as a low‐cost and effective cathodic catalyst. By introducing a small amount of Fe2O3−x into the cathode, the battery can deliver a high capacity of 512 mAh g−1 over 500 cycles at 4 C, with a capacity fade rate of 0.049% per cycle. In addition, a self‐supporting porous S@KB/Fe2O3−x cathode with a high sulfur loading of 12.73 mg cm−2 is prepared by freeze‐drying, which can achieve a high areal capacity of 12.24 mAh cm−2 at 0.05 C. Both the calculative and experimental results demonstrate that the Fe2O3−x has a strong adsorption toward soluble polysulfides and can accelerate their subsequent conversion to insoluble products. As a result, this work provides a low‐cost and effective catalyst candidate for the practical application of lithium–sulfur batteries.

NiMoO4 Nanosheets Anchored on NS Doped Carbon Clothes with Hierarchical Structure as a Bidirectional Catalyst toward Accelerating Polysulfides Conversion for LiS Battery

“…with O 2− anion provide strong polar sites to anchor LiPSs. [12] Especially, some single transitional metal oxides, such as MoO 3−x , [13] NiO, [14] Fe 2 O 3 , [15] and Co 3 O 4 , [14] have been reported as the catalyst of LiPSs to speed up the conversion kinetics of LiPSs. Unfortunately, single transitional metal oxide shows inferior conductivity and insufficient catalytic ability, leading to worse redox LiPSs kinetics.…”

Designing principles of advanced sulfur cathodes toward practical lithium‐sulfur batteries

“…Besides naturally generated vacancies, artificial vacancies are obtained by different treatments. 182,196,197 For example, various vacancies, such as oxygen, 46 sulfur, 198 selenide, 193 nitride, 104 and metal cation, 194 were introduced into host materials of Li-S batteries. Notably, in parallel with prefabricated defective host materials, in-situ generated vacancies in pristine host materials were attained by LiPSs etching during the cycling (Figure 7B).…”

CoSe2/MoS2 Heterostructures to Couple Polysulfide Adsorption and Catalysis in Lithium‐Sulfur Batteries†

“…However, non‐polar surfaces of carbon‐based materials could not trap polar polysulfides sufficiently. [ 15 ] In view of this, polar materials such as metal oxides, [ 16‐17 ] sulfides, [ 18‐19 ] selenides, [ 20 ] phosphates, [ 21 ] nitrides [ 22 ] and carbides [ 23 ] have been developed as sulfur hosts to take advantages of their strong chemical interactions with polysulfides. Such strategies can effectively suppress the shuttling effect and modestly increase the utilization of active sulfur species.…”