Selective Catalysis Remedies Polysulfide Shuttling in Lithium‐Sulfur Batteries

Abstract

The shuttling of soluble lithium polysulfides between the electrodes leads to serious capacity fading and excess use of electrolyte, which severely bottlenecks practical use of Li‐S batteries. Here, selective catalysis is proposed as a fundamental remedy for the consecutive solid‐liquid‐solid sulfur redox reactions. The proof‐of‐concept Indium (In)‐based catalyst targetedly decelerates the solid‐liquid conversion, dissolution of elemental sulfur to polysulfides, while accelerates the liquid‐solid conversion, deposition of polysulfides into insoluble Li2S, which basically reduces accumulation of polysulfides in electrolyte, finally inhibiting the shuttle effect. The selective catalysis is revealed, experimentally and theoretically, by changes of activation energies and kinetic currents, modified reaction pathway together with the probed dynamically changing catalyst (LiInS2 catalyst), and gradual deactivation of the In‐based catalyst. The In‐based battery works steadily over 1000 cycles at 4.0 C and yields an initial areal capacity up to 9.4 mAh cm−2 with a sulfur loading of ≈9.0 mg cm−2.

Revealing the Sulfur Redox Paths in a Li–S Battery by an In Situ Hyphenated Technique of Electrochemistry and Mass Spectrometry

“…There are relatively few studies devoted to the mechanisms by the theoretical simulations. [ 19 ] Very little experimental evidence is available, [ 20 ] especially for the direct detection of key polysulfides‐SACs intermediates. For example, Shan et al.…”

“…There are relatively few studies devoted to the mechanisms by the theoretical simulations. [19] Very little experimental evidence is available, [20] especially for the direct detection of key polysulfides-SACs intermediates. For example, Shan et al proved that CoPc could accelerate the LIPS redox kinetics to alleviate the shuttle effect and improved the cycling stability of the Li-S battery.…”

Design Rules of a Sulfur Redox Electrocatalyst for Lithium–Sulfur Batteries

“…[ 7,8 ] Therefore, exploring effective strategies to accelerate the conversion of LiPSs from the liquid to the solid state is essential to boost the practical energy density and lifespan of lithium–sulfur batteries. [ 9,10 ]…”

“…[7,8] Therefore, exploring effective strategies to accelerate the conversion of LiPSs from the liquid to the solid state is essential to boost the practical energy density and lifespan of lithium-sulfur batteries. [9,10] Considerable efforts have been devoted to addressing the aforementioned problems, typically by using sulfides, nitrides, phosphides as host materials to trap the LiPSs in the sulfur cathode. [11][12][13][14] However, these physical or electrostatic confinement/trapping methods fail to entirely avoid the dissolution and accumulation of LiPSs in the electrolyte.…”

Deciphering the defectmicro‐environmentof graphene for highly efficient Li–S redox reactions

“…[20][21][22][23][24] As indispensable intermediate products during the transformation reaction between sulfur and Li 2 S, the most fundamental way is not only to impede the soluble LiPS dissolution to electrolyte, but also to accelerate their conversion to final solid products, which is of utmost importance to relieve the shuttle effect of LiPSs. 9,[25][26][27][28][29] Therefore, the use of electrocatalysts has emerged as a promising strategy for promoting Li-S redox kinetics.…”