Chemical Immobilization and Conversion of Active Polysulfides Directly by Copper Current Collector: A New Approach to Enabling Stable Room‐Temperature Li‐S and Na‐S Batteries

Abstract

Room-temperature Li/Na-S batteries are promising energy storage solutions, but unfortunately suffered from serious cycling problems rooted in their polysulfide intermediates.Conventional strategy to tackle with this issue is to design host materials for trapping polysulfides via weak physical confinement and interfacial chemical interactions. Even though beneficial, their capability for the polysulfide immobilization is still limited. Herein, we revisit the unique sulfiphilic nature of metallic Cu. Upon the exposure to polysulfide in aqueous or aprotic solution, the surface sulfidization rapidly took place, resulting in the formation of Cu 2 S nanoflake arrays with tunable This article is protected by copyright. All rights reserved. 2 texture. When sulfidized Cu current collector is directly used as the sulfur-equivalent cathode, it enables high-performance Li/Na-S batteries at room temperature with reasonable high sulfur loading. Specific capacities up to ~1200 mAh g −1 for Li-S and ~400 mAh g −1 for Na-S are measured when normalized to the amount of equivalent sulfur, and can be readily sustained for >1000 cycles.

CuS and Cu2S as Cathode Materials for Lithium Batteries: A Review

“…Copyright (2013) Elsevier Ltd. Cu to react with sulfur ions and prevent dissolution. This effect is confirmed by Li et al, [55] who found that Cu enables to react with dissolved sulfur species. Following this finding, a LiÀ S battery system with stable cycling stability and Coulombic efficiency was generated by injecting polysulfide solution into sulfiphilic Cu foam.…”

“…Charge and discharge characteristics of Cu 2 S on Cu foam cycled between a) 0.02 and 3.0 V and b) 0.5 V and 3.5 V. [52] Reproduced with permission from Ref. This effect is confirmed by Li et al, [55] who found that Cu enables to react with dissolved sulfur species. Copyright (2013) Elsevier Ltd. Cu to react with sulfur ions and prevent dissolution.…”

A Multifunctional Separator Enables Safe and Durable Lithium/Magnesium–Sulfur Batteries under Elevated Temperature

“…Irregular inorganic particles and acetylene blacks are observed to embed on the surface of graphene nanosheets ( Figure S32a, Supporting Information), demonstrating the morphology changes of CuNWs. [14,23,35] These results clearly demonstrate the presence of both the copper sulfide intermediates (mainly the high Chalcocite Cu 1.96 S and Chalcocite Cu 2 S) and Li 2 S redistributed on the surface of graphene nanosheet. The lattice spacing of 0.27 nm and the selected-area electron diffraction (SAED) pattern are also shown in Figure S32b,c in the Supporting Information, which should be ascribed to the (103) plane of high Chalcocite Cu 1.96 S. The EDS and XPS analysis ( Figure S33a,b, Supporting Information) also reveal the existence of copper and sulfur.…”

Long‐Life Room‐Temperature Sodium–Sulfur Batteries by Virtue of Transition‐Metal‐Nanocluster–Sulfur Interactions

“…[1] However,RT-Na/S batteries present apractical challenge (widely known to also afflict Li-S batteries) of low reversible capacity and rapid capacity fade. [2] Thel ow accessible capacity is caused by the insulating nature of sulfur and the sluggish reactivity of sulfur with sodium. This results in an incomplete reduction, rather than the complete production of Na 2 S. [3] Thed issolution of polysulfides into the electrolyte during cycling that is,t he shuttle effect, is the key reason for rapid capacity fade.…”