Three-Dimensional Growth of Li<sub>2</sub>S in Lithium–Sulfur Batteries Promoted by a Redox Mediator

Gerber, Laura C. H.; Frischmann, Peter D.; Fan, Frank Y.; Doris, Sean E.; Qu, Xiaohui; Scheuermann, Angelique M.; Persson, Kristin A.; Chiang, Yet‐Ming; Helms, Brett A.

doi:10.1021/acs.nanolett.5b04189

Cited by 213 publications

(161 citation statements)

References 68 publications

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“…However, the severe shuttle effect and dendrite growth, and the inferior Coulombic efficiency that characterize these Li‐S batteries have greatly limited their lifespan 4, 8, 9, 10. Although much effort has been expended in the development of novel sulfur‐host electrodes,11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36 separators,37, 38, 39, 40 and electrolytes41, 42, 43, 44, 45 to resolve these issues, some of which are rather dangerous, the results have been at best minimal in improving current Li‐S battery technology. As a result, the cycling life and Coulombic efficiency of Li‐S batteries, especially in the high‐rate regime, are still far behind the state of the art in lithium‐ion battery technology.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Suppression of the Dendrite Formation and Shuttle Effect in a Lithium–Sulfur Battery by Bilateral Solid Electrolyte Interface

et al. 2018

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Although the reversible and inexpensive energy storage characteristics of the lithium–sulfur (Li‐S) battery have made it a promising candidate for electrical energy storage, the dendrite growth (anode) and shuttle effect (cathode) hinder its practical application. Here, it is shown that new electrolytes for Li‐S batteries promote the simultaneous formation of bilateral solid electrolyte interfaces on the sulfur‐host cathode and lithium anode, thus effectively suppressing the shuttle effect and dendrite growth. These high‐capacity Li‐S batteries with new electrolytes exhibit a long‐term cycling stability, ultrafast‐charge/slow‐discharge rates, super‐low self‐discharge performance, and a capacity retention of 94.9% even after a 130 d long storage. Importantly, the long cycle stability of these industrial grade high‐capacity Li‐S pouch cells with new electrolytes will provide the basis for creating robust energy dense Li‐S batteries with an extensive life cycle.

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Section: Introductionmentioning

confidence: 99%

Simultaneous Suppression of the Dendrite Formation and Shuttle Effect in a Lithium–Sulfur Battery by Bilateral Solid Electrolyte Interface

et al. 2018

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“…[20][21][22][23][24] Modifications of carbons using polymers decorated with polar functional groups established another path to bind LiPSs without compromising the conductivity. [37][38][39][40] In light of the above advances, it is now also appreciated that the low volumetric energy density (ED) of many Li-S batteries still pose a concern due to two aspects: the low density of sulfur (2.07 mg cm −3 ) that is often reported with a high fraction of carbon (>40 wt%), and high electrolyte/sulfur ratios. [28][29][30][31][32][33][34][35] Their strong chemical interaction with LiPSs based on polar-polar interactions, Lewis acid-base bonding or chemical catenation plays an essential role in suppressing the shuttling.…”

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confidence: 99%

A Comprehensive Approach toward Stable Lithium–Sulfur Batteries with High Volumetric Energy Density

Pang

Liang

Kwok

et al. 2016

Advanced Energy Materials

295

228

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across the whole electrode and suppressed LiPSs shuttling to the lithium anode are required. [8][9][10][11] Great efforts have been made to address these aforementioned issues with a primary focus on the cathode materials. Nano-carbons and graphenes with micro/ mesoporous channels are representative of early stage sulfur host materials, which provide conductivity and physical entrapment of the LiPSs. [12][13][14][15][16][17][18][19] The lack of strong interaction with the LiPSs lead to rapid capacity fading on cycling in most of these studies, however. Functionalized carbons, exemplified by graphene oxides and heteroatoms-doped carbons, demonstrate chemical entrapment of the LiPSs and enable longer-term cycling. [20][21][22][23][24] Modifications of carbons using polymers decorated with polar functional groups established another path to bind LiPSs without compromising the conductivity. [25][26][27] Departing from carbonaceous materials, inorganic metal-based materials including metal oxides, metal sulfides, metal organic frameworks, and MXene phases have been recently studied as sulfur hosts. [28][29][30][31][32][33][34][35] Their strong chemical interaction with LiPSs based on polar-polar interactions, Lewis acid-base bonding or chemical catenation plays an essential role in suppressing the shuttling. Adsorption of LiPSs results in controlled precipitation of Li 2 S and S 8 , which enhances uniform distribution of active materials. [30,36] Aside from the cathode, rationally designed electrolyte modifications and redox mediators have also shown promise in controlling polysulfide dissolution and Li 2 S deposition. [37][38][39][40] In light of the above advances, it is now also appreciated that the low volumetric energy density (ED) of many Li-S batteries still pose a concern due to two aspects: the low density of sulfur (2.07 mg cm −3 ) that is often reported with a high fraction of carbon (>40 wt%), and high electrolyte/sulfur ratios. Achieving high areal sulfur loading (>7 mg cm −2 ) with low electrolyte volume is critical to maximize the ED, but this is not the case for most reported systems to date. [41] Moreover, the challenge for high-performance thick cathodes resides in all cathode components: the individualized nanosized porous C/S composites, the polyvinylidene fluoride (PVDF) binder that lacks elasticity and insufficient interparticle conductivity. [9][10][11] In order to fabricate high-loading Li-S cathodes, two approaches have been used. One is to construct 3D conductive frameworks, [42][43][44][45][46][47] and the other is to integrate the host nanomaterials before slurry processing. [48][49][50] Pure carbon 3D networks, usually composed A comprehensive approach is reported to construct stable and high volumetric energy density lithium-sulfur batteries, by coupling a multifunctional and hierarchically structured sulfur composite with an in-situ cross-linked binder. Through a combination of first-principles calculations and experimental studies, it is demonstrated that a hybrid sulfur host composed b...

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“…3,[15][16][17][18] Low sulfur utilization results in initially low capacity that then continues to decrease with subsequent cycles. [19][20][21] Batteries are spatially and chemically heterogeneous, and deciphering the speciation and distribution of dissolved polysulfides in the anode, cathode, and especially the electrolyte during cycling is critical for realizing the potential of Li-S.…”

mentioning

confidence: 99%

Operando Spectromicroscopy of Sulfur Species in Lithium-Sulfur Batteries

Miller

Kasse

Heath

et al. 2017

J. Electrochem. Soc.

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In this study, a novel cross-sectional battery cell was developed to characterize lithium-sulfur batteries using X-ray spectromicroscopy. Chemically sensitive X-ray maps were collected operando at energies relevant to the expected sulfur species and were used to correlate changes in sulfur species with electrochemistry. Significant changes in the sulfur/carbon composite electrode were observed from cycle to cycle including rearrangement of the elemental sulfur matrix and PEO 10 LiTFSI binder. Polysulfide concentration and area of spatial diffusion increased with cycling, indicating that some polysulfide dissolution is irreversible, leading to polysulfide shuttle. Fitting of the maps using standard sulfur and polysulfide XANES spectra indicated that upon subsequent discharge/charge cycles, the initial sulfur concentration was not fully recovered; polysulfides and lithium sulfide remained at the cathodes with higher order polysulfides as the primary species in the region of interest. Quantification of the polysulfide concentration across the electrolyte and electrode interfaces shows that the polysulfide concentration before the first discharge and after the third charge is constant within the electrolyte, but while cycling, a significant increase in polysulfides and a gradient toward the lithium metal anode forms. This chemically and spatially sensitive characterization and analysis provides a foundation for further operando spectromicroscopy of lithium-sulfur batteries. New "beyond lithium-ion" battery chemistries are essential to meet the increasing demand for long-lasting, high capacity energy storage in portable electronics and electric vehicles. Lithium-sulfur (Li-S) batteries are an attractive Li-ion alternative that provides large capacity (1672 mAh g −1 ) and energy density (2500 Wh kg −1 ) while also being low cost, earth-abundant, and lightweight.1-3 Li-S batteries have a unique chemistry that achieves high capacity via chemical transformation rather than Li intercalation. Elemental sulfur (S 8 ) is reduced through a series of soluble Li polysulfides (Li 2 S x , 2 ≤ x ≤ 8) to a final solid discharge product (Li 2 S), and the process is reversed upon charging. [4][5][6] However, Li-S suffers from unrealized theoretical capacity and rapid capacity fade due to loss processes that are not well-understood. 2,7 While many advances in electrode and electrolyte engineering have been made in an attempt mitigate these performance issues, 8-14 a gap remains in the mechanistic understanding of Li-S battery operation. Several mechanisms for reduced capacity and capacity fade have been proposed. Lithium polysulfides, which are necessary for operation, dissolve into the liquid electrolyte, remain dissolved, and "shuttle" between the electrodes rather than participating in the electrochemical reactions, decreasing the amount of active material available. 3,[15][16][17][18] Low sulfur utilization results in initially low capacity that then continues to decrease with subsequent cycles. [19][20][21] Batteries are spatiall...

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Three-Dimensional Growth of Li₂S in Lithium–Sulfur Batteries Promoted by a Redox Mediator

Cited by 213 publications

References 68 publications

Simultaneous Suppression of the Dendrite Formation and Shuttle Effect in a Lithium–Sulfur Battery by Bilateral Solid Electrolyte Interface

Simultaneous Suppression of the Dendrite Formation and Shuttle Effect in a Lithium–Sulfur Battery by Bilateral Solid Electrolyte Interface

A Comprehensive Approach toward Stable Lithium–Sulfur Batteries with High Volumetric Energy Density

Operando Spectromicroscopy of Sulfur Species in Lithium-Sulfur Batteries

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Three-Dimensional Growth of Li2S in Lithium–Sulfur Batteries Promoted by a Redox Mediator

Cited by 213 publications

References 68 publications

Simultaneous Suppression of the Dendrite Formation and Shuttle Effect in a Lithium–Sulfur Battery by Bilateral Solid Electrolyte Interface

Simultaneous Suppression of the Dendrite Formation and Shuttle Effect in a Lithium–Sulfur Battery by Bilateral Solid Electrolyte Interface

A Comprehensive Approach toward Stable Lithium–Sulfur Batteries with High Volumetric Energy Density

Operando Spectromicroscopy of Sulfur Species in Lithium-Sulfur Batteries

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Three-Dimensional Growth of Li₂S in Lithium–Sulfur Batteries Promoted by a Redox Mediator