Dissolution Of Polysulfides Research Articles

Improvement of Lithium-Sulfur Battery Performance by Porous Carbon Selection and LiFSI/DME Electrolyte Optimization.

High-concentration lithium bis(fluorosulfonyl)imide/1,2-dimethoxyethane (LiFSI/DME) electrolytes are promising candidates for highly reversible lithium-metal anodes. However, the performance of lithium-sulfur (Li-S) batteries with a high concentration of LiFSI/DME declines because LiFSI reacts irreversibly with lithium polysulfide, which is formed during the charge-discharge process of Li-S batteries. Hence, to apply high-concentration LiFSI/DME to Li-S batteries, we investigated carbon with an appropriate pore size for use in a sulfur composite cathode and optimized the composition of high-concentration LiFSI/DME. The results showed that the combination of carbon with mesopores of 2-3 nm diameter and 3 M LiFSI in DME/1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropylether (HFE) (1:1 by vol.) provided a high-rate capability (943 mA h g-1 at a rate of 2 C). Moreover, the ratio of the 50th discharge capacity to the 2nd discharge capacity (capacity retention) improved from 50.0 to 61.6% with HFE dilution of high-concentration LiFSI/DME. The improved performance was achieved by suppressing the dissolution of lithium polysulfide, decreasing the viscosity of the electrolyte, and forming a thin solid electrolyte interface on the lithium-metal anode due to HFE dilution.

Guiding maps of solvents for lithium-sulfur batteries via a computational data-driven approach

Practical realization of lithium-sulfur batteries requires designing optimal electrolytes with controlled dissolution of polysulfides, high ionic conductivity, and low viscosity. Computational chemistry techniques enable tuning atomistic interactions to discover electrolytes with targeted properties. Here, we introduce ComBat (Computational Database for Lithium-Sulfur Batteries), a public database of ∼2,000 quantum-chemical and molecular dynamics properties for lithium-sulfur electrolytes composed of solvents spanning 16 chemical classes. We discuss the microscopic origins of polysulfide clustering and the diffusion mechanism of electrolyte components. Our findings reveal that polysulfide solubility cannot be determined by a single solvent property like dielectric constant. Rather, observed trends result from the synergistic effect of multiple factors, including solvent C/O ratio, fluorination degree, and steric hindrance effects. We propose binding energy as a proxy for Li+ dissociation, which is a property that impacts the ionic conductivity. The insights obtained in this work can serve as guiding maps to design optimal lithium-sulfur electrolyte compositions.

Polysulfide Rejection Strategy in Lithium-Sulfur Batteries Using an Ion-Conducting Gel-Polymer Interlayer Membrane.

Lithium-sulfur batteries (LiSBs) are emerging as promising alternative to conventional secondary lithium-ion batteries (LiBs) due to their high energy density, low cost, and environmental friendliness. However, preventing polysulfide dissolution is a great challenge for their commercial viability. The present work is focused on preparing a lithium salt and ionic liquid (IL) solution (SIL) impregnated ion (lithium ion)-conducting gel-polymer membrane (IC-GPM) interlayer to prevent polysulfide migration toward the anode by using an electrostatic rejection and trapping strategy. Herein, we introduce an SIL-based freestanding optimized IC-GPM70 (70 wt % SIL) interlayer membrane with high lithium-ion conductivity (2.58 × 10-3 S cm-1) along with excellent thermal stability to suppress the migration of polysulfide toward the anode and prevent polysulfide dissolution in the electrolyte. Because of the coulombic interaction, the anionic groups, -CF2 of the β-phase polymer host PVdF-HFP, TFSI- anion of IL EMIMTFSI, and anion BOB- of LIBOB salt, allow hopping of positively charged lithium ions (Li+) but reject negatively charged and relatively large-sized polysulfide anions (Sx-2, 4 <x <8). The cationic group EMIM+ of the IL is electrostatically able to attract and trap the polysulfides in the interlayer membrane. Since the shuttle effect of lithium polysulfides in LiSBs has been suppressed by the prepared IC-GPM70 interlayer, the resulting lithium-sulfur cell exhibits significantly higher cycling stability (1200 cycles), rate performance (1343, 1208, 1043, 875, and 662 mAh g-1 at 0.1C, 0.2C, 0.5C, 1C, and 2C, respectively), and structural integrity during cycling than its counterpart without the IC-GPM70 interlayer. The interlayer membrane has been found to improve the performance and durability of LiSBs, thus making them a viable alternative to conventional LiBs.

Construction of heterojunctions for Mn-Sn bimetallic sulfides @N-doped carbon nanorods as high-performance anode for lithium-ion batteries

MnS is considered as a potential anode own to its merits of high specific capacity, suitable voltage potential, and unique α→β phase transition reaction. Nevertheless, its intrinsic low conductivity, volume variation, and polysulfide dissolution during the lithiation/delithiation process, resulting in inferior cycling performance, then limit its practical application for LIBs. Herein, a novel anode material composited of Mn-Sn bimetallic sulfides heterostructure and N-doped carbon shell (MnS/SnS@NC) is designed. In such a designed MnS/SnS@NC composite, the N-doped carbon is tightly wrapped in the inner MnS/SnS heterostructure through the C-S-Mn bond, which is beneficial to keep the structural stability and enhance the electrochemical reaction kinetics during the lithiation/delithiation process. Furthermore, the heterostructure boosts the ion and electron transfer, and the N-doped carbon buffers the volume change during the cycling process. As a result, the MnS/SnS@NC delivers an excellent long-cycle performance (719.6 mAh g−1 at 1.0 A g−1 after 1000 cycles) and an outstanding rate performance (416.6 mAh g−1 at 5 A g−1).

3D layered structure Ti3C2Tx MXene/Ni(OH)2/C with strong catalytic and adsorption capabilities of polysulfides for high-capacity Sodium–Sulfur battery

The room temperature sodium-sulfur battery has attracted researchers' attention due to its ultra-high energy storage capacity and extremely low cost, but its poor cycling performance and severe dissolution of sodium polysulfide hinder its practical application. Here, we report a stable MXene derived composite sulfur host material based on nickel hydroxide coated with carbon nano network, to achieve the adsorption and conversion of sodium polysulfides. Due to the physical constraints provided by the closed layered structure and the synergistic effect of MXene adsorption and Ni(OH)2catalytic activity, the shuttling effect is effectively suppressed. The ex-situ analysis of electrode after reaction shows that the composite material has strong adsorption on polysulfides. In addition, Ni(OH)2can also accelerate the reaction process from sulfur to sodium sulfide. Therefore, Ti3C2Tx/Ni(OH)2/C/S composite cathode can provide extraordinary reversible capacity 1175.3 mAh/g at 0.22C after 100 cycles and excellent long cycle stability (673.5 mAh/g at 2.2 C with a low decay rate of only 0.032% per cycle over 800 cycles).

Hierarchical hybrid architecture of carbon nanotube branches grown onto steam activated-reduced graphene oxide/Ni nanoparticle for lithium-sulfur battery cathode

Hierarchically structured carbon architecture is considered as a promising candidate of lithium-sulfur battery cathodes owing to its large surface area and percolated electron/ion pathways. However, the synthesis of hierarchical carbonaceous materials requires complicated processes and the resulting materials usually provide weak physical interactions to capture lithium polysulfides, which significantly hinders the performance of lithium-sulfur batteries. In order to resolve these problems, we have demonstrated a facile microwave-assisted synthesis of carbon nanotubes branches grown onto steam-activated reduced graphene oxide (sGNC) to simultaneously synthesize hierarchical carbon structure and nickel nanoparticles for the inhibition of lithium polysulfides shuttle. The hierarchical structure of carbon nanotubes branched from anchored nickel nanoparticle seeds, and uniform distribution of sulfur is attributed to the facilitated electron/ion diffusion pathway, sufficient space to impregnate sulfur, and the lithium polysulfides capturing sites. Accordingly, sGNC-sulfur (sGNC-S) cathode achieved the initial discharge capacity of 829.3 mAh g − 1 at 0.5 C, which is much higher than 531.8 mAh g − 1 of steam-activated reduced graphene oxide-sulfur (sG-S) cathode. When the current rates increased from 0.1 C to 1 C, the capacity retention of the sGNC-S cathode was 67.0%, greater than 62.5% of the sG-S cathode. The decay rate of 0.155%/cycle with the Coulombic efficiency of almost 100% over 200 cycles of the sGNC-S cathode was greater than 0.219%/cycle of the sG-S cathode, originating from facile kinetics and restricted polysulfide dissolution.

Uncovering the solid-phase conversion mechanism via a new range of organosulfur polymer composite cathodes for lithium-sulfur batteries

The sulfur cathodes operating via solid phase conversion of sulfur have natural advantages in suppressing polysulfide dissolution and lowering the electrolyte dosage, and thus realizing significant improvements in both cycle life and energy density. To realize an ideal solid-phase conversion of sulfur, a deep understanding of the regulation path of reaction mechanism and a corresponding intentional material and/or cathode design are highly essential. Herein, via covalently fixing of sulfur onto the triallyl isocyanurate, a series of S-triallyl isocyanurate organosulfur polymer composites (STIs) are developed. Relationship between the structure and the electrochemical conversion behavior of STIs is systematically investigated. It is found that the structure of STIs varies with the synthetic temperature, and correspondingly the electrochemical redox of sulfur can be controlled from conventional “solid–liquid–solid” conversion to the “solid–solid” one. Among the STI series, the STI-5 composite realizes an ideal solid-phase conversion and demonstrates great potential for building a Li–S battery with high-energy density and long-cycle-life: it realizes stable cycling over 1000 cycles in carbonate electrolyte, with a degradation rate of 0.053% per cycle; the corresponding pouch cell shows almost no capacity decay for 125 cycles under the conditions of high sulfur loading (4.5 mg cm−2) and lean electrolyte (8 μL mgs−1). In addition, the tailoring strategy of STI can also apply to other precursors with allyl functional groups to develop new organosulfur polymers for “solid–solid” sulfur cathodes. The vulcanized triallyl phosphate (STP) and triallylamine (STA) both show great lithium storage potential. This strategy successfully develops a new family of organosulfur polymers as cathodes for Li–S batteries via solid-phase conversion of sulfur, and brings insights to the mechanism study in Li–S batteries.

Spherical Sulfur-Infiltrated Carbon Cathode with a Tunable Poly(3,4-ethylenedioxythiophene) Layer for Lithium-Sulfur Batteries.

Li-S batteries have received significant attention owing to their high energy density, nontoxicity, low cost, and eco-friendliness. However, the dissolution of lithium polysulfide during the charge/discharge process and its extremely low electron conductivity hinder practical applications of Li-S batteries. Herein, we report a sulfur-infiltrated carbon cathode material with a spherical morphology and conductive polymer coating. The material was produced via a facile polymerization process that forms a robust nanostructured layer and physically prevents the dissolution of lithium polysulfide. The thin double layer composed of carbon and poly(3,4-ethylenedioxythiophene) provides sufficient space for sulfur storage and effectively prevents the elution of polysulfide during continuous cycling, thereby playing an essential role in increasing the sulfur utilization rate and significantly improving the electrochemical performance of the battery. Sulfur-infiltrated hollow carbon spheres with a conductive polymer layer demonstrate a stable cycle life and reduced internal resistance. The as-fabricated battery demonstrated an excellent capacity of 970 mA h g-1 at 0.5 C and a stable cycle performance, exhibiting ∼78% of the initial discharge capacity after 50 cycles. This study provides a promising approach to significantly improve the electrochemical performance of Li-S batteries and render them as valuable and safe energy devices for large-scale energy storage systems.

Nitrogen-doped porous biochar spheres/Mn3O4 heterostructure as an efficient sulfur host for high performance lithium-sulfur batteries

Improving the conductivity of sulfur and enhancing the anchoring of lithium polysulfides (LiPSs) are the two key points to obtain high performance and good cyclic stability of lithium sulfur batteries (LSBs). So, a composite material with heterostructure of nitrogen-doping porous carbon spheres and Mn3O4 is designed. Nitrogen and Mn3O4 can relieve the dissolution and shuttling of polysulfides through chemisorption and reduce the loss of active substances. The induced electric field of the heterostructure can further strengthen the adsorption and transformation of lithium ions, thus accelerating the reaction process. The synergetic merits make NPCS/Mn3O4@S nanocomposites exhibit significantly better electrochemical performances than NPCS. At 1.0 C, its initial specific capacity can reach 744 mA h g−1, and can stabilize 600 cycles. When the current density is 2.0 C, the initial specific discharge capacity is 674 mA h g−1, and the reversible capacity is still 478 mA h g−1 after 200 cycles.

Cobalt Vanadate (Co3V2O8) Hollow Microspheres as a Polysulfide Adsorption and Conversion Catalyst for Li–S Batteries

A lithium–sulfur battery (Li–S) is considered as one of the most suitable emerging energy storage technologies for electric vehicles (EVs) due to its higher specific capacity, energy density, and low cost. However, the dissolution of lithium polysulfides (LiPS) in an electrolyte causes a huge shuttle effect, which results in poor cycle life and rate performance. Herein, Co3V2O8 (CVO) hollow microspheres have been prepared by the solvothermal method and used as catalyst additives to the sulfur electrode (cathode host). It was found that CVO acts as a bifunctional additive, the vanadium and oxygen sites immobilize the LiPS through V–S and Li–O interactions, while the cobalt site facilitates the rapid conversion of long-chain LiPS into short ones (Li2S2/Li2S). Furthermore, the hollow microspheres act as a sulfur reservoir and can confine (encapsulate) more LiPS during the electrochemical conversion process, thus inhibiting the shuttle effect. In this work, the chemical adsorption and polysulfide conversion ability of CVO is corroborated by XPS and cyclic voltammetry studies, respectively. Even at a higher sulfur loading of 5.4 mg cm–2, CVO containing the Li–S cell (denoted as S@CVO/CNT Vs Li) demonstrates an initial discharge capacity of 694 mAh g–1 at 0.5 C, and after 200 cycles, the observed capacity is 566 mAh g–1, which amounts to 81% capacity retention. Similarly, the cell delivers an excellent rate capability of up to 5 C rate. At the 1 C rate, the cell shows an initial discharge capacity of 904 mAh g–1 (S-loading of 3 mg cm–2) and 692 mAh g–1 after 300 cycles with 77% capacity retention.

Performance Stabilization of Lithium-Sulfur Batteries Containing Sulfolane-based Electrolyte and Microporous Cathode by Controlling Working Voltage Range

For lithium-sulfur (Li-S) batteries, high-concentration electrolyte that inhibits the dissolution of Li polysulfide has been widely studied; one such electrolyte contains sulfolane. This study investigates the conditions under which a microporous activated carbon cathode, derived from azurmic acid, operates stably in a sulfolane-based electrolyte. We expected this cathode to maintain a stable capacity in a sulfolane-based electrolyte because its micropores stabilize the S species. However, Li-S batteries containing this cathode and electrolyte exhibit significant capacity decay during cycling. The cutoff voltage during charge-discharge cycling is varied to suppress the capacity decay. At a discharge voltage of 1.4 V or lower, the cycle life of the Li-S batteries is significantly reduced. Conversely, increasing the cutoff voltage during discharge suppresses the capacity decay of Li-S batteries. On the other hand, increasing the upper voltage limit during charging increases the reversible capacity. Thus, the operating voltage range is optimized. This study indicates that the voltage range of Li-S batteries should be carefully determined depending on the type of cathode material and electrolyte.

Vanadium nitride/reduced graphene oxide composite interlayer with dual lithium-polysulfide adsorption effect for lithium-sulfur batteries

Lithium-sulfur batteries (LSBs) have been developed as next-generation power sources owing to their high theoretical capacities and energy densities, cost effectiveness, and abundance. However, the low electrical conductivity of sulfur in the cathode and the dissolution of lithium polysulfides (LiPS) into the liquid electrolyte are challenging issues that deteriorate both capacity and energy density. Herein, a porous vanadium nitride and reduced graphene oxide (VN/rGO) composite is prepared as an LSB interlayer that enhances conversion and redox reactions and increases sulfur utilization. Polar VN in the VN/rGO interlayer chemically adsorbs LiPS while rGO provides excellent electrical conduction and a high specific surface area for the physical adsorption of LiPS. The dual LiPS adsorption effect of VN/rGO suppresses shuttle effect and enhances electrochemical performance, leading to specific capacities of 1025 and 693 mA h g−1 at 0.5 and 2 C, respectively, and a retention of 81 % at 0.5 C after 200 cycles.

Growing Intact Membrane by Tuning Carbon Down to Ultrasmall 0.37 nm Microporous Structure for Confining Dissolution of Polysulfides Toward High‐Performance Sodium–Sulfur Batteries

Room temperature sodium–sulfur (Na–S) batteries are severely hampered by dissolution of polysulfides into electrolytes. Herein, a facile approach is used to tune a biomass‐derived carbon down to an ultrasmall 0.37 nm microporous structure for the first time as a cathode in sodium–sulfur batteries. This produced an intact uniform Na2S membrane to greatly confine the dissolution of polysulfides while realizing a direct solid phase conversion for complete reduction of sulfur to Na2S, which delivers a sulfur loading of 1 mg cm−2 (50 wt.%), an excellent rate capacity (933 mAh g−1 @ 0.1 A g−1 and 410 mAh g−1 @ 2 A g−1), long cycle performance (0.036% per cycle decay at 1 A g−1 after 1500 cycles), and a high energy density for 373 Wh kg−1 (0.1 A g−1) based on whole electrode weight (active sulfur loading + carbon), ranking the best among all reported plain carbon cathode‐based room temperature sodium–sulfur batteries in terms of the cycle life and rate capacity. It is proposed that the solid Na2S produced in the ultrasmall pores (0.37 nm) can be squeezed out to grow an intact membrane on the electrode surface covering the outlet of the pores and greatly depressing the dissolution effect of polysulfides for the long cycle life. This work provides a green chemistry to recycle wastes for sustainable energies and sheds light on design of a unique pore structure to effectively block the dissolution of polysulfides for high‐performance sodium–sulfur batteries.

Bioinspired urchin-like murray carbon nanostructure with protection shell for advanced lithium-sulfur batteries

Commercial application of lithium-sulfur (Li-S) batteries is hindered by the insulating nature of sulfur and the dissolution of polysulfides. Here, a bioinspired 3D urchin-like N-doped Murray’s carbon nanostructure (N-MCN) with interconnected micro-meso-macroporous structure and a polydopamine protection shell has been designed as an effective sulfur host for high-performance Li-S batteries. The advanced 3D hierarchically porous framework with the characteristics of the generalized Murray’s law largely improves electrolyte diffusion, facilitates electrons/ions transfer and provides strong chemisorption for active species, leading to the synergistic structural and chemical confinement of polysulfides. As a result, the obtained P@S/N-MCN electrode with high areal sulfur loading demonstrates high capacity at high current densities after long cycles. This work reveals that following the generalized Murray’s law is feasible to design high-performance sulfur cathode materials for potentially practical Li-S battery applications.

Reversible Sodium–Sulfur Batteries Enabled by a Synergistic Dual-Additive Design

We demonstrate here that a combination of bismuth triflate and 1,3,2-dioxathiolane 2,2-dioxide additives in a conventional ether-based electrolyte enables Na metal to cycle with a high Coulombic efficiency of above 99% and completely suppresses the dissolution of sodium polysulfides. Bismuth triflate enables a facile dissolution of sodium triflate based on a salt-in mechanism, which increases the sodium salt concentration and effectively prevents the decomposition of the solvent and additive. This process also facilitates the formation of an anion-derived inorganic solid electrolyte interphase. Additionally, the 1,3,2-dioxathiolane 2,2-dioxide additive spontaneously reacts with sodium sulfide to form a thiosulfate-based robust cathode–electrolyte interphase on a sulfurized polyacrylonitrile (SPAN) cathode. The full cell operated under a practical cell configuration attains a capacity retention of 79% for 150 cycles with a capacity of 535 mAh/g of SPAN. This work reveals the synergistic effects of commonly used additives on stabilizing the aggressive sodium–sulfur chemistry and opens great opportunities for practical applications.

Nickel Oxide Decorated Halloysite Nanotubes as Sulfur Host Materials for Lithium-Sulfur Batteries.

Lithium-sulfur batteries with high energy density still confront many challenges, such as polysulfide dissolution, the large volume change of sulfur, and fast capacity fading in long-term cycling. Herein, a naturally abundant clay material, halloysite, is introduced as a sulfur host material in the cathode of Li-S batteries. Nickel oxide nanoparticles are embedded into the halloysite nanotubes (NiO@Halloysite) by hydrothermal and calcination treatment to improve the affinity of halloysite nanotubesto polysulfides. The NiO@Halloysite composite loaded with sulfur (S/NiO@Halloysite) is employed as the cathode of Li-S batteries, which combines the physical confinements of tubular halloysite particles and good chemical adsorption ability of NiO. The S/NiO@Halloysite electrode exhibits a high discharge capacity of 1205.47mAhg-1 at 0.1C. In addition, it demonstrates enhanced cycling stability, retaining ≈60% of initial capacity after 450 cycles at 0.5C. The synthesized NiO@Halloysite can provide a promising prospect and valuable insight into applying natural clay materials in Li-S batteries.

Suppressing polysulfide shuttle in lithium-sulfur batteries using CNTs/C3N4/S cathodes

To suppressing the shuttle effect of lithium polysulfides during cycling, a synergism strategy is proposed to prepare CNTs/C3N4-X composites with an adjustable ratio of carbon nanotubes (CNTs) to carbon nitride (C3N4). When the mass of C3N4 is 10% of the total mass of CNTs/C3N4-X composites, the sulfur loading is high up to about 70%. Evaluated as cathodic host material of lithium-sulfur (Li-S) batteries, CNTs/C3N4-10/S cathode exhibits superior cyclical stability and rate capability. The first cycle discharge specific capacity is as high as 1074.3 mA h g−1 at 0.1 C, and it persists 830.3 mA h g−1 after 100 cycles. Even at 0.5 C, the discharge specific capacitance still retains 559.2 mA h g−1 after 650 cycles with a capacity retention ratio of 73.0%. The discharge specific capacities are 890.3, 783.9, 625.9 and 510.1 mA h g−1 at 0.2, 0.5, 1.0 and 2.0 C, indicating high rate capability. The superior performances are mainly ascribed to the synergism of CNTs and C3N4, which restricts the dissolution of lithium polysulfide, relieves volume expansion and improves the electrical conductivity, leading to enhanced cycle stability and rate capability of Li-S batteries.

Ex‐Situ Raman Microscopic Investigation of the High‐Order Polysulfide Restriction of Encapsulated Sulfur Nanowires

Lithium-sulfur (Li−S) batteries are attracting significant research attention because of their high theoretical energy density (2500 Wh kg−1) and excellent economic feasibility. However, commercialization has proven difficult owing to their low electronic conductivity and the dissolution of lithium polysulfide (Li2Sx; x=1–8). In particular, lithium polysulfide dissolution is known to be caused by high-order polysulfide generated at the start of the discharge process. Thus, the control of this factor is important because it determines the electrochemical performance of the cell. In this study, three types of sulfur nanocomposites in the orthorhombic, amorphous, and monoclinic phases, were designed and successfully manufactured. The mechanism of polysulfide generation was confirmed to differ according to the location of sulfur on the carbon matrix (inner pores and surfaces) and allotropic form of sulfur (S4–S8) via electrochemical tests. Furthermore, the electrochemical reaction mechanism was identified by tracing the lithium polysulfide species according to the reaction region using ex-situ Raman spectroscopy. In this research, suppression of the high-order polysulfide generation reaction by controlling the monoclinic sulfur was represented by a single plateau galvanostatic curve, suggesting a clear strategy for maximizing cycle stability in next-generation Li−S batteries

Boosting sulfur‐based cathode performance via confined reactions in covalent organic frameworks with polarized sites

AbstractThe widespread promotion of the sulfur‐based cathode is continuously threatened by the dissolution or slow kinetic reactions of polysulfides, resulting in a deterioration of capacity and volume expansion. Herein, a hierarchical imine‐based covalent organic framework (COFs) with AA stacking structure is constructed as a sulfur host matrix. The one‐dimensional channels in COF are decorated with polarized methoxy groups which can confine and immobilize sulfur species through weak interactions, alleviating the shuttle effect during the battery tests. The composite electrode (COF@S) is fabricated through the melt‐diffusion method in one‐pot synthesis and exhibits a slow fading rate (0.20% each cycle) in a 0.5 C stability test. A promising mechanism for constructing the cathode composite is demonstrated in lithium‐sulfur chemistry in this work.

Evaluating the Effect of Binder for Sulfurized Polyacrylonitrile Cathode via Optical Fiber Sensors

AbstractSulfurized polyacrylonitrile (SPAN) is a very stable and promising sulfur‐based cathode material for high energy density lithium–sulfur (Li–S) batteries, which can circumvent the polysulfides dissolution issue. However, the stress concentration caused by volume change in SPAN cathodes is relatively significant but is rarely focused on. It is widely reckoned that the binder plays a key role in buffering the stress induced by electrode materials and hence maintains the integrity of electrodes. Nevertheless, the understanding of the actual effect of binders to SPAN cathodes from the aspect of mechanics remains to be deepened. Here, the optical fiber Bragg grating (FBG) is implanted into SPAN cathode films to in situ evaluate the electrochemo‐mechanical behaviors by using four different binders. The internal strain evolution of SPAN cathodes is affected by multiple factors of adhesion and mechanical properties of different binders. It is found that the SPAN cathode using poly(acrylic acid) (PAA) binder with outstanding mechanical properties experiences the largest strain change but the electrochemical performance is even better under high sulfur loading. Furthermore, the strain evolution is monitored under high sulfur loading condition and how the sulfur loading affects the signals of the built‐in FBG sensors is tried to figure out.