Lithium Sulfur Research Articles

Nanocarbon/aramid fiber 3D porous current collector enhanced electrochemical performance in lithium sulfur batteries

Nanocarbon/aramid fiber 3D porous current collector enhanced electrochemical performance in lithium sulfur batteries

Role and Evolution of FeS2 Cathode Microstructure in Argyrodite-Based All-Solid-State Lithium–Sulfur Batteries

Role and Evolution of FeS₂ Cathode Microstructure in Argyrodite-Based All-Solid-State Lithium–Sulfur Batteries

Stress-tolerant sulfur cathode with a super-stretchable polymer coating via initiated chemical vapor deposition

The mechanical deterioration of the sulfur cathode during cycling from repeated voltage changes is a limiting factor of the cycling stability of lithium-sulfur batteries. Herein, we present a stress-tolerant sulfur cathode by conformally coating the surface with a super-stretchable thin polymer layer via an initiated chemical vapor deposition method. A layer tens of nanometers thick is formed in the sulfur cathode via the copolymerization of hydroxyethyl acrylate and 1,3,5-trivinyl-1,3,5-trimethylcyclotrisiloxane in a gas-phase reaction, and its mechanical properties are tuned by varying the copolymer composition. In comparison with a bare sulfur cathode, which exhibited cracking after cycling, the sulfur cathode with an optimized polymer layer exhibited a crack-free morphology and showed significantly improved cycling stability owing to its high elastic modulus and high elongation at break. Furthermore, the coating reduced the polysulfide shuttle current, demonstrating its function as a polysulfide-blocking layer. This super-stretchable polymer coating provides a unique platform for mechanically robust and high-performance sulfur cathodes.

Diamondoid All-Carbon Porous Aromatic Framework Host for Lithium-Sulfur Batteries.

Lithium-sulfur batteries (LSBs) hold incredible potential as next-generation energy storage systems. However, practical applications of LSBs are significantly hindered by several critical challenges. For the first time, scalable all-carbon porous 3D polymers (3DPs) that do not contain heteroatoms or functional groups and do not require post-functionalization are investigated as hosts in lithium-sulfur batteries, demonstrating enhanced cycling stability and overall battery performance. The pyrene-containing 3DP exhibits 75% capacity retention after 600 cycles at 1 C and 52% capacity retention after 1300 cycles at 0.2 C, better than phenyl comprising 3DP. Furthermore, even at higher sulfur loading (4.1mgcm-2) with an electrolyte/sulfur ratio of 5µLmg-1, pyrene 3DP displayed a high capacity of 600mA hg-1 and stable performance over 250 cycles with negligible capacity fade. The defined pore structure of 3DPs prevents the migration of polysulfides through physical confinement and the large π-clouds of 3DPs interact with the negative charge-bearing polysulfides generated in charge-discharge cycles through anion-π interaction. In this way, The design ensures that the host 3DPs interact with neutral sulfur and anionic polysulfides, resulting in an excellent performance.

Unraveling Multiphase Conversion Pathways in Lithium-Sulfur Batteries through Cryo Transmission Electron Microscopy and Machine Learning-Assisted Operando Neutron Scattering.

Understanding the complex physicochemical processes in conversion-type batteries requires investigations across multiple length scales. Here, we present a methodological approach to examine Li-S batteries on the nanoscale by combining cryogenic transmission electron microscopy (cryoTEM) with operando small-angle neutron scattering (SANS). CryoTEM revealed discharge products with a biphasic structure consisting of nanocrystalline Li2S within an amorphous Li2Sx matrix. Data analysis of complementary operando SANS measurements was accelerated by a convolutional neural network trained to predict scattering curves based on plurigaussian random fields, enabling comprehensive parameter space exploration for model fitting. Our findings are in line with disproportionation-driven deposition of Li2S2 particles that agglomerate and partially reduce to Li2S via solid-state conversion. This challenges the conventional view of direct, stepwise electroreduction of polysulfides at the electrode-electrolyte interface. Overall, our multitechnique approach demonstrates the value of combining localized high-resolution imaging with time-resolved operando scattering measurements to understand complex electrochemical conversion pathways in next-generation energy storage systems.

MOF-Based Electrocatalysts for Water Electrolysis, Energy Storage, and Sensing: Progress and Insights.

Metal-organic frameworks (MOFs) and their derivatives have shown broad application prospects in fields such as water electrolysis, electrochemical energy storage, and sensing due to their high specific surface area, tunable structures, and abundant active sites. This article provides a comprehensive overview of our research group's recent advancements in developing MOF-based electrocatalysts for Oxygen Evolution Reaction (OER) and Urea Oxidation Reaction (UOR) at anodes, as well as Hydrogen Evolution Reaction (HER) at cathodes during water electrolysis. Furthermore, we have integrated these catalysts into practical applications, including metal-air batteries, lithium-sulfur batteries, and non-enzymatic glucose sensors. To further demonstrate the innovative contributions of our work, we systematically compare it with the advanced work by other groups. Based on these findings and performance benchmarking analyses, we identify critical challenges that must be addressed to advance MOFs-based electrocatalysts toward next-generation energy conversion and sensing.

Ni/Zn-Anchored/N-Doped Porous Carbon Microtubes Derived from Palm Threads for High-Performance Li-S Batteries.

Nitrogen-doped porous carbon microtubes embedded with Ni/Zn catalytic sites (NiZn-NPCT) are constructed from palm threads and can be used as both a S cathodic host and a separator modifier for advanced lithium-sulfur batteries. NiZn-NPCT possesses unique interconnected porous tunnels and abundantly exposed active sites, which increase the affinity for lithium polysulfides (LiPSs) and thus inhibit the shuttle effect. The kinetic studies indicate that NiZn-NPCT can accelerate the redox transformation of sulfur species. The battery assembled with the NiZn-NPCT-modified separator achieves high initial discharge capacities of 1220 and 409.1 mAh g-1 at 0.1C and 5C, respectively, with good cycling stability (418.1 mAh g-1 after 500 cycles at 1C). In addition, with a higher sulfur/NiZn-NPCT mass ratio (9:1), the battery still exhibited high initial discharge capacities of 1234.4 (0.1C) and 551.3 mAh g-1 (5C). This study offers an effective strategy to utilize renewable biomass with a unique microstructure and realize high-performance Li-S batteries.

Unveiling the Entropic Effect of Electrolytes on Kinetics and Cyclability for Practical Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries under low-temperature and lean electrolyte conditions for practical application are hindered by a sluggish conversion reaction, low sulfur utilization, and cycling stability. Herein, we designed a high-entropy (HE) electrolyte by mixing three Li salts. The HE electrolyte simultaneously improves lithium sulfide (Li2S) conversion reaction kinetics, sulfur utilization, and cyclability due to the anticlustering effect on lithium polysulfides, three-dimensional Li2S growth, and robust anion-derived solid electrolyte interphase layer formation, respectively. Consequently, the HE electrolyte exhibits a high initial reversible capacity (1159.9 mAh g-1) and cycling stability for 40 cycles under a low electrolyte-to-sulfur ratio (3.5 μL mg-1) at the pouch cell level. In addition, the Li-S cell with HE electrolyte exhibits high cycling stability with a capacity decay of 0.01% per cycle during 200 cycles at -15 °C.

An Expansion-Mitigant Binder for Stable Cycling of High-Loading Lithium-Sulfur Batteries.

Lithium-sulfur batteries with high sulfur content and mass loading are promising energy storage technologies due to sulfur's exceptional theoretical energy density. However, in practice, their actual capacity drastically decays when the sulfur cathode is loaded to the commercially required levels of 4 mgsulfur cm-2 and above, significantly reducing the energy density. This reduction is due to the excessive formation of polysulfides during sulfur lithiation, which not only deteriorates battery performance through their detrimental shuttling but also results in substantial stress buildup due to their significantly larger volume compared to sulfur. To address these challenges, we have developed an approach to suppress lithium polysulfide shuttling by limiting the space for sulfur expansion while improving the Li+ ion diffusion. This was achieved through a straightforward but effective method to cross-link the organic binder used in sulfur electrodes. Specifically, PVDF, one of the most common binder materials for battery electrodes, was studied. The chemical, mechanical, and structural properties of the cross-linked PVDF binder were thoroughly investigated, compared with standard PVDF, and correlated to the achieved electrochemical performance of sulfur electrodes. As a result, sulfur cathodes with cross-linked PVDF binder exhibited prolonged cycle life compared to their standard counterparts. Moreover, using this expansion-mitigant binder, cathodes with areal sulfur loading of 4 mg cm-2 showed exceptional stability for more than 200 cycles and a Coulombic efficiency above 97%. This approach offers a promising avenue to alleviate the major roadblocks of lithium-sulfur battery commercialization while allowing the utilization of the commonly accessible and well-studied binder chemistries.

MoO2–Stabilized MoS2 Heterojunction Catalyst for Enhanced Lithium–Sulfur Battery

MoO₂–Stabilized MoS₂ Heterojunction Catalyst for Enhanced Lithium–Sulfur Battery

Two-Stage Solvation of Lithium Polysulfides in Working Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are promising in achieving high energy density but inferior in cycling lifespan since Li polysulfides (LiPSs) corrode Li metal anode. Weakening the electrolyte solvating power (ESP) for LiPSs effectively mitigates anodic corrosion but inevitably retards cathodic reaction kinetics. Herein, the correlation between the ESP and the LiPS redox kinetics in weakly solvating electrolyte is unveiled for achieving high-performance Li-S batteries. The ESP exhibits a two-stage variation tendency as the weakly solvating solvent (WSS) content increases, where the transition depends on whether the WSS enters the LiPS inner solvation shell. Once the WSS directly coordinates with LiPSs, the LiPS charge-transfer kinetics deteriorate dramatically, with a rapid increase in activation polarization. To overcome the kinetic sluggishness, advanced electrocatalysts are introduced to endow Li-S batteries with reduced polarization and prolonged cycling lifespan. An ultrahigh energy density of 607 W h kg-1 is realized in 10 Ah-level pouch cells with a stable cycling lifespan. This work deepens the current understanding of LiPS solvation and kinetics, highlighting the significance of weakly solvating electrolytes toward high-energy-density and long-cycling Li-S batteries.

Polysulfide barrier comprising bismuth selenide nanocrystals well anchored within N-doped carbon microspheres for stable Li-S batteries

The development of functional interlayers to effectively anchor lithium polysulfide and enhance the integrity of sulfur cathodes in lithium-sulfur (Li-S) batteries has received significant global consideration. However, identifying an interlayer that is both highly conductive and structurally robust remains a major challenge. This study presents the synthesis of three-dimensional nitrogen-doped carbon microspheres embedded with bismuth selenide nanocrystals (referred to as “three-dimensional (3D) Bi2Se3@N-C” microspheres) and evaluates their role as a polysulfide barrier for enhanced Li-S battery performance. The embedded Bi2Se3 nanocrystals within the microspheres provide numerous active spots for chemical captivity and electrocatalytic transformation of lithium polysulfide species. Moreover, the N-doped carbon framework facilitates speedy transfer of charge moieties, resulting in faster redox activity. Correspondingly, cells paired with 3D Bi2Se3@N-C microsphere modified separators exhibit excellent rate capability (297 mA h g-1 at 2.0 C-rate) and prolonged stable cycling performance at different C-rates (863 mA h g-1 after 100 cycles at 0.1 C, 440 mA h g-1 after 200 cycles at 0.5 C, and 219 mA h g-1 after 500 cycles at 2.0 C). The cell demonstrates satisfactory cycling performance retaining 57% of its capacity after 200 cycles when the active material loading was raised to 3.5 mg cm-2, confirming the practical feasibility of the prepared nanostructure. The detailed physical and electrochemical results presented in this study offer valuable perceptions for the expansion of structurally superior, conductive, and easily scalable nanostructures for various energy storage demands.

Sulfur-doped biocarbon as a sulfur host and a polysulfide trapping agent in lithium-sulfur batteries

Sulfur-doped biocarbon as a sulfur host and a polysulfide trapping agent in lithium-sulfur batteries

Catalytic V5S8 anchored on PCMFs boosting polysulfides conversion for lithium-sulfur batteries

Catalytic V5S8 anchored on PCMFs boosting polysulfides conversion for lithium-sulfur batteries

Construction of MXene-Based Heterostructured Hybrid Separators for Lithium–Sulfur Batteries

The advancement of lithium–sulfur (Li-S) batteries has been hindered by the shuttle effect of lithium polysulfides (LiPSs) and sluggish redox kinetics. The engineering of functional hybrid separators is a relatively simple and effective coping strategy. Layered transition-metal carbides, nitrides, and carbonitrides, a class of emerging two-dimensional materials termed MXenes, have gained popularity as catalytic materials for Li-S batteries due to their metallic conductivity, tunable surface chemistry, and terminal groups. Nonetheless, the self-stacking flaws and easy oxidation of MXenes pose disadvantages, and developing MXene-based heterostructures is anticipated to circumvent these issues and yield other remarkable physicochemical characteristics. Herein, recent advances in the construction of MXene-based heterostructured hybrid separators for improving the performance of Li-S batteries are reviewed. The diverse conformational forms of heterostructures and their constitutive relationships with LiPS conversion are discussed, and the general principles of MXene surface chemistry alterations and heterostructure designs for enhancing electrochemical performance are summarized. Lastly, tangible challenges are addressed, and advisable insights for future research are shared. This review aims to highlight the immense superiority of MXene-based heterostructures in Li-S battery separator modification and inspire researchers.

Halide Chemistry Boosts All-Solid-State Li-S Batteries.

All-solid-state Li-S batteries (ASSLSBs) are emerging as a promising energy storage solution due to their low cost and high energy density. Their solid-state configuration effectively eliminates the notorious shuttle effect caused by soluble polysulfides in conventional liquid electrolytes. However, the heterogeneous solid-to-solid interfaces introduce significant challenges, including sluggish ion/electron transport and interfacial instability among electrode materials, conductive additives, and solid electrolytes (SEs). Recently, halide-based strategies have gained attention for enabling high-performance ASSLSBs. This perspective highlights these strategies, emphasizing the role of halide chemistry in enhancing ASSLSB kinetics. It is contended that halides (e.g., iodides) in sulfur-based cathode composites-such as Li2S and transition metal sulfides-can activate S/Li2S redox reactions, improving both ionic and electronic conductivities. This "catalytic effect" of halides accelerates the reversible transition, even in the absence of conductive additives like SEs or conductive carbons. Moreover, halides at the anode interface play a crucial role in preventing Li dendrite formation and SE degradation, owing to their large polarizability and high interfacial energy. This perspective provides a timely and insightful summary of halide chemistry's impact on ASSLSB kinetics, offering inspiration for further research and broader adoption of halide-based strategies in next-generation solid-state Li-S batteries.

Mitigation of Polysulfide Shuttling in Lithium-Sulfur Batteries Utilizing Vanadium Pentoxide/Polypyrrole Nanocomposite Separators.

Lithium-sulfur (Li-S) batteries are promising energy storage devices due to their high theoretical energy density and cost-effectiveness. However, the shuttle effect of polysulfides during the charging and discharging processes leads to a rapid decline in capacity, thereby restricting their application in energy storage. The separator, a crucial component of Li-S batteries, facilitates the transport of Li+ ions. However, the large pores present on the surface of the separator are insufficient to prevent the shuttling effect of polysulfides. This paper proposes a straightforward coating method to introduce a vanadium pentoxide (V2O5) /polypyrrole (PPy) functional coating on the surface of a conventional polymer separator. The unique composition of the V2O5/PPy layer plays an essential role in effectively preventing the bidirectional movement of polysulfides and the subsequent formation of inactive sulfur. Compared to those using polypyrrole separators,when equipped with a V2O5/PPy separator, the capacity retention after 100 cycles was recorded at 98 %, with a measured rate of capacity degradation at just 0.016 %, despite the sulfur content being as high as 1.84 mg cm-2. Furthermore, after 400 cycles at 1 C, the capacity retention rate reached 57.6 %. The thoughtful design of this modified separator represents an effective strategy for improving the performance of Li-S batteries.

Shortening the Reaction Pathway of Sulfur Redox Kinetics with 2,5-Dichloro-1,4-Benzoquinone to Minimize the Shuttle Effect in Lithium-Sulfur Batteries.

The low active material utilization, sluggish sulfur redox kinetics, and formation of unstable interfacial layers remain critical challenges in lithium-sulfur (Li-S) batteries. To minimize these effects, 2, 5-dichloro-1,4-benzoquinone (DCBQ) was demonstrated in this study as an electrolyte additive. Leveraging its unique symmetrical structure, DCBQ interacted with polysulfides during charge and discharge cycles to form insoluble symmetric cyclic organic polysulfide intermediates. These intermediates served as a cathode-electrolyte interphase (CEI) by attaching to the sulfur cathode surface, which mitigated the shuttle effect by reducing the accumulation of insoluble Li2S and suppressing polysulfide dissolution. In the presence of DCBQ, the discharge pathway for Li2S6 transitioned from Li2S6 → Li2S4 → Li2S2 → Li2S to a shortened sequence of Li2S6 → Li2S3 → Li2S, enhancing sulfur utilization and streamlining redox processes. On the anode side, the formation of LiCl and intermediate compounds contributed to an organic-inorganic solid-electrolyte interface (SEI), which protected the lithium anode, improved the Li+ diffusion coefficient (6.63 × 10-11 cm2 S-1), and eventually enhanced the battery's cycling stability. Consequently, the Li-S battery that included the DCBQ additive exhibited nearly 100% Coulombic efficiency at a rate of 0.2 C. It showed an initial discharge-specific capacity of 992.24 mAh g-1 and experienced a low-capacity degradation of just 0.45% per cycle over 120 cycles. These results highlight the effectiveness of DCBQ as an electrolyte additive in enhancing both the performance and stability of the battery.

Ten‐Electron Count Rule of MXene‐Supported Single‐Atom Catalysts for Sulfur Reduction in Lithium–Sulfur Batteries

ABSTRACTLithium–sulfur (Li–S) batteries are proposed as next‐generation energy storage devices due to their high theoretical capacity and specific energy. However, the actual capacity utilization is greatly limited by the poor reactivity of the sulfur reduction reaction (SRR), which motivates us to develop corresponding high‐efficient catalysts. Inspired by the application of MXene and single‐atom catalysts (SACs) in improving SRR, a virtual screening on the MXene‐supported SACs from the imp2d database is carried out. Finally, six kinds of top catalysts are identified for SRR, and most of them can be considered as variants of the previous representative SRR catalysts, which reflects the rationality of our screening. Meanwhile, the stability and reactivity metrics of the SACs are calculated by density functional theory (DFT) and show obvious trends depending on the type of adatom/MXene. For the critical intermediate binding that can tune SRR activity, further electronic structure analysis reveals the so‐called 10‐electron count rule, whose decisive role is also reflected by the Shapley value analysis from machine learning (ML). It is noteworthy that this count rule was used to analyze the SACs for hydrogen/carbon/nitrogen‐related reactions before, and our successful attempt to optimize SRR further indicates its universality in catalysis fields. Overall, the 10‐electron count rule not only rationalizes the nature of SAC–adsorbate interactions but also provides intuitive design guidance for novel SRR catalysts.

Advances in Standardised Battery Testing for Enhanced Safety and Innovation in Electric Vehicles: A Comprehensive Review

Standardised battery tests are essential for evaluating the safety, reliability, and performance of modern battery technologies, especially with the rapid emergence of innovations such as solid-state and lithium–sulphur batteries. This review reveals critical shortcomings in current international standards (e.g., IEC, IEEE, SAE), which often do not keep pace with technological developments and are not harmonised across regions, limiting their effectiveness in real-world applications. The paper stresses the need for the continuous review of test protocols through collaboration between researchers, manufacturers, and regulators. A detailed case study of the BYD Dolphin battery demonstrates the practical importance of comprehensive testing in real-world conditions, spanning electrical, thermal, and mechanical ranges. The review concludes that up-to-date, harmonised, and scenario-specific test methods are needed to ensure accurate battery assessment, support global comparability, and enable the safe introduction of next-generation batteries for electric mobility and energy storage. Future work should prioritise operational monitoring, open access data sharing, and the development of sustainability-focused practices such as recycling and reclamation.