Accurate prediction of range of an electric vehicle (EV) is a significant issue and a key market qualifier. EV range forecasting can be made practicable through the application of advanced modelling and estimation techniques. Battery modelling and state-of-charge estimation methods play a vital role in this area. In addition, battery modelling is essential for safe charging/discharging and optimal usage of batteries. Much existing work has been carried out on incumbent Lithium-ion (Li-ion) technologies, but these are reaching their theoretical limits and modern research is also exploring promising next-generation technologies such as Lithium–Sulphur (Li–S). This study reviews and discusses various battery modelling approaches including mathematical models, electrochemical models and electrical equivalent circuit models. After a general survey, the study explores the specific application of battery models in EV battery management systems, where models may have low fidelity to be fast enough to run in real-time applications. Two main categories are considered: reduced-order electrochemical models and equivalent circuit models. The particular challenges associated with Li–S batteries are explored, and it is concluded that the state-of-the-art in battery modelling is not sufficient for this chemistry, and new modelling approaches are needed.

Abstract The research and development of advanced energy-storage systems must meet a large number of requirements, including high energy density, natural abundance of the raw material, low cost and environmental friendliness, and particularly reasonable safety. As the demands of high-performance batteries are continuously increasing, with large-scale energy storage systems and electric mobility equipment, lithium-sulfur batteries have become an attractive candidate for the new generation of high-performance batteries due to their high theoretical capacity (1675 mA h g -1 ) and energy density (2600 Wh kg -1 ). However, rapid capacity attenuation with poor cycle and rate performances make the batteries far from ideal with respect to real commercial applications. Outstanding breakthroughs and achievements have been made to alleviate these problems in the past ten years. This paper presents an overview of recent advances in lithium-sulfur battery research. We cover the research and development to date on various components of lithium-sulfur batteries, including cathodes, binders, separators, electrolytes, anodes, collectors, and some novel cell configurations. The current trends in materials selection for batteries are reviewed and various choices of cathode, binder, electrolyte, separator, anode, and collector materials are discussed. The current challenges associated with the use of batteries and their materials selection are listed and future perspectives for this class of battery are also discussed.

The commercialization of lithium ulfur batteries is hindered by serious capacity fading that mainly results from the irreversible oxidation of sulfur active material during cycling, but so far the underlying oxidation mechanism still remains unclear. The research results reveal that the most practical solvent DOL and DME are not stable and large amount of degradation products with -OLi edge groups become the oxygen source. The shuttle phenomenon is an important reason leading to the irreversible oxidation of sulfur active material, which results from series chemical reductions of lithium polysulfide, and they keep charge conservation by their selves, but prolong the charge process and lead to the overcharging. In charge process, the low speed reactions of long-chain lithium polysulfide oxidized to LixSOy species exist in the electrolyte, which are indistinctly in the systems without overcharging. As the shuttle phenomenon prolongs the charge process, the irreversible oxidation reactions become distinctly, and the LixSOy species are detectable. The overcharging capacity could be explained as a reversible part and an irreversible part. The reversible capacity is from the cathode active material oxidized to long-chain lithium polysulfide and elemental sulfur, and the irreversible capacity is from the long-chain lithium polysulfide oxidized to LixSOy species.

Abstract Due to their high energy density and low material cost, lithium-sulfur batteries represent a promising energy storage system for a multitude of emerging applications, ranging from stationary grid storage to mobile electric vehicles. This review aims to summarize major developments in the field of lithium-sulfur batteries, starting from an overview of their electrochemistry, technical challenges and potential solutions, along with some theoretical calculation results to advance our understanding of the material interactions involved. Next, we examine the most extensively-used design strategy: encapsulation of sulfur cathodes in carbon host materials. Other emerging host materials, such as polymeric and inorganic materials, are discussed as well. This is followed by a survey of novel battery configurations, including the use of lithium sulfide cathodes and lithium polysulfide catholytes, as well as recent burgeoning efforts in the modification of separators and protection of lithium metal anodes. Finally, we conclude with an outlook section to offer some insight on the future directions and prospects of lithium-sulfur batteries.

Amid burgeoning environmental concerns, electrochemical energy storage has rapidly gained momentum. Among the contenders in the ‘beyond lithium’ energy storage arena, the lithium-sulfur (Li-S) battery has emerged as particularly promising, owing to its potential to reversibly store considerable electrical energy at low cost. Whether or not Li-S energy storage will be able to fulfil this potential depends on simultaneously solving many aspects of its underlying conversion chemistry. Here, we review recent developments in tackling the dissolution of polysulfides — a fundamental problem in Li-S batteries — focusing on both experimental and computational approaches to tailor the chemical interactions between the sulfur host materials and polysulfides. We also discuss smart cathode architectures enabled by recent materials engineering, especially for high areal sulfur loading, as well as innovative electrolyte design to control the solubility of polysulfides. Key factors that allow long-life and high-loading Li-S batteries are summarized.

The use of sulfur in the next generation Li-ion batteries is currently precluded by its poor cycling stability caused by irreversible Li2S formation and the dissolution of soluble polysulfides in organic electrolytes that leads to parasitic cell reactions. Here, a new C/S cathode material comprising short-chain sulfur species (predominately S2) confined in carbonaceous subnanometer and the unique charge mechanism for the subnano-entrapped S2 cathodes are reported. The first charge–discharge cycle of the C/S cathode in the carbonate electrolyte forms a new type of thiocarbonate-like solid electrolyte interphase (SEI). The SEI coated C/S cathode stably delivers ≈600 mAh g611 capacity over 4020 cycles (0.0014% loss cycle611) at ≈100% Coulombic efficiency. Extensive X-ray photoelectron spectroscopy analysis of the discharged cathodes shows a new type of S2 species and a new carbide-like species simultaneously, and both peaks disappear upon charging. These data suggest a new sulfur redox mechanism involving a separated Li+/S261 ion couple that precludes Li2S compound formation and prevents the dissolution of soluble sulfur anions. This new charge/discharge process leads to remarkable cycling stability and reversibility.

Abstract The emergence of flexible and wearable electronic devices with shape amenability and high mobility has stimulated the development of flexible power sources to bring revolutionary changes to daily lives. The conventional rechargeable batteries with fixed geometries and sizes have limited their functionalities in wearable applications. The first-ever graphene-based fibrous rechargeable batteries are reported in this work. Ultralight composite fibers consisting of reduced graphene oxide/carbon nanotube filled with a large amount of sulfur (rGO/CNT/S) are prepared by a facile, one-pot wet-spinning method. The liquid crystalline behavior of high concentration GO sheets facilitates the alignment of rGO/CNT/S composites, enabling rational assembly into flexible and conductive fibers as lithium–sulfur battery electrodes. The ultralight fiber electrodes with scalable linear densities ranging from 0.028 to 0.13 mg cm611 deliver a high initial capacity of 1255 mAh g611 and an areal capacity of 2.49 mAh cm612 at C/20. A shape-conformable cable battery prototype demonstrates a stable discharge characteristic after 30 bending cycles.

Highly porous carbon has played an important role in tackling down the energy and environmental problems due to their attractive features such as high specific surface area (SSA), stability, and mass productivity. Especially, the desirable characteristics of the highly porous carbon such as lightweight, fast adsorption/desorption kinetics, and high SSA have attracted extensive attention in the “hydrogen storage” application which is a main bottleneck for the realization of on-board hydrogen fuel cell vehicles. We herein presented porous carbon with hierarchical pore structure derived from highly crystalline metal organic frameworks (denoted as MOF-derived carbon: MDC) without any carbon source and showed it as a promising hydrogen storage adsorbent. MDCs can be fabricated by a simple heat adjustment of MOFs without complicated process and environmental burden. The MDC displayed hierarchical pore structures with high ultramicroporosity, high SSA, and very high total pore volume. Due to its exceptional poro...

Abstract Lithium-sulfur (Li-S) battery is one of the most attractive candidates for the next-generation energy storage system. However, the intrinsic insulating nature of sulfur and the notorious polysulfide shuttle are the major obstacles, which hinder the commercial application of Li-S battery. Confining sulfur into conductive porous carbon matrices with designed polarized surfaces is regarded as a promising and effective strategy to overcome above issues. Herein, we propose to use microalgaes (Schizochytrium sp.) as low-cost, renewable carbon/nitrogen precursors and biological templates to synthesize N-doped porous carbon microspheres (NPCMs). These rational designed NPCMs can not only render the sulfur-loaded NPCMs (NPCSMs) composites with high electronic conductivity and sulfur content, but also greatly suppress the diffusion of polysulfides by strongly physical and chemical adsorptions. As a result, NPCSMs cathode demonstrates a superior reversible capacity (1030.7 mA h g-1) and remarkable capacity retention (91%) at 0.1 A g-1 after 100 cycles. Even at an extremely high current density of 5 A g-1, NPCSMs still can deliver a satisfactory discharge capacity of 692.3 mAh g-1. This work reveals a sustainable and effective biosynthetic strategy to fabricate N-doped porous carbon matrices for high performance sulfur cathode in Li-S battery, as well as offers a fascinating possibility to rationally design and synthesize novel carbon-based composites.

Abstract Because of the high theoretical capacity of 1675 mAh g-1 and high energy density of 2600 Wh kg-1, respectively, lithium-sulfur batteries are attracting intense interest. However, it remains an enormous challenge to realize high utilizations and loadings of sulfur in cathode for the practical applications of Li-S batteries. Herein, we design a quasi-2D Co@N-C composite with honeycomb architecture as multi-functional sulfur host via a simple sacrificial templates method. The cellular flake with large surface area and honeycomb architecture can encapsulate much more sulfur leading to high sulfur content (HSC) composites, and by stacking these HSC flakes, a high sulfur loading (HSL) electrode can be realized due to their high layer bulk density. Compared to our previous work in multi-functional Co-N-C composite, the cellular Co@N-C composite displays a distinct enhancement in the sulfur content, sulfur loading, cycle stability and rate performance. Benefitting from the cellular morphology, a composite with HSC of 93.6 wt% and an electrode with HSL of 7.5 mg cm-2 can be obtained simultaneously, which exhibited excellent rate performance up to 10 C (3.6 mg cm-2) and great cycling stability.

The rechargeable lithium–sulfur battery is regarded as a promising option for electrochemical energy storage systems owing to its high energy density, low cost and environmental friendliness. Further development of the Li–S battery, however, is still impeded by capacity decay and kinetic sluggishness caused by the polysulfide shuttle and electrode/electrolyte interface issues. Herein, a new type of metal–organic-framework-derived sulfur host containing cobalt and N-doped graphitic carbon (Co–N-GC) was synthesized and reported, in which the catalyzing for S redox, entrapping of polysulfides and an ideal electronic matrix were successfully achieved synchronously, leading to a significant improvement in the Li–S performance. The large surface area and uniform dispersion of cobalt nanoparticles within the N-doped graphitic carbon matrix contributed to a distinct enhancement in the specific capacity, rate performance and cycle stability for Li–S batteries. As a result of this multi-functional arrangement, cathodes with a high sulfur loading of 70 wt% could operate at 1C for over 500 cycles with nearly 100% coulombic efficiency and exhibited an outstanding high-rate response of up to 5C, suggesting that the S@Co–N-GC electrode was markedly improved by the proposed strategy, demonstrating its great potential for use in low-cost and high-energy Li–S batteries.

61Mechanism of Li2S activation.61Direct conversion of Li2S to sulfur.61Impact of ionic conductivity on Li2S batteries behavior.61Absence of polysulfides during charging.