The Lithium-Sulfur (Li-S) battery is the most promising next-generation secondary battery due to its high theoretical energy density but suffers from complex Li-S reaction kinetics. In article number 1900574, key factors and insights into the kinetics process in Li-S electrochemistry are reviewed. Additionally, insights are provided on the direction of future kinetic investigations of Li-S batteries. More details can be found in article number 1900574 by Xiaonan Tang and co-workers.

In article number 1900077, a composite electrode is fabricated for the high-rate operation of all-solid-state lithium–sulfur batteries. The composite electrode is made of sulfur and carbon with “interconnected mesopores” with a diameter of 5 nm. The all-solid-state lithium–sulfur battery shows a high capacity of 1100 mA h g⁻¹ per sulfur after 400 cycles at 1.3 mA cm⁻² at 25°C. More details can be found in article number 1900077 by Atsushi Sakuda and co-workers.

Lithium–sulfur (Li–S) batteries are the most promising next-generation secondary batteries due to a high theoretical energy density, but suffer from complex Li–S reaction kinetics. Herein, the key factors and insights into improvements of the kinetics process in Li–S electrochemistry are given. Finally, insights are provided for the direction of future kinetic investigations of Li–S batteries.

In the development of room-temperature metal–sulfur batteries (Li–S, RT Na–S, K–S, Mg–S, and Al–S), the electrolyte plays a key role. To achieve a high-performance battery system, the electrolyte needs to combat the polysulfide diffusing and shuttling problem, transport ions, and be compatible with both the cathode and the anode.

CoS₂/carbon nanotubes (CNTs) is obtained by an in situ synthesis method and used as an advanced sulfur host. The interconnected CNTs facilitate electron transport and mitigate volume expansion of the cathode. The CoS₂ nanoparticles provide a chemical trap for soluble polysul-fides and enhance their redox reactions. Because of such synchronous advantages, the CoS₂/CNTs-based sulfur cathode delivers enhanced electrochemical performances.

A sulfur-based composite electrode for the high-rate operation of all-solid-state Li/S batteries is prepared using carbon with interconnected mesopores. This structure drastically improves the rate capability of the composite electrode. The all-solid-state Li/S battery has a high capacity of 1100 mA h g⁻¹ per sulfur after 400 cycles at a high current density of 1.3 mA cm⁻² at 25 °C.

Simple electrolyte composition controls the chemical stability of the reactive intermediate of the Li₂S_x electrode and leads to high-performance of Li–S cells for next-generation batteries.

A porous organic architecture is developed as a dual-confinement host cathode in lithium–sulfur batteries via a simple temperature-regulating strategy. Increasing the sulfur infiltration temperature to a suitable value triggers covalent attachment of sulfur on pore walls. The synergetic chemical and physical confinement effect restrains the shuttling of polysulfides, thus leading to superior sulfur utilization, high-rate performances, and good cycle stability.

A new type of organosulfur material, sulfurized alcohol composite (SAC), is applied to an all-solid-state cell. The cell shows high specific capacity (600–800 mAh g⁻¹) and improved initial coulomb efficiency by milling SAC and solid electrolyte. The improvement is attributed to the partial lithiation of the SAC sample and is advantageous for fabricating high-energy-density all-solid-state cells.

Embedding ethylenediamine molecules into Li₂S particles decreases their crystallinity, leading to smaller activation barriers. This is specifically beneficial to solid-state cells, where the material is directly converted from Li₂S to sulfur. The result is solid-state cells with high specific capacities and coulombic efficiency from the first cycle onward.

The capabilities of using a high-intensity mixing process to produce composite particles of carbon and sulfur for the use in cathodes for lithium–sulfur batteries are shown. The effects of the process parameters on the structure and properties of the composites are investigated. Furthermore, the effect of the composite particles on the performance properties of the sulfur cathodes are evaluated.

Nonuniformity of sulfur and lithium distribution in a Li–S pouch cell is identified as a major reason for the rapid capacity fading. The mobile polysulfides lead to the agglomeration of bulk sulfur and reduction of lithium source in the central anode sheets, which thus induce the sluggish liquid–solid conversion low utilization of active sulfur cathode.

Self-discharge (reversible capacity loss) and aging (irreversible capacity loss) are important problems in the development of lithium–sulfur batteries. This work summarizes the results of studying the effect of the sulfur/carbon ratio (Ketjenblack EC-600JD) in the positive electrode and the prehistory of the cells on their irreversible and reversible capacity loss.

The challenges associated with sulfur cathodes in Li–S battery technology, such as the polysulphide shuttle and its detrimental effects, can be effectively addressed by the use of ultramicroporous carbon–sulfur (UMC-S). The quasi-solid-state lithiation/delithiation of the UMC-S cathode enables stable performance under lean electrolyte conditions and at increased sulfur loadings. This article holds potential for future applications of the UMC-S cathode in practical Li–S batteries.

In the Li/S battery, a composite electrode formed by sulfur surrounding a metallic core of nanometric tin shows a highly reversible electrochemical process evolving between 1.9 and 2.8 V with efficiency approaching 100%. The battery shows a maximum specific capacity of about 1200 mAh g⁻¹, high rate capability, and suitable retention upon 100 charge/discharge cycles.

New polysulfide dissolution resistant complex framework materials (CFMs) based sulfur cathodes are generated using the chemical interaction of carbon–nitrogen moieties with sulfur. The absence of carbonate moieties prevents unwanted sulfate formation. The resultant carbon–nitrogen containing CFMs exhibit complete polysulfides trapping combined with stable capacities (≈1000 mAh g⁻¹) compared with commercial sulfur showing their potential for cathode use in rechargeable lithium–sulfur batteries.

The role of physically restrained, noncrystalline sulfur species in rechargeable lithium–sulfur batteries is examined by electrochemical and high-resolution material characterizations. Composites are created by a melting and sublimation process for lithium–sulfur batteries. These noncrystalline sulfur cathodes demonstrate a high specific capacity of ≈1000 Ah kg⁻¹ after 100 cycles with a gravimetric current of 557 A kg⁻¹.

N-doped biomass-derived porous carbon (N-OSC), which is derived from common okra wastes, okra shells, is successfully fabricated. N-OSC exhibits a high specific surface area of 2702 m² g⁻¹, large pore volume (0.17 cm³ g⁻¹), and high sulfur loading (69.71 wt%). The cell with N-OSC/sulfur composite as an electrode manifests excellent performance, where the capacity is up to 750 mA h g⁻¹ even at 2 C rate.

W⁶⁺-doped V₂O₅ can greatly enhance the adsorption speed of V₂O₅ for lithium polysulfide (LiPS), which makes a red LiPS solution fade in 1 min. The metal oxide is mixed with the graphene/carbon nanotube composite to modify the separator, which can greatly improve the cycle performance of the lithium–sulfur battery.

Herein, a nonpolar and polar matrix is comprised of intertwined multiwalled carbon nanotubes (MWCNTs) and ionic-liquid-derived nitrogen-rich porous carbon. Benefiting from the nonpolar physical binding of microporous and mesoporous structure (diameter < 8 nm) and polar chemical anchoring of N-doped (7.42 At%) carbon, the cathode exhibits a very stable cycle stability of 0.021% attenuation for each cycle with 300 cycles at 1 C.

The facile synthesis of stable TiO₂/TiC composite materials as sulfur immobilizers for lithium–sulfur batteries is shown. The conductivity of TiC and the strong adsorption of the Ti—O bond on sulfur in TiO₂ are combined together. After sulfur-loading, the achieved specific capacity is 1044.68 mAh g⁻¹, and the capacity retention rate is still over 50% after 400 cycles.

A low-density electrolyte composition is introduced for lithium 1,3-dioxolane sulfur batteries. The choice of the solvent limits the dissolution of polysulfides, leading to successful polysulfide shuttle suppression. In contrast to concepts relying on hydrofluoro ether dilution, the presented electrolyte features a significantly reduced mass density possibly enabling significant weight reduction on the Li–S prototype cell level.

Low-temperature atomic layer deposition of Al₂O₃ is presented as a strategy to suppress performance degradation of 2D graphene–sulfur hybrid cathodes. Superior electrochemical performance is credited to the synergy between the high electronic conductivity of multilayered graphene platelets and low charge transfer resistance, resulting from effective polysulfide blocking by atomic scale Al₂O₃ coating.