Organosulfur Materials for Rechargeable Batteries: Structure, Mechanism, and Application.

Lithium-ion batteries have received significant attention over the last decades due to the wide application of portable electronics and increasing deployment of electric vehicles. In order to further enhance the performance of the batteries and overcome the capacity limitations of inorganic electrode materials, it is imperative to explore new cathode and functional materials for rechargeable lithium batteries. Organosulfur materials containing sulfur-sulfur bonds as a kind of promising organic electrode materials have the advantages of high capacities, abundant resources, tunable structures, and environmental benignity. In addition, organosulfur materials have been widely used in almost every aspect of rechargeable batteries because of their multiple functionalities. This review aims to provide a comprehensive overview on the development of organosulfur materials including the synthesis and application as cathode materials, electrolyte additives, electrolytes, binders, active materials in lithium redox flow batteries, and other metal battery systems. We also give an in-depth analysis of structure-property-performance relationship of organosulfur materials, and guidance for the future development of organosulfur materials for next generation rechargeable lithium batteries and beyond.

Electrochemical Reactivation of Dead Li2 S for Li-S Batteries in Non-Solvating Electrolytes.

The use of non-solvating, or as-called sparingly-solvating, electrolytes (NSEs), is regarded as one of the most promising solutions to the obstacles to the practical applications of Li-S batteries. However, it remains a puzzle that long-life Li-S batteries have rarely, if not never, been reported with NSEs, despite their good compatibility with Li anode. Here, we find the capacity decay of Li-S batteries in NSEs is mainly due to the accumulation of the dead Li2 S at the cathode side, rather than the degradation of the anodes or electrolytes. Based on this understanding, we propose an electrochemical strategy to reactivate the accumulated Li2 S and revive the dead Li-S batteries in NSEs. With such a facile approach, Li-S batteries with significantly improved cycling stability and accelerated dynamics are achieved with diglyme-, acetonitrile- and 1,2-dimethoxyethane-based NSEs. Our finding may rebuild the confidence in exploiting non-solvating Li-S batteries with practical competitiveness.

Al2O3-YAG:Ce/YAG composite ceramic phosphor in a transmissive configuration for high-brightness laser-driven lighting.

High-power, high-brightness laser lighting promotes new requirements for light-conversion materials, such as high thermal conductivity, high saturation threshold and compact encapsulation. In this paper, we designed and fabricated a novel composite structure ceramic including a 1.0 × 1.0 mm2 Al2O3-YAG:Ce ceramic and a φ=16.0 mm transparent YAG ceramic for the transmissive configuration in laser lighting. When pumped by blue laser from 0∼60 W mm2, all the samples exhibited no luminous saturation phenomenon, and the 10.0 wt.%Al2O3-YAG:Ce/YAG composite ceramic with the thickness of 0.3 mm maintained white light with a luminous efficacy over 200 lm/W. Moreover, a maximal luminous flux over 1000 lm, a correlated color temperature (CCT) of 5471 K, and an operating temperature as low as 92.3 °C were obtained under the excitation power density as high as 60 W/mm2. The configuration that Al2O3-YAG:Ce encapsulated by YAG reflects an excellent optical and thermal properties by using transparent and highly thermally conductive YAG materials. These results indicate that Al2O3-YAG:Ce/ YAG composite ceramic phosphor is a promising candidate in transmissive configuration for automotive lighting and laser searchlight.

Treatment of Severe Ptosis by Conjoint Fascial Sheath Suspension.

OBJECTIVE: To explore the role of conjoint fascial sheath (CFS) suspension in the treatment of severe ptosis. METHODS: A total of 110 patients with severe ptosis who were admitted to our hospital from May 2018 to December 2020 were included. Fifty-seven patients treated with frontalis suspension were assigned into group A, and the remaining 53 patients treated with CFS suspension were assigned into group B. The curative effect, ocular surface alterations, complications, and satisfaction in the two groups were compared. RESULTS: Patients in group B suffered from severe upper eyelid retraction and lid lag than those in group A, as well as more limited range of motion (ROM) (P < 0.05). The curative effect and patient satisfaction in group B were higher than those in group A (P < 0.05). Postsurgical complications in group B were fewer than those in group A (P < 0.05). CONCLUSION: CFS suspension is effective in the treatment of severe ptosis.

Two-Plateau Li-Se Chemistry for High Volumetric Capacity Se Cathodes.

For Li-Se batteries, ether- and carbonate-based electrolytes are commonly used. However, because of the "shuttle effect" of the highly dissoluble long-chain lithium polyselenides (LPSes, Li2 Sen , 4≤n≤8) in the ether electrolytes and the sluggish one-step solid-solid conversion between Se and Li2 Se in the carbonate electrolytes, a large amount of porous carbon (>40 wt % in the electrode) is always needed for the Se cathodes, which seriously counteracts the advantage of Se electrodes in terms of volumetric capacity. Herein an acetonitrile-based electrolyte is introduced for the Li-Se system, and a two-plateau conversion mechanism is proposed. This new Li-Se chemistry not only avoids the shuttle effect but also facilitates the conversion between Se and Li2 Se, enabling an efficient Se cathode with high Se utilization (97 %) and enhanced Coulombic efficiency. Moreover, with such a designed electrolyte, a highly compact Se electrode (2.35 gSe cm-3 ) with a record-breaking Se content (80 wt %) and high Se loading (8 mg cm-2 ) is demonstrated to have a superhigh volumetric energy density of up to 2502 Wh L-1 , surpassing that of LiCoO2 .

Polyphenyl polysulfide: a new polymer cathode material for Li-S batteries.

We report a new class of polyphenyl polysulfides synthesized by condensation reactions between 4,4'-thiobisbenzenethiol (TBBT) and sulfur with four different molar ratios in a toluene/carbon disulfide mixture at room temperature. Through comprehensive material and electrochemical characterization, we found that they have great application potential for Li-S batteries.