Tuning Solid Interfaces via Varying Electrolyte Distributions Enables High-Performance Solid-State Batteries

Solid/solid interface is the major challenge for high-performance solid-state batteries.Solid electrolytes(SEs)play a crucial role in the fabrication of effective interfaces in solid-state batteries.Herein,the electrolyte distribution with varied particle sizes is tuned to construct solid-state batteries with excellent performance at different operating temperatures.Solid-state batteries with the configuration S/L(small-sized SE in composite cathode and large-sized SE in electrolyte layer)show the best performance at room temperature(168 mA h g^(−1) at 0.2 C,retention of 99%,100 cycles)and−20°C(89 mA h g^(−1) at 0.05 C),while the configuration S/S displays better performance at elevated temperature.The superior performance of S/L battery is associated with faster lithium-ion dynamics due to the better solid/solid interface between active materials and electrolytes.Moreover,the inferior performance at 60℃is caused by the formation of voids and cracks in the electrolyte layer during cycling.In contrast,the S/S battery delivers superior performance at elevated operating temperature because of the integrated structure.This work confirms that tailoring electrolyte size has significant effect on fabricating all-climate solid-state batteries.

Fluorobenzene diluted low-density electrolyte for high-energy density and high-performance lithium-sulfur batteries

The mass fraction of electrolytes is the crucial factor affecting the energy density of lithium-sulfur(Li-S)batteries. Due to the high porosity within the C/S cathode, high concentration of polysulfides, and side reaction in lithiun metal anode under lean electrolyte, it is extremely challenging to improve performance while reducing the electrolyte volume. Here, we report a novel electrolyte with relatively low density(1.16 g cm^(-2)), low viscosity(1.84 m Pa s), and high ionic conductivity, which significantly promotes energy density and cyclability of Li-S batteries under practical conditions. Moreover, such electrolyte enables a hybrid cathode electrolyte interphase(CEI) and solid electrolyte interface(SEI) layer with plentiful Li F, which leads to fast kinetics of ions transport and stable cyclability even under low temperatures.Compared to Li-S batteries in electrolyte employing 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether(TTE) diluent, the ultra-thick cathode(20 mg cm^(-2)) shows a high capacity of 9.48 m Ah cm^(-2)and excellent capacity retention of 80.3% over 191 cycles at a low electrolyte-to-sulfur ratio(E/S = 2) and negative-to-positive capacity ratio(N/P = 2.5), realizing a 19.2% improvement in energy density in coin cells(from 370 to 441 Wh kg^(-1)) and a high energy density up to 467 Wh kg^(-1) in pouch cells. This study not only provides guidance for the electrolyte design but also paves the way for the development of high performance Li-S batteries under practical conditions.

Gelation mechanisms of gel polymer electrolytes for zinc-based batteries

Zinc-based batteries(ZBs)have been deemed as a potential substitute for lithium-ion batteries due to its unique advantages of abundant resources,low cost and acceptable energy density.Despite great progress in designing electrode materials has been made,the development of high-performance ZBs still remain challenges,such as the dendrite growth of zinc anode,hydrogen evolution reaction,limited electrochemical stability window,water evaporation and liquid leakage.Gel polymer electrolytes(GPEs),including hydrous GPEs with low content of active water and anhydrous GPEs without the presence of water,are proposed to avoid these problems.Furthermore,employing GPEs is conductive to fabricate flexible devices owing to the good mechanical strength.To date,most of researches focus on discovering new GPEs and exploring its application on flexible or wearable devices.Recent reviews also have outlined the polymer matrixes and advances of GPEs in various battery systems.Given this,herein,we seek to summarize the gelation mechanisms of GPEs,involving physical gel of polymer,chemical crosslinking of polymer and chemical polymerization of monomers.Peculiarly,the preparation methods are also classified.In addition,not only the features and central conundrum of GPEs are analyzed but also the corresponding strategies are discussed,contributing to design GPEs with ideal properties for high-performance ZBs.

隧道技术治疗上前牙黑三角1例

目的本文通过报道上前牙邻面黑三角的治疗过程1例,希望为黑三角的治疗提供新的思路。诊疗经过:患者女性,33岁。上前牙邻面龈乳头退缩1月余。使用隧道技术(tunnel technique,TUN)+结缔组织移植术(connective tissue graft,CTG)联合树脂充填,治疗其上前牙邻面龈乳头退缩,术后随访2年。结果2年后前牙区龈乳头外形丰满,完全充盈邻间隙,美学效果改善明显。结论TUN+CTG联合树脂充填可以治疗前牙区黑三角,其适应证和优缺点还有待进一步临床研究去证明。