Battery Separators Functionalized with Edge-Rich MoS2/C Hollow Microspheres for the Uniform Deposition of Li2S in High-Performance Lithium-Sulfur Batteries

As promising energy storage systems,lithium-sulfur(Li-S)batteries have attracted significant attention because of their ultra-high energy densities.However,Li-S battery suffers problems related to the complex phase conversion that occurs during the charge-discharge process,particularly the deposition of solid Li2S from the liquid-phase polysulfides,which greatly limits its practical application.In this paper,edge-rich MoS2/C hollow microspheres(Edg-MoS2/C HMs)were designed and used to functionalize separator for Li-S battery,resulting in the uniform deposition of Li2S.The microspheres were fabricated through the facile hydrothermal treatment of MoO3-aniline nanowires and a subsequent carbonization process.The obtained Edg-MoS2/C HMs have a strong chemical absorption capability and high density of Li2S binding sites,and exhibit excellent electrocatalytic performance and can effectively hinder the polysulfide shuttle effect and guide the uniform nucleation and growth of Li2S.Furthermore,we demonstrate that the Edg-MoS2/C HMs can effectively regulate the deposition of Li2S and significantly improve the reversibility of the phase conversion of the active sulfur species,especially at high sulfur loadings and high C-rates.As a result,a cell containing a separator functionalized with Edg-MoS2/C HMs exhibited an initial discharge capacity of 935 mAh g-1 at 1.0 C and maintained a capacity of 494 mAh g-1 after 1000 cycles with a sulfur loading of 1.7 mg cm-2.Impressively,at a high sulfur loading of 6.1 mg cm-2 and high rate of 0.5 C,the cell still delivered a high reversible discharge capacity of 478 mAh g-1 after 300 cycles.This work provides fresh insights into energy storage systems related to complex phase conversions.

基于卡诺模型的老年慢性病患者使用智能药物管理系统的需求研究

目的信息技术及相关产品在老年人的用药安全管理中具有广阔的市场前景。研究旨在探讨老年慢性病患者对自主研发的智能药物管理系统的需求,了解用户体验,为开发和完善适老化数字产品提供参考。方法通过横断面调查了解老年人对自主研发的智能药物管理系统的技术需求,并基于Kano模型对数据进行分析。于2020年7—10月采用基于Kano模型设计的问卷,对354例使用该智能药物管理系统的老年慢性病患者进行需求调查。结果调查结果显示,大字体、简化操作流程、定时用药提醒、硬件性能可靠为必备型属性;在微信上查询药品说明书、提高系统灵敏性、提高电池续航能力为魅力型属性;将疾病信息同步到微信为期望型属性;终端显示屏简洁美观、自动拦截广告、提供用户隐私保护、仅绑定用户可查看个人医疗信息、记录所服用的全部药品、通过微信订购药品为无差异型属性。具备相应功能时满意度值为0.24-0.69,未提供相应功能时不满意度值为0.06-0.94o结论老年人对信息技术存在个性化需求,满足其技术需求和倾向有助于提高老人对移动医疗健康技术的满意度和接受度,帮助老人迈过数字鸿沟。本研究基于需求分析结果,提出了智能药物管理系统的优化方案,为技术人员开发适老化智能产品及护士实施以老年人为中心的口服药智能化管理提供了参考。

Decorating ketjen black with ultra-small Mo_(2)C nanoparticles to enhance polysulfides chemisorption and redox kinetics for lithium-sulfur batteries

The low sulfur utilization and fast capacity fading resulting from the sluggish redox reaction and abominable polysulfides shuttle greatly hinder the practical applications of lithium-sulfur(Li-S) batteries.Herein, we develop a facile "in-situ growth" method to decorate ultra-small Mo2 C nanoparticles(USMo2 C) on the surface of Ketjen Black(KB) to functionalize the commercial polypropylene(PP) separators,which can accelerate the redox kinetics of lithium polysulfides conversion and effectively increase the utilization of sulfur for Li-S batteries. Importantly, the US-Mo2 C nanoparticles have abundant sites for chemical adsorption towards polysulfides and the conductive carbon networks of KB have cross-linked pore channels, which can promote electron transport and provide physical barrier and volume expansion space for polysulfides. Due to the combined effects of the US-Mo2 C and KB, Li-S cells employing the multifunctional PP separators modified with KB/US-Mo2 C composite(KB/US-Mo2 C@PP) exhibit a high specific capacity(1212.8 mAh g^(-1) at 0.2 C), and maintain a reversible capacity of 1053.3 m Ah g^(-1) after 100 cycles.More importantly, the KB/US-Mo2 C@PP cells with higher sulfur mass loading of 4.9 mg cm^(-2) have superb areal capacity of 2.3 mAh cm^(-2). This work offers a novel and promising perspective for high-performance Li-S batteries from both the shuttle effect and the complex polysulfides conversion.

Recent advances in long-persistent luminescence materials based on host–guest architecture

Organic long-persistent luminescence(LPL)materials,featuring low preparation cost,eco-friendly synthesis,and easy modification of functional groups,have exhibited extensive applications in information encryption,anti-counterfeiting,and biological imaging.Several design strategies including crystallization-inducement,H-aggregation,and host-guest doping to enhance persistent-room-temperature phosphorescence(RTP)effect by precisely controlling intersystem crossing(ISC)constant and suppressing nonradiative decay rates,those are important strategies to enable LPL performance.Among the strategies,researchers have made several efforts to enhance persistent-RTP effect by host-guest interaction,in which the host matrices provide a rigid environment for phosphor guest molecules.The interaction of the luminescent guest molecules with the host matrix can effectively reduce the vibration and rotation of the luminescent molecules,and suppress the non-radiative inactivation,thereby improving the phosphorescence quantum yield.This review aims to summarize several design strategies of pure organic LPL materials based on persistent-RTP effect through host-guest interaction,and describe some applications of pure organic LPL materials in different fields.

Regulated extravascular microenvironment via reversible thermosensitive hydrogel for inhibiting calcium influx and vasospasm

Arterial vasospasm after microsurgery can cause severe obstruction of blood flow manifested as low tissue temperature,leading to tissue necrosis.The timely discovery and synchronized treatment become pivotal.In this study,a reversible,intelligent,responsive thermosensitive hydrogel system is constructed employing both the gel–sol transition and the sol–gel transition.The“reversible thermosensitive(RTS)”hydrogel loaded with verapamil hydrochloride is designed to dynamically and continuously regulate the extravascular microenvi-ronment by inhibiting extracellular calcium influx.After accurate implantation and following in situ gelation,the RTS hydrogel reverses to the sol state causing massive drug release to inhibit vasospasm when the tissue tem-perature drops to the predetermined transition temperature.Subsequent restoration of the blood supply allevi-ates further tissue injury.Before the temperature drops,the RTS hydrogel maintains the gel state as a sustained-release reservoir to prevent vasospasm.The inhibition of calcium influx and vasospasm in vitro and in vivo is demonstrated using vascular smooth muscle cells,mice mesenteric arterial rings,and vascular ultrasonic Doppler detection.Subsequent animal experiments demonstrate that RTS hydrogel can promote tissue survival and alleviate tissue injury responding to temperature change.Therefore,this RTS hydrogel holds therapeutic po-tential for diseases requiring timely detection of temperature change.

利用"Find-eat"策略通过受体功能化凋亡小体纳米囊泡靶向内皮细胞

慢性创面的缺氧微环境导致血管化不足,进而使得伤口延迟愈合.内皮细胞作为组成新生血管的关键细胞,在血管化过程中发挥着核心作用.本研究构建了CX3CR1功能化凋亡小体纳米囊泡(nABs).“Find-eat”策略通过受体-配体组合,靶向低氧微环境中高表达CX3CR1的内皮细胞(ECs),从而放大“Find-eat”信号,促进血管生成.作者首先通过化学诱导脂肪干细胞(ADSCs)凋亡获得ABs,然后通过优化的低渗处理-温和超声-药物混合-挤压一系列处理步骤,获得载有去铁胺(DFO)的功能化凋亡小体纳米囊泡.体外实验显示ABs纳米囊泡生物相容性良好;可以通过CX3CL1/CX3CR1诱导缺氧微环境中的内皮细胞实现对其的“Find-eat”,进而促进内皮细胞的增殖、迁移、成管能力.体内实验中,ABs纳米囊泡可以促进伤口快速闭合,并可通过释放“Find-eat”信号靶向内皮细胞的同时实现促血管药物的缓释,促进糖尿病大鼠创面的新生血管形成.这种能够通过释放双重信号靶向内皮细胞并实现促血管药物缓释的ABs纳米囊泡为慢性糖尿病创面的愈合提供了一种新思路.

Ni/Ni_(2)P异质结/多孔碳修饰隔膜用于加速多硫化物催化转化

锂硫电池固有的缓慢转化动力学和严重的穿梭效应导致其可逆容量和循环寿命差,严重阻碍了其实际应用.为了解决这些问题,我们设计并构建了一种Ni/Ni_(2)P异质结嵌入介孔碳纳米球的复合材料(Ni/Ni_(2)P-MCN),将其用于锂硫电池隔膜改性以促进多硫化物的催化转化.研究发现,Ni/Ni_(2)P-MCN改性隔膜可以通过丰富的异质结化学吸附位点吸附多硫化物、抑制穿梭效应,而且对多硫化物的转化具有优异的催化活性.此外,具有暴露介孔结构的导电碳球可以作为物理屏障,容纳沉积的不溶性Li_(2)S.因此,使用Ni/Ni_(2)P-MCN改性隔膜的电池显示出优异的倍率性能(5 C下431 mA h g^(-1))和循环稳定性(1500次循环下平均容量衰减约0.031%).在4.2 mg cm^(-2)的高载硫下,输出面积比容量约3.5 mA h cm^(-2).我们认为,这种独特的Ni/Ni_(2)P异质结/多孔碳复合材料在高性能、可持续储能器件中具备巨大的应用潜力.