A fast ionic transport copolymeric network for stable quasi-solid lithium metal battery

Solid-state lithium(Li) metal batteries overwhelm the lithium-ion batteries by harvesting high energy from Li metal anode with ultrahigh capacities and gaining excellent safety from solid electrolytes.However,the uncontrollable solvents in solid electrolytes usually aggravate poor interfacial contact with lithium metal anode and deteriorate Li^(+) pathways.Here a copolymeric network-structured ion conductor by rationally integrating cellulose nanofibril as a two-in-one functional material is employed to anchor the solvent.Taking advantages of tightly anchoring of cellulose nanofibril to solvent,the asconstructed quasi-solid polymer-based electrolyte offers rapid Li^(+) transport channels and realizes effective Li-dendrite suppression,which enables high ionic conductivity of 1.93 × 10^(-3)S cm^(-1) at room temperature,long-term Li plating/stripping over 1900 h,and high capacity retention of 99%.This work provides a fresh strategy for creating solid electrolytes that meet both high ionic conductivity and interfacial stability requirements for practical solid-state lithium metal battery.

Highly active cobalt-doped nickel sulfide porous nanocones for high-performance quasi-solid-state zinc-ion batteries

Flexible quasi-solid zinc-ion batteries(ZIBs)have large potential in power applications due to the low price,wearable nature,safety,and high capacity.However,the use of transition metal sulfide cathodes in ZIBs has not been studied extensively and the underlying mechanism and theoretical basis of this type of batteries are not well understood.Herein,a highly active cobalt-doped Ni_(3)S_(2) porous nanocone framework(C12NS)is designed and demonstrated as a zinc-ion battery electrode.First-principles calculation and experiments reveal that the cobalt dopant improves the battery properties greatly.The assembled flexible zinc-ion battery exhibits a high specific capacity of 453.3 mAh g^(−1)at a current density of 0.4 A g^(−1)in as well as excellent cycling stability as manifested by a capacity retention ratio of 89.5%at a current density of 4 A g^(−1)after 5000 cycles.The peak energy density of 553.9 Wh kg^(−1)is also superior to those of most recently reported NiCo-based zinc-ion batteries.More importantly,the flexible battery can be operated under severe mechanical bending and even continues to work after physical puncturing without showing leakage.These exciting results not only reveal a novel design of cathode materials for zinc-based batteries,but also suggest their immense commercial potential in portable and wearable electronics.

Recent research progress on quasi-solid-state electrolytes for dye-sensitized solar cells

Dye-sensitized solar cells （DSSCs） are the most promising, low cost and most extensively investigated solar cells. They are famous for their clean and efficient solar energy conversion. Nevertheless this, long-time sta- bility is still to be acquired. In recent years research on solid and quasi-solid state electrolytes is extensively in- creased. Various quasi-solid electrolytes, including composites polymer electrolytes, ionic liquid electrolytes, thermoplastic polymer electrolytes and thermosetting polymer electrolytes have been used. Performance and stability of a quasi-solid state electrolyte are between liquid and solid electrolytes. High photovoltaic performances of QS-DSSCs along better long-term stability can be obtained by designing and optimizing quasi-solid electrolytes. It is a prospective candidate for highly efficient and stable DSSCs.

Research of quasi-solid fracture behavior of casting AI-4.5Cu alloys

The influencing mechanisms of elements Ti and Ce and their interactions on fracture behaviors of casting alloys AI-4.5Cu-0.6Mn were studied by observing tensile fracture behavior in quasi-solid zone under SEM and EDX instruments. The results indicate that the resistance stress against hot cracking can be improved obviously by addition of Ti, because of its grain refining function. It is also found that, when Ce is added into the alloys, besides its effect in refining crystalline, the mechanical behavior of lower melting point eutectic phase in quasi-solid zone can be improved efficiently by some compounds with Ce formed and deposited between dendrites. Therefore, a colligating effect of Ti and Ce on improving resistance stress against hot cracking is more efficient than that only single alloy element is applied. When hot cracking occurs, grains yield at first, and then crack spreads. Both inter-grain and trans-grain fractures are observed, but the major fracture manner is brittleness.

Effect of flow field distribution on the synthesis of sub-micron ZSM-5 molecular sieve in a quasi-solid system

Scale-up synthesis of sub-micron ZSM-5 molecular sieve in a quasi-solid system was investigated. Compared with traditional hydrothermal synthesis, the synthesis in a quasi-solid system has the advantages of high yield, short crystallization time, low energy consumption as well as low emissions. However, the high solid content in the quasi-solid system can cause the mass and heat transfer problems and make scalable production difficult. In order to solve the problem, we have developed a method for the optimization of the mass and heat transfer. By this method one can vary the flow field in the reactor by changing the stirrer speed. Scale-up synthesis of the sub-micron ZSM-5 molecular sieve in a quasi-solid system was carried out in a 5 L reactor with double propeller-type agitators. The process was investigated with product characterization using X-ray diffraction （XRD） and scanning electron microscopy （SEM） and the flow field information was collected using laser Doppler velocimetry （LDV）. The results showed that the flow field patterns can be tuned by using different stirrer speeds, the morphology and size of assynthesized of ZSM-5 can be effectively controlled.

A high-performance rechargeable Li–O_2 battery with quasi-solid-state electrolyte

A novel transparent and soft quasi-solid-state electrolyte （QSSE） was proposed and fabricated, which consists of ionic liquid （PYR14TFSI） and nano-fumed silica. The QSSE demonstrates high ionic conductivity of 4.6× 10-4 S/cm at room temperature and wide electrochemical stability window of over 5 V. The Li-O2 battery using such quasi-solidstate electrolyte exhibits a low charge-discharge overpotential at the first cycle and excellent long-term cyclability over 500 cycles.

A low cost composite quasi-solid electrolyte of LATP, TEGDME,and LiTFSI for rechargeable lithium batteries

The composite quasi solid state electrolytes（CQSE） is firstly synthesized with quasi solid state electrolytes（QSE） and lithium-ion-conducting material Li1.4Al0.4Ti1.6（PO4）3（LATP）, and the QSE consists of [LiG4][TFSI] with fumed silica nanoparticles. Compared with LATP, CQSE greatly improves the interface conductance of solid electrolytes. In addition,it has lower liquid volume relative to QSE. Although the liquid volume fraction of CQSE is droped to 60%, its conductivity can also reach 1.39 × 10^-4S/cm at 20℃. Linear sweep voltammetry（LSV） is conducted on each composite electrolyte.The results show the possibility that CQSE has superior electrochemical stability up to 5.0 V versus Li/Li^＋1. TG curves also show that composite electrolytes have higher thermal stability. In addition, the performance of Li/QSE/Li Mn2O4 and Li/CQSE/Li Mn2O4 batteries is evaluated and shows good electrochemical characteristics at 60℃.

Lamellar quasi-solid electrolyte with nanoconfined deep eutectic solvent for high-performance lithium battery

Electrolytes with high-efficiency lithium-ion transfer and reliable safety are of great importance for lithium battery.Although having superior ionic conductivity(10^(−3)–10^(−2) S·cm^(−1)),traditional liquid-state electrolytes always suffer from low lithium-ion transference number(tLi+<0.4)and thus undesirable battery performances.Herein,the deep eutectic solvent(DES)is vacuum-filtered into the~1 nm interlayer channel of vermiculite(Vr)lamellar framework to fabricate a quasi-solid electrolyte(Vr-DES QSE).We demonstrate that the nanoconfinement effect of interlayer channel could facilitate the opening of solvation shell around lithiumion.Meanwhile,the interaction from channel wall could inhibit the movement of anion.These enable high-efficiency lithium-ion transfer:2.61×10^(−4)S·cm^(−1)at 25℃.Importantly,the tLi+value reaches 0.63,which is 4.5 times of that of bulk DES,and much higher than most present liquid/quasi-solid electrolytes.In addition,Vr-DES QSE shows significantly improved interfacial stability with Li anode as compared with DES.The assembled Li symmetric cell can operate stably for 1000 h at 0.1 mA·cm^(−2).The lithium iron phosphate(LFP)|Vr-DES QSE|Li cell exhibits high capacity of 142.1 mAh·g^(−1)after 200 cycles at 25℃ and 0.5 C,with a capacity retention of 94.5%.The strategy of open solvation shell through nanoconfinement effect of lamellar framework may shed light on the development of advanced electrolytes.

Preparation of chitosan and citric acid crosslinked membrane and its application in quasi-solid supercapacitors

Quasi-solid electrolytes promote the development of safe and flexible energy storage devices.In this work,a chitosan and citric acid crosslinked membrane is prepared by a freeze-thaw cross-linking method,in which the chemical crosslinking of chitosan and citric acid increase the viscoelastic behavior of the polymer membrane,and the freeze-thaw assist freeze drying process to create abundant interconnected open-pores and three-dimensional(3D)network.Due to the good viscoelasticity,excellent electrolyte loading capacity(596%)and high ion conductivity(7.7×10^(-3)S·cm^(-)1),as quasi-solid electrolyte,our proposed chitosan and citric acid crosslinked membrane helps ZnICCFT-ZnSO4lAC hybrid supercapacitor to delivers wide operating voltage,high specific capacity of 100.5 F·g^(-1)and stable cycle life(93%after1000 cycles),which suggests that our proposed freezethaw assisted freeze drying method has great potential in designing quasi-solid state electrolyte for energy storage device.

基于Na-BP-DME@C阳极的长寿命准固态钠-空气电池

钠-空气电池因其能量密度高、成本低而成为金属-空气电池领域的研究热点。然而,以金属钠为阳极的钠-空气电池存在钠枝晶生长、金属钠界面稳定性差以及金属钠的反应活性高等问题,限制了钠-空气电池的快速发展。为解决上述问题,将联苯钠与导电炭黑复合材料Na-BP-DME@C作为阳极,单壁碳纳米角(SWCHNs)作为催化剂,构建准固态钠-空气电池。基于Na-BP-DME@C阳极的准固态钠-空气电池表现出优异的电化学性能,其电压差为1.5 V,功率密度为3.32 mW/cm^(2),在0.1 mA/cm^(2)电流密度下可稳定循环459 h(约459次)。

Janus Quasi‑Solid Electrolyte Membranes with Asymmetric Porous Structure for High‑Performance Lithium‑Metal Batteries

Quasi-solid electrolytes(QSEs)based on nanoporous materials are promising candidates to construct high-performance Limetal batteries(LMBs).However,simultaneously boosting the ionic conductivity(σ)and lithium-ion transference number(t^(+)) of liquid electrolyte confined in porous matrix remains challenging.Herein,we report a novel Janus MOFLi/MSLi QSEs with asymmetric porous structure to inherit the benefits of both mesoporous and microporous hosts.This Janus QSE composed of mesoporous silica and microporous MOF exhibits a neat Li^(+) conductivity of 1.5.10^(–4)S cm^(−1) with t^(+) of 0.71.A partially de-solvated structure and preference distribution of Li^(+)near the Lewis base O atoms were depicted by MD simulations.Meanwhile,the nanoporous structure enabled efficient ion flux regulation,promoting the homogenous deposition of Li^(+).When incorporated in Li||Cu cells,the MOFLi/MSLi QSEs demonstrated a high Coulombic efficiency of 98.1%,surpassing that of liquid electrolytes(96.3%).Additionally,NCM 622||Li batteries equipped with MOFLi/MSLi QSEs exhibited promising rate performance and could operate stably for over 200 cycles at 1 C.These results highlight the potential of Janus MOFLi/MSLi QSEs as promising candidates for next-generation LMBs.

实用化高比能准固态锂离子电池体系的研究

针对锂离子电池中电解液易泄漏、易燃烧,甚至引发爆炸等潜在安全问题,本文将单一的醚类小分子物质作为单体,与LiPF_(6)基电解液混合制备预聚前驱体,在60℃下原位衍生为非流动态的黏弹性凝聚体。通过调控单体比例、优化原位固化工艺,制备出高镍/高硅准固态锂离子电池。经测试,2.1 Ah电池体系在0.3 C电流下循环寿命达600圈,保持率比同期液态高1.8%。由更高硅含量的负极构成的36 Ah电池体系的比能量高达351 Wh/kg,500圈循环容量保持率达88.36%,准固态锂离子电池具有优异的低温性能,-20℃下容量保持率达85.6%,结果表明固化电解质在电池层内部及层间起到了良好的结构稳定性作用。该高比能准固态锂离子电池体系的开发为后续固态电池的进一步实用化提供了切实可行的途径。

MXene在锌离子电池中的应用:研究进展与展望

可充电锌离子电池(ZIBs)以其低成本、固有安全性、高比能量和环保特性而在大规模储能领域中引起了极大的关注。尽管对ZIBs的正极、负极以及电解质的研究不断取得突破,ZIBs的实际性能仍难以达到实用化的要求,关键在于缺少先进材料的开发。MXene作为一种新型的二维材料,具有各种优异的特性包括丰富的原料、可定制的结构和独特的理化特性。二维(2D)MXene在ZIBs中的应用已经取得了重大进展。本文简要总结了用于ZIBs的MXene的多种合成路线、MXene的环境稳定性、形态和结构特征以及化学性质的进展;详细阐述了MXene基阴极、阳极和电解质/隔膜的最新发展,丰富的成果表明MXene材料具有实现高性能ZIBs的巨大潜力;归纳探讨了增强基于MXene的ZIBs性能的策略,包括离子插层调控、表面接枝修饰、杂原子掺杂、层间距拓宽等;最后,提出了基于MXene的ZIBs面临的挑战,展望了未来前景,旨在为开发实用化MXene基储能器件指明方向。

Flame-retardant quasi-solid polymer electrolyte enabling sodium metal batteries with highly safe characteristic and superior cycling stability

Con ventio nal liquid electrolytes based sodium metal batteries suffer from severe safety hazards owing to electrolyte leakage,in flammability and dendritic sodium deposit!on.Herein,we report a flame-retardant quasi-solid polymer electrolyte with poly(methyl vinyl ether-alt-maleic an hydride)(P(MVE-alt-MA))as host,bacterial cellulose(BC)as reinforceme nt,and triethyl phosphate/vinyle ne carb on ate/sodium perchlorate(TEP/VC/NaClO4)as plasticizer for highly safe sodium metal batteries.The as-obtained quasi-solid polymer electrolyte exhibits superior flame retardancy(self-extinguish within 1 s),complete non-leakage property and wide electrochemical windows(4.4 V).More importantly,Na3V2(PO4)3/Na metal batteries using such polymer electrolyte delivers superior I on g-term cycli ng stability(84.4%capacity rete ntion after 1000 cycles)which is significantly better than that(only 2%after 240 cycles)of liquid electrolyte.In addition,this flame-retardant quasi-solid polymer electrolyte provides favorable cycle performance(80.2%capacity retention after 70 cycles at 50°C and 84.8%capacity retention after 50 cycles at-10°C)for Na3V2(PO4)3/Na metal batteries.And this battery also displayed a normal charge/discharge property even at-15°C.These fascinating cycle properties are mainly ascribed to the effective pro怕ctive layers formed on Na3V2(PC>4)3 cathode and sodium metal ano de.More thorough in vestigati on elucidates that such flame-retardant quasi-solid polymer electrolyte plays a multif unctional role in the adva need sodium metal batteries:(1)being in volved in the formatio n of a favorable cathode electrolyte in terface(CEI)to inhibit the dissolutio n of van adium and maintai n the structure integrity of the Na3V2(PO4)3;(2)participati ng in building a stable solid electrolyte in terface(SEI)to suppress the growth of Na dendrites;(3)integrating flame-retardanee into polymer sodium batteries to enhance flame-resistanee,eliminate electrolyte leakage,and thus improve safety of sodium batteries.Based on these results,we further assembled Na3V2(PO4)3/MoS2 pouch cell which can withsta nd harsh conditions(be nded or cut off a corn er),confirming the obtai ned polymer electrolyte with superior non-leakage property.In all,these outstanding characteristics would endow this flame-retardant quasi-solid polymer electrolyte a very promising can didate for highly-safe sodium metal batteries.

基于低含水量普鲁士蓝正极的准固态钠离子电池

与锂离子电池相比,钠离子电池具有成本低、低温性能与安全性更佳等优势,在成本与可靠性敏感的应用领域备受瞩目。高容量、低成本的普鲁士蓝类材料(PBAs)是极具前景的钠离子电池正极材料,但结构中存在的结晶水导致电池性能快速衰减,是限制其应用的瓶颈。本研究提出了一种简便易行的热处理策略,以高效脱除PBAs正极材料中的结晶水,340次循环后的容量保持率由73%提升到88%。利用原位技术揭示了PBAs正极在充放电过程中,其晶体结构由三方向立方发生不可逆转变是造成首次库仑效率损失的机制,并针对性地提出在正极中添加Na_(2)C_(2)O_(4)钠补偿剂可以解决这一问题。在此基础上,采用高离子电导率、高电化学稳定性的聚乙二醇二丙烯酸酯(PEGDA)准固态电解质,匹配添加Na_(2)C_(2)O_(4)钠补偿剂的低含水量PBAs正极与硬碳(HC)负极,构建了高性能准固态钠离子电池。此类电池在20~500mA·g^(-1)电流密度下的比容量为58~105mAh·g^(-1),并可稳定循环超过200次。研究表明高效脱除结晶水,可以显著提高PBAs正极的稳定性与比容量。

Novel Quasi-solid-state Dye-sensitized Solar Cell Based on Monolayer Capped TiO_2 Nanoparticles Framework Materials

Dodecylbenzenesulfonate (DBS)-capped TiO2 nanoparticles have been synthesized and employed in dye-sensitized solar cells to form a quasi-solid state electrolyte. Owing to the long alkyl-chain capping around the TiO2 nanoparticles interacting with the liquid solvent, the dye sensitized solar cell based on such DBS-capped TiO2 nanoparticle framework material gel electrolyte shows higher stability compared with the non-capped one in the long-term application and gives a comparable overall efficiency of 6.3% at AM 1.5 illumination.

室温钠硫电池体系催化调控硫转化路径研究进展

本文重点阐释了催化活性中心对硫转化路径的调控作用,系统总结了各种功能结构载体对长链多硫化钠、短链多硫化钠及小硫分子转化路径的催化调控。展望了构建新型准固态转化硫正极的可行性,以期从根本上提高室温钠硫电池的放电容量及循环稳定性。

典型储液类结构流-固耦合问题的扩展研究

为了明晰流体与固体耦合力学机理及其相互作用力,本文以典型储液类流固耦合问题为研究对象,综合应用变积方法、Lagrange乘子法和对合变换法,建立了非保守流固耦合问题的一类变量和二类变量的拟变分原理。经推导其驻值条件得到一类变量和二类变量流固耦合问题的控制方程。应用Lagrange乘子表示流固耦合界面处耦合因子,分别给出应用流体力学变量和固体力学变量表达的耦合因子。将拟变分原理应用于有限元素法,建立了流-固耦合动力学的协调元和杂交元计算模型。本文对流固耦合问题的变分方法发展和提高计算效率具有重要作用。

Effect of the self-assembled gel network formed from a low molecular mass organogelator on the electron kinetics in quasi-solid-state dye-sensitized solar cells

A low molecular mass organogelator(LMOG),N,N’-1,5-pentanediylbis-dodecanamide, was applied to quasi-solid-state dye-sensitized solar cells(QS-DSSCs). The crosslinked gel network was self-assemblied by the LOMG in the liquid electrolyte, and the in situ assembly process of gelator can be obtained by the polarized optical microscopy(POM). On one hand, the network hinders the diffusion of redox species and accelerates the electron recombination at the interface of the TiO_2 photoanode/electrolyte. On the other hand, Li+ can interact with the amide carbonyl groups of the gelators and the adsorption of Li+ onto the TiO_2 surface decreases, leading to a negative shift of the TiO_2 conduction band edge, accelerated electron transport and decreased electron injection efficiency(η_(inj)) of QS-DSSC. As a result, the incidental photon-to-electron conversion efficiency(IPCE),the short circuit photocurrent density(J_(sc)) and the open circuit voltage(V_(oc)) of the QS-DSSC are decreased compared with those of the liquid electrolyte based DSSC(L-DSSC),which indicates that the electron recombination plays a great role in the photovoltaic performances of DSSC. Remarkably,the QS-DSSC exhibits excellent thermal and light-soaking stabilities during accelerated aging tests for 1000 h, which is attributed to a great intrinsic stability of the gel electrolyte with a high gel to solution transition temperature(T_(gel)=108°C).

Ionic Liquid Based Electrolyte with Mesoporous Silica SBA-15 as Framework for Quasi-solid-state Dye-sensitized Solar Cells

Quasi-solid-state electrolytes were fabricated with mesoporous silica SBA-15 as a framework material. Ionic conductivity measurements revealed that SBA-15 can enhance the conductivity of the quasi-solid-state electrolyte. The diffusion coefficients of polyiodide ions such as Ⅰ3ˉ and Ⅰ5ˉ which were confirmed by Raman spectroscopic measurement, were about twice larger than that of I-. The optimized photoenergy conversion efficiency of dye-sensitized solar cells （DSSC） with the quasi-solid-state electrolyte was 4.3% under AM 1.5 irradiation at 75 mW·cm^-2 light intensity.