锂硫银锗矿固态电解质研究进展

全固态电池因其较高的安全性和能量密度而成为下一代电动汽车和智能电网用储能器件的重点研究方向之一。开发具有高室温锂离子电导率、化学/电化学稳定性优异、对电极材料兼容性优异等特点的固态电解质材料是推动全固态电池发展的重要研究课题之一。硫化物电解质因其相对较高的室温电导率(~10^(-3) S·cm^(-1))、较低的电解质/电极固-固界面阻抗等优点而在众多无机固体电解质材料中成为研究热点。本文基于作者多年研究成果和当前国内外发表的相关工作,从电解质的结构、离子传导、合成、综合性能改善及在全固态电池中的应用等方面系统总结了锂硫银锗矿固态电解质材料研究,并分析了该类电解质面临的问题和挑战,最后探讨了其未来可能的研究方向和发展趋势。

卤化物固态电解质研究进展

全固态电池因其高能量密度和高安全性而成为具有发展前景的下一代储能技术。开发具有高室温离子电导率、优异化学/电化学稳定性、良好正/负极兼容性的固态电解质是实现全固态电池实用化的关键。卤化物固态电解质因其优异的电化学窗口、高正极稳定性、可接受的室温锂离子电导率等优势,受到了广泛的关注。本文通过对近年来卤化物电解质的相关研究进行总结,综述了该类电解质的组成、结构、离子传导路径及制备方法,并分析了金属卤化物电解质的电导率、稳定性特点,归纳了近年来该电解质在全固态电池中具有代表性的应用,并基于以上总结和分析,指出了卤化物固态电解质的研究难点及发展方向。

Investigation of Li-ion transport in Li7P3S11 and solid-state lithium batteries

The high Li-ion conductivity of the Li7P3S11 sulfide-based solid electrolyte makes it a promising candidate for all-solid-state lithium batteries. The Li-ion transport over electrode-electrolyte and electrolyteelectrolyte interfaces, vital for the performance of solid-state batteries, is investigated by impedance spectroscopy and solid-state NMR experiments. An all-solid-state Li-ion battery is assembled with the Li7P3S11 electrolyte, nano-Li2S cathode and Li-In foil anode, showing a relatively large initial discharge capacity of 1139.5 m Ah/g at a current density of 0.064 m A/cm^ 2 retaining 850.0 m Ah/g after 30 cycles. Electrochemical impedance spectroscopy suggests that the decrease in capacity over cycling is due to the increased interfacial resistance between the electrode and the electrolyte. 1D exchange ^7Li NMR quantifies the interfacial Li-ion transport between the uncycled electrode and the electrolyte, resulting in a diffusion coefficient of 1.70(3) ×10^-14cm^2/s at 333 K and an energy barrier of 0.132 e V for the Li-ion transport between Li2S cathode and Li7P3S11 electrolyte. This indicates that the barrier for Li-ion transport over the electrode-electrolyte interface is small. However, the small diffusion coefficient for Li-ion diffusion between the Li2S and the Li7P3S11 suggests that these contact interfaces between electrode and electrolyte are relatively scarce, challenging the performance of these solid-state batteries.

Facile synthesis of the Mn_(3)O_(4)polyhedron grown on N-doped honeycomb carbon as high-performance negative material for lithium-ion batteries

Because of their large volume variation and inferior electrical conductivity,Mn_(3)O_(4)-based oxide anode materials have short cyclic lives and poor rate capability,which obstructs their development.In this study,we successfully prepared a Mn_(3)O_(4)/N-doped honeycomb carbon composite using a smart and facile synthetic method.The Mn_(3)O_(4)nanopolyhedra are grown on N-doped honeycomb carbon,which evidently mitigates the volume change in the charging and discharging processes but also improves the electrochemical reaction kinetics.More importantly,the Mn-O-C bond in the Mn_(3)O_(4)/N-doped honeycomb carbon composite benefits electrochemical reversibility.These features of the Mn_(3)O_(4)/N-doped honeycomb carbon(NHC)composite are responsible for its superior electrochemical performance.When used for Li-ion batteries,the Mn_(3)O_(4)/N-doped honeycomb carbon anode exhibits a high reversible capacity of 598 mAh·g^(−1)after 350 cycles at 1 A·g^(−1).Even at 2 A·g^(−1),the Mn_(3)O_(4)/NHC anode still delivers a high capacity of 472 mAh·g^(−1).This work provides a new prospect for synthesizing and developing manganese-based oxide materials for energy storage.

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.

Sn-O dual-doped Li-argyrodite electrolytes with enhanced electrochemical performance

As a type of candidate for all-solid-state Li batteries,argyrodite solid electrolytes possess high ionic conductivity,but poor compatibility against Li metal.Here,we report novel Li_(6) PS_(5) I-based argyrodite sulfides with Sn-O dual doping,which is a powerful solution to comprehensively improve the performance of a material.The combination of O and Sn-aliovalent doping not only enables an improved ionic conductivity but more importantly realizes an intensively enhanced interfacial compatibility between argyrodite and Li metal and Li dendrite suppression capability.The assembled battery with Sn-O dual-doped electrolyte and Li anode demonstrates high capacity and decent cycling stability.Dual doping is thus believed to be an effective way to develop high performance sulfide solid electrolytes.

High performance room temperature all-solid-state Na-SexS battery with Na3SbS4-coated cathode via aqueous solution

All-solid-state(ASS)Na-S batteries are promising for large-scale energy storage because of the incombustible solid electrolyte and avoiding the dissolution of intermediates.However,the poor contact between the active material and the solid electrolyte in the positive electrode leads to poor electrochemical performance.Here,we report an aqueous solution approach to fabricate Na3SbS4-coated SexS-based active materials for a Na-S battery working at room temperature.Compared with the Na3SbS4 and SexS mixed cathode,the coated cathode achieves significantly improved Na-ion diffusion kinetics and reduced impedance resistance.Additionally,the nanoparticle coating sustains the volume expansion of the cathode during cycling.The resulting batteries deliver an intensively enhanced specific capacity at various rates.Regardless of the mass loading,the Na3SbS4-coated cathode maintains a decent reversible capacity for the long-term discharge/charge cycling.The best battery achieves an initial discharge capacity of509 mAh g^-1 at a current density of 437.4 mA g^-1 and capacity retention of 98.9%for 100 cycles.To the best of our knowledge,this is one of the best room temperature ASS Na-S battery so far.This work demonstrates that Na3SbS4 is very promising for the cathode coating purpose for ASS Na-S batteries.

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.

Synergy of I-Cl co-occupation on halogen-rich argyrodites and resultant dual-layer interface for advanced all-solid-state Li metal batteries

The(electro)chemical stability and Li dendrite suppression capability of sulfide solid electrolytes(SEs)need further improvement for developing all-solid-state Li batteries(ASSLBs).Here,we report advanced halogen-rich argyrodites via I and Cl co-occupation on the crystal lattice.Notably,a proper I content forms a single phase,whereas an excessive I causes precipitation of two argyrodite phases like a superlattice structure.The resultant synergistic effect of the optimized composition allows to gain high ionic conductivities at room temperature and-20℃,and enhances the(electro)chemical stability against Li and Li dendrite suppression capability.The Li|argyrodite interface is very sensitive to the ratio of I and Cl.A LiCl-and LiI-rich double-layer interface is observed from the cell using the SE with optimized composition,whereas too high I content forms only a single interface layer with a mixture of Lil and LiCl.This double-layer interface is found to effectively mitigate the Li/SE reaction.The proper designed argyrodite enables ASSLBs to achieve good electrochemical properties at a broad temperature range regardless of the electrode materials.This co-occupation strategy provides a novel exploration for advanced halogen-rich argyrodite system.

Construction of LiCl/LiF/LiZn hybrid SEI interface achieving high-performance sulfide-based all-solid-state lithium metal batteries

Sulfide-based all-solid-state lithium metal batteries(ASSLMBs)have received extensive attention due to their high energy density and high safety,while the poor interface stability between sulfide electrolyte and lithium metal anode limits their development.Hence,a hybrid SEI(LICl/Li F/Li Zn)was constructed at the interface between Li_(5.5)PS_(4.5)Cl_(1.5)sulfide electrolyte and lithium metal.The Li Cl and Li F interface phases with high interface energy effectively induce the uniform deposition of Li^(+)and reduce the overpotential of Li^(+)deposition,while the Li Zn alloy interface phase accelerates the diffusion of lithium ions.The synergistic effect of the above functional interface phases inhibits the growth of lithium dendrites and stabilizes the interface between the sulfide electrolyte and lithium metal.The hybrid SEI strategy exhibits excellent electrochemical performance on symmetric batteries and all-solid-state batteries.The symmetrical cell exhibits stable cycling performance over long duration over 500 h at 1.0 mA cm^(-2).Moreover,the LiNbO_(3)@NCM712/Li_(5.5)PS_(4.5)Cl_(1.5)/Li-10%Zn F_(2)battery exhibits excellent cycle stability at a high rate of 0.5 C,with a capacity retention rate of 76.4%after 350 cycles.

Tungsten separation behavior on preparation of high-purity cerium by combined vacuum gravity sedimentation-directional solidification

In light of the difficult removal of harmful impurity tungsten(W)in Ce metal,in this paper a combined vacuum gravity sedimentation-directional solidification method was innovatively designed and the W separation behavior was investigated.By reducing the electron beam power instantly and gradually at reduction rates of 1,3 and 5 kW/min,it is found that W is enriched at the bottom of ingots as the melt solidifies.The enrichment effect is much better than that of single purification method and the enrichment degree increases as the beam reduction rate decreases,attributed to the k0(W)>1 andρ(W)>ρ(Ce).Overall,the minimum content of W impurity can decrease from 630 to 0.1 ppm at the top of the ingot,and the purity of Ce increases from 99.932 wt%to 99.995 wt%by this combined method.Additionally,this paper provides a new method for the removal of high density and low evaporation coefficient impurities in low vapor pressure rare earth metals.

Improved performance of LiMn_(0.8)Fe_(0.2)PO_(4) by addition of fluoroethylene carbonate electrolyte additive

The addition of electrolyte additives is an effective strategy for tuning the property of the electrolyte to engineer the electrode/electrolyte interface,and there exist obvious discrepancies regarding the effect of fluoroethylene carbonate(FEC)as an electrolyte additive on the performance of cathodes.Herein FEC is introduced into the electrolyte of the LiMn_(0.8)Fe_(0.2)PO_(4)/Li cell and its effect on the properties of the LiMn_(0.8)Fe_(0.2)PO_(4) is investigated.It is found that the addition of FEC in the electrolyte has a positive effect on the performance of the LiMn_(0.8)Fe_(0.2)PO_(4) cathode,which can be attributed to the reduced products generated by the interfacial side-reactions on the LiMn_(0.8)Fe_(0.2)PO_(4) cathode surface and the decreased metal dissolution in the FEC-containing electrolyte,thanks to the higher oxidation resistance of FEC and the easier and stronger binding of FEC and PF_6^(-).

Si-doped Li_(6)PS_(5)I with enhanced conductivity enables superior performance for all-solid-state lithium batteries

Lithium argyrodites Li_(6)PS_(5)X(X=Cl,Br,I)show great potential as solid electrolytes for solid-state lithium batteries due to their high Li-ion conductivities and excellent electrode compatibility.However,the relatively low conductivity of Li_(6)PS_(5)I(10^(-6)m S/cm)compared to the other two compositions limits its applications.Herein,Si-doped Li_(6.5)P_(0.5)Si_(0.5)S_(5)I electrolyte is designed and synthesized with superior high conductivity of 3.6 mS/cm.Structural characterization proves the increase due to the anion disorder and volume expansion caused by Si-doping.However,the poor interfacial stability between layered oxide cathode Li Ni_(0.6)Co_(0.2)Mn_(0.2)O_(2)and Li_(6.5)P_(0.5)Si_(0.5)S_(5)I inhibits its battery performance.By introducing Li_(3)InCl6electrolyte in the configuration,the corresponding battery delivers high initial discharge capacity of 150.2m Ah/g and superior cyclability during 250 cycles at 0.5 C.This work offers design strategy to obtain Li_(6)PS_(5)I-based electrolytes for high performance solid-state batteries.

Revealing the size effect of Fe S2on solid-state battery performances at different operating temperatures

FeS_(2) shows significant potential as cathode material for all-solid-state lithium batteries(ASSLBs)due to its high theoretical specific capacity,low cost,and environmental friendliness.However,the poor ion/electron conductivity and large volume variation effect of FeS_(2) inhibit its practical applications.Here,the influence of particle size of FeS_(2) on the corresponding sulfide-based solid-state batteries is carefully investigated by tuning FeS_(2) size.Moreover,low operating temperature is chosen to mitigate the large volume changes during cycling in the battery.S-FeS_(2) with smaller particle sizes delivers superior electrochemical performances than that of the larger L-FeS_(2) in Li_(5.5)PS_(4.5)Cl_(1.5)-based ASSLBs under different operating temperatures.S-FeS_(2) shows stable discharge capacities during 50 cycles with a current density of 0.1 m A/cm^(2)under -20℃.When the current density rises to 1.0 m A/cm^(2),it delivers an initial discharge capacity of 146.9 m Ah/g and maintains 63% of the capacity after 100 cycles.This work contributes to constructing ASSLBs enables excellent electrochemical performances under extreme operating temperatures.

Enabling superior electrochemical performance of NCA cathode in Li_(5.5)PS_(4.5)Cl_(1.5)-based solid-state batteries with a dual-electrolyte layer

LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA) is a promising cathode for sulfide-based solid-state lithium batteries(ASSLBs)profiting from its high specific capacity and voltage plateau, which yielding high energy density. However, the inferior interfacial stability between the bare NCA and sulfides limits its electrochemical performance. Hereien, the dual-electrolyte layer is proposed to mitigate this effect and enhance the battery performances of NCA-based ASSLIBs. The Li_(3)InCl_6 wih high conductivity and excellent electrochemcial stability act both as an ion additives to promote Li-ion diffusion across the interface in the cathode and as a buffer layer between the cathode layer and the solid electrolyte layer to avoid side reactions and improve the interface stability. The corresponding battery exhibits high discharge capacities and superior cyclabilities at both room and elevated temperatures. It exhibits discharge performance of 237.04 and216.07 m Ah/g at 0.1 and 0.5 C, respectively, when cycled at 60 ℃, and sustains 95.9% of the capacity after100 cycles at 0.5 C. The work demonstrates a simple strategy to ensure the superior performances of NCA in sulfide-based ASSLBs.

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.

中国海相黏土的压缩指数的EPR-RCGA回归模型和RMSE-AIC-BIC模型选择及其工程应用（英文）

目的:压缩指数是软土工程领域的关键参数。本文旨在提出一个基于进化多项式回归和实编码遗传算法(EPR-RCGA)的回归分析方法,将压缩指数与物理特性建立相关关系并应用于工程实践。创新点:结合EPR和RCGA方法,将中国沿海21个不同区域的黏土的压缩性指数与天然含水率和液塑限之间建立相关关系,并采用均方根误差(RMSE)、赤池信息量准则(AIC)和贝叶斯信息准则(BIC)对所建立的不同回归模型进行优选。方法:1.从文献中收集中国沿海21个地区的黏土的压缩指数和常见的基本物理性质,并对数据进行整理和分类。2.进行压缩指数和天然含水量及液塑限之间的EPR回归关系分析,并采用新近提出的RCGA优化方法来提高回归关系的精度。3.采用RMSE、AIC和BIC对不同组合下的回归关系进行优选,并确定最佳回归关系。4.将得到的关系式应用到有限元路堤计算来验证所得关系式的实用性和准确性。结论:1.本文提出的压缩指数关系式比现有的经验公式更好,预测得到的压缩指数更为精确。2.采用所提出的压缩指数回归模型预测了东南沿海一路堤下不同土层的压缩指数,并应用所得数据和有限元方法对路堤的沉降进行了模拟分析,验证了所提方法的可靠性。3.所有结果表明,结合基于EPR和RCGA的回归分析方法以及基于RMSE、AIC和BIC的模型选择方法对分析压缩指数与黏土的物理性质的相关关系是切实可行的,可以更好地服务于中国沿海地区的工程设计。

O-doping strategy enabling enhanced chemical/electrochemical stability of Li_(3)InCl_(6) for superior solid-state battery performance

Solid-state electrolytes with high oxidation stability are crucial for achieving high power density allsolid-state lithium batteries.Halide electrolytes are promising candidates due to their outstanding compatibility with cathode materials and high Li^(+)conductivity.However,the electrochemical stability of chloride electrolytes is still limited,leaving them unsuitable for ultrahigh voltage operation.Besides,chemical compatibility issue between sulfide and halide electrolytes affects the electrochemical performance of all-solid-state batteries.Herein,Li-ion conductor Li_(3+x)InCl_(6-x)O_(x) is designed to address these challenges.Li_(3.25)InCl_(5.75)O_(0.25)shows a Li-ion conductivity of 0.90 mS cm^(-1)at room temperature,a high onset oxidation voltage of 3.84 V,fewer by-products at ultrahigh operation voltage,and good chemical compatibility with Li_(5.5)PS_(4.5)Cl_(1.5).The Li_(3.25)InCl_(5.75)O_(0.25)@LiNi_(0.7)Co_(0.1)Mn_(0.2)O_(2)-Li_(3.25)InCl_(5.75)O_(0.25)-VGCF/Li_(3.25)InCl_(5.75)O_(0.25)/Li_(5.5)PS_(4.5)Cl_(1.5)/Li-In battery delivers good electrochemical performances at high operating voltage.This work provides a simple,economical,and effective strategy for designing high-voltage all-solid-state electrolytes.

Tactile perception of textile fabrics based on friction and brain activation

Tactile perception plays a critical role in the interaction of humans and environment.It begins with the mechanical stimulation induced by friction and is processed in the somatosensory cortex.To quantify the tactile perceptions of textile fabrics,the mechanical properties of fabrics and the features extracted from the friction and vibration signals were correlated with the subjective sensation rated by questionnaires.Meanwhile,the technique of functional magnetic resonance imaging(fMRI)was used to identify the brain areas responsible for the tactile perception of textile fabrics.The results showed that during the tactile perception of textile fabrics,the coefficient of friction increased with the increasing normal load,indicating that the deformation mechanism of skin was relevant to the friction of skin against fabrics.The features of spectral centroid(SC),coefficient of friction,and diameter and critical buckling force of fiber had a strong correlation with the perceived fineness,slipperiness,and prickliness of fabrics,respectively.The postcentral gyrus,supramarginal gyrus,and precentral gyrus,with the corresponding functional regions of the primary somatosensory cortex(SI),secondary somatosensory cortex(SII),primary motor cortex(MI),and secondary motor cortex(MII),were involved with the perceptions of fabric textures.The fiber properties and fabric surface structures that caused the multidimensional feelings tended to induce the large area,intensity,and percent signal change(PSC)of brain activity.This study is meaning for evaluating the tactile stimulation of textile fabrics and understanding the cognitive mechanism in the tactile perception of textile fabrics.

Improvement of stability and solid-state battery performances of annealed 70Li_(2)S–30P_(2)S_(5) electrolytes by additives

The replacement of liquid electrolyte with solid electrolyte can significantly improve the safety and power/energy density of lithium batteries.70Li_(2)S–30P_(2)S_(5) is one of the most promising solid electrolytes with high conductivity for solid–state batteries.In this work,the ionic conductivity and stability toward moisture and lithium metal of 70Li_(2)S–30P_(2)S_(5) were enhanced by introducing the different amounts of Li_(2)O additives.65Li_(2)S–30P_(2)S_(5)–1%Li_(2)O delivered the highest conductivity,while 65Li_(2)S–30P_(2)S_(5)–5%Li_(2)O showed the best moisture stability and improved lithium compatibility.Solid-state batteries using 65Li_(2)S–30P_(2)S_(5)–5%Li_(2)O electrolyte and high-voltage LiNi_(0.6)Mn_(0.2)Co_(0.2)O_(2) cathode exhibited low initial discharge capacity(100 mAh·g^(-1))and Coulombic efficiency(69%).Li_(3)InCl_(6) electrolytes were introduced both in the cathode mixture to replace sulfide electrolyte and in the interface layer to improve the cathode compatibility for the solid-state batteries,showing enhanced discharge capacity(175 mAh·g^(-1))and improved initial Coulombic efficiency(86%).Moreover,it also exhibited good performance at-20℃.