LiNbO3-coated LiNi0.8Co0.1Mn0.1O2 cathode with high discharge capacity and rate performance for all-solid-state lithium battery

In order to obtain high power density,energy density and safe energy storage lithium ion batteries(LIB)to meet growing demand for electronic products,oxide cathodes have been widely explored in all-solidstate lithium batteries(ASSLB)using sulfide solid electrolyte.However,the electrochemical performances are still not satisfactory,due to the high interfacial resistance caused by severe interfacial instability between sulfide solid electrolyte and oxide cathode,especially Ni-rich oxide cathodes,in charge-discharge process.Ni-rich LiNi0.8Co0.1Mn0.1O2(NCM811)material at present is one of the most key cathode candidates to achieve the high energy density up to 300 Wh kg^-1 in liquid LIB,but rarely investigated in ASSLB using sulfide electrolyte.To design the stable interface between NCM811 and sulfide electrolyte should be extremely necessary.In this work,in view of our previous work,LiNbO3 coating with about 1 wt% content is adopted to improve the interfacial stability and the electrochemical performances of NCM811 cathode in ASSLB using Li10GeP2S12 solid electrolyte.Consequently,LiNbO3-coated NCM811 cathode displays the higher discharge capacity and rate performance than the reported oxide electrodes in ASSLB using sulfide solid electrolyte to our knowledge.

Effect of TiB2 content on microstructure and properties of in situ Ti–TiB composites

This study determined the optimal concentration of titanium diboride (TiB2) particles for the development of in situ titanium– titanium boride (Ti–TiB) metal matrix composites (MMCs) prepared by a conventional powder metallurgy route to be used for industrial applications. The effect of concentration of TiB2 particles was studied by reinforcing TiB2 powder in different mass fractions (2wt%, 5wt%, 10wt%, and 20wt%) into pure Ti powder during the fabrication process. The MMCs were sintered at high temperatures under vacuum. The transmission electron microscopy (TEM) results revealed the formation of needle-shaped TiB whiskers, indicating that in situ reaction occurred during vacuum sintering of the powder compacts. All the composite samples had a high sintered density, and the hardness of the composites increased with an increase in the mass fraction of reinforcement. Mechanical and tribological properties such as flexural strength, impact, and wear properties were determined and found to be dependent on the mass fraction of the reinforcement. However, the mechanism for the in situ reaction needs further investigation by high-energy in situ X-ray diffraction techniques.

Ameliorating the interfacial issues of all-solid-state lithium metal batteries by constructing polymer/inorganic composite electrolyte

Lithium metal is one of the most promising anodes for next-generation batteries due to its high capacity and low reduction potential.However,the notorious Li dendrites can cause the short life span and safety issues,hindering the extensive application of lithium batteries.Herein,Li_(7)La_(3)Zr_(2)O_(12)(LLZO)ceramics are integrated into polyethylene oxide(PEO)to construct a facile polymer/inorganic composite solid-state electrolyte(CSSE)to inhibit the growth of Li dendrites and widen the electrochemical stability window.Given the feasibility of our strategy,the designed PEO-LLZO-LiTFSI composite solid-state electrolyte(PLLCSSE)exhibits an outstanding cycling property of 134.2 mAh g^(-1) after 500 cycles and the Coulombic efficiency of 99.1%after 1000 cycles at 1 C in LiFePO_(4)-Li cell.When cooperated with LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cathode,the PLL-CSSE renders a capacity retention of 82.4%after 200 cycles at 0.2 C.More importantly,the uniform dispersion of LLZO in PEO matrix is tentative tested via Raman and FT-IR spectra and should be responsible for the improved electrochemical performance.The same conclusion can be drawn from the interface investigation after cycling.This work presents an intriguing solid-state electrolyte with high electrochemical performance,which will boost the development of all-solid-state lithium batteries with high energy density.

In/ex-situ Raman spectra combined with EIS for observing interface reactions between Ni-rich layered oxide cathode and sulfide electrolyte

The interfacial instability between Ni-rich layered oxide cathodes and sulfide electrolytes is a serious problem,leading to poor electrochemical properties of all-solid-state lithium batteries(ASSLB).The chemical/electrochemical side reactions are considered to be the origin of the interfacial deterioration.However,the influence of chemical and electrochemical side reactions on the interfacial deterioration is rarely studied specifically.In this work,the deterioration mechanism of the interface between LiNi0.85-xCo0.15AlxO2 and Li10GeP2S12 is investigated in detail by combining in/ex-situ Raman spectra and Electrochemical Impedance Spectroscopy(EIS).It can be determined that chemical side reaction between LiNi0.8Co0.15Al0.05O2 and Li10GeP2S12 will occur immediately once contacted,and the interfacial deterioration becomes more serious after charge-discharge process under the dual effects of chemical and electrochemical side reactions.Moreover,our research reveals that the interfacial stability and the cycle performance of ASSLB can be greatly enhanced by increasing Al-substitution for Ni in LiNi0.85-xCo0.15AlxO2.In particular,the capacity retention of LiNi0.6Co0.15Al0.25O2 cathode after 200 cycles can reach 81.9%,much higher than that of LiNi0.8Co0.15Al0.05O2 cathode(12.5%@200 cycles).This work gives an insight to study the interfacial issues between Ni-rich layered oxide cathode and sulfide electrolyte for ASSLBs.

High-speed measurement of thickness of a water film formed by a jet obliquely impinging onto a plate using an LED-induced fluorescence method

A transient thickness distribution measured with a high temporal resolution is elemental for exploring the flow characteristics and mechanism of a liquid film formed by an impinging jet.Therefore,this paper develops a high-speed Light-Emitting Diode-Induced Fluorescence(LEDIF)system based on the brightness measured directly above the liquid film.An Ultraviolet(UV)LED lamp is used to provide sufficient and continuous excitation light.Then,a system performance analysis proves that the system can continuously measure the global film thickness at a high acquisition frequency of 5000 Hz when the dye concentration is 200 mg/L.The influence of the irregularity of the excitation intensity,including the spatial non-uniformity,temporal instability,and long-term instability,on the measurement uncertainty is analyzed in detail.The analysis indicates that the system has an acceptable uncertainty of 10%.Compared with theoretical results,experimental results verify that the LEDIF system can accurately measure the global thickness of a liquid film formed by a water jet obliquely impinging onto a plate.An experimental investigation of the radial section of the raised zone demonstrates that the radial section changes from a sewing needle to an oval when the azimuth angle increases from 10°to 90°.Meanwhile,the dynamic contact angle exponentially decreases from 41.4°to 30.1°.A dynamic analysis of surface waves shows that the measured wave velocity decreases from 12 m/s to 1 m/s and the dominant frequency decreases from 1000 Hz to 10 Hz along the flow direction.

Towards safe lithium-sulfur batteries from liquid-state electrolyte to solid-state electrolyte

Lithium-sulfur(Li-S)battery has been considered as one of the most promising future batteries owing to the high theoretical energy density(2600 W-h-kg-1)and the usage of the inexpensive active materials(elemental sulfur).The recent progress in fundamental research and engineering of the Li-S battery,involved in electrode,electrolyte,membrane,binder,and current collector,has greatly promoted the performance of Li s batteries from the laboratory level to the approaching practical level.However,the safety concerns still deserve attention in the following application stage.This review focuses on the development of the electrolyte for Li S batteries from liquid state to solid state.Some problems and the corresponding solutions are emphasized,such as the soluble lithium polysulfides migration,ionic conductivity of electrolyte,the interface contact between electrolyte and electrode,and the reaction kinetics.Moreover,future perspectives of the safe and high-performance Li S batteries arealso introduced.

Tunable nonlinear refractive index of two-dimensional MoS2, WS2, and MoSe2 nanosheet dispersions [Invited]

Liquid-phase-exfoliation technology was utilized to prepare layered MoS2, WS2, and MoSe2 nanosheets in cyclohexylpyrrolidone. The nonlinear optical response of these nanosheets in dispersions was investigated by observing spatial self-phase modulation（SSPM） using a 488 nm continuous wave laser beam. The diffraction ring patterns of SSPM were found to be distorted along the vertical direction right after the laser traversing the nanosheet dispersions. The nonlinear refractive index of the three transition metal dichalcogenides dispersions n2 was measured to be 10-7cm2W-1, and the third-order nonlinear susceptibility χ（3）10-9 esu. The relative change of effective nonlinear refractive index Δn2e∕n（2e） of the MoS2, WS2, and MoSe2 dispersions can be modulated 0.012–0.240, 0.029–0.154, and 0.091–0.304, respectively, by changing the incident intensities. Our experimental results imply novel potential application of two-dimensional transition metal dichalcogenides in nonlinear phase modulation devices.

补锂材料Li_(6)CoO_(4)提高锂离子电池容量和循环性能

SiO和Si/C具有高容量,被认为是高能量密度锂离子电池有前景的负极材料.然而,副反应(形成Li;O和硅酸锂)和固体电解质界面(SEI)膜的形成,导致这些负极材料初始库仑效率、活性锂离子数量以及放电容量的降低.在正极或负极中添加补锂材料是解决这一问题的有效方法.最常用的补锂材料是稳定锂金属粉末(SLMP),但这种策略存在安全风险高、成本高且难以实现定量补锂的缺点.本文合成并研究了Li_(6)CoO_(4)锂补偿材料,分析和讨论了其制备条件、空气中的稳定性、脱锂机制和结构转变机理.研究结果表明,添加Li_(6)CoO_(4)能在发挥补锂作用的同时,显著提高软包全电池(3-Ah)的循环性能.这项工作提供了一种有效的补锂策略,是提高锂离子电池电化学性能的有效方法.

Interface structure and strain controlled Pt nanocrystals grown at side facet of MoS_(2)with critical size

The heterostructure of transition metal nanocrystal on two-dimensional(2D)materials exhibits unique physical and chemical properties through various interfacial interactions.It has been established that the atomic structure and strain in the vicinity of the interface determine the band structure and phonon modes of the nanocrystal,regulating the optical and electrical properties of such heterostructures.Hence,metal–support interfacial engineering is a demonstrated approach to acquiring desired properties of the nanocrystals.However,a fundamental understanding of the interfacial structures remains elusive and precise control of the interactions has yet achieved.Herein,we explore the regulation of interface on MoS_(2)supported Pt nanocrystals which were prepared by reducing ultrasonic dispersed potassium chloroplatinate.The Pt-MoS_(2)heterostructure interface was systematically studied by aberration corrected transmission electron microscopy.Three types of Pt-MoS_(2)interfaces with distinct atomic configurations were identified.The strain within the Pt nanocrystals is sensitive to the atomic configuration of the supporting MoS_(2),which regulates the size of the Pt nanocrystals.These results provide insights on tuning of nanocrystal strain,paving the way for precise control of 2D semiconductor heterostructures.

Erratum to:Interface structure and strain controlled Pt nanocrystals grown at side facet of MoS_(2)with critical size

Erratum to Nano Research 2022,15(9):8493–8501 https://doi.org/10.1007/s12274-022-4449-5 The name of the first author in original paper was unfortunately misspelled.It should be“Yuchen Zhu”,instead of“Yucheng Zhu”.