From Liquid to Solid‑State Lithium Metal Batteries:Fundamental Issues and Recent Developments

The widespread adoption of lithium-ion batteries has been driven by the proliferation of portable electronic devices and electric vehicles,which have increasingly stringent energy density requirements.Lithium metal batteries(LMBs),with their ultralow reduction potential and high theoretical capacity,are widely regarded as the most promising technical pathway for achieving high energy density batteries.In this review,we provide a comprehensive overview of fundamental issues related to high reactivity and migrated interfaces in LMBs.Furthermore,we propose improved strategies involving interface engineering,3D current collector design,electrolyte optimization,separator modification,application of alloyed anodes,and external field regulation to address these challenges.The utilization of solid-state electrolytes can significantly enhance the safety of LMBs and represents the only viable approach for advancing them.This review also encompasses the variation in fundamental issues and design strategies for the transition from liquid to solid electrolytes.Particularly noteworthy is that the introduction of SSEs will exacerbate differences in electrochemical and mechanical properties at the interface,leading to increased interface inhomogeneity—a critical factor contributing to failure in all-solidstate lithium metal batteries.Based on recent research works,this perspective highlights the current status of research on developing high-performance LMBs.

Quantification and visualization of spatial distribution of dendrites in solid polymer electrolytes

Integrating lithium metal anodes with polymer electrolytes is a promising technology for the next generation high-energy-density rechargeable batteries.As the progress is often hindered by the dendrite growth upon cycling,quantifying three-dimensional(3D)microstructures of dendrites in polymer electrolytes is essential to better understanding of dendrite formation for the development of mitigation strategies.Techniques for 3D quantification and visualization of dendrites,especially those with low Li contents,are rather limited.This study reports quantitative measurements of the spatial distribution of Li dendrites grown in solid polymer electrolytes using 3D tomographic neutron depth profiling(NDP)with improved spatial resolution,compositional range,and data presentation.Data reveal heterogeneous distribution of Li over length scales from tens nanometers to centimeters.While most dendrites grow from the plating toward the stripping electrode with dwindling Li quantities,dendrites apparently grown from the Li-stripping electrode are also observed.The discovery is only possibly due to the unique combination of the high specificity and high sensitivity of the neutron activation analysis of Li isotope.

Li4-xSbxSn1-xS4 solid solutions for air-stable solid electrolytes

The sulfide solid electrolytes have the characteristics of high ionic conductivity and low grain boundary resistance, which make them suitable for bulk-type all-solid-state batteries. However, most of them suffer from poor stability in air. Here, we explore the air stable sulfide solid electrolytes in Li4-xSbxSn1-xS4 system. The solid solutions of Li4-xSbxSn1-xS4(0 ≤ x ≤ 0.5) can be formed in Li4-xSbxSn1-xS4 system. Li3.8 Sb0.2 Sn0.8 S4 achieves the highest ionic conductivity of 3.5 × 10-4 S cm-1 in this system,which is 5 times as that of Li4 Sn S4 and 3 orders of magnitude higher than that of Li3 Sb S4, respectively. Li3.8 Sb0.2 Sn0.8 S4 crystallizes into the same structure with high ionic conductivity phase of β-Li3 PS4. Moreover, Li3.8 Sb0.2 Sn0.8 S4 owns good stability in humid air. Matching with LiCoO2 and Li4 Ti5 O12,Li3.8 Sb0.2 Sn0.8 S4 exhibits the potential to be applied in all-solid-state batteries.

Carbon‐based materials for all‐solid‐state zinc–air batteries

Solid‐state Zn–air batteries(ZABs)hold great potential for application in wearable and flexible electronics.However,further commercialization of current ZABs is still limited by the poor stability and low energy efficiency.It is,thus,crucial to develop efficient catalysts as well as optimize the solid electrolyte system to unveil potential of the ZAB technology.Due to the low cost and versatility in tailoring the structures and properties,carbon materials have been extensively used as the conductive substrates,catalytic air electrodes,and important components in the electrolytes for the solid‐state ZABs.Within this context,we discuss the challenges facing current solid‐state ZABs and summarize the strategies developed to modify properties of carbon‐based electrodes and electrolytes.We highlight the metal−organic framework/covalent organic framework‐based electrodes,heteroatom‐doped carbon,and the composites formed of carbon with metal oxides/sulfides/phosphides.We also briefly discuss the progress of graphene oxide‐based solid electrolyte.

Effect of H_2S Flow Rate and Concentration on Performance of H_2S/Air Solid Oxide Fuel Cell

A solid state H2S/air electrochemical cell having the configuration of H2S, (MoS2+NiS+Ag)/YSZ/Pt, air has been examined with different H2S flow rates and concentrations at atmospheric pressure and 750-850 ℃. Performance of the fuel cell was dependent on anode compartment H2S flow rate and concentration. The cell open-circuit voltage increased with increasing H2S flow rate. It was found that increasing both H2S flow rate and H2S concentration improved current-voltage and power density performance. This is resulted from improved gas diffusion in anode and increased concentration of anodic electroactive species. Operation at elevated H2S concentration improved the cell performance at a given gas flow rate. However, as low as 5% H2S in gas mixture can also be utilized as fuel feed to cells. Highest current and power densities, 17500mA·cm-2 and 200mW·cm-2, are obtained with pure H2S flow rate of 50ml·min-1 and air flow rate of 100ml·min-1 at 850℃.

Formation and Evolution of Non-dendritic Microstructures of Semisolid Alloys Prepared by Shearing/Cooling Roll Process

The shearing/cooling roll （SCR） process was adopted to prepare semi-solid A2017 alloy. The formation and evolution of non-dendritic microstructures in semi-solid A2017 alloy were studied. It is shown that the microstructures of semi-solid billets transform from coarse dendrites into fine equiaxed grains as the pouring temperature of molten alloy decreases o.r roll-shoe cavity height is reduced. From the inlet to the exit of roll-shoe cavity, microstructure of semi-solid slurry near the shoe surface is in the order of coarse dendrites, degenerated dendrites or equiaxed grains, but fine equiaxed grains are near the roll surface. Microstructural evolution of semi-solid slurry prepared by SCR process is that the molten alloy nucleates and grows into dendrite firstly on the roll and shoe＇s surface. Under the shearing and stirring given by the rotating roll, the dendrites crush off and disperse into the melt. Under the shearing and stirring on semi-solid slurry with high volume fraction of solid, the dendrite arms fracture and form equiaxed grain microstructures.

Integrated interface configuration by in-situ interface chemistry enabling uniform lithium deposition in all-solid-state lithium metal batteries

All-solid-state lithium metal batteries(ASSLMBs)are considered as one of the ultimate goals for the development of energy storage systems due to their high energy density and high safety.However,the mismatching of interface transport kinetics as well as interfacial instability induces the growth of lithium dendrite and thus,leads to severe degradation of battery electrochemical performances.Herein,an integrated interface configuration(IIC)consisting of in-situ generated Li I interphase and Li-Ag alloy anode is proposed through in-situ interface chemistry.The IIC is capable of not only regulating charge transport kinetics but also synchronously stabilizing the lithium/electrolyte interface,thereby achieving uniform lithium platting.Therefore,Li||Li symmetric cells with IIC achieve a critical current density of up to 1.6 mA cm^(-2)and achieve stable cycling over 1600 hours at a high current density of 0.5 mA cm^(-2).Moreover,a high discharge capacity of 140.1 mA h g-1at 0.1 C is also obtained for the Li(Ni_(0.6)Co_(0.2)Mn_(0.2))O_(2)(NCM622)full battery with a capacity retention of 65.6%after 300 cycles.This work provides an effective method to synergistically regulate the interface transport kinetics and inhibit lithium dendrite growth for high-performance ASSLMBs.

A review on system and materials for aqueous flexible metal-air batteries

The exploration of aqueous flexible metal-air batteries with high energy density and durability has attracted many research efforts with the demand for portable and wearable electronic devices.Aqueous flexible metal-air batteries feature Earth-abundant materials,environmental friendliness,and operational safety.Each part of one metal-air battery can significantly affect the overall performance.This review starts with the fundamental working principles and the basic battery configurations and then highlights on the common issues and the recent advances in designing high-performance metal electrodes,solid-state electrolytes,and air electrodes.Bifunctional oxygen electrocatalysts with high activity and long-term stability for constructing efficient air electrodes in flexible metal-air batteries are summarized including metal-free carbon-based materials and nonprecious Co/Fe-based materials(alloys,metal oxides,metal sulfites,metal phosphates,metal nitrates,single-site metal-nitrogen-carbon materials,and composites).Finally,a perspective is provided on the existing challenges and possible future research directions in optimizing the performance and lifetime of the flexible aqueous solid-state metal-air batteries.

Bifunctional flame retardant solid-state electrolyte toward safe Li metal batteries

Solid polymer electrolytes(SPEs)are one of the most promising alternatives to flammable liquid electrolytes for building safe Li metal batteries.Nevertheless,the poor ionic conductivity at room temperature(RT)and low resistance to Li dendrites seriously hinder the commercialization of SPEs.Herein,we design a bifunctional flame retardant SPE by combining hydroxyapatite(HAP)nanomaterials with Nmethyl pyrrolidone(NMP)in the PVDF-HFP matrix.The addition of HAP generates a hydrogen bond network with the PVDF-HFP matrix and cooperates with NMP to facilitate the dissociation of Li TFSI in the PVDF-HFP matrix.Consequently,the prepared SPE demonstrates superior ionic conductivity at RT,excellent fireproof properties,and strong resistance to Li dendrites.The assembled Li symmetric cell with prepared SPE exhibits a stable cycling performance of over 1200 h at 0.2 m A cm^(-2),and the solid-state LiFePO_4||Li cell shows excellent capacity retention of 85.3%over 600 cycles at 0.5 C.

The Experiment and Simulation of Solid Desiccant Dehumidification for Air-Conditioning System in a Tropical Humid Climate

The aim of this research was to study and design a solid desiccant dehumidification system suitable for tropical climate to reduce the latent load of air-conditioning system and improve the thermal comfort. Different dehumidifiers such as desiccant column and desiccant wheel were investigated. The ANSYS and TRASYS software were used to predict the results of dehumidifiers and the desiccant cooling systems, respectively. The desiccant bed contained approximately 15 kg of silica-gel, with 3 mm average diameter. Results indicated that the pressure drop and the adsorption rate of desiccant column are usually higher than those of the desiccant wheel. The feasible and practical adsorption rate of desiccant wheel was 0.102 kgw/h at air flow rate 1.0 kg/min, regenerated air temperature of 55?C and at a wheel speed of 2.5 rpm. The humidity ratio of conditioning space and cooling load of split-type air conditioner was decreased to 0.002 kgw/kgda (14%) and 0.71 kWth (19.26%), respectively. Consequently, the thermal comfort was improved from 0.5 PMV (10.12% PPD) to 0.3 PMV (7.04% PPD).

Synthesis, Characterization and Performance Evaluation of an Advanced Solid Electrolyte and Air Cathode for Rechargeable Lithium-Air Batteries

Synthesis and characterization of a tri-layered solid electrolyte and oxygen permeable solid air cathode for lithium-air battery cells were carried out in this investigation. Detailed fabrication procedures for solid electrolyte, air cathode and real-world lithium-air battery cell are described. Materials characterizations were performed through FTIR and TGA measurement. Based on the experimental four-probe conductivity measurement, it was found that the tri-layered solid electrolyte has a very high conductivity at room temperature, 23。C, and it can be reached up to 6 times higher at 100。C. Fabrication of real-world lithium-air button cells was performed using the synthesized tri-layered solid electrolyte, an oxygen permeable air cathode, and a metallic lithium anode. The lithium-air button cells were tested under dry air with 0.1 mA - 0.2 mA discharge/ charge current at elevated temperatures. Experimental results showed that the lithium-air cell performance is very sensitive to the oxygen concentration in the air cathode. The experimental results also revealed that the cell resistance was very large at room temperature but decreased rapidly with increasing temperatures. It was found that the cell resistance was the prime cause to show any significant discharge capacity at room temperature. Experimental results suggested that the lack of robust interfacial contact among solid electrolyte, air cathode and lithium metal anode were the primary factors for the cell’s high internal resistances. It was also found that once the cell internal resistance issues were resolved, the discharge curve of the battery cell was much smoother and the cell was able to discharge at above 2.0 V for up to 40 hours. It indicated that in order to have better performing lithium-air battery cell, interfacial contact resistances issue must have to be resolved very efficiently.

快掘面风流动态调控参数与压抽比对粉尘运移的影响及降尘分析

随着矿山快掘设备的逐渐引进,快掘面粉尘污染问题愈加严重。为有效减少快掘面生产过程中的粉尘污染,设计出风流动态调控降尘净化系统,通过调节风流的状态并设计了不同工况下的风流调控方案,以降低司机处粉尘浓度与粉尘的扩散距离。以陕西某矿快掘面为例,建立了风流—粉尘耦合场有限元模型,并对模型进行了井下验证;分析了风流动态调控降尘净化系统中出风口偏角、出风口缩放口径、出风口距端头距离及风量压抽比4个参数对风流与粉尘场的影响规律;设计正交试验分析了各参数与司机处粉尘浓度与粉尘扩散距离之间的关联性,确定了最佳调控净化方案。结果表明:各参数对司机处粉尘浓度与粉尘扩散距离影响程度的显著性排序由大到小依次为风量压抽比、出风口偏角、出风口距端头距离、出风口缩放口径。确定的最佳调控净化方案为出风口距离端头10 m、出风口偏角20°、出风口缩放口径1.0 m及风量压抽比1。设计搭建试验平台进行了准确性及净化效果测试验证,模拟值与试验值的平均误差小于8.91%,净化后司机处粉尘浓度由327.22 mg/m^(3)降低至156.47 mg/m^(3),降低了52.18%,粉尘扩散距离由39.74 m缩短至25.91 m,缩短了34.80%,有效改善了快掘面的空气环境。

基于CESE方法的煤矿风井泄爆全过程模拟与消波增效研究

为揭示煤矿风井泄爆过程、探寻增强泄爆效果方法,针对现行泄爆方法和多种改进泄爆方法,建立了系列全尺寸三维仿真模型,利用LS−DYNA软件的CESE求解器,进行了全过程流固耦合模拟分析。结果表明:现行防爆门在泄爆过程中会引发较强烈的反射冲击波且不能快速有效地予以消弱,致使风硐中先后出现可对风机造成二次冲击的2道冲击波;去除防爆门立壁结构对提升泄爆效果作用不明显,但可使防爆门受到的冲击明显减弱;在一定范围内,减轻防爆门质量对提高泄爆效果的作用较为有限,且会使防爆门吸收的爆炸能量明显增加;在增量不大的情况下,增大防爆门到风井和风硐交岔点的距离即能有效改善泄爆效果;侧向和正向先行泄爆方法均能明显增强泄爆效果,并对防爆门有显著的减冲和保护作用,在算例条件下,最优可使反射波超压峰值下降49.4%和28.3%;防爆门开启时间、泄爆面积和防爆门到风井/风硐交岔点的距离是影响泄爆效果的重要因素;风井达到良好泄爆效果所需要的开启时间比现行防爆门要短得多;仅在井口设置防爆门存在不能消减风硐中第1道冲击波超压峰值的局限性。基于对风井泄爆过程、机理和方法的新认识,提出了以“两区域多通道”泄爆为特征的主辅防爆门协同泄爆方法,以系统提升风井泄爆效果和防爆水平。

综掘工作面风流调控装置与射流风幕综合调控粉尘场优化分析

为解决目前综掘工作面传统混合式通风下粉尘聚集污染严重的问题,提出了利用出风口风流调控装置与抽风口射流风幕综合调控优化粉尘场的思路。以陕北某矿综掘工作面为研究对象,建立了风流-粉尘气固耦合场有限元模型,分析了调控装置口径、调控装置右偏角、风幕出口宽度、风幕出口速度及风幕出口张角等参数对粉尘场的影响;设计了正交试验以确定最佳综合调控方案,设计搭建了实验平台进行综合调控方案准确性和降尘效果验证。结果表明:在该综掘工作面通风系统布局下,当调控装置口径1.2 m,调控装置右偏角9°,风幕出口宽度0.14 m,风幕出口速度7 m/s,风幕出口张角60°时,司机位置粉尘质量浓度和行人呼吸带高度平均粉尘质量浓度分别降低91.7%和74.9%,测试误差均在10%以下,有效改善了通风环境。

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)。

马钢2×380m^(2)烧结机节能减排实践

为进一步适应烧结生产优质、降耗、减排的发展的需求,马钢2×380m^(2)烧结机采取了一系列提质降耗技术措施。通过持续优化厚料层烧结生产经济潜力;降低固体燃耗;点火炉升级改造、带冷机改环冷机、烧结机漏风治理、大型风机变频技术等多项节能新技术的应用以及创新管理,在烧结矿质量以及节能降耗方面取得了显著改善效果,工序能耗由55 kgce/t下降至47kgce/t水平。同时对当前2×380m^(2)烧结机烧结高效、低耗生产存在的问题提出了改进方向,以进一步促进节能减排工作的持续发展。

等温热处理对Mg-7Zn-0.3Li-xNd合金组织的影响

使用等温热处理法对不同Nd含量的Mg-7Zn-0.3Li-xNd合金(x=0.1, 0.3, 0.5, 0.7)进行不同温度不同保温时间的热处理,研究保温温度与保温时间对Mg-7Zn-0.3Li-xNd合金非枝晶组织演变规律的影响,分析非枝晶颗粒的形成机理。结果表明:Mg-7Zn-0.3Li-0.5Nd合金在580℃保温30 min后得到理想的球状非枝晶颗粒,其固相率、平均晶粒尺寸和形状因子分别为71.9%、47μm和1.85。随着保温温度的增加或保温时间的延长,非枝晶颗粒的平均晶粒尺寸和形状因子呈现先降低后升高的趋势,固相率则持续降低。随着温度和时间的变化,非枝晶组织的演变过程主要分为三部分:枝晶的粗化,分离与球化,合并与熟化。

常减压装置电脱盐污水治理的工艺改造与优化

针对常减压装置电脱盐污水中H2S和可燃气体含量高、水质因含油含渣的影响不能稳定达标的突出问题。采用常压闪蒸和高效旋流溶气气浮(CDFU)相结合技术路线配套原有重力沉降除油技术工艺,有效解决电脱盐污水中高含油含渣、可燃气和硫化氢含量较高的问题,改造后石油类降低73.6%,COD(化学需氧量)降低32.7%,H2S、可燃气体和VOCS体积浓度分别下降56.85%、57.93%和38.25%。电脱盐污水水质明显改善,减少对下游污水系统的影响,消除安全隐患。

基于流固耦合的正压呼吸面罩抗变形分析

随着正压呼吸防护装备的设计向轻量化方向发展,面罩的厚度逐渐降低,在实际的使用过程中,送风系统产生的进气流量导致面罩存在变形的问题。为研究不同材质的呼吸防护面罩的抗变形能力,采用流固耦合数值模拟及实验验证的方法,分析PP、PET、PVC 3种材质对进气流量的抗变形能力,并且,结合不同环境温度对面罩变形量的影响进行综合分析。结果表明,进气量对PP材料的影响较大,PVC次之,PET变形程度最小;在380 L/min的进气流量下,PP变形量约为3.7 mm,PET变形量约为1.6 mm;除此以外,在不同环境温度下,对3种材料进行变形分析发现,环境温度对PVC的影响较大,PP次之,PET变形程度最小。综合以上分析结果,选择PET材料作为正压呼吸面罩材料。

全固态锂电池热安全性研究进展

随着液态锂电池的广泛应用,热失控现象时有发生,其热安全性成为亟待解决的问题。全固态锂电池以其优异的安全性显示出巨大的应用潜力。该文简要介绍了全固态锂电池的基本概念及组成结构,重点阐述了氧化物、硫化物以及聚合物固体电解质的最新研究进展,并对这3类全固态锂电池的热安全性差异进行了总结,包括固体电解质材料级别、固体电解质与活性材料或锂金属负极混合时界面级别以及全电池级别的热安全性。此外,锂枝晶现象对全固态锂电池安全性的影响仍不可忽视。目前,针对材料和界面级别的热安全性研究众多,但全电池级别的研究较少,且多集中在小容量电池,针对全电池级别的热安全性仍需进一步探究。最后,指出了未来高安全性全固态锂电池的商业化应用应着力于解决全固态锂电池中的关键界面问题以及锂枝晶问题。