A Ternary Hybrid-Cation Room-Temperature Liquid Metal Battery and Interfacial Selection Mechanism Study

The dendrite-free sodium–potassium (Na–K) liquid alloy composed of two alkali metals is one of the ideal alternatives for Li metal as an anode material while maintaining large capacity, low potential, and high abundance. However, Na- or K-ion batteries have limited cathode materials that can deliver stably large capacity. Combining advantages of both, a hybrid-cation liquid metal battery is designed for a Li-ion-insertion-based cathode to deliver stable high capacity using a Na–K liquid anode to avoid dendrites. The mechanical property of the Na–K alloy is confirmed by simulation and experimental characterization, which leads to stable cycling performance. The charge carrier selection principle in this ternary hybrid-cation system is investigated, showing consistency with the proposed interfacial layer formation and ion distribution mechanism for the electrochemical process as well as the good stability. With Li ions contributing stable cycling as the cathode charge carrier, the K ion working as charge carrier on the anode, and Na as the medium to liquefy K metal, such a ternary hybrid battery system not only inherits the rich battery chemistry of Li-insertion cathodes but also broadens the understanding of alkali metal alloys and hybrid-ion battery chemistry.     

An Interfacial Solar‐Driven Atmospheric Water Generator Based on a Liquid Sorbent with Simultaneous Adsorption–Desorption

Water scarcity is one of the greatest challenges facing human society. Because of the abundant amount of water present in the atmosphere, there are significant efforts to harvest water from air. Particularly, solar‐driven atmospheric water generators based on sequential adsorption–desorption processes are attracting much attention. However, incomplete daytime desorption is the limiting factor for final water production, as the rate of water desorption typically decreases very quickly with decreased water content in the sorbents. Hereby combining tailored interfacial solar absorbers with an ionic‐liquid‐based sorbent, an atmospheric water generator with a simultaneous adsorption–desorption process is generated. With enhanced desorption capability and stabilized water content in the sorbent, this interfacial solar‐driven atmospheric water generator enables a high rate of water production (≈0.5 L m^?2 h^?1) and 2.8 L m^?2 d^?1 for the outdoor environment. It is expected that this interfacial solar‐driven atmospheric water generator, based on the liquid sorbent with a simultaneous adsorption–desorption process opens up a promising pathway to effectively harvest water from air.     

Understanding the Reaction Chemistry during Charging in Aprotic Lithium–Oxygen Batteries: Existing Problems and Solutions

The aprotic lithium–oxygen (Li–O₂) battery has excited huge interest due to it having the highest theoretical energy density among the different types of rechargeable battery. The facile achievement of a practical Li–O₂ battery has been proven unrealistic, however. The most significant barrier to progress is the limited understanding of the reaction processes occurring in the battery, especially during the charging process on the positive electrode. Thus, understanding the charging mechanism is of crucial importance to enhance the Li–O₂ battery performance and lifetime. Here, recent progress in understanding the electrochemistry and chemistry related to charging in Li–O₂ batteries is reviewed along with the strategies to address the issues that exist in the charging process at the present stage. The properties of Li₂O₂ and the mechanisms of Li₂O₂ oxidation to O₂ on charge are discussed comprehensively, as are the accompanied parasitic chemistries, which are considered as the underlying issues hindering the reversibility of Li–O₂ batteries. Based on the detailed discussion of the charging mechanism, innovative strategies for addressing the issues for the charging process are discussed in detail. This review has profound implications for both a better understanding of charging chemistry and the development of reliable rechargeable Li–O₂ batteries in the future.     

Overcoming the Interfacial Limitations Imposed by the Solid–Solid Interface in Solid‐State Batteries Using Ionic Liquid‐Based Interlayers

Li‐garnets are promising inorganic ceramic solid electrolytes for lithium metal batteries, showing good electrochemical stability with Li anode. However, their brittle and stiff nature restricts their intimate contact with both the electrodes, hence presenting high interfacial resistance to the ionic mobility. To address this issue, a strategy employing ionic liquid electrolyte (ILE) thin interlayers at the electrodes/electrolyte interfaces is adopted, which helps overcome the barrier for ion transport. The chemically stable ILE improves the electrodes‐solid electrolyte contact, significantly reducing the interfacial resistance at both the positive and negative electrodes interfaces. This results in the more homogeneous deposition of metallic lithium at the negative electrode, suppressing the dendrite growth across the solid electrolyte even at high current densities of 0.3 mA cm^?2. Further, the improved interface Li/electrolyte interface results in decreasing the overpotential of symmetric Li/Li cells from 1.35 to 0.35 V. The ILE modified Li/LLZO/LFP cells stacked either in monopolar or bipolar configurations show excellent electrochemical performance. In particular, the bipolar cell operates at a high voltage (≈8 V) and delivers specific capacity as high as 145 mAh g^?1 with a coulombic efficiency greater than 99%.     

Initiating Hexagonal MoO3 for Superb-Stable and Fast NH4+ Storage Based on Hydrogen Bond Chemistry

Nonmetallic ammonium (NH₄⁺) ions are applied as charge carriers for aqueous batteries, where hexagonal MoO₃ is initially investigated as an anode candidate for NH₄⁺ storage. From experimental and first-principle calculated results, the battery chemistry proceeds with reversible building–breaking behaviors of hydrogen bonds between NH₄⁺ and tunneled MoO₃ electrode frameworks, where the ammoniation/deammoniation mechanism is dominated by nondiffusion-controlled pseudocapacitive behavior. Outstanding electrochemical performance of MoO₃ for NH₄⁺ storage is delivered with 115 mAh g⁻¹ at 1 C and can retain 32 mAh g⁻¹ at 150 C. Furthermore, it remarkably exhibits ultralong and stable cyclic performance up to 100 000 cycle with 94% capacity retention and high power density of 4170 W kg⁻¹ at 150 C. When coupled with CuFe prussian blue analogous (PBA) cathode, the full ammonium battery can deliver decent energy density 21.3 Wh kg⁻¹ and the resultant flexible ammonium batteries at device level are also pioneeringly developed for potential realistic applications.     

Solar-Powered Interfacial Evaporation and Deicing Based on a 3D-Printed Multiscale Hierarchical Design

Solar-powered interfacial heating has emerged as a sustainable technology for hybrid applications with minimal carbon footprints. Aerogels, hydrogels, and sponges/foams are the main building blocks for state-of-the-art photothermal materials. However, these conventional three-dimensional (3D) structures and related fabrication technologies intrinsically fail to maximize important performance-enhancing strategies and this technology still faces several performance roadblocks. Herein, monolithic, self-standing, and durable aerogel matrices are developed based on composite photothermal inks and ink-extrusion 3D printing, delivering all-in-one interfacial steam generators (SGs). Rapid prototyping of multiscale hierarchical structures synergistically reduce the energy demand for evaporation, expand actual evaporation areas, generate massive environmental energy input, and improve mass flows. Under 1 sun, high water evaporation rates of 3.74 kg m⁻² h⁻¹ in calm air and 25.3 kg m⁻² h⁻¹ at a gentle breeze of 2 m s⁻¹ are achieved, ranking among the best-performing solar-powered interfacial SGs. 3D-printed microchannels and hydrophobic modification deliver an icephobic surface of the aerogels, leading to self-propelled and rapid removal of ice droplets. This work shines light on rational fabrication of hierarchical photothermal materials, not merely breaking through the constraints of solar-powered interfacial evaporation and clean water production, but also discovering new functions for photothermal interfacial deicing.     

Recent Progress in Multivalent Metal (Mg,Zn, Ca,and Al) and Metal‐Ion Rechargeable Batteries with Organic Materials as Promising Electrodes

The emerging demand for electronic and transportation technologies has driven the development of rechargeable batteries with enhanced capacity storage. Especially, multivalent metal (Mg, Zn, Ca, and Al) and metal‐ion batteries have recently attracted considerable interests as promising substitutes for future large‐scale energy storage devices, due to their natural abundance and multielectron redox capability. These metals are compatible with nonflammable aqueous electrolytes and are less reactive when exposed in ambient atmosphere as compared with Li metals, hence enabling potential safer battery systems. Luckily, green and sustainable organic compounds could be designed and tailored as universal host materials to accommodate multivalent metal ions. Considering these advantages, effective approaches toward achieving organic multivalent metal and metal‐ion rechargeable batteries are highlighted in this Review. Moreover, organic structures, cell configurations, and key relevant electrochemical parameters are presented. Hopefully, this Review will provide a fundamental guidance for future development of organic‐based multivalent metal and metal‐ion rechargeable batteries.     

不同温度下Sn-0.7Cu钎料在非晶Fe84.3Si10.3B5.4合金上的润湿行为及界面特征

采用座滴法及利用SEM-EDS分别对Sn、Sn-37Pb、Sn-58Bi和Sn-0.7Cu四种钎料在非晶Fe_(84.3)Si_(10.3)B_(5.4)合金上的静态润湿及界面特征进行了对比研究,优选出Sn-0.7Cu钎料作为适用于非晶Fe_(84.3)Si_(10.3)B_(5.4)合金的焊接钎料。进而采用座滴法研究了不同温度下Sn-0.7Cu钎料在非晶Fe_(84.3)Si_(10.3)B_(5.4)合金上的动态润湿行为,并利用SEM-EDS观察分析了其在非晶Fe_(84.3)Si_(10.3)B_(5.4)合金表面润湿后的界面微观组织形貌及成分。结果表明,Sn-0.7Cu钎料在非晶Fe_(84.3)Si_(10.3)B_(5.4)合金上的最终平衡润湿角随着温度的升高而变小,润湿性越来越好;同时Sn-0.7Cu与非晶Fe_(84.3)Si_(10.3)B_(5.4)合金界面上形成的FeSn_2金属间化合物由间断分布变为连续分布,且其厚度逐渐增加,界面反应逐渐增强。     

复合材料泡沫夹层结构界面的温度-应变分布

复合材料泡沫夹层结构由于其比强度高、比刚度高、耐腐蚀等特点已广泛在土木工程领域中获得应用。然而,由于复合材料面板与夹芯材料在温度荷载作用下热膨胀系数显著不同,因此在面板与芯材之间的粘结层会产生温度应力,因此会降低界面的粘结性能。本文通过试验研究,系统地给出了复合材料泡沫夹层结构界面温度-应变分布规律,并通过理论建模,提出了界面温度-应变分布规律的计算模型,通过对比实验值与理论值,验证了理论分析模型的精确性。     

Interlayer‐Spacing‐Regulated VOPO4 Nanosheets with Fast Kinetics for High‐Capacity and Durable Rechargeable Magnesium Batteries

Owing to the low‐cost, safety, dendrite‐free formation, and two‐electron redox properties of magnesium (Mg), rechargeable Mg batteries are considered as promising next‐generation secondary batteries with high specific capacity and energy density. However, the clumsy Mg²⁺ with high polarity inclines to sluggish Mg insertion/deinsertion, leading to inadequate reversible capacity and rate performance. Herein, 2D VOPO₄ nanosheets with expanded interlayer spacing (1.42 nm) are prepared and applied in rechargeable magnesium batteries for the first time. The interlayer expansion provides enough diffusion space for fast kinetics of MgCl⁺ ion flux with low polarization. Benefiting from the structural configuration, the Mg battery exhibits a remarkable reversible capacity of 310 mAh g^?1 at 50 mA g^?1, excellent rate capability, and good cycling stability (192 mAh g^?1 at 100 mA g^?1 even after 500 cycles). In addition, density functional theory (DFT) computations are conducted to understand the electrode behavior with decreased MgCl⁺ migration energy barrier compared with Mg²⁺. This approach, based on the regulation of interlayer distance to control cation insertion, represents a promising guideline for electrode material design on the development of advanced secondary multivalent‐ion batteries.     

相反转界面细乳液聚合法制备石蜡纳胶囊与表征

采用相反转乳化的界面细乳液聚合法制备了以交联聚甲基丙烯酯甲酯为壁材,以石蜡为芯材的纳胶囊。利用光学显微镜、激光粒度分析仪、透射电镜、红外光谱仪、差示扫描量热分析仪等研究了含氟助乳化剂FC-4430、丙烯酸十八酯(SA)及芯材投料量对聚合过程、产品表面形貌、粒径、化学结构、储热性能和包覆率的影响。结果表明,FC-4430对相反转有促进作用,可降低胶囊粒子尺寸且利于包封;SA能提高纳胶囊的包覆率和热稳定性;当FC-4430用量为0.4%,SA用量为2%,m(core)∶m(shell)为2∶1时,纳胶囊的相变潜热为91.7 J/g,包覆率为63.3%,包覆效率为95.0%,胶囊粒子为球形,表面光滑,粒径为0.6~1μm,呈明显的核壳结构,芯材直径为300~500 nm。     

Size‐, Water‐, and Defect‐Regulated Potassium Manganese Hexacyanoferrate with Superior Cycling Stability and Rate Capability for Low‐Cost Sodium‐Ion Batteries

Potassium manganese hexacyanoferrate (KMHCF) is a low‐cost Prussian blue analogue (PBA) having a rigid and open framework that can accommodate large alkali ions. Herein, the synthesis of KMHCF and its application as a high‐performance cathode in sodium‐ion batteries (NIBs) is reported. High‐quality KMHCF with low amounts of crystal water and defects and with homogeneous microstructure is obtained by controlling the nucleation and grain growth by using a high‐concentration citrate solution as a precipitation medium. The obtained KMHCF exhibits superior cycling and rate performance as a NIB cathode, showing 80% capacity retention after 1000 cycles at 1 C and a high capacity of 95 mA h g^?1 at 20 C. Unlike conventional single‐cation batteries, the hybrid NIB with KMHCF as cathode and Na as anode in Na‐ion electrolyte displays three reversible plateaus that involve stepwise insertion/extraction of both K⁺ and Na⁺ in the PBA framework. In later cycling, the K⁺–Na⁺ cointercalated phase is partially converted into a cubic sodium manganese hexacyanoferrate (NaMHCF) phase due to the increasing replacement of Na⁺ for K⁺.     

An Overview of Fiber-Shaped Batteries with a Focus on Multifunctionality,Scalability, and Technical Difficulties

Flexible and wearable energy storage devices are receiving increasing attention with the ever-growing market of wearable electronics. Fiber-shaped batteries display a unique 1D architecture with the merits of superior flexibility, miniaturization potential, adaptability to deformation, and compatibility with the traditional textile industry, which are especially advantageous for wearable applications. In the recent research frontier in the field of fiber-shaped batteries, in addition to higher performance, advances in multifunctional, scalable, and integrable systems are also the main themes. However, many difficulties exist, including difficult encapsulation and installation of separators, high internal resistance, and poor durability. Herein, the design principles (e.g., electrode preparation and battery assembly) and device performance (e.g., electrochemical and mechanical properties) of fiber-shaped batteries, including lithium-based batteries, zinc-based batteries, and some other representative systems, are summarized, with a focus on multifunctional devices with environmental adaptability, stimuli-responsive properties, and scalability up to energy textiles, with the hope of enlightening future research directions. Finally, technical challenges in the realistic wearable application of these batteries are also discussed with the aim of providing possible solutions and new insights for further improvement.     

Multifunctional Interlayer Based on Molybdenum Diphosphide Catalyst and Carbon Nanotube Film for Lithium–Sulfur Batteries

A multifunctional interlayer, composed of molybdenum diphosphide (MoP₂) nanoparticles and a carbon nanotube (CNT) film, is introduced into a lithium–sulfur (Li–S) battery system to suppress polysulfide migration. Molybdenum diphosphide acts as the catalyst and can capture polysulfides and improve the polysulfide conversion activity during the discharge/charge processes. The CNT film acts as a conductive skeleton to support the MoP₂ nanoparticles and to ensure their uniform distribution. The CNT film physically hinders polysulfide migration, acts as a current collector, and provides abundant electron pathways. The Li–S battery containing the multifunctional MoP₂/CNT interlayer exhibits excellent electrochemical performance. It delivers a reversible specific capacity of 905 mA h g^?1 over 100 cycles at 0.2 C, with a capacity decay of 0.152% per cycle. These results suggest the introduction of the multifunctional CNT/MoP₂ interlayer as an effective and practical method for producing high‐performance Li–S batteries.     

基于划痕试验的超硬铝7A04微弧氧化膜基结合力的测试与评定

目前基于划痕试验法的金属防护层与基体结合力的研究大多是针对微弧氧化膜外的其他硬质膜层,且鲜有验证性试验.采用微弧氧化技术在7A04超硬铝合金表面成功制备出陶瓷膜层并观察了其微观形貌,利用WS-2005膜层附着力自动划痕仪在膜层上进行了划痕试验,采集了声发射信号,利用数显材料显微镜观察声发射图谱特征声信号峰对应划痕处的微观形貌,检测了划痕附近膜层显微硬度,判定了干扰信号,对膜基结合力进行了综合分析和评定.结果表明:7A04铝合金微弧氧化陶瓷膜层表面呈“火山喷射口”层叠状,划痕试验中膜层破坏仅发生在划痕内部,划痕周围没有发生大面积崩落,膜层与基体间结合力良好.     

High-pressure,high-temperature thermophysical measurements on tantalum and tungsten

A submillisecond resistive heating technique under high pressure (0.2 GPa) has been applied to the measurement of thermophysical properties of tantalum and tungsten metals in the solid and the liquid state. Agreement between previously published and most of the present results is good.Paper presented at the Ninth Symposium on Thermophysical Properties, June 24–27, 1985, Boulder, Colorado, U.S.A.     

A Carbonyl Compound‐Based Flexible Cathode with Superior Rate Performance and Cyclic Stability for Flexible Lithium‐Ion Batteries

A sulfur‐linked carbonyl‐based poly(2,5‐dihydroxyl‐1,4‐benzoquinonyl sulfide) (PDHBQS) compound is synthesized and used as cathode material for lithium‐ion batteries (LIBs). Flexible binder‐free composite cathode with single‐wall carbon nanotubes (PDHBQS–SWCNTs) is then fabricated through vacuum filtration method with SWCNTs. Electrochemical measurements show that PDHBQS–SWCNTs cathode can deliver a discharge capacity of 182 mA h g⁻¹ (0.9 mA h cm⁻²) at a current rate of 50 mA g⁻¹ and a potential window of 1.5 V–3.5 V. The cathode delivers a capacity of 75 mA h g⁻¹ (0.47 mA h cm⁻²) at 5000 mA g⁻¹, which confirms its good rate performance at high current density. PDHBQS–SWCNTs flexible cathode retains 89% of its initial capacity at 250 mA g⁻¹ after 500 charge–discharge cycles. Furthermore, large‐area (28 cm²) flexible batteries based on PDHBQS–SWCNTs cathode and lithium foils anode are also assembled. The flexible battery shows good electrochemical activities with continuous bending, which retains 88% of its initial discharge capacity after 2000 bending cycles. The significant capacity, high rate performance, superior cyclic performance, and good flexibility make this material a promising candidate for a future application of flexible LIBs.     

Flexible,High‐Wettability and Fire‐Resistant Separators Based on Hydroxyapatite Nanowires for Advanced Lithium‐Ion Batteries

Separators play a pivotal role in the electrochemical performance and safety of lithium‐ion batteries (LIBs). The commercial microporous polyolefin‐based separators often suffer from inferior electrolyte wettability, low thermal stability, and severe safety concerns. Herein, a novel kind of highly flexible and porous separator based on hydroxyapatite nanowires (HAP NWs) with excellent thermal stability, fire resistance, and superior electrolyte wettability is reported. A hierarchical cross‐linked network structure forms between HAP NWs and cellulose fibers (CFs) via hybridization, which endows the separator with high flexibility and robust mechanical strength. The high thermal stability of HAP NW networks enables the separator to preserve its structural integrity at temperatures as high as 700 °C, and the fire‐resistant property of HAP NWs ensures high safety of the battery. In particular, benefiting from its unique composition and highly porous structure, the as‐prepared HAP/CF separator exhibits near zero contact angle with the liquid electrolyte and high electrolyte uptake of 253%, indicating superior electrolyte wettability compared with the commercial polyolefin separator. The as‐prepared HAP/CF separator has unique advantages of superior electrolyte wettability, mechanical robustness, high thermal stability, and fire resistance, thus, is promising as a new kind of separator for advanced LIBs with enhanced performance and high safety.     

Effect of Alloying Elements on Microstructure,Martensitic Transformation and Mechanical Properties of Ni-Mn Based Alloys

The microstructural features,shape memory behavior and mechanical properties of Ni-Mn based alloys were investigated by dierential scanning calorimetry(DSC),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and thermal cycling test under various stresses.The transformation temperatures shifted toward lower temperatures when adding a third element into the Ni-Mn system.The addition of 10 at. pct Fe increased considerably the mechanical properties exhibiting still high transformation temp...     

乙醇对纳米CuO晶型及脱硫性能的影响

分别以硝酸铜水溶液和乙醇溶液为原料、氢氧化钠为沉淀剂,采用直接沉淀法制备了纳米CuO.通过TEM、XRD和XPS技术对比分析了乙醇对纳米CuO粒径及晶型的影响,并对比测试了制得的两种纳米CuO室温脱硫性能.实验结果表明:乙醇为分散剂制得的纳米CuO主要是球形,其平均粒径约为7nm,水为分散剂制得的样品中出现了大量棒形纳米CuO,尺寸约为8 nm×36 nm,说明溶剂极性影响纳米材料的粒径和晶型的形成;球形纳米CuO室温脱除H2S的活性时间是棒形纳米CuO的近两倍,表明纳米粒子的结构是影响脱硫性能的重要因素.