Cathode materials account for around one third of the manufacturing cost of lithium-ion battery, which are the major factor preventing the wider applications of power battery packs. Flame synthesis (FS) is a new manufacturing technology of nanostructured materials with few equipment and high efficiency, which potentially can substantially bring down the manufacturing cost of cathode materials. The primary objective of the present study was to quantitatively evaluate the resources, energy consumption and economic feasibility of largescale production of cathode materials though FS. In the analysis process, the mass flow of reactants and resultants as well as the minimum cathode material selling price (MCSP) of ternary cathode material LiNixCoyMn(1-x-y)O2 (x + y + z = 1) produced by FS were calculated, and compared with that of the conventional hydroxide coprecipitation method. Results show that the production of ternary cathode material through FS can reduce CO2 emissions by similar to 60% and water consumption by similar to 30%. MCSP of LiNi0.5Co0.2Mn0.3O2 (NCM523), LiNi0.6Co0.2Mn0.2O2 (NCM622), and LiNi0.8Co0.1Mn0.1O2 (NCM811) produced by FS are 224.8 k(sic)/t, 235.1 k(sic)/t, 240.0 k(sic)/t, which respectively are about 2%, 10% and 14% lower than the average selling prices in Chinese market, indicating that FS is economically feasible for producing ternary cathode materials. Particularly, for the production of high-nickel cathode materials, FS has notable potential in simplifying the production process and manufacturing costs. Sensitivity analysis of NCM811 produced by FS shows that when raw material price, fuel and power costs are reduced by 25%, MCSP can be as low as 186.4 k(sic)/t. When the metal cation concentration of the solution increases to 3.2 mol/L, it enables FS to meet the most rigorous energy consumption limitation standards in China. When the lithium excess is reduced from 10% to 5%, MCSP of NCM811 can be further reduced by 5.6 k(sic)/t, indicating that lithium loss due to high temperatures in FS is a moderate factor for reducing the manufacturing cost. Finally, this work presents a life cycle assessment (LCA) of NCM materials produced by FS in China. Comparison to the global warming potential (GWP) of the co-precipitation method in the literature indicated that GWP of FS is lower.

Heavy metal contamination is widely present in the spinning field. Some heavy metal ions such as Fe3+ may accumulate in the coagulation bath using ionic liquids (ILs) as green solvents to prepare regenerated cellulose fibers (RCFs), which seriously affect the performance of RCFs and the subsequent regeneration of ILs. This study proposed a new strategy to selectively adsorb Fe3+ from ILs aqueous solution using carboxyl-functionalized wood microchannel (CW). The CW was optimized by citric acid concentration, reaction time, and temperature using carboxyl group contents as an indicator. The physic-chemical properties of CW were characterized, and its adsorption performance for Fe3+ was also evaluated in a water system. Furthermore, the adsorption selectivity of CW for Fe3+ and ILs was investigated. The results demonstrate that the CW had a high adsorption ratio for Fe3+ (94.73%), while that for ILs was 4.20%. The selective adsorption mechanism, in which the Fe3+ is mainly separated from ILs aqueous solution by complexation with carboxyl group, was confirmed by FTIR, XPS, MIP, and DFT calculation. Accordingly, this paper may provide a new strategy to selectively adsorb Fe3+ from ILs aqueous solution, thus offering an economical and efficient method for ILs recovery and water purification.

Keratin, a naturally occurring biomaterial, has gained substantial recognition for its application in various domains. Given its abundant presence in human hair, the pursuit of efficient methods for dissolving and extracting keratin is motivated by the dual objectives of maximizing the utility of human hair and promoting ecological sustainability. In this work, a series of deep eutectic solvents (DES) were designed for extraction of keratin from human hair under mild experimental conditions. The effects of DES structure, molar ratios of HBA to HBD, dissolution temperature, and time on the dissolving ability of DES for human hair were investigated in depth. The results showed that ChCl/MEA can effectively dissolve human hair under mild conditions (80 degrees C, 4 h) with a solubility of 84% and a mass percentage of 20%. FT-IR, XRD, SDS-PAGE, and TGA results showed that the structure of the regenerated keratin was slightly destroyed but still exhibited stable thermal property. Analysis of the reduced density gradient (RDG) and surface electrostatic potential (ESP) verified that the hydrogen bond driven by electrostatic attraction is formed in DESs. Independent gradient model (IGMH) analysis confirmed that the weak interaction between human hair and DES is mainly caused by van der Waals interactions. Additionally, ChCl/MEA displayed an excellent performance in extracting keratin from human hair even after recycling for three cycles.

Bacterial infections have become a serious threat to public health. The utilization of antibacterial textiles offers an effective way to combat bacterial infections at the source, instead of relying solely on antibiotic consumption. Herein, efficient and durable antibacterial fibers based on quercetin and cellulose were prepared by a triaxial microfluidic spinning technology using ionic liquids (ILs) as the solvents. It was indicated that the structure and properties of the antibacterial fibers were affected by the type of IL and the flow rates during the triaxial microfluidic spinning process. Quercetin regenerated from [Emim]Ac underwent structural transformation and obtained an increased water solubility, while quercetin regenerated from [Emim]DEP remained unchanged, which was proven by FI-IR, XRD, and UV analyses. Furthermore, antibacterial fibers regenerated from [Emim]Ac exhibited the highest antibacterial activity of 96.9% against S. aureus, achieved by reducing the inner-to-outer flow rate ratio to 0 and concentrating quercetin at the center of fibers. On the other hand, when [Emim]DEP was used as the solvent, balancing the inner-to-outer flow rate ratio to concentrate quercetin in the middle layer of the fiber was optimal for achieving the best antibacterial activity of 93.3% because it promised both the higher encapsulation efficiency and release rate. Computational fluid dynamics (CFD) mathematically predicted the solvent exchange process during triaxial spinning, explaining the influence of IL types and flow rates on quercetin distribution and encapsulation efficiency. It was indicated that optimizing the distribution of antibacterial agents within the fibers can fully unleash its antibacterial potential while preserving the mechanical properties of the fiber. Therefore, the proposed simple triaxial spinning strategy provides valuable insights into the design of biomedical materials.

Development of thermal storage material from recycled solid waste resources can further enhance the economic and environmental benefits of thermal energy storage system. Thermal properties of steel slag as sensible heat storage material are examined and further enhanced by Na2CO3 activation. The steel slag remains stable until 1200 degrees C in TG-DSC test, and the morphology kept unchanged after 200 thermal cycles (400-900 degrees C), indicating good thermal cyclic stability. The thermal energy storage density of steel slag is 797.9 kJ.kg(-1) (400-900 degrees C), the thermal conductivity was measured as 0.505, 0.532 and 0.670 W.(m.K)(-1) at 25, 250 and 500 degrees C, respectively. When the steel slag is further modified by Na2CO3, the morphology and phase of the material remained stable, and the DSC curve trend unchanged after thermal cycle. The thermal energy storage density reaches 997.0 kJ.kg(-1) (400-900 degrees C), which is 25.3% higher than original steel slag. Even more, the thermal conductivity is 1.331, 1.323, 0.889 W.(m.K)(-1) at 25, 250, and 500 degrees C, respectively, which is 32.7% higher than that of steel slag. Hence, the thermal properties of steel slag have been significantly improved by the developed Na2CO3 activation process.

碳酸盐(Na2CO3和K2CO3)是极具潜力的高温相变材料,高炉矿渣(blast furnace slag,BS)作为基体材料兼具环境和经济效益,但是碳酸盐在高温熔融状态下通常会与高炉矿渣发生反应.为此,本工作发展两步法制备路线以攻克这一问题.首先,使用碳酸盐对高炉矿渣进行改性,得到化学性质稳定的改性矿渣(modified blast furnace slag,MBS);其次,通过混合烧结法制备碳酸盐/改性矿渣定型复合相变材料(form-stable phase change materials,FSPCMs).经过冷热循环测试制备的K2CO3/KMBS复合相变材料比Na2CO3/NMBS的定型效果更优.分析发现,K2CO3与KMBS具有良好的化学相容性,随着K2CO3含量增加,K2CO3/KMBS定型相变材料的潜热逐渐增加,且测试结果与计算一致,在质量比4:6(40K2CO3/60KMBS)时,潜热为94.8 kJ/kg,且热稳定性最好.

Keratin, the naturally derived biomaterials have been developed and widely applied in many different fields. Among the resources containing keratin, human hair is one of the most abundant natural fibers rich in keratin and one of the most abundant waste materials produced by humans. It is critical for both value-added human hair utilization and environmental protection if suitable solvents for the dissolution and regeneration of the keratin were developed. Ionic liquids (ILs) have been evidenced to be the green solvents to extract keratin from waste human hair. In this work, five novel Protic ILs were designed and synthesized in one step with inexpensive raw materials under mild conditions. The effect of different anions and cations, temperature, and water content on the dissolution ability of Protic ILs for human hair was investigated in depth. The best IL [MEA]HCOO with high solubilization capacity (9 h, 130 degrees C) for human hair was finally obtained by considering the time required for complete hair dissolution and the properties of regenerated keratin. The results of FTIR, XRD, and TGA showed that the a-helix structure of regenerated keratin was not destroyed. The recycling result indicates that the dissolution ability of [MEA]HCOO for human hair kept stable after 5 times recovery. Furthermore, the density functional theory (DFT) calculations and independent gradient model (IGM) analysis uncover the dissolution of human hair by ILs through synergistic interaction between the cations and anions of ILs. (c) 2022 Elsevier B.V. All rights reserved.

It is of practical importance to develop form stable composite phase change materials (FSPCMs) for high temperature thermal energy storage. Carbonates are promising candidates as the phase change material and steel slag is a promising economical skeleton material. However, the molten carbonates (Na2CO3 and K2CO3) react with steel slag (SS) at high temperature. Here, a two-step process was developed to overcome this problem. Firstly, the modified steel slag (MSS) was obtained by activation of the two carbonates, and secondly, FSPCMs were synthesized by mix-sintering method. The obtained K2CO3/KMSS FSPCMs kept better shape than that of Na2CO3/NMSS FSPCMs after the thermal cycles. Further test showed that K2CO3 had good chemical compatibility with KMSS and was uniformly distributed. With the increased K2CO3 content, the latent heat of K2CO3/KMSS FSPCMs gradually increases, and the measured latent heat was consistent with the calculated values. With mass ratio 4:6 (40K2CO3/60KMSS), the developed FSPCM showed the best thermal stability, the latent heat attenuation was 7.08%, and the mass loss was 6.56% after 200 thermal cycles.

This work presents an experimental and numerical study on the leakage of phase change materials through a micropore under gravity during the melting process. The effects of the pore size, wettability and physical properties of phase change materials on the packaging performance of composite phase change materials are discussed in details. The leakage process is divided into four stages, including breaking through the pore, wetting, necking and rupture. Dimensional analysis shows that the leakage process is mainly governed by the dimensionless Bond number (Bo) and Ohnesorge number (Oh). The results demonstrate that increasing the pore size significantly enhances the potential of leakage because of the increase of Bo. With a fixed Bo, the leakage can be efficiently suppressed by increasing Oh, which gives rise to a larger viscous resistance. Furthermore, it is discovered that reducing the contact angle could also prevent the leakage, as the larger surface tension is provided.(c) 2022 Elsevier Ltd. All rights reserved.

以石蜡作为相变材料(PCM),采用六面通圆孔三维结构模型,对泡沫金属复合PCM内相变熔化过程进行了数值模拟.研究了不同材料(Cu、Al、Ni、Fe)泡沫金属孔密度和孔隙率对复合PCM传热和储热性能的影响.结果表明,泡沫金属复合PCM传热过程受热传导和自然对流作用综合影响;随孔密度增加,复合PCM完全熔化时间缩短幅度逐渐减小,且泡沫金属热导率越高,孔密度对传热速率影响越大;泡沫金属复合PCM内存在非热平衡现象,孔密度和孔隙率增加均可减小最大平均温差,但对最终平衡时间的影响却截然不同;此外,泡沫金属复合PCM单位质量储热密度随孔隙率增大而增大,相比泡沫Cu、Ni、Fe复合PCM,泡沫Al复合PCM的单位质量储热密度较大,增加速率也较大.

列管式换热器在相变储热领域应用广泛,但由于部分相变材料热导率偏低,导致相变换热器的换热性能较差,因此提高相变储热单元的换热效率从而缩短固液相变时间是研究重点之一.本文开展列管式相变储热单元储热过程的三维非稳态模拟工作,研究了翅片型式、螺旋翅片厚度、数目及螺旋周期对储热性能的影响规律,并探讨了相变材料熔化过程中平均温度、液相率以及储热量的变化趋势.模拟结果表明,与平板翅片相比,螺旋翅片储热单元熔化时间可缩短12.21％;随着螺旋翅片的厚度、数目、螺旋周期增加,虽储热量略降,但相变材料的熔化时间缩短,换热性能不断提升.

全球范围内的能源短缺和环境污染问题迫使人们积极开发可再生新能源.储热技术是解决新能源不稳定性问题的关键技术.相变材料是重要的储热介质之一.熔盐相变材料因其储热密度高,可操作温度范围广的优势,成为储热材料领域研究的热点.为解决熔盐液相易泄漏、低导热和高成本的问题,选择钢渣为基体材料,制备了太阳盐/钢渣定型复合相变储热材料,并通过扫描电子显微镜(SEM),热重-差示扫描量热法(TG-DSC),闪射法导热仪(LFA)和X射线衍射仪(XRD)对复合材料的微观结构、热性能和化学相容性进行了测试与表征.结果表明,钢渣与熔盐质量比5:5的复合材料定型效果最优.复合材料结构紧密;钢渣与熔盐化学相容性良好;复合材料潜热为64.0kJ/kg,100?500℃内储热密度为945kJ/kg,热导率高达2.23 W/(m·K).太阳盐/钢渣复合相变储热材料不仅有利于储热技术的大规模应用,而且为钢铁工业废弃物回收利用提供了良好的参考,对节约资源、保护环境以及提高经济效益具有重要的意义.