留言板

尊敬的读者、作者、审稿人, 关于本刊的投稿、审稿、编辑和出版的任何问题, 您可以本页添加留言。我们将尽快给您答复。谢谢您的支持!

姓名
邮箱
手机号码
标题
留言内容
验证码

优先发表

优先发表栏目展示本刊经同行评议确定正式录用的文章,这些文章目前处在编校过程,尚未确定卷期及页码,但可以根据DOI进行引用。
显示方式:
研究论文
Ablation behaviour and mechanical performance of ZrB2-ZrC-SiC modified carbon/carbon composites prepared by vacuum filtration combined with reactive melt infiltration
ZHANG Jia-ping, SU Xiao-xuan, LI Xin-gang, WANG Run-ning, FU Qian-gang
, doi: 10.1016/S1872-5805(24)60841-3
摘要(94) HTML(66) PDF(33)
摘要:
The development of advanced aircrafts relies on high performance thermal-structural materials and composites of carbon/carbon (C/C) with ultrahigh-temperature ceramics are ideal candidates. However, traditional routes of compositing are either inefficient and expensive or lead to non-uniform distribution of ceramics in the matrix. Here, vacuum filtration of ZrB2 was successfully applied to introduce ZrB2-ZrC-SiC into C/C as a supplement for reactive melt infiltration ZrSi2, which contributed to the content increase and uniform distribution of the introduced ceramic phases. The mass and linear ablation rates of the composites were reduced by 68.9% and 29.7%, respectively, compared to those of C/C-ZrC-SiC composites prepared through reactive melt infiltration. The ablation performance was improved because of the volatilization of B2O3, taking a part of the heat away, and more uniformly distributed ZrO2 that could promote the formation of ZrO2-SiO2 continuous protective layer. This efficiently resisted the mechanical denudation and hindered the oxygen infiltration. The development of advanced aircrafts relies on high performance thermal-structural materials and composites of carbon/carbon (C/C) with ultrahigh-temperature ceramics are ideal candidates. However, traditional routes of compositing are either inefficient and expensive or lead to non-uniform distribution of ceramics in the matrix. Here, vacuum filtration of ZrB2 was successfully applied to introduce ZrB2-ZrC-SiC into C/C as a supplement for reactive melt infiltration ZrSi2, which contributed to the content increase and uniform distribution of the introduced ceramic phases. The mass and linear ablation rates of the composites were reduced by 68.9% and 29.7%, respectively, compared to those of C/C-ZrC-SiC composites prepared through reactive melt infiltration. The ablation performance was improved because of the volatilization of B2O3, taking a part of the heat away, and more uniformly distributed ZrO2 that could promote the formation of ZrO2-SiO2 continuous protective layer. This efficiently resisted the mechanical denudation and hindered the oxygen infiltration.
A potent assistor of firm MoO2/MoS2 heterojunction for high-rate and ultralong-life lithium/sodium storage
ZHANG Chun-hui, ZHANG Jia-yuan, ZHAN Jie-yang, YU jian, FAN Lin-lin, YANG An-ping, LIU hong, GAO Guang-gang
, doi: 10.1016/S1872-5805(24)60845-0
摘要(14) HTML(13) PDF(1)
摘要:
It is imperative to design the suitable anode materials of both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) with high-rate performance and ultralong cycling life. Herein, we fabricate a MoO2/MoS2 heterostructure that is homogeneously distributed in N,S-doped carbon nanofibers (MoO2/MoS2@NSC) by electrospinning technique and sulfuration engineering. The one-dimensional carbon fiber skeleton serves as a conductive frame to decrease the diffusion pathway of Li+/Na+. The doping of N/S heteroatoms in carbon fibers creates abundant active sites and significantly enhances ion diffusion kinetics. Moreover, the in situ formation of MoS2 nanosheets on the MoO2 phase bulk intensifies the heterointerface, and the construction of heterointerface between MoO2 and MoS2 enables the fast Li+/Na+ transport, which is crucial for achieving the high efficiency energy storage. Consequently, as the anode for LIBs, MoO2/MoS2@NSC delivers fantabulous cycle stability of 640 mAh g−1 upon 2000 cycles under 5.0 A g−1 with an ultralow average capacity drop rate of 0.002% per cycle and exceptional rate capability of 614 mAh g−1 at 10.0 A g−1. In SIBs, it still renders the significantly enhanced electrochemical performance (reversible capacity of 242 mAh g−1 under 2.0 A g−1 upon 2000 loops and 261 mAh g−1 under 5.0 A g−1). The current work exploits a novel interface manipulation strategy to rationally develop anode materials, achieving rapid Li+/Na+ storage kinetics and durable cycling performance. It is imperative to design the suitable anode materials of both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) with high-rate performance and ultralong cycling life. Herein, we fabricate a MoO2/MoS2 heterostructure that is homogeneously distributed in N,S-doped carbon nanofibers (MoO2/MoS2@NSC) by electrospinning technique and sulfuration engineering. The one-dimensional carbon fiber skeleton serves as a conductive frame to decrease the diffusion pathway of Li+/Na+. The doping of N/S heteroatoms in carbon fibers creates abundant active sites and significantly enhances ion diffusion kinetics. Moreover, the in situ formation of MoS2 nanosheets on the MoO2 phase bulk intensifies the heterointerface, and the construction of heterointerface between MoO2 and MoS2 enables the fast Li+/Na+ transport, which is crucial for achieving the high efficiency energy storage. Consequently, as the anode for LIBs, MoO2/MoS2@NSC delivers fantabulous cycle stability of 640 mAh g−1 upon 2000 cycles under 5.0 A g−1 with an ultralow average capacity drop rate of 0.002% per cycle and exceptional rate capability of 614 mAh g−1 at 10.0 A g−1. In SIBs, it still renders the significantly enhanced electrochemical performance (reversible capacity of 242 mAh g−1 under 2.0 A g−1 upon 2000 loops and 261 mAh g−1 under 5.0 A g−1). The current work exploits a novel interface manipulation strategy to rationally develop anode materials, achieving rapid Li+/Na+ storage kinetics and durable cycling performance.
N-doped hollow carbon nanospheres embedded in N-doped graphene forming a three-dimensional interconnected layered porous support loaded with palladium nanoparticles as an efficient electrocatalyst for formic acid oxidation
FANG Yue, YANG Fu-kai, QU Wei-li, DENG Chao, WANG Zhen-bo
, doi: 10.1016/S1872-5805(24)60844-9
摘要(18) HTML(16) PDF(9)
摘要:
The efficient electrocatalysts with low cost, high activity and good durability plays a crucial role in the application of direct formic acid fuel cells. Herein, Pd nanoparticles supported on N-doped hollow carbon nanospheres (NHCN) embedded in N-doped graphene (NG) with three-dimensional (3D) layered porous configuration by a simple and economical method were investigated as direct formic acid fuel cell catalysts. Owing to the unique 3D interconnected layered porous configuration doped with nitrogen atoms, Pd/NHCN@NG catalyst with smaller Pd nanoparticle size shows large catalytic active surface area, superior electrocatalytic activity, high steady-state current density, strong ability to resist CO poisoning, far surpassing those of conventional Pd/C, Pd/NG, and Pd/NHCN catalysts for formic acid electrooxidation. By optimizing the HCN/GO ratio, it is found that when the HCN/GO mass ratio is 1∶1, Pd/NHCN@NG catalyst has the most outstanding performance in catalytic oxidation of formic acid, with an activity 4.21 times that of Pd/C. This work has developed a superior carbon-based support material for electrocatalysts, which brings broad application prospects for the development of fuel cells. The efficient electrocatalysts with low cost, high activity and good durability plays a crucial role in the application of direct formic acid fuel cells. Herein, Pd nanoparticles supported on N-doped hollow carbon nanospheres (NHCN) embedded in N-doped graphene (NG) with three-dimensional (3D) layered porous configuration by a simple and economical method were investigated as direct formic acid fuel cell catalysts. Owing to the unique 3D interconnected layered porous configuration doped with nitrogen atoms, Pd/NHCN@NG catalyst with smaller Pd nanoparticle size shows large catalytic active surface area, superior electrocatalytic activity, high steady-state current density, strong ability to resist CO poisoning, far surpassing those of conventional Pd/C, Pd/NG, and Pd/NHCN catalysts for formic acid electrooxidation. By optimizing the HCN/GO ratio, it is found that when the HCN/GO mass ratio is 1∶1, Pd/NHCN@NG catalyst has the most outstanding performance in catalytic oxidation of formic acid, with an activity 4.21 times that of Pd/C. This work has developed a superior carbon-based support material for electrocatalysts, which brings broad application prospects for the development of fuel cells.
Polyimide-assisted fabrication of highly oriented graphene-based all-carbon foams for enhancing thermal conductivity in polymer composites
XIONG Ke, SUN Zhi-peng, HU Ji-chen, MA Cheng, WANG Ji-tong, GE Xiang, QIAO Wen-ming, LING Li-cheng
, doi: 10.1016/S1872-5805(24)60835-8
摘要(55) HTML(21) PDF(19)
摘要:
Graphene often tends to be horizontally oriented during processing owing to its two-dimensional layer structure with a high aspect ratio. As a consequence, thermal interface materials (TIM) composed of polymer and graphene often have elevated in-plane (IP) thermal conductivities (K), however, the restricted TP conductivity (K) renders them less favorable for practical implementations. This study presents the development of vertically aligned skeletons of high-quality polyimide/graphite nanosheets (PG) in order to enhance the TP K of polymer-based composites using a straightforward directional freezing technique. Notably, the graphene-based graphite nanosheets (GNs) are obtained by crushing from highly thermally conductive graphene film scraps. Water-soluble polyamic acid salt solution is used for direct dispersion of hydrophobic GNs fillers to achieve directional freezing. The polyimide, which facilitated the directional alignment of GNs, underwent graphitization and was subsequently transformed to graphite. Moreover, the introduction of GNs enhances the orderliness and density of the PG, thus further improving the strength and heat performance of its polydimethylsiloxane (PDMS) composite. The obtained PDMS/PG composite (PG: 21.1%, mass fraction) exhibits an impressive TP K of 14.56 W·m−1·K−1, 81 times that of pure PDMS. This facile polyimide-assisted graphene alignment method provides ideas for the widespread fabrication of anisotropic TIM and enables the reuse of graphene film scraps. Graphene often tends to be horizontally oriented during processing owing to its two-dimensional layer structure with a high aspect ratio. As a consequence, thermal interface materials (TIM) composed of polymer and graphene often have elevated in-plane (IP) thermal conductivities (K), however, the restricted TP conductivity (K) renders them less favorable for practical implementations. This study presents the development of vertically aligned skeletons of high-quality polyimide/graphite nanosheets (PG) in order to enhance the TP K of polymer-based composites using a straightforward directional freezing technique. Notably, the graphene-based graphite nanosheets (GNs) are obtained by crushing from highly thermally conductive graphene film scraps. Water-soluble polyamic acid salt solution is used for direct dispersion of hydrophobic GNs fillers to achieve directional freezing. The polyimide, which facilitated the directional alignment of GNs, underwent graphitization and was subsequently transformed to graphite. Moreover, the introduction of GNs enhances the orderliness and density of the PG, thus further improving the strength and heat performance of its polydimethylsiloxane (PDMS) composite. The obtained PDMS/PG composite (PG: 21.1%, mass fraction) exhibits an impressive TP K of 14.56 W·m−1·K−1, 81 times that of pure PDMS. This facile polyimide-assisted graphene alignment method provides ideas for the widespread fabrication of anisotropic TIM and enables the reuse of graphene film scraps.
N, S co-doped coal-based hard carbon prepared by two-step carbonization and melting salt template method for sodium storage
NIU Hui-zhu, WANG Hai-hua, SUN Li-yu, YANG Chen-rong, WANG Yu, CAO Rui, YANG Cun-guo, WANG Jie, SHU Ke-wei
, doi: 10.1016/S1872-5805(24)60842-5
摘要(83) HTML(93) PDF(22)
摘要:
Hard carbon, known for its abundant resources, stable structure and high safety, has emerged as the most popular anode material for sodium-ion batteries (SIBs). Among various sources, coal-derived hard carbon has attracted extensive attention. In this work, N and S co-doped coal-based carbon material (NSPC1200) was synthesized through a combination of two-step carbonization process and heteroatom doping using long-flame coal as a carbon source, thiourea as a nitrogen and sulfur source, and NaCl as a template. The two-step carbonization process played a crucial role in adjusting the structure of carbon microcrystals and expanding the interlayer spacing. The N and S co-doping regulated the electronic structure of carbon materials, endowing more active sites. Additionally, the introduction of NaCl as a template contributed to the construction of pore structure, which facilitates better contact between electrodes and electrolytes, enabling more efficient transport of Na+ and electrons. Under the synergistic effect, NSPC1200 exhibited exceptional sodium storage capacity, reaching 314.2 mAh g−1 at 20 mA g−1. Furthermore, NSPC1200 demonstrated commendable cycling stability, maintaining a capacity of 224.4 mAh g−1 even after 200 cycles. This work successfully achieves the strategic tuning of the microstructure of coal-based carbon materials, ultimately obtaining hard carbon anode with excellent electrochemical performance. Hard carbon, known for its abundant resources, stable structure and high safety, has emerged as the most popular anode material for sodium-ion batteries (SIBs). Among various sources, coal-derived hard carbon has attracted extensive attention. In this work, N and S co-doped coal-based carbon material (NSPC1200) was synthesized through a combination of two-step carbonization process and heteroatom doping using long-flame coal as a carbon source, thiourea as a nitrogen and sulfur source, and NaCl as a template. The two-step carbonization process played a crucial role in adjusting the structure of carbon microcrystals and expanding the interlayer spacing. The N and S co-doping regulated the electronic structure of carbon materials, endowing more active sites. Additionally, the introduction of NaCl as a template contributed to the construction of pore structure, which facilitates better contact between electrodes and electrolytes, enabling more efficient transport of Na+ and electrons. Under the synergistic effect, NSPC1200 exhibited exceptional sodium storage capacity, reaching 314.2 mAh g−1 at 20 mA g−1. Furthermore, NSPC1200 demonstrated commendable cycling stability, maintaining a capacity of 224.4 mAh g−1 even after 200 cycles. This work successfully achieves the strategic tuning of the microstructure of coal-based carbon materials, ultimately obtaining hard carbon anode with excellent electrochemical performance.
基于柔性多功能Fe2O3/CC正极宿主实现高效吸附与催化多硫化物的锂硫电池研究
田真, 薛磊磊, 丁红元
, doi: 10.1016/S1872-5805(24)60825-5
摘要(35) HTML(27) PDF(9)
摘要:
锂硫电池因其高能量密度和低成本而成为最有发展前景的电化学储能器件之一。然而,多硫化物的“穿梭效应”、硫导电率低是锂硫电池商业化进程面临的主要挑战。本工作中,以九水合硝酸铁(Fe(NO)3·9H2O)为铁源,氟化铵(NH4F)为表面活性剂,通过简单的水热及煅烧处理制备了Fe2O3纳米棒修饰炭布(CC)的柔性Fe2O3/CC复合材料。其中,Fe2O3中介孔的存在有利于电解质的渗透和充放电过程中锂离子的传输和扩散,同时其密集阵列暴露出的丰富活性位点可以实现多硫化物的高效吸附和快速转化,降低多硫化物的穿梭效应。电化学分析显示:Fe2O3/CC正极在0.1 C(1 C=1672 mA g−1)的电流密度下具有1250 mAh g−1的高放电比容量,经过100圈循环后比容量保持在789 mAh g−1。在2 C的倍率下循环1000圈后仍能实现576 mAh g−1的放电比容量,容量保持率为70%,明显优于对比样品。上述结果表明,Fe2O3/CC能够很好地抑制多硫化物的穿梭,提高电池倍率性能和循环稳定性。 锂硫电池因其高能量密度和低成本而成为最有发展前景的电化学储能器件之一。然而,多硫化物的“穿梭效应”、硫导电率低是锂硫电池商业化进程面临的主要挑战。本工作中,以九水合硝酸铁(Fe(NO)3·9H2O)为铁源,氟化铵(NH4F)为表面活性剂,通过简单的水热及煅烧处理制备了Fe2O3纳米棒修饰炭布(CC)的柔性Fe2O3/CC复合材料。其中,Fe2O3中介孔的存在有利于电解质的渗透和充放电过程中锂离子的传输和扩散,同时其密集阵列暴露出的丰富活性位点可以实现多硫化物的高效吸附和快速转化,降低多硫化物的穿梭效应。电化学分析显示:Fe2O3/CC正极在0.1 C(1 C=1672 mA g−1)的电流密度下具有1250 mAh g−1的高放电比容量,经过100圈循环后比容量保持在789 mAh g−1。在2 C的倍率下循环1000圈后仍能实现576 mAh g−1的放电比容量,容量保持率为70%,明显优于对比样品。上述结果表明,Fe2O3/CC能够很好地抑制多硫化物的穿梭,提高电池倍率性能和循环稳定性。
废旧三元锂电池石墨负极电化学除杂及其性能研究
张锐, 田勇, 张维丽, 宋佳音, 闵杰, 庞博, 陈建军
, doi: 10.1016/S1872-5805(24)60843-7
摘要(22) HTML(12) PDF(7)
摘要:
随着新能源汽车迅速发展,动力锂离子电池应用越来越广泛,大量锂电池也迎来退役高峰期,废旧锂电池的回收综合利用已经引起世界各国高度关注。废旧锂电池石墨负极因其层状结构基本未变化,不需高温石墨化,只关注其内部杂质的去除。本文将废旧石墨负极热处理、超声分离和酸浸处理后,创新性地采用电化学处理将内部金属杂质深度去除。对比不同回收阶段的石墨,发现石墨中有机杂质的存在会严重影响各项电化学性能,微量Cu、Fe等无机杂质的存在对初始放电比容量影响不大,但会降低石墨的循环稳定性。最终回收的石墨内部主要金属杂质含量低于20 mg/kg,在0.1 C倍率下放电比容量达到358.7 mAh/g,循环150圈后容量保持率为95.85%。对比已报道的废旧石墨回收方法,此方法可深度去除石墨负极内部杂质,解决了目前酸碱用量大、除杂不彻底、能耗高等问题,回收再生石墨负极电化学性能较好,为废旧锂电池石墨负极提供了一条新的回收再生路径。 随着新能源汽车迅速发展,动力锂离子电池应用越来越广泛,大量锂电池也迎来退役高峰期,废旧锂电池的回收综合利用已经引起世界各国高度关注。废旧锂电池石墨负极因其层状结构基本未变化,不需高温石墨化,只关注其内部杂质的去除。本文将废旧石墨负极热处理、超声分离和酸浸处理后,创新性地采用电化学处理将内部金属杂质深度去除。对比不同回收阶段的石墨,发现石墨中有机杂质的存在会严重影响各项电化学性能,微量Cu、Fe等无机杂质的存在对初始放电比容量影响不大,但会降低石墨的循环稳定性。最终回收的石墨内部主要金属杂质含量低于20 mg/kg,在0.1 C倍率下放电比容量达到358.7 mAh/g,循环150圈后容量保持率为95.85%。对比已报道的废旧石墨回收方法,此方法可深度去除石墨负极内部杂质,解决了目前酸碱用量大、除杂不彻底、能耗高等问题,回收再生石墨负极电化学性能较好,为废旧锂电池石墨负极提供了一条新的回收再生路径。
综合评述
Carbon electrodes for electrocatalytic synthesis of hydrogen peroxide: A mini-review
HUANG Xian-huai, YANG Xin-ke, GUI Ling, LIU Shao-gen, WANG Kun, RONG Hong-wei, WEI Wei
, doi: 10.1016/S1872-5805(24)60846-2
摘要(18) HTML(21) PDF(6)
摘要:
Electrocatalytic oxygen reduction by a two-electron pathway enables the instantaneous synthesis of hydrogen peroxide, which is far superior to the conventional anthraquinone process. In recent years, the electrocatalytic synthesis of hydrogen peroxide using carbon electrodes has attracted more and more attention due to its excellent catalytic performance and superior stability. In this paper, the relationship between material modification, wettability adjustment and the rate of hydrogen peroxide synthesis, service life is considered together with the three-phase interface. The structure of carbon electrodes and the principle of electrocatalytic hydrogen peroxide synthesis are first introduced. Then, four main catalysts are reviewed, namely, monolithic carbon materials, metal-free catalysts, noble metal catalysts and non-precious metal catalysts. The effects of metal anode and electrolyte on the three-phase interface are described. Next, the relationship between carbon electrode wettability and the three-phase interface is described, pointing out that modification focusing on the improvement of the selectivity of the two-electron pathway can also impact electrode wettability. In addition, the relationship between the rational design of the components in the electrochemical system and the enhancement of the efficient of hydrogen peroxide synthesis at carbon electrodes is also discussed. Finally, we present our viewpoints on the current problems in the electrocatalytic synthesis of hydrogen peroxide at carbon electrodes and future research directions. Electrocatalytic oxygen reduction by a two-electron pathway enables the instantaneous synthesis of hydrogen peroxide, which is far superior to the conventional anthraquinone process. In recent years, the electrocatalytic synthesis of hydrogen peroxide using carbon electrodes has attracted more and more attention due to its excellent catalytic performance and superior stability. In this paper, the relationship between material modification, wettability adjustment and the rate of hydrogen peroxide synthesis, service life is considered together with the three-phase interface. The structure of carbon electrodes and the principle of electrocatalytic hydrogen peroxide synthesis are first introduced. Then, four main catalysts are reviewed, namely, monolithic carbon materials, metal-free catalysts, noble metal catalysts and non-precious metal catalysts. The effects of metal anode and electrolyte on the three-phase interface are described. Next, the relationship between carbon electrode wettability and the three-phase interface is described, pointing out that modification focusing on the improvement of the selectivity of the two-electron pathway can also impact electrode wettability. In addition, the relationship between the rational design of the components in the electrochemical system and the enhancement of the efficient of hydrogen peroxide synthesis at carbon electrodes is also discussed. Finally, we present our viewpoints on the current problems in the electrocatalytic synthesis of hydrogen peroxide at carbon electrodes and future research directions.
A review of metal oxide-carbon composite materials for shuttle effect inhibition in lithium-sulfur batteries
ZHOU Zhi-qiang, WANG Hui-min, YANG Lu-bin, MA Cheng, WANG Ji-tong, QIAO Wen-ming, LING Li-cheng
, doi: 10.1016/S1872-5805(24)60838-3
摘要(87) HTML(31) PDF(22)
摘要:
Lithium-sulfur (Li-S) batteries are among the most promising next-generation electrochemical energy-storage systems due to their exceptional theoretical specific capacity, inexpensive production cost and environmental friendliness. However, the poor conductivity of S and Li2S, severe polysulfides shuttling and sluggish redox kinetics of phase transformation greatly hinder the practical commercialization of Li-S batteries. Carbonaceous materials could potentially rescue Li-S batteries from this predicament by leveraging the inherently high specific surface area, excellent electrical conductivity, and structural diversity. However, non-polar carbon materials are unable to interact closely with highly polar polysulfides, resulting in a low sulfur utilization and serious shuttle effect. Due to the advantages of strong polarity and rich adsorption sites of transition metal oxides (TMOs), integrating TMOs with carbon-based materials (CM) is essential to enhance chemical adsorption and electrochemical reaction activity for lithium polysulfides (LiPSs). In this review, first, the working principles and main challenges in Li-S batteries are discussed followed by the recent research progress of ex-situ and in-situ synthesis strategies of TMOs-CM. Subsequently, the overall structural construction of TMOs-CM with different dimensionalities from 1D to 3D are reviewed. Moreover, the representative works and working mechanisms of modulation strategies including heterostructures design, vacancies engineering and facets manipulating are overviewed in detail. Finally, an outlook of TMOs-CM in Li-S batteries is proposed based on the review's conclusions. Lithium-sulfur (Li-S) batteries are among the most promising next-generation electrochemical energy-storage systems due to their exceptional theoretical specific capacity, inexpensive production cost and environmental friendliness. However, the poor conductivity of S and Li2S, severe polysulfides shuttling and sluggish redox kinetics of phase transformation greatly hinder the practical commercialization of Li-S batteries. Carbonaceous materials could potentially rescue Li-S batteries from this predicament by leveraging the inherently high specific surface area, excellent electrical conductivity, and structural diversity. However, non-polar carbon materials are unable to interact closely with highly polar polysulfides, resulting in a low sulfur utilization and serious shuttle effect. Due to the advantages of strong polarity and rich adsorption sites of transition metal oxides (TMOs), integrating TMOs with carbon-based materials (CM) is essential to enhance chemical adsorption and electrochemical reaction activity for lithium polysulfides (LiPSs). In this review, first, the working principles and main challenges in Li-S batteries are discussed followed by the recent research progress of ex-situ and in-situ synthesis strategies of TMOs-CM. Subsequently, the overall structural construction of TMOs-CM with different dimensionalities from 1D to 3D are reviewed. Moreover, the representative works and working mechanisms of modulation strategies including heterostructures design, vacancies engineering and facets manipulating are overviewed in detail. Finally, an outlook of TMOs-CM in Li-S batteries is proposed based on the review's conclusions.
Graphdiyne: A novel material for synthesizing effective adsorbents for aqueous contaminants
Gaurav Sharma, Yaksha Verma, Amit Kumar, Pooja Dhiman, WANG Tong-tong, Florian J. Stadler
, doi: 10.1016/S1872-5805(24)60830-9
摘要(123) HTML(23) PDF(37)
摘要:
A nascent two-dimensional (2D) carbon molecule called graphdiyne (GDY) has gained prominence recently and is expected to have supplications in the expulsion of contaminants from aqueous medium. GDY demonstrates superior conjugation, peculiar and tunable electronic properties, and exceptional chemical and thermal endurance because it is the framework of sp and sp2 hybridized carbon atoms that are combined to produce benzene rings and diacetylenic bonds in a two-dimensional symmetrical network. GDY’s molecular chemistry encompasses carbon-carbon triple bonds, along with its regular distribution of triangle pores in structure, which provides reaction sites and various reaction pathways. Here, GDY is considered to exhibits an adsorption phenomenon this can serve as an adsorbent, demonstrating excellent efficiency for the removal of oil, organic pollutants, dyes, and metals from contaminated water. There is limited evidence of GDY being used as an adsorbent in the literature review. This review's objective is to offer a modern perspective on the application of GDY as an adsorbent material. A nascent two-dimensional (2D) carbon molecule called graphdiyne (GDY) has gained prominence recently and is expected to have supplications in the expulsion of contaminants from aqueous medium. GDY demonstrates superior conjugation, peculiar and tunable electronic properties, and exceptional chemical and thermal endurance because it is the framework of sp and sp2 hybridized carbon atoms that are combined to produce benzene rings and diacetylenic bonds in a two-dimensional symmetrical network. GDY’s molecular chemistry encompasses carbon-carbon triple bonds, along with its regular distribution of triangle pores in structure, which provides reaction sites and various reaction pathways. Here, GDY is considered to exhibits an adsorption phenomenon this can serve as an adsorbent, demonstrating excellent efficiency for the removal of oil, organic pollutants, dyes, and metals from contaminated water. There is limited evidence of GDY being used as an adsorbent in the literature review. This review's objective is to offer a modern perspective on the application of GDY as an adsorbent material.
石墨烯基材料在电磁屏蔽领域的研究进展
杨赏娟, 曹赟, 贺艳兵, 吕伟
, doi: 10.1016/S1872-5805(24)60840-1
摘要(82) HTML(69) PDF(21)
摘要:
通信技术在为人类的生活带来便利的同时,其产生的电磁辐射对社会安全、人体健康产生的危害也受到了社会各界的广泛关注,宽屏蔽范围、高吸收效率和高稳定性的电磁屏蔽材料逐渐成为研究热点。石墨烯是一种导电性高、比表面积大且可调控性高的轻质材料,可有效实现电磁衰减,保护精密电子设备和人体健康,在电磁屏蔽领域具有广阔的应用前景。本文从电磁屏蔽的基本原理与石墨烯基材料的结构特性出发,阐述了石墨烯及其衍生物的电磁屏蔽特点,总结了结构调控以及表面异质化、复合化策略在电磁屏蔽领域的应用。结构调控有利于提高石墨烯基材料对电磁波的吸收损耗和多重反射损耗;表面异质化和复合化策略有利于提高石墨烯基材料的界面极化和磁特性,从而加强对电磁波的吸收损耗和磁损耗。本文总结了石墨烯基电磁屏蔽材料的改性方法,旨在为开发新一代绿色、轻薄、高屏蔽带宽的电磁屏蔽材料提供启发,指明石墨烯基电磁屏蔽材料的未来发展方向。 通信技术在为人类的生活带来便利的同时,其产生的电磁辐射对社会安全、人体健康产生的危害也受到了社会各界的广泛关注,宽屏蔽范围、高吸收效率和高稳定性的电磁屏蔽材料逐渐成为研究热点。石墨烯是一种导电性高、比表面积大且可调控性高的轻质材料,可有效实现电磁衰减,保护精密电子设备和人体健康,在电磁屏蔽领域具有广阔的应用前景。本文从电磁屏蔽的基本原理与石墨烯基材料的结构特性出发,阐述了石墨烯及其衍生物的电磁屏蔽特点,总结了结构调控以及表面异质化、复合化策略在电磁屏蔽领域的应用。结构调控有利于提高石墨烯基材料对电磁波的吸收损耗和多重反射损耗;表面异质化和复合化策略有利于提高石墨烯基材料的界面极化和磁特性,从而加强对电磁波的吸收损耗和磁损耗。本文总结了石墨烯基电磁屏蔽材料的改性方法,旨在为开发新一代绿色、轻薄、高屏蔽带宽的电磁屏蔽材料提供启发,指明石墨烯基电磁屏蔽材料的未来发展方向。
三维整体式碳基光热转换材料在太阳能界面水蒸发中的应用研究进展
韩悦, 张鹏, 赵晓明
, doi: 10.1016/S1872-5805(24)60827-9
摘要(174) HTML(142) PDF(34)
摘要:
光热驱动的海水淡化技术被认为是最具潜力的解决全球淡水资源短缺难题的方法之一。其中,太阳能界面水蒸发(SVG)是海水淡化效率的核心过程,是保证光热海水淡化技术具有能量转换效率高、设备简单、成本效益高的关键。在所有高效SVG候选材料中,三维整体式碳基光热转换材料具有成本低、吸光效率高、结构可调性好、水蒸发速率高、无二次污染等优点。本综述首先简述了SVG 的基本原理,以此为依据介绍了高效 SVG 材料的工作机制和设计原则,最后系统归纳和概述了四种不同类型的三维整体式碳基光热转换材料的研究进展。所以本综述为未来三维整体式碳基光热转换材料的构建及其在SVG领域的应用研究提供理论基础和研究指导。 光热驱动的海水淡化技术被认为是最具潜力的解决全球淡水资源短缺难题的方法之一。其中,太阳能界面水蒸发(SVG)是海水淡化效率的核心过程,是保证光热海水淡化技术具有能量转换效率高、设备简单、成本效益高的关键。在所有高效SVG候选材料中,三维整体式碳基光热转换材料具有成本低、吸光效率高、结构可调性好、水蒸发速率高、无二次污染等优点。本综述首先简述了SVG 的基本原理,以此为依据介绍了高效 SVG 材料的工作机制和设计原则,最后系统归纳和概述了四种不同类型的三维整体式碳基光热转换材料的研究进展。所以本综述为未来三维整体式碳基光热转换材料的构建及其在SVG领域的应用研究提供理论基础和研究指导。
Electrode for microsupercapacitors based on MoS2 modified reduced graphene oxide aerogels achieved by 3D printing
WANG Meng-ya, LI Shi-you, GAO Can-kun, FAN Xiao-qi, QUAN Yin, LI Xiao-hua, LI Chun-lei, ZHANG Ning-shuang
, doi: 10.1016/S1872-5805(24)60823-1
摘要(71) HTML(72) PDF(16)
摘要:
Micro-supercapacitors (MSCs) have garnered significant interest thanks to their high power density and excellent cyclic performance, offering a broad array of potential applications. However, preparing MSCs electrodes with extremely high areal capacitance and energy density remains a challenging pursuit. In this study, reduced graphene oxide aerogel (GA) and MoS2 were used as active materials, combined with 3D printing and surface modification methods, to construct MSCs electrodes with ultra-high area capacitance and energy density. Through 3D printing technology, we obtained electrodes with stable macro structure and GA crosslinked micropore structure. In addition, we used the solution method to load molybdenum disulfide nanosheets on the surface of the 3D printed electrode, further improving the electrochemical performance. The surface capacitance of the prepared electrode reached 3.99 F cm−2, the power density was 194 µW cm−2, and the energy density was 1997 mWh cm−2, attesting the excellent electrochemical performance and cycle stability. This work provides a simple and efficient method for preparing MSC electrodes with high areal capacitance and energy density, making them ideal for portable electronic devices. This research holds crucial innovative significance in the field of MSCs electrodes. Micro-supercapacitors (MSCs) have garnered significant interest thanks to their high power density and excellent cyclic performance, offering a broad array of potential applications. However, preparing MSCs electrodes with extremely high areal capacitance and energy density remains a challenging pursuit. In this study, reduced graphene oxide aerogel (GA) and MoS2 were used as active materials, combined with 3D printing and surface modification methods, to construct MSCs electrodes with ultra-high area capacitance and energy density. Through 3D printing technology, we obtained electrodes with stable macro structure and GA crosslinked micropore structure. In addition, we used the solution method to load molybdenum disulfide nanosheets on the surface of the 3D printed electrode, further improving the electrochemical performance. The surface capacitance of the prepared electrode reached 3.99 F cm−2, the power density was 194 µW cm−2, and the energy density was 1997 mWh cm−2, attesting the excellent electrochemical performance and cycle stability. This work provides a simple and efficient method for preparing MSC electrodes with high areal capacitance and energy density, making them ideal for portable electronic devices. This research holds crucial innovative significance in the field of MSCs electrodes.
Improving the mechanical properties and thermal conductivity of the mesophase-pitch-based carbon fibers by regulating spinning temperature in an industrial spinning equipment
YE Gao-ming, SHI Kui, WU Huang, HUANG Dong, YE Chong, OUYANG Ting, ZHU Shi-peng, FAN Zhen, LIU Hong-bo, LIU Jin-shui
, doi: 10.1016/S1872-5805(24)60826-7
摘要(90) HTML(56) PDF(23)
摘要:
The mesophase-pitch-based carbon fibers (MPCFs) were prepared by controlling the spinning temperature under a constant extrusion flowrate of pitch in an industrial equipment to investigate the influence of the spinning temperature on their microstructures, mechanical properties and thermal conductivities. Results show that the graphite layer of MPCFs shifts from a fine-and-folded radial-split structure to a large-and-flat radial-split structure and exhibits an improved perfection of graphite microcrystallites with increasing the spinning temperature from 309 to 320 °C. Meanwhile, the thermal conductivity and tensile strength of MPCFs increase, respectively, from 704 W·m−1·K−1 and 2.16 GPa at 309 °C to 1078 W·m−1·K−1 and 3.23 GPa at 320 °C. The lower viscosity and the weaker die-swell effect of mesophase pitch at the outlets of spinnerets at the higher spinning temperature contribute to the improved orientation of mesophase pitch molecules in the pitch fibers, which plays a positive role in improving the crystal size and orientation of MPCFs. The mesophase-pitch-based carbon fibers (MPCFs) were prepared by controlling the spinning temperature under a constant extrusion flowrate of pitch in an industrial equipment to investigate the influence of the spinning temperature on their microstructures, mechanical properties and thermal conductivities. Results show that the graphite layer of MPCFs shifts from a fine-and-folded radial-split structure to a large-and-flat radial-split structure and exhibits an improved perfection of graphite microcrystallites with increasing the spinning temperature from 309 to 320 °C. Meanwhile, the thermal conductivity and tensile strength of MPCFs increase, respectively, from 704 W·m−1·K−1 and 2.16 GPa at 309 °C to 1078 W·m−1·K−1 and 3.23 GPa at 320 °C. The lower viscosity and the weaker die-swell effect of mesophase pitch at the outlets of spinnerets at the higher spinning temperature contribute to the improved orientation of mesophase pitch molecules in the pitch fibers, which plays a positive role in improving the crystal size and orientation of MPCFs.
Oxidation reaction mechanism and kinetics of ethylene tar for preparation of carbonaceous precursor
GUO Tian-rui, CHEN Rong-qi, GAO Wei, WANG Yan-li, ZHAN Liang
, doi: 10.1016/S1872-5805(22)60597-3
摘要(324) HTML(281) PDF(102)
摘要:
To obtain excellent carbonaceous precursors, the oxidation reaction mechanism and kinetics of ethylene tar were investigated. Meanwhile, a high softening point pitch was produced to apply to the coating modification of the graphite anode in lithium-ion batteries. The oxidation process of ethylene tar was divided into 3 stages (350-550, 550-700 and 700-900 K) according to the thermogravimetric curve. To reveal the oxidation reaction mechanism of ethylene tar, the components of the evolved gases at different stages were further analyzed online by mass spectrometry and infrared technology. Then, based on the thermogravimetric curve of ethylene tar at different reaction temperatures, the whole reaction process was divided into four parts to perform kinetics simulation calculations. With the help of the iso-conversional method (Coats-Redfern) to analyze the linear regression rates (R2) between 17 common reaction kinetics models and experimental data, the optimal reaction kinetics model for expressing the oxidation process of ethylene tar was determined. The results show that: 1) In the oxidation process, the side chains of aromatic compounds react with oxygen to form alcohols and aldehydes first, leaving peroxy-radicals to aromatic rings. Subsequently, the aromatic compounds with peroxy-radicals undergo polymerization/condensation reactions to form larger molecules. 2) The fourth-order reaction model is adopted to describe the first 3 parts of the oxidation process, and the activation energies are 47.330, 18.689 and 9.004 kJ·mol−1, respectively. The three-dimensional diffusion model is applied to the fourth part of the oxidation process, and the activation energy is 88.369 kJ·mol−1. 3) After the coating modification, the capacity retention rate grows from 51.54% to 79.07% after 300 cycles. To obtain excellent carbonaceous precursors, the oxidation reaction mechanism and kinetics of ethylene tar were investigated. Meanwhile, a high softening point pitch was produced to apply to the coating modification of the graphite anode in lithium-ion batteries. The oxidation process of ethylene tar was divided into 3 stages (350-550, 550-700 and 700-900 K) according to the thermogravimetric curve. To reveal the oxidation reaction mechanism of ethylene tar, the components of the evolved gases at different stages were further analyzed online by mass spectrometry and infrared technology. Then, based on the thermogravimetric curve of ethylene tar at different reaction temperatures, the whole reaction process was divided into four parts to perform kinetics simulation calculations. With the help of the iso-conversional method (Coats-Redfern) to analyze the linear regression rates (R2) between 17 common reaction kinetics models and experimental data, the optimal reaction kinetics model for expressing the oxidation process of ethylene tar was determined. The results show that: 1) In the oxidation process, the side chains of aromatic compounds react with oxygen to form alcohols and aldehydes first, leaving peroxy-radicals to aromatic rings. Subsequently, the aromatic compounds with peroxy-radicals undergo polymerization/condensation reactions to form larger molecules. 2) The fourth-order reaction model is adopted to describe the first 3 parts of the oxidation process, and the activation energies are 47.330, 18.689 and 9.004 kJ·mol−1, respectively. The three-dimensional diffusion model is applied to the fourth part of the oxidation process, and the activation energy is 88.369 kJ·mol−1. 3) After the coating modification, the capacity retention rate grows from 51.54% to 79.07% after 300 cycles.
Study on PES-C toughened E51/DETDA epoxy resin and its carbon fiber composites
WU Rong-peng, ZHANG Xing-hua, WEI Xing-hai, JING De-qi, SU Wei-guo, ZHANG Shou-chun
, doi: 10.1016/S1872-5805(23)60741-3
摘要(170) HTML(112) PDF(49)
摘要:
It is meaningful to find a toughener with a low dosage and effective improvement of interlaminar toughness in carbon fiber composites. In this paper, the toughening effect of phenolphthalein-based poly (ether sulfone) (PES-C) on E51/ DETDA epoxy and its carbon fiber composites (CFCs) was investigated. The SEM results showed that PES-C/epoxy blends formed sea-island phase and bicontinuous phase structure, which were associated with reaction-induced phase separation. After adding 15 phr PES-C, the glass transition temperature (Tg) of blends was increased by 51.5 °C. Meanwhile, the flexural strength, impact strength and fracture toughness of the blends were improved by 41.1%, 186.2% and 42.7%, respectively. These improvements could be attributed to the phase separation structure of the PES-C/epoxy system. Moreover, PES-C film was used to improve the mode-II fracture toughness (GIIC) of CFCs. GIIC value of the 7 μm PES-C film toughened laminate was improved by 80.3% than that of control laminate. The increase in GIIC could be attributed to cohesive failure and plastic deformation in the interleaving region. It is meaningful to find a toughener with a low dosage and effective improvement of interlaminar toughness in carbon fiber composites. In this paper, the toughening effect of phenolphthalein-based poly (ether sulfone) (PES-C) on E51/ DETDA epoxy and its carbon fiber composites (CFCs) was investigated. The SEM results showed that PES-C/epoxy blends formed sea-island phase and bicontinuous phase structure, which were associated with reaction-induced phase separation. After adding 15 phr PES-C, the glass transition temperature (Tg) of blends was increased by 51.5 °C. Meanwhile, the flexural strength, impact strength and fracture toughness of the blends were improved by 41.1%, 186.2% and 42.7%, respectively. These improvements could be attributed to the phase separation structure of the PES-C/epoxy system. Moreover, PES-C film was used to improve the mode-II fracture toughness (GIIC) of CFCs. GIIC value of the 7 μm PES-C film toughened laminate was improved by 80.3% than that of control laminate. The increase in GIIC could be attributed to cohesive failure and plastic deformation in the interleaving region.
Wet-composition-induced amorphous adhesion toward a high interfacial shear strength between carbon fiber and polyetherketoneketone
ZHANG Feng, LI Bo-lan, JIAO Meng-xiao, LI Yan-bo, WANG Xin, YANG Yu, YANG Yu-qiu, ZHANG Xiao-hua
, doi: 10.1016/S1872-5805(22)60646-2
摘要(344) HTML(222) PDF(51)
摘要:
Interfacial adhesion between carbon fiber (CF) and polyetherketoneketone (PEKK) is a key factor that affects the mechanical performances of their composites. Therefore, it is of great importance to impregnate PEKK into CF bundles as efficiently as possible. Here we report that owing to the high dissolubility, PEKK can be introduced onto CF surfaces via a wet strategy. The excellent wettability of PEKK guarantees a full covering and tight binding on CFs, making it possible to evaluate the interfacial shear strength (IFSS) with the microdroplet method. Furthermore, the interior of CF bundles can be completely and uniformly filled with PEKK by the solution impregnation, leading to a high interlaminar shear strength (ILSS). The maximum IFSS and ILSS can reach 107.8 and 99.3 MPa, respectively. Such superior shear properties are ascribed to the formation of amorphous PEKK confined in the limited spacing between CFs. Interfacial adhesion between carbon fiber (CF) and polyetherketoneketone (PEKK) is a key factor that affects the mechanical performances of their composites. Therefore, it is of great importance to impregnate PEKK into CF bundles as efficiently as possible. Here we report that owing to the high dissolubility, PEKK can be introduced onto CF surfaces via a wet strategy. The excellent wettability of PEKK guarantees a full covering and tight binding on CFs, making it possible to evaluate the interfacial shear strength (IFSS) with the microdroplet method. Furthermore, the interior of CF bundles can be completely and uniformly filled with PEKK by the solution impregnation, leading to a high interlaminar shear strength (ILSS). The maximum IFSS and ILSS can reach 107.8 and 99.3 MPa, respectively. Such superior shear properties are ascribed to the formation of amorphous PEKK confined in the limited spacing between CFs.
Synergistic Enhancement of Toughness and Viscosity of Carbon Nanotubes/Polyether Imide/Polyether Ether Ketone Nanocomposites
SONG Jiu-peng, ZHAO Yan, LI Xue-kuan, XIONG Shu, LI Shuang, WANG Kai
, doi: 10.1016/S1872-5805(22)60643-7
摘要(421) HTML(225) PDF(33)
摘要:
Polyether ether ketone (PEEK) has favorable mechanical properties. However, its high melt viscosity limits its applications because it is hard to process. In this study, PEEK nanocomposites modified with carbon nanotubes (CNTs) and polyether imide (PEI) were prepared using a direct wet powder blending method. The melt viscosity of the nanocomposites decreased by approximately 50%. Under optimal conditions, the addition of CNTs and PEI resulted in a synergistic increase in the toughness of the nanocomposites. The elongation at break increased by 129%, and the fracture energy increased by 97%. The uniformly dispersed CNTs/PEI powder reduces the processing difficulty of PEEK nanocomposites without affecting the heat resistance. The nanocomposites prepared by this method have lower melt viscosity. This improvement of the properties of PEEK would facilitate its use in the preparation of thermoplastic composites by powder impregnation or laser sintering technology. Polyether ether ketone (PEEK) has favorable mechanical properties. However, its high melt viscosity limits its applications because it is hard to process. In this study, PEEK nanocomposites modified with carbon nanotubes (CNTs) and polyether imide (PEI) were prepared using a direct wet powder blending method. The melt viscosity of the nanocomposites decreased by approximately 50%. Under optimal conditions, the addition of CNTs and PEI resulted in a synergistic increase in the toughness of the nanocomposites. The elongation at break increased by 129%, and the fracture energy increased by 97%. The uniformly dispersed CNTs/PEI powder reduces the processing difficulty of PEEK nanocomposites without affecting the heat resistance. The nanocomposites prepared by this method have lower melt viscosity. This improvement of the properties of PEEK would facilitate its use in the preparation of thermoplastic composites by powder impregnation or laser sintering technology.