Direct electrochemical N-doping to carbon paper in molten LiCl-KCl-Li3N

Graphite materials are widely used as electrode materials for electrochemical energy storage.N-doping is an effective method for enhancing the electrochemical properties of graphite.A novel one-step N-doping method for complete and compact carbon paper was proposed for molten salt electrolysis in the Li Cl-KCl-Li3 N system.The results show that the degree of graphitization of carbon paper can be improved by the electrolysis of molten salts,especially at 2.0 V.Nitrogen gas was produced at the anode and nitrogen atoms can substitute carbon atoms of carbon paper at different sites to create nitrogen doping during the electrolysis process.The doping content of N in carbon paper is up to 13.0 wt%.There were three groups of nitrogen atoms,i.e.quaternary N(N-Q),pyrrolic N(N-5),and pyridinic N(N-6)in N-doping carbon paper.N-doping carbon paper as an Al-ion battery cathode shows strong charge-recharge properties.

A superhigh discharge capacity induced by a synergetic effect between high-surface-area carbons and a carbon paper current collector in a lithium–oxygen battery

This paper invesitages the synergetic effect between high-surface-area carbons, such as Ketjan Black(KB) or Super P(SP) carbon materials, and low-surface-area carbon paper(CP) current collectors and it also examines their influence on the discharge performance of nonaqueous Li–O2cells. Ultra-large specific discharge capacities are found in the KB/CP cathodes, which are much greater than those observed in the individual KB or CP cathodes. Detailed analysis indicates that such unexpectedly large capacities result from the synergetic effect between the two components. During the initial discharges of KB or SP materials, a large number of superoxide radical(O·-2) species in the electrolytes and Li2O2 nuclei at the CP surfaces are formed, which activate the CP current collectors to contribute considerable capacities. These results imply that CP could be a superior material for current collectors in terms of its contribution to the overall discharge capacity.On the other hand, we should be careful to calculate the specific capacities of the oxygen cathodes when using CP as a current collector; i.e., ignoring the contribution from the CP may cause overstated discharge capacities.

Improving electrochemical properties of carbon paper as negative electrode for vanadium redox battery by anodic oxidation

Anodic oxidation with different electrolyte was employed to improve the electrochemical properties of carbon paper as negative electrode for vanadium redox battery(VRB).The treated carbon paper exhibits enhanced electrochemical activity for V^2+/V^3+redox reaction.The sample(CP-NH3)treated in NH3 solution demonstrates superior performance in comparison with the sample(CP-NaOH)treated in NaOH solution.X-ray photoelectron spectroscopy results show that oxygen-and nitrogen-containing functional groups have been introduced on CP-NH3 surface by the treatment,and Raman spectra confirm the increased surface defect of CP-NH3.Energy storage performance of cell was evaluated by charge/discharge measurement by using CP-NH3.Usage of CP-NH3 can greatly improve the cell performance with energy efficiency increase of 4.8%at 60 mA/cm^2.The excellent performance of CP-NH3 mainly results from introduction of functional groups as active sites and improved wetting properties.This work reveals that anodic oxidation is a clean,simple,and efficient method for boosting the performance of carbon paper as negative electrode for VRB.

3D MoS_(2) foam integrated with carbon paper as binder-free anode for high performance sodium-ion batteries

Molybdenum sulfide(MoS_(2))with well-designed porous structure has the potential to be great electrode materials in sodium-ion batteries due to its high theoretical capacity and abundant resource,however,hindered by its intrinsic low conductivity and stability.Herein,MoS_(2) with 3 D macroporous foam structure and high conductivity was obtained through SiO_(2) templates and integrated with carbon paper(3 D FMoS_(2)/CP).It has showed superior specific capacity(225 m A h g^(-1),0.4–3 V)and cycling stability(1000 cycles)at high rate(2000 m A g^(-1)),with a low decay rate(0.033%per cycle)in sodium-ion batteries.The excellent electrochemical performance may originate from its unique integrated structure:3 D MoS_(2) macropores providing high surface area and abundant transfer channels while carbon paper enhancing the conductivity of MoS_(2) and avoiding unnecessary side reactions brought by binder addition.

Flexible self-charging power units for portable electronics based on folded carbon paper

The urgent demand for portable electronics has promoted the development of high-efficienc）9 sustainable, and even stretchable self-charging power sources. In this work, we propose a flexible self-charging power unit based on folded carbon （FC） paper for harvesting mechanical energy from human motion and power portable electronics. The present unit mainly consists of a triboelectric nanogenerator （FC-TENG） and a supercapacitor （FC-SC）, both based on folded carbon paper, as energy harvester and storage device, respectively. This favorable geometric design provides the high Young＇s modulus carbon paper with excellent stretchability and enables the power unit to work even under severe deformations, such as bending, twisting, and rolling. In addition, the tensile strain can be maximized by tuning the folding angle of the triangle-folded carbon paper. Moreover, the waterproof property of the packaged device make it washable, protect it from human sweat, and enable it to work in harsh environments. Finally, the as-prepared self-charging power unit was tested by placing it on the human body to harvest mechanical energy from hand tapping, foot treading, and arm touching, successfully powering an electronic watch. This work demonstrates the impressive potential of stretchable self-charging power units, which will further promote the development of high Young＇s modulus materials for wearable/portable electronics.

Impact of carbon paper structural parameters on the performance of a polymer electrolyte fuel cell cathode via lattice Boltzmann method

Polymer electrolyte fuel cells(PEFCs)being employed in fuel cell electric vehicles(FCEVs)are promising power generators producing electric power from fuel stream via porous electrodes.Structure of carbon paper gas diffusion layers(GDLs)applying in the porous electrodes can greatly affect the PEFC performance,especially at the cathode side where electrochemical reaction is more sluggish.To discover the role of carbon paper GDL structure on the mass transfer properties,different cathode electrodes with dissimilar structural parameters are simulated via lattice Boltzmann method(LBM).3D contours of oxygen and water vapor concentration through the GDL as well as the 2D contours of current density on the catalyst layer are illustrated and examined.The results indicate that the carbon fiber diameter has a negligible impact on the current density while the impact of carbon paper thickness and porosity is significant.In fact,increasing of carbon paper thickness or porosity leads to lack of cell performance.

Corrugated rGO-supported Pd composite on carbon paper for efficient cathode of Mg-H_(2)O_(2)semi-fuel cell

A corrugated reduced graphene oxide(rGO)-supported Pd composite on carbon paper(Pd/rGO/CP)is prepared via a simple chemical reduction process combined with electrodeposition.The micros tructure,morphology,and surface chemical state of the composite and its performance in H_(2)O_(2)reduction in an acidic medium are investigated.An rGO film with ample corrugated wrinkles coated closely on CP is prepared,and Pd nanoparticles are evenly decorated on the surface of rGO/CP.The Pd/rGO/CP electrode has a low Pd loading and high catalytic performance for H_(2)O_(2)reduction in acidic media compared to Pd/CP.An excellent mass normalized activity(11,783 A·g_(Pd)^(-1))of the Pd/rGO/CP electrode for H_(2)O_(2)reduction is achieved at 0 V due to the corresponding low Pd loadings.Mg-H_(2)O_(2)semi-fuel cells using Pd/rGO/CP electrode as the cathode exhibits a peak power density of215 mW·cm^(-2)at 60℃and perfect stability during a 50-h discharge.The rGO interlayer forms a microscopic threedimensional(3 D)structure on the surface of CP,thereby improving the utilization of precious metals and the specific surface area,as well as providing more Pd sites due to the transfer of electrons to Pd.Consequently,the performance of the electrode is improved.

Plasma treated carbon paper electrode greatly improves the performance of iron-hydrogen battery for low-cost energy storage

A novel iron-hydrogen battery system, whose Fe^(3+)/Fe^(2+)cathode circumvents slowly dynamic oxygen reduction reaction and anode is fed with clean and cordial hydrogen, is systematically investigated. The maximum discharge power density of the iron-hydrogen battery reaches to 96.0 m W/cm^(2) under the room temperature. The capacity reaches to 17.2 Ah/L and the coulombic and energy efficiency are achieved to99% and 86%, respectively, during the galvanostatic charge-discharge test. Moreover, stable cycling test is observed for more than 240 h and 100 cycles with the iron sulfate in the sulfuric acid solutions. It is found that air plasma treatment onto the cathode carbon paper can generate the oxygen-containing groups and increase the hydrophilic pores proportion to ca. 40%, enlarging nearly 6-fold effective diffusion coefficient and improving the mass transfer in the battery performance. The simple iron-hydrogen energy storage battery design offers us a new strategy for the large-scale energy storage and hydrogen involved economy.

Improved properties of carbon fiber paper as electrode for fuel cell by coating pyrocarbon via CVD method

The fabrication of a pyrocarbon coated carbon paper and its application to the gas diffusion lay(GDL) of proton exchange membrane(PEM) fuel cell were described.This carbon paper was fabricated by using conventional carbon paper as the precursor,and coating it with pyrocarbon by pyrolyzing propylene via the chemical vapor deposition(CVD) method.For comparison,conventional carbon paper composites were also prepared by using PAN-based carbon fiber felt as the precursor followed by impregnation with resin,molding and heat-treatment.SEM characterization indicates that pyrocarbon is uniformly deposited on the surface of the fiber in the pyrocarbon coated carbon paper and made the fibers of carbon felt bind more tightly.In contrast,there are cracks in matrix and debonding of fibers due to carbonization shrinkage in the conventional carbon paper.Property measurements show that the former has much better conductivity and gas permeability than the latter.In addition,current density-voltage performance tests also reveal that the pyrocarbon coating can improve the properties of carbon paper used for electrode materials of fuel cell.

Integrated Co3O4/carbon fiber paper for high-performance anode of dual-ion battery

In dual-ion batteries (DIBs), energy storage is achieved by intercalation/de-intercalation of both cations and anions. Due to the mismatch between ion diameter and layer space of active materials, however, volume expansion and exfoliation always occur for electrode materials. Herein, an integrated electrode Co3O4/carbon fiber paper (CFP) is prepared as the anode of DIB. As the Co3O4 nanosheets grow on CFP substrate vertically, it promotes the immersion of electrolyte and shortens the pathway for ionic transport. Besides, the strong interaction between Co3O4 and CFP substrate reduces the possibility of sheet exfoliation. An integrated-electrode-based DIB is therefore packaged using Co3O4/CFP as anode and graphite as cathode. As a result, a high energy density of 72 Wh/kg is achieved at a power density of 150 W/kg. The design of integrated electrode provides a new route for the development of high-performance DIBs.

Electromagnetic Interference Shielding Properties of Electroless Nickel-coated Carbon Fiber Paper Reinforced Epoxy Composites

Carbon fibers（CFs） were coated with a nickel-phosphorus（Ni-P） film using an electroless plating process. The morphology, elemental composition and phases in the coating layer of the CFs were investigated by scanning electron microscopy（SEM）, energy dispersive spectroscopy（EDS） and X-ray diffraction（XRD）, respectively. Wet paper-making method was used to prepare nickle coated carbon fiber paper（NCFP）. Vacuum assisted infusion molding process（VAIMP） was employed to manufacture the NCFP reinforced epoxy composites, and carbon fiber paper（CFP） reinforced epoxy composites were also produced as a comparison. Electromagnetic interference（EMI） shielding properties of the composites were measured in the 3.22-4.9 GHz frequency range using waveguide method. Both NCFP and CFP reinforced epoxy composites of 0.5 mm thickness exhibited high EMI shielding effectiveness（SE） at 8wt% fiber content, 35 d B and 30 d B, respectively, and reflection was the dominant shielding mechanism.

The Carbon Reduction Effect of the Trade of Paper Products in China

Through using the data of import and export trading of China's paper products in 2012,we utilize the method of volume source biomass equation and net primary productivity( NPP) to calculate the carbon reduction effect of papermaking raw materials trade,and utilize the method of IPCC guidelines for inventories to calculate the carbon emission effect of paper and paper products trade. The results show that the distinctive characteristics of China's paper products trade has resulted in the dual effects on the domestic carbon emissions. On the one hand,large imports of paper-making raw materials make China reduce domestic forest felling,with the effect of carbon emission reduction. On the other hand,net exports of paper and paper products increase the domestic carbon emissions,with the effect of carbon emission. The carbon emission reduction effect of China's paper-making raw materials trade is obvious and up to 19. 0211 million tons. This is equal to the total volume of 180. 5709 million cubic meters forest's annual carbon sequestration. The carbon emission effect of paper and paper products trade is only 0. 5136 million tons,which is not significant compared with the former. In general,China's paper product trade causes the significant effect on carbon emission reduction.

Preparation of Mono-Dispersed Carbon Nanotubes (CNTs) with Dodecyl Itaconate and Its Utilization in Paper-Making

Dodecyl itaconate (DI) was used as the dispersant for preparation of mono-dispersed carbon nanotubes in aqueous solution in this study. It is a unique type of anionic surfactant synthesized by the authors, and its high capability for dispersing CNTs is attributed to the double bond moiety on its head-group. Furthermore, author mixed aqueous mono-dispersed CNTs with pulp to produce the CNT-based paper. Different from the reported papermaking process, a novel adjusting PH process was employed to prepare paper. This method could transfer easily dispersing mono-dispersed CNTs in aqueous onto the surfaces of cellulose fibers, because PH adjustment of CNT-pulp is from the initial neutrality to weak acidity and then raising to alkalinity, The dispersion of tubes in cellulose matrix and characteristics of composite were investigated. Also, electrical resistance for retrieved CNT-based sheets was measured using fore-probe method.

双碳视角下绿色产业政策对造纸产业转型升级影响研究

围绕双碳目标,通过研究绿色产业政策与造纸产业发展的相关关系,探究了绿色产业政策对造纸产业转型升级的影响机理,并以京津冀及周边地区为例进行实证分析。得出如下结论:绿色产业政策有利于造纸产业的发展;“碳排放权交易”对造纸企业转型升级有一定程度的促进作用,而“碳排放权交易”“环境保护税”和“排污许可证”等对造纸企业转型升级具有一定的抑制作用。为促进我国造纸业高质量发展和实现双碳目标,政府应继续加大绿色政策扶持力度,大力推广清洁生产工艺和技术,引导企业积极开展节能减排改造活动,同时制定企业环境行为准则并加强对企业环境的责任落实与监督。

碳纤维纸张电热及温敏性效应研究

碳纤维纸张可作为优良的面状发热材料,若将其作为采暖地板中的电热元件,可实现地板、采暖一体化,具有广阔的市场前景,为避免碳纤维纸张在使用过程中出现安全隐患,需对碳纤维在碳纤维纸张中的电热和负温度系数(NTC)效应的作用机制进行研究。为了探究碳纤维纸张在通电加热条件下电热及电阻随温度变化的规律,采用红外热成像仪、体式显微镜等仪器分析了碳纤维单丝、搭接单丝、平行单丝及碳纤维纸张4种发热单元的电热和温敏效应,结果表明:碳纤维单丝、搭接单丝及碳纤维纸张表面温度变化趋势均随着输入功率的增加呈现线性增加,在单丝平行方向和垂直方向温度均呈GaussAmp方程曲线分布,碳纤维单丝相互距离等于或者小于0.8 cm,即可将两单丝间温度不均匀度控制在1℃以内;通电加热初期,发热单元电阻随温升的增加而急剧下降,当碳纤维单丝加载80 mW功率(即单丝温度接近35℃),纸张加载2000 mW功率(即纸张表面温度接近97℃)时,电阻值变化趋势趋于稳定,表明碳纤维单丝及碳纤维纸张均具有明显的NTC效应,并且发热单元中搭接单丝的NTC效应和电热效应在碳纤维纸张中起着主导作用,这对于创制适宜的采暖地板发热元件具有积极的指导意义。

福建省造纸工业碳排放的灰色关联度、Tapio脱钩分析及情景预测

随着中国2030年前“碳达峰”目标的临近,福建省高能耗、高排放的造纸工业面临严峻的碳减排压力。本研究运用灰色关联度模型,计算总资产、总资产产值率、能源强度和能源结构与CO_(2)排放之间的关联度,通过Tapio脱钩模型,确定造纸工业产出与CO_(2)排放的脱钩状态,利用STIRPAT模型,预测4种情景下CO_(2)排放量,评估福建省造纸工业2030年前实现“碳达峰”目标的潜力。结果表明:(1)福建省造纸工业的总资产、总资产产值率、能源强度和能源结构与CO_(2)排放量关联度相近,且关联性较高;(2) 2007—2021年,福建省造纸工业产出与碳排放呈现6种脱钩状态,在研究期内的大多数年份表现为强脱钩与弱脱钩状态;总资产和能源结构对碳排放起到主要的拉动作用,能源强度是碳排放脱钩的主要驱动力;(3)预测期内(2022—2030年)基准情景与快速发展情景下CO_(2)排放量快速上升,低碳发展情景下CO_(2)排放量增长率相对较低,强低碳发展情景下CO_(2)排放量呈现非常缓慢的上升趋势。最后对降低福建省造纸工业碳排放,促进造纸工业可持续发展提出建议。

炭黑/废纸导电纤维的制备及其在聚丙烯中的应用

利用多巴胺氧化自聚合将炭黑粘附到废纸纤维表面,制备了炭黑/废纸柔性导电纤维,分析了炭黑含量对纤维导电性能的影响,然后,将该导电纤维与聚丙烯熔融共混制备复合材料,分析了导电纤维添加量对复合材料导电和力学性能的影响。结果表明,聚多巴胺将炭黑均匀粘附在废纸纤维表面,纤维的电阻率随着炭黑含量增加而逐渐降低,当炭黑含量为15%时,废纸纤维的电阻率logρ下降至2.16Ω·cm。柔性导电纤维能更好地控制聚丙烯复合材料电导率降低幅度,当纤维添加量为15%(炭黑含量为2.27%)时,复合材料的表面电阻率为3.71×10^(10)Ω,体积电阻率为2.45×10^(11)Ω·cm,能达到抗静电级别。此时,复合材料的弹性模量和拉伸强度分别为565.65和17.01 MPa,模量提高了1.07%,但强度降低了32.82%。

绿色视域下造纸产业经济现状及碳中和实现策略研究

碳中和是未来我国造纸产业优化产业结构、推进绿色可循环发展的重要目标。总结了当前我国造纸产业经济绿色可循环发展现状,阐述了我国造纸产业发展绿色可循环经济的问题,着重强调了碳中和对我国造纸产业的影响并对碳中和视角下我国造纸产业经济绿色可循环发展策略进行分析,旨在为我国造纸产业在碳中和目标下的发展提供借鉴。

高性能碳纤维纸研究

研究了用于燃料电池气体扩散层的高性能碳纤维纸,把针叶木浆纤维和碳纤维进行复合制备;对工序及其参数,如碳纤维的表面预处理和分散、针叶木浆打浆工艺、碳纤维配比、不同定量等开展了综合研究,分析了工艺参数对碳纤维纸物性指标和纤维形态的影响。结果表明,对碳纤维表面进行去胶处理时,使用乙醇加热回流萃取的方法效果较佳;针叶木浆较佳的打浆工艺为:疏解10min+2.1kg压力打浆10min+3.1kg压力打浆10min(打浆度24°SR);普通碳纤维导电纸较佳的碳纤维配比为15%,高性能碳纤维纸较佳的碳纤维配比为40%,所制备的高性能碳纤维纸电阻率低、强度较好、透气度较高。

碳中和视角下区域性造纸产业绿色可持续发展研究

节约能源、降低二氧化碳排放量是当今时代及未来的发展趋势。造纸产业是我国碳排放几大重点行业之一,对我国碳中和战略目标的达成有义不容辞的担当和责任。对此,进行了碳中和目标下造纸产业发展的思考,简述了我国造纸产业碳排放现状与碳减排潜力,分析了碳中和视角下区域性造纸产业绿色可持续发展面临的诸多机遇与挑战,提出了推进造纸产业绿色可持续发展的有效路径,即制订区域造纸产业低碳发展规划、创新节能减碳技术、促进区域产业协同发展、优化地方政府行为等,以加快区域性造纸产业绿色发展,着力推进碳中和目标的实现。