Modified carbon cloth as positive electrode with high electrochemical performance for vanadium redox flow batteries

Carbon cloth modified by hydrothermal treatment in ammonia water is developed as the positive electrode with high electrochemical performance for vanadium redox flow batteries. The SEM shows that the treatment has no obvious influence on the morphology of carbon cloth. XPS measurements indicate that the nitrogenous functional groups can be introduced on the surface of carbon cloth successfully. The electrochemical performance of V(IV)/V(V) redox couple on the prepared electrode is evaluated with cyclic voltammetry and linear sweep voltammetry measurements. The N-doped carbon cloth exhibits outstanding electrochemical activity and reversibility toward V(IV)/V(V) redox couple. The rate constant of V(IV)/V(V) redox reaction on carbon cloth can increase to 2.27 x 10(-4) cm/s from 1.47 x 10(-4) cm/s after nitrogen doping. The cell using N-doped carbon cloth as positive electrode has larger discharge capacity and higher energy efficiency compared with the cell using pristine carbon cloth. The average energy efficiency of the cell using N-doped carbon cloth for 50 cycles at 30 mA/cm(2) is 87.8%, 4.3% larger than that of the cell using pristine carbon cloth. It indicates that the N-doped carbon cloth has a promise application prospect in vanadium redox flow batteries. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

MXene-coated silk-derived carbon cloth toward flexible electrode for supercapacitor application

Flexible supercapacitors are promising energy storage devices in wearable smart electronics. Exploring cost-efficient electrodes with high capacitance would promote the wide-scale application of such capacitors. Herein, in order to explore a methodology for preparing low cost, flexible, tough, and up-scalable supercapacitor electrodes, silk textile is directly carbonized to make a conductive free-standing textile substrate. Through mildly baking the surfactant-free TiCTflakes suspension loaded on the carbonized silk cloth, a uniform and adhesive coating consisting of nanometer-thick TiCTflakes is well established on the conductive fabric support, forming a MXene-coated flexible textile electrode. The fabricated electrode exhibits a high areal capacitance of 362 m F/cm~2 with excellent cyclability and flexibility. Moreover,capacitance changes neglegibly under the bending deformation mode. This study elucidates the feasibility of using silk-derived carbon cloth from biomss for MXene-based flexible supercapacitor.

Enhanced electrocatalytic activity of carbon cloth by synergetic effect of plasma and acid treatment

Commercial carbon cloth(CC)is an ideal electrocatalysis material to produce oxygen evolution reaction(OER)due to its high conductive and 3D flexible structure,but the lacked active sites limit its application.For improving its OER performance,the present study proposed an effective method combining plasma and acid treatment to introduce oxygen-containing functional groups and produce more active sites on its surface.Compared to the pristine CC,the plasma and acid treated carbon cloth(PN-CC)delivers a reduced overpotential by 34.6%to achieve current density of 10 mA cm^(−2).The Tafel slope declines from 97.5 mV dec^(–1)(pristine CC)to 55.9 mV dec–1(PN-CC),showing an increased OER kinetic.Additionally,PN-CC electrocatalyst shows outstanding stability after 5000 cycles or 25000 s.The combination of plasma and acid treatment shows a significant potential in surface modification for electrocatalysts.

Porous NiCo_2O_4 nanowires supported on carbon cloth for flexible asymmetric supercapacitor with high energy density

Recently, binary metal oxides have been considerably researched for energy storage since it can provide higher electrical conductivity and electrochemical activity than single components. Besides, rational arrays structure design can effectively enhance the utilization of active material. In this article, we synthesis a porous NiCo_2O_4 nanowires arrays, which were intimate contact with flexible carbon cloth（CC）by a facile hydrothermal reaction and calcination treatment. The rational array structures of NiCo_2O_4 facilitate the diffusion of electrolyte and effectively increase the utilization of active material. The asobtained NiCo_2O_4@CC electrode exhibits a high capacitance of 1183 mF cm^（-2） and an outstanding capacitance retention of 90.4% after 3000 cycles. Furthermore, a flexible asymmetric supercapacitor（ASC）using NiCo_2O_4@CC as positive electrode and activated carbon cloth（ACC） as negative electrode was fabricated, which delivers a large capacitance of 750 mF cm^（-2）（12.5 F cm^（-3））, a high energy density of 0.24 mWh cm^（-2）（3.91 mWh cm^（-3））, as well as excellent cycle stability under different bending states.These remarkable results suggest that as-assembled NiCo_2O_4@CC//ACC ASC is a promising candidate in flexible energy storage applications.

Facile carbon cloth activation strategy to boost oxygen reduction reaction performance for flexible zinc-air battery application

Flexible and all-solid-state zinc-air batteries(ZABs)are highly useful and also in demand due to their theoretical high energy densities and special applications.The limitation in their performance arises due to their catalyst-coated cathode electrodes in terms of catalytic activity and stability as well as cost.In this paper,a novel and environmentally friendly activation strategy is developed to activate the carbon cloth(CC)for the electrodes.The activated CC serves as a catalyst-free air cathode with high conductivity,excellent mechanical strength,and flexibility,in addition to low cost.The strategy is performed by simply electro-oxidizing and electroreducing CC under ultrahigh direct current(DC)voltage in a diluted NH4Cl aqueous electrolyte.It is found that the electro-oxidation not only results in the formation of a graphene-like exfoliated carbon layer on the surface of CC but also induces the incorporation of oxygen-containing groups and doping of nitrogen and chloride atoms.After the electroreduction,theπ-conjugated carbon network of CC is partially restored,leading to the recovery of electroconductivity.Such an electroactivated CC shows excellent oxygen reduction reaction activity.The aqueous flexibility and all-solid-state ZABs are assembled using such an electroactivated CC cathode without any catalyst loading.Both ZABs can achieve good durability and deliver high peak power density and an energy density as high as 690 Wh kg^(−1),demonstrating the excellent potential of this electroactivated CC in practical devices.

Uniform zinc deposition on O,N-dual functionalized carbon cloth current collector

The society’s urgent demand for environmentally friendly, safe and low-cost energy storage devices has promoted the research of aqueous zinc-ion batteries. However, the uneven deposition of Zn ions on anodes will lead to the growth of the dendrite and reduce the Coulombic efficiency as well as the lifespan of the devices. Herein, we construct an O,N-dual functionalized carbon cloth current collector via a simple hydrothermal strategy, in which the oxygen-containing functional groups and the N heteroatoms can regulate the transmission and deposition of Zn ions, respectively. The proposed synergistic strategy ensures the uniform distribution of Zn ions on the surface of the Zn anode and inhibits the formation of dendrites. The symmetric cell based on the O,N-dual doped carbon cloth presents superior cycling stability(318 h) with a low voltage hysteresis(11.2 mV) at an areal capacity of 1 m Ah cm^(-2)(20% depth of diacharge). Meanwhile, the appreciably low overpotential(16 m V) and high Columbic efficiency(98.2%)also demonstrate that the O,N-dual functionalized carbon cloth can be worked as a promising host for Zn ions deposition.

Controlled Growth of NiMoO_(4) Nano-rods on Carbon Cloth:A Novel Electrode for the Hydrogen Evolution Reaction in Alkaline Media and Simulated Sea Water

A series of NiMoO_(4)-nano rod/carbon cloth composite electrodes with different loadings(x)of NiMoO_(4)-NRs was synthesized with a view to implementing an efficient hydrogen evolution reaction(HER).The NiMoO_(4) nano-rods(NRs)were prepared by growing them directly on carbon cloth(CC)via a simple hydrothermal reaction coupled with an annealing treatment.The resulting NiMoO_(4)-NR/CC-x composites served directly as electrodes for electrolysis of an alkaline medium and a simulated sea water.The results indicated that among the NiMoO_(4)-NR/CC-x composites,the NiMoO_(4)-NR/CC-10 composite possessed the highest HER activity with an overpotential of 244.8 mV at 10 mA/cm^(2),a Tafel slope of 95 mV/dec,the fastest charge transfer rate(R_(ct)<1Ω)and good stability in alkaline media.Even in simulated seawater,the NiMoO_(4)-NR/CC-10 composite showed good stability.The outstanding HER activity and stability may originate from the strong interaction between Ni and Mo in the NiMoO_(4) NRs as well as the efficient charge transfer process and the rate of the HER due to the synergistic effect involving the CC and NiMoO_(4) NRs.

MnO_(2) nanosheet modified N, P co-doping carbon nanofibers on carbon cloth as lithiophilic host to construct high-performance anodes for Li metal batteries

Lithium (Li) metal batteries have attracted much attention owing to its ultra-high energy density.However,as important part of Li metal batteries,Li anodes still face many challenges,mainly including uncontrolled dendritic Li formation,dramatical volume variation and serious pulverization.Herein,manganese dioxide (MnO_(2)) nanosheet modified nitrogen (N),phosphorus (P) co-doping carbon nanofibers(NPC) on carbon cloth (CC)(MnO_(2)@NPC-CC) is successfully fabricated through electrodeposition approach and further treated with Li by the molten-infusion method to prepare Li based Mn@NPC-CC(Li-Mn@NPC-CC) electrode.The synergy of MnO_(2) and NPC obviously increases the reaction rate between MnO_(2)@NPC-CC and Li and guides even Li distribution over infusion process.Additionally,theoretical calculation,simulation and experimental results further indicate that N,P,Mn multi-doping effectively improves the superior lithiophilicity of Li-Mn@NPC-CC,which induces uniform Li deposition/dissolution to suppress dendrite growth over cycles.Moreover,conductive and porous NPC matrix not only effectively improves the stability of Li-Mn@NPC-CC,but also provides abundant spaces to accelerate the transfer of ion/electron and buffer electrode dimension variation during cycling.Hence,Li-Mn@NPC-CC-based symmetric cells exhibit extra-long cycling life (over 2200 h) with small hysteresis of 20 mV.When the LiMn@NPC-CC anode couples with air,Li iron phosphate (LiFePO_(4)),or hard carbon (C) cathode,the assembled full cells exhibit outstanding performance with low hysteresis and stable cycling properties.Especially,the corresponding pouch-typed Li–air cells also exhibit good performance at different bending angles and even power a series of electronic devices.

One-Step Solution Synthesis of Carbon Cloth@SiO_(2) Composite for Flexible Anode of Advanced Lithium-Ion Battery

A flexible anode composite,carbon cloth@SiO_(2)composite(CC@SiO_(2)),was synthesized by a one-step solution method using tetraethyl orthosilicate(TEOS)as the silica source.CC@SiO_(2)can be directly used as the negative electrode material for lithium-ion battery,and its initial reversible deintercalation capacity reaches 1358.7 mA·h·g^(-1).The electrode shows a capacity of 863.8 mA·h·g^(-1)up to 130 cycles at 0.5 A·g^(-1),displaying excellent rate performance and cycle stability.

CoS Nanosheets Coated with Dopamine-Derived Carbon Standing on Carbon Fiber Cloth as Binder-Free Anode for Li-ion Batteries

Cobalt sulphides attract much attention as anode materials for Li-ion batteries(LIBs).However,its poor conductivity,low initial column efficiency and large volume changes during cycling have hindered its further development.Herein,novel interlaced CoS nanosheets were firstly prepared on Carbon Fiber Cloth(CFC)by two hydrothermal reactions followed with carbon coating via carbonizing dopamine(CoS NS@C/CFC).As a freestanding anode,the nanosheet structure of CoS not only accommodates the volume variation,but also provides a large interface area to proceed the charge transfer reaction.In addition,CFC works as both a three-dimensional skeleton and an active substance which can further improve the areal capacity of the resulting electrode.Furthermore,the coated carbon combined with the CFC work as a 3D conductive network to facilitate the electron conduction.The obtained CoS NS@C/CFC,and the contrast sample prepared with the same procedure but without carbon coating(CoS NS/CFC),are characterized with XRD,SEM,TEM,XPS and electrochemical measurements.The results show that the CoS NS@C/CFC possesses much improved electrochemical performance due to the synergistic effect of nanosheet CoS,the coated carbon and the CFC substrate,exhibiting high initial columbic efficiency(~87%),high areal capacity(2.5 at 0.15 mA cm−2),excellent rate performance(1.6 at 2.73 mA cm−2)and improved cycle stability(87.5%capacity retention after 300 cycles).This work may provide a new route to explore freestanding anodes with high areal specific capacity for LIBs.

Nanostructured porous polyaniline(PANI)coated carbon cloth(CC)as electrodes for flexible supercapacitor device

Nanostructured porous polyaniline(PANI)has been synthesized and coated simultaneously on a highly flexible and conductive carbon cloth(CC)substrate using a simple in-situ chemical oxidative polymerization technique.PANI coated CC(PANI-CC)based flexible electrodes were further used for the fabrication of flexible supercapacitor devices.For the comparison purpose,pure PANI has also been synthesized and tested for its electrochemical performance.The energy storage capacity of PANI and PANI–CC composite was investigated using electrochemical techniques like CV,GCD,and EIS in a potential range from 0 to 0.8 V in 1 M H_(2)SO_(4)electrolyte.PANI-CC flexible electrodes exhibited the highest specific capacitance of 691 F/g;whereas,pure PANI could only achieve 575 F/g of specific capacitance at 1 A/g.Composite also exhibited outstanding cyclic stability by recollecting 94%of its initial capacitance after 2000 GCD cycles.For actual implementation,a flexible supercapacitor device has been fabricated using stainless steel sheets and PANI-CC flexile electrodes.The energy storage performance of the PANI-CC flexible supercapacitor device was tested at several bending angles,which resulted in 72%of capacitance retention at a maximum bending angle of 140°compared to the capacitance obtained at an angle 0°(flat state).PANI-CC exhibited improved electrochemical performance than pure PANI due to the synergistic effect between PANI and CC.Here,CC helped in enhancing the conductivity and stability;whereas,PANI boosted the capacitance owing to its excellent porosity and fast pseudocapacitive charge storage response.

Self-supported ternary Co0.5Mn0.5P/carbon cloth （CC） as a high-performance hydrogen evolution electrocatalyst

Scalable production of earth-abundant, easy-to-prepare, and cost-effective electrocatalysts for the hydrogen evolution reaction （HER） is essential for sustainable energy-based systems. Herein, we systematically studied the electrocatalytic HER performance of a self-supported ternary Co0.5Mn0.5P/carbon cloth （CC） nanomaterial prepared using a hydrothermal reaction and phosphorizafion process. Electrochemical tests demonstrated that the ternary Co0.5Mn0.5P/CC nanomaterial could be a highly active electrocatalyst in acidic media, with overpotentials of only 41 and 89 mV, affording current densities of 10 and 100 mA.cm-2, respectively, and a Tafel slope of 41.7 mV.dec-1. Furthermore, the electrocatalyst exhibited superior stability, with 3,000 cycles of cyclic voltammetry from -0.2 to 0.2 V at a scan rate of 100 mV.s-1 and 40 h of static polarization at a fixed overpotential of large-scale hydrogen production. 83 mV, indicating its potential for

Ionic liquid assisted electrochemical coating zinc nanoparticles on carbon cloth as lithium dendrite suppressing host

The application of lithium metal anode with high specific capacity and energy density is limited by the volume expansion and pulverization caused by dendrite growth during cycle process.We propose a composite lithium anode by immersing molten lithium on the flexible three-dimensional(3D)carbon cloth scaffold with the zinc nanoparticles.The lithiophilic zinc nanoparticles layer of framework is synthesized by fast and easy electrochemical deposition from ionic liquid avoiding high temperature,high pressure and toxic reagent.The lithium is infused into the 3D lithiophilic framework,the composite anode is obtained.The steady network structure can confine the lithium and lead to Li dendrite restraining and reducing volume change due to the low interfacial resistance and reduce the effective current density,which induced the homogeneous Li growth.Benefiting from this,the Li infused 3D carbon cloth-Zn symmetric battery exhibits a low stripping/plating overpotential(~30 mV)and can be stable over 900 h at 1 mA cm-2.The Li//LiFePO4 battery delivers higher reversible capacity(140 mAh g^-1 at 2 C and 120 mAh g^-1 at 5 C)and stable cycling for 1500 and 2000 cycles than bare Li.

Construction of nickel cobalt sulfide nanosheet arrays on carbon cloth for performance-enhanced supercapacitor

Materials featured with self-supported three-dimensional network,hierarchical pores and rich electrochemical active sites are considered as promising electrodes for pseudocapacitors.Herein,a novel strategy for the growth of nickel-cobalt bisulfide(Ni Co S)nanosheets arrays on carbon cloth(CC)as supercapacitor electrodes is reported,involving deposition of two-dimensional metal-organic framework(MOF)precursors on the CC skeletons,conversion of MOF into nickel-cobalt layered double-hydroxide by ion exchange process and formation of Ni Co S by a sulfidation treatment.The Ni Co S nanosheets with rough surface and porous structures are uniformly anchored on the CC skeletons.The unique architecture endows the composite(Ni Co S/CC)with abundant accessible active sites.Besides,robust electrical/mechanical joint between the nanosheets and the substrates is attained,leading to the improved electrochemical performance.Moreover,an asymmetric supercapacitor device is constructed by using Ni Co S/CC and activated carbon as a positive electrode and a negative electrode,respectively.The optimized device exhibits a high specific capacitance,large energy density and long cycle life.The Ni Co S/CC electrode with intriguing electrochemical properties and mechanical flexibility holds great prospect for next-generation wearable devices.

Nano-SnO_(2) Decorated Carbon Cloth as Flexible,Self-supporting and Additive-Free Anode for Sodium/Lithium-Ion Batteries

In this study,nano-sized SnO_(2) decorated on carbon cloth(SnO_(2)/CC)is prepared through a simple and facile solid method.The nano-sized SnO_(2) is uniformly distributed on the surface of carbon fibers in carbon cloth,providing sufficient free space to relieve volume expansion and reduce electrode pulverization during cycling.The as-prepared SnO_(2)/CC as a flexible,self-supporting and additive-free anode electrode for sodium-ion/lithium-ion batteries(SIBs/LIBs)can demonstrate outstanding electrochemical performance.SnO_(2)/CC after annealing at 350℃(SC-350)as an anode for SIBs can deliver a reversible capacity of 0.587 mA h cm^(-2)at the current density of 0.3 mA cm^(-2)after 100 cycles.In addition,when cycling at 1.5 mA cm^(-2),SC-350 can maintain 1.69 mA h cm^(-2)after 500 cycles when used as LIB anode.These results illustrate that the as-prepared SnO_(2)/CC can be a promising flexible anode material for flexible SIBs/LIBs and provide a simple and practical method for designing new flexible electrode materials.

A facile strategy of in-situ anchoring of Co_(3)O_(4) on N doped carbon cloth for an ultrahigh electrochemical performance

Enhancement of supercapacitors(SCs)with high-energy density and high-power density is still a great challenge.In this paper,a facile strategy for in situ anchoring of Co_(3)O_(4) particles on N doped carbon cloth(pCoNCC)is reported.Due to the interaction of the doped N and Co_(3)O_(4),the electrochemical performance improves significantly,reaching 1,940.13 mF·cm^(−2) at 1 mA·cm^(−2) and energy density of 172.46μWh·cm^(−2) at the power density of 400μW·cm^(−2),much larger than that without N doping electrode of 28.5 mF·cm^(−2).An aqueous symmetric supercapacitor(ASSC)assembled by two pCoNCC electrodes achieves a maximum energy density of 447.42μWh·cm^(−2) and a highest power density of 8,000μW·cm^(−2).Utilizing such a high-energy storage ASSC,a digital watch and a temperature-humidity detector are powered for nearly 1 and 2 h,respectively.Moreover,the ASSC displays a superb electrochemical stability of 87.7%retention after 10,000 cycles at 40 mA·cm^(−2).This work would provide a new sight to enhance active materials performance and be beneficial for the future energy storage and supply systems.

Z-scheme CdS/WO_(3)on a carbon cloth enabling effective hydrogen evolution

Photocatalytic water splitting for hydrogen(H2)generation is a potential strategy to solve the problem of energy crisis and environmental deterioration.However,powder-like photocatalysts are difficult to recycle,and the agglomeration of particles would affect the photocatalytic activity.Herein,a direct Z-scheme CdS/WO_(3)composite photocatalyst was fabricated based on carbon cloth through a two-step process.With the support of carbon cloth,photocatalysts tend to grow uniformly for further applications.The experimental results showed that the H2 yield of adding one piece of CdS/WO_(3)composite material was 17.28μmol/h,which was 5.5 times as compared to that of pure CdS-loaded carbon cloth material.A cycle experiment was conducted to verify the stability of the asprepared material and the result demonstrated that the H2 generation performance of CdS/WO_(3)decreased slightly after 3 cycles.This work provides new ideas for the development of recyclable photocatalysts and has a positive significance for practical applications.

Ultrahigh “Relative Energy Density” and Mass Loading of Carbon Cloth Anodes for K-Ion Batteries

Mass loading and potential plateau are the two most important issues of potassium(K)-ion batteries(KIBs),but they have long been ignored in previous studies.Herein,we report a simple and scalable method to fabricate acidized carbon clothes(A-CC)as high mass loading(13.1 mg cm−2)anode for KIBs,which achieved a reversible areal-specific capacity of 1.81 mAh cm−2 at 0.2 mA cm−2.Besides,we have proposed the concept of“relative energy density”to reasonably evaluate the electrochemical performance of the anode.According to our calculation method,the A-CC electrode exhibited an ultrahigh relative energy density of 46 Wh m−2 in the initial charge process and remained at 40 Wh m−2 after 50 cycles.Furthermore,we performed the operando Raman spectroscopy(ORS)to investigate the K-ion storage mechanism.We believe that our work might provide a new guideline for the evaluation of anode performance,thereby,opening an avenue for the development of commercial anode.

Ultra-stable K metal anode enabled by oxygen-rich carbon cloth

The K metal batteries are emerged as promising alternatives beyond commercialized Li-ion batteries.However,suppressing uncontrolled dendrite is crucial to the accomplishment of K metal batteries.Herein,an oxygen-rich treated carbon cloth(TCC)has been designed as the K plating host to guide K homogeneous nucleation and suppress the dendrite growth.Both density function theory calculations and experimental results demonstrate that abundant oxygen functional groups as K-philic sites on TCC can guide K nucleation and deposition homogeneously.As a result,the TCC electrode exhibits an ultra-long-life over 800 cycles at high current density of 3.0 mA·cm^(−2)for 3.0 mA·h·cm^(−2).Furthermore,the symmetrical cells can run stably for 2,000 h with low over-potential less than 20 mV at 1.0 mA·cm^(−2)for 1.0 mA·h·cm^(−2).Even at a higher current of 5.0 mA·cm^(−2),the TCC electrode can still stably cycle for 1,400 h.

An Organic Solvent-free Approach towards PDI/Carbon Cloth Composites as Flexible Lithium Ion Battery Cathodes

An acidic solution based method towards flexible lithium ion battery(LIB)cathodes is developed in this work with perylene diimide(PDI)as the electroactive component and carbon cloth(CC)as the current collector.In this approach,PDI is firstly dispersed in concentrated sulfuric acid(H2S04)and then deposited on CC substrate after the dilution of H2S04,which provides an organic solvent-free strategy to construct integrated LIB cathodes.The acdic solution based fabrication process also allows the facile adjusting of loading amounts of PDI in the cathodes,which can effectively influence the battery performances of the PDI/CC cathodes.As the result,the acidic solution processed PDI/CC cathode can deliver a high specific capacity of-36 mAh·g^-1 at the current density of 50 mA·g^-1 in both half cell with lithium foil as anode and full cell with pre-lithiated CC as anode.In both types of the batteries,the PDI/CC cathodes show good cycling stabilities by retaining^84%of the initial capacities after 300 charge-discharge cycles at 500 mA·g^-1.Additionally,the excellent mechanical stability of the PDI/CC cathode enables the LIBs in pouch cell to maintain the electrochemical performances under various bending states,demonstrating their potentials for flexible LIBs.