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1.
The manganese sulfide (MnS) has attracted more attention as anode material on energy storage and conversion field, owing to its high theoretical capacity (616 ​mA ​h ​g−1) and good electrochemical activity. However, low electronic conductivity and large volume expansion during charge-discharge processes have limited its further application. In order to address above mentioned problems, the composites, MnS nanoparticles embedded in N,S-codoped porous carbon skeleton (named as MnS/N,S–C composites), herein have been prepared successfully using metal organic framework (Mn-NTA) as template. The porous carbon skeleton not only can enhance electrode conductivity, but also relieve volume expansion during charge-discharge processes. Thus, the rational design towards electrode architectures has endowed MnS/N,S–C nanocomposites with superior electrochemical performance, which delivers the specific capacities of 676.7 ​mA ​h ​g−1 at the current density of 100 ​mA ​g−1.  相似文献   

2.
Four activated carbon(AC) samples prepared from rice husk under different activation temperatures have been characterized by N2adsorption–desorption isotherms, thermogravimetric analysis(TGA–DTA), Fourier transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM). The specific surface area of AC sample reached 2681 m2 g 1under activation temperature of 800 1C. The AC samples were then tested as electrode material; the specific capacitance of the as-prepared activated carbon electrode was found to be 172.3 F g 1using cyclic voltammetry at a scan rate of 5 mV s 1and 198.4 F g 1at current density 1000 mA g 1in the charge/discharge mode.& 2014 Chinese Materials Research Society. Production and hosting by Elsevier B.V. All rights reserved.  相似文献   

3.
Highly uniform and tight adhering of Fe3O4 particles on carbon fiber film (Fe3O4/CFF) is achieved through a simple in-situ thermal oxidation method. Particularly, 3D CFF with interconnected structure can shorten transfer path and buffer the volume expansion during charge-discharge cycling. Herein, the obtained Fe3O4/CFF anode exhibits a stable cycling performance and excellent high rate capability. The cell delivers a reversible capacity of 1 711 mAh·g–1 at a current density of 100 mA·g–1 after 100 cycles. Even at a high rate density of 2 A·g–1, the specific capacity also can maintain 1 034 mAh·g–1 after 100 cycles. The simplified fabrication is featured with low-cost and this binder-free perspective holds great potential in mass-production of high-performance metal oxide electrochemical devices.  相似文献   

4.
The uniform porous structure makes activated porous carbons(APCs) superior electrode material.Traditionally,APCs are produced by a combination of time-consuming high-temperature heat treatment and activation,with a production time of up to several hours.The produced APCs have relatively low specific surface area(SSA) and porosity.Therefore,the electrochemical performance is poor,which limits its application in high-power energy storage devices.Here,APCs materials are directly synthesized by a hi...  相似文献   

5.
Lithium-ion capacitors(LICs) were fabricated using mesocarbon microbeads(MCMB) as a negative electrode and a mixture of activated carbon(AC) and LiFePO4 as a positive electrode(abbreviated as LAC).The phase structure and morphology of LAC samples were characterized by X-ray diffraction(XRD) and field emission scanning electron microscopy(FESEM).The electrochemical performance of the LICs was studied using cyclic voltammetry,charge-discharge rate measurements,and cycle performance testing.A LIC with 30 wt% LiFePO4 was found to have the best electrochemical performance with a specific energy density of 69.02 W h kg-1 remaining at 4 C rate after 100 cycles.Compared with an AC-only positive electrode system,the ratio of practical capacity to theoretical calculated capacity of the LICs was enhanced from 42.22% to 56.59%.It was proved that adding LiFePO4 to AC electrodes not only increased the capacity of the positive electrode,but also improved the electrochemical performances of the whole LICs via Li+ pre-doping.  相似文献   

6.
为了解决电解水析氢过程中所用贵金属材料的高昂成本问题,采用水热-低温磷化法制备了一种低廉、环保、高效的析氢催化剂FexNi1-x-P。与传统制备方法比较,该方法在水热合成前驱体过程中,利用镍盐和铁盐与无水乙醇发生氧化还原反应,生成的OH-可以沉淀金属离子,随后前驱体与NaH2PO2低温磷化制得FexNi1-x-P。通过研究发现,Fe0.5Ni0.5-P电极材料表现出优异的催化活性。在1.0 mol·L-1 KOH溶液中,电流密度为10 mA·cm-2时,电极Fe0.5Ni0.5-P需要的过电位仅为113 mV,1 000圈循环伏安测试后,极化曲线无明显衰减。提供了一种制备FexNi1-x-P的简便方法,为开发清洁能源系统的环境友好型催化剂提供了新思路。  相似文献   

7.
Fe2O3 electrode materials exhibit excellent electrochemical performance in electrochemical energy storage system. However, its poor electrical conductivity limits its future practical application. The binder-free Ni Co2O4@Fe2O3 composites was reasonably designed and fabricated on carbon fiber paper with NiCo2 O4 nanowires as conductive scaffold in the present investigation. The three-dimensional nanostructure...  相似文献   

8.
To promote substantially the performances of red phosphorous(P) anode for lithium and sodium-ion batteries, a simple plasma assisted milling(P-milling) method was used to in-situ synthesize SeP2/C composite. The results showed that the amorphous SeP2/C composite exhibits the excellent lithium and sodium storage performances duo to the small nano-granules size and complete combination of selenium(Se) and phosphorous(P) to generate Se–P alloy phase. It was observed that insid...  相似文献   

9.
通过两步微波和离子交换的方法得到一种直径约为 1.5 μm 的微球形貌铜离子掺杂钒基配位聚合物 (V-Cu-HHTP). 聚合物中部分取代的 Cu$^{2+}$提高了配位聚合物的导电性和结构稳定性, 并提供 V、Cu 的协同效应, 在用于超级电容器电极材料时表现出良好的电化学性能. 在 1 A$\cdot$g$^{-1}$ 的电流密度下, V-Cu-HHTP 表现出 287 F$\cdot$g$^{-1}$ 的比容量, 在 10 A$\cdot$g$^{-1}$ 的大电流密度下循环 3 000 圈后, V-Cu-HHTP 的电容保持率仍有 98.6%, 比相同测试条件下未掺杂的 V-HHTP 电极表现优异 (比容量为 227 F$\cdot$g$^{-1}$, 电容保持率为 94.2%). 选取 V-Cu-HHTP 作为正极, 活性炭 (activated carbon, AC) 作为负极, 组装非对称超级电容器 V-Cu-HHTP//AC, 电压窗口达到 1.6 V. V-Cu-HHTP//AC 在功率密度为 795.0 W$\cdot$Kg$^{-1}$ 时, 最大能量密度为44.1 Wh$\cdot$Kg$^{-1}$, 优于许多钒基超级电容器. 优异的电化学性能归因于: 双金属配位聚合物的设计为体系提供了优异的协同效应, 提高了结构稳定性; Cu 离子掺杂提高了导电性; V-Cu-HHTP 的多孔特征为体系暴露更多活性位点, 提供优异的双电层电容特性.  相似文献   

10.
Iron sulfides are promising anode materials for lithium ion batteries(LIBs) owe to their high theoretical capacity and low cost. However, unsatisfactory electronic conductivity, dissolution of polysulfides, and severe agglomeration during the cycling process limit their applications. To solve these issues, a ternary FeS2/Fe7S8@nitrogensulfur co-doping reduced graphene oxide hybrid(FeS2/Fe7S8@NSG) was designed and synthesized throu...  相似文献   

11.
Bionic titania coating carbon multi-layer material was fabricated by employing canna leaves as substrate and carbon precursor. Titania nanocrystals were assembled and coated on the natural films. The carbonation treatment under pure N_2 atmosphere yielded the ultrathin multi-film hybrid material. The carbon layer was coated with small anatase titania crystallite(8–10 nm) and possessed a highly specific surface area of 248.3 m~2 g~(-1). Examination using UV–visible spectrophotometer(UV–vis) showed that the band gap of the multi-layer material was reduced to 2.75 eV, and the hydrogen production by photocatalytic splitting of water under visible light irradiation was about 302 μmol g~(-1) after six hour.  相似文献   

12.
This work reports the effects of activation temperatures on the porous development and electrochemical performance of activated carbons. Herein, activated carbons were prepared from the biowaste of mangosteen peel by using KOH activation at temperatures of 400, 600, and 800 ?°C. The results demonstrate that the specific surface area increases with increasing the activation temperatures in which the well-developed porous structure after KOH activation at 800 ?°C provides the highest specific surface area of 1039 ?m2 ?g?1. At 600 ?°C, the activated carbon delivers the highest specific capacitance value of 182 ?F ?g?1 ?at a current density of 0.5 ?A ?g?1 in 3 ?M KOH aqueous electrolyte. This is correlated well with its high micropore fractions (99%). Moreover, it was found that the activation temperature changes the major contribution of oxygen-containing functional group on surface of activated carbon, which is beneficial for the enhancement of the specific capacitance value of activated carbon at the temperature of 600 ?°C. This work suggests that the activation temperature is a key to optimizing the electrochemical performance of activated carbons. Overall, our activated carbons can be considered as a strong candidate for use as electrode materials in supercapacitors.  相似文献   

13.
Mesoporous carbons were synthesized using thermoplastic phenolic resin (PF) as carbonaceous precursor and magnesium citrate as template precursor. Pore structure was determined as ink-bottle-like geometry through TEM, N2 adsorption analysis combined with TG curves. The porous carbons prepared were then applied as electrode material for electric double-layer capacitors. The capacitor performance was examined in 30 wt% KOH aqueous solution by cyclic voltammetry and galvanostatic charge/discharge measurements. The carbon prepared with MgO/PF mass ratio of 8/2 had a BET surface area of 1920 m2 g?1 and exhibited a capacitance of 220 F g?1 at a current density of 50 mA g?1. Besides, the carbon with the ratio of 4/6 had the optimize proportion of mesopores, which ensures its good rate performance that up to 98.3%, expressed as the ratio of the capacitance measured at 1000 mA g?1 against that at 50 mA g?1.  相似文献   

14.
Sodium-ion batteries (SIBs) have been recently considered as an intriguing candidate for next-generation battery systems with their advantages in large-scale energy storage applications. However, the design of electrode materials of SIBs still suffers from severe volume expansion and low capacity caused by the larger ion radius, high re-dox potential and heavy atom weight of Na. Organic electrode materials with structural flexibility have attracted great attention recently for their potential in alleviating volume expansion. However, most organic electrode materials suffer from dissolution in electrolytes and consequent capacity fading during the long-term cycling process. In this work, a method coordinating with Co2+ was applied to solve the shuttle effect of H4salphdc (N, N’-phenylene-bis-(salicylideneimine) dicarboxylic acid). By virtue of the Co2+ coordination, the Co(H2salphdc) electrode delivered a desirable discharge capacity of 123 mAh g?1 after 1500 cycles at the current density of 200 ?mA ?g?1, while the H4salphdc electrode exhibited severe capacity fading. Such excellent electrochemical performance can be credited to the Co2+ coordination repressing the electrode dissolution and improving the structure stability.  相似文献   

15.
High-capacity anode materials have stimulated much attention to developing high-performance lithium-ion batteries. However, high-capacity anode materials commonly suffer from the pulverization matter that greatly hinders their practical applications, especially in terms of the high proportion of active materials. In this work, a Ga2O3nanowire electrode is synthesized by thermal evaporation and immediately used as an anode without the aid of binders and conductive additives....  相似文献   

16.
FeCo-based non-noble metal electrocatalysts (NNMEs) of FeCo/MCS-NPCS was fabricated by immobilization of hemin on mesoporous carbon shells modified N-doped porous carbon spheres (MCS-NPCS). The obtained FeCo/MCS-NPCS exhibits a half-wave potential (E1/2) of 0.851 ​V versus the reversible hydrogen electrode (vs. RHE) and a limited-diffusion current density (JL) of 5.45 ​mA ​cm−2. In addition, FeCo/MCS-NPCS shows comparable oxygen reduction reaction (ORR) performances to 20 ​wt% Pt/C in terms of E1/2 and JL and better electrochemical properties, including the methanol tolerance and durability in alkaline solution. Such outstanding electrochemical activities of FeCo/MCS-NPCS can be ascribed to Fe and/or Co-based nitrides and carbides as well as N-doped carbon matrixes modified with mesoporous carbon shells. This research introduces a promising path to design and synthesize highly efficient FeCo–N–C electrocatalysts towards ORR.  相似文献   

17.
Superparamagnetic carbon-coated Fe3O4 nanoparticles with high magnetization (85 emu·g-1) and high crystallinity were synthesized using polyethylene glycol-4000 (PEG (4000)) as a carbon source. Fe3O4 water-based bilayer-surfactant-enveloped ferrofluids were subsequently prepared using sodium oleate and PEG (4000) as dispersants. Analyses using X-ray photoelectron spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy indicate that the Fe3O4 nanoparticles with a bilayer surfactant coating retain the inverse spinel-type structure and are successfully coated with sodium oleate and PEG (4000). Transmission electron microscopy, vibrating sample magnetometry, and particle-size analysis results indicate that the coated Fe3O4 nanoparticles also retain the good saturation magnetization of Fe3O4 (79.6 emu·g-1) and that the particle size of the bilayer-surfactant-enveloped Fe3O4 nanoparticles is 42.97 nm, which is substantially smaller than that of the unmodified Fe3O4 nanoparticles (486.2 nm). UV–vis and zeta-potential analyses reveal that the ferrofluids does not agglomerate for 120 h at a concentration of 4 g·L-1, which indicates that the ferrofluids are highly stable.  相似文献   

18.
石墨相氮化碳纳米薄片(g-C3N4NSs)具有优良的电化学发光(ECL)性能和良好的成膜特性.以g-C3N4NSs作为ECL材料,利用其良好的成膜性能将其固定在玻碳电极(GCE)上,再以毒死蜱(CPF)作模板分子,甲基丙烯酸(MAA)作功能单体,通过分子自组装制备分子印迹聚合物(MIP).将该聚合物引入g-C3N4NSs修饰电极,构建了一个MIP-ECL传感器.除去模板分子的传感器能够选择性识别CPF,利用CPF对g-C3N4NSs ECL信号的淬灭作用实现了CPF的高灵敏、高选择性检测.传感器对CPF的线性响应范围是1.0×10-8~1.0×10-4mol·L-1,检出限(LOD)是5.0 nmol·L-1,用于蔬菜中CPF残留量检测,结果令人满意.  相似文献   

19.
We apply antilocalization measurements to experimentally study the interactions and exchange between InAs surface accumulation electrons and local magnetic moments of the rare earth ions Sm3?,Gd3?,Ho3?,and Dy3?,of the transition metal ions Ni2?,Co2?,and Fe3?,and of Fe3O4nanoparticles and Fe3?-phthalocyanine deposited on the surface.The influence of the deposited species on the surface electrons is observed through the changes in the spin–orbit scattering and magnetic spin-flip scattering rates,which carry information about magnetic interactions.Experiments indicate a temperature-dependent magnetic spin-flip scattering for Ho3?,Dy3?,Ni2?,and Co2?.Concerning the spin–orbit scattering rate,we observe an increase,except for the cases of Ni2?,Fe3?,Fe3O4nanoparticles and Fe3?-phthalocyanine.We also observe an increase in SO scattering in another system where we study the interactions of Au nanoparticles and ferromagnetic Co0.6Fe0.4nanopillars and an In0.53Ga0.47As quantum well.Experimental results are analyzed and compared to theoretical models.Our method provides a controlled way to probe the quantum properties of two-dimensional electron systems,either on the surface of InAs or in a quantum well.  相似文献   

20.
LaFeO_3-xwt% r GO composite(x = 8, 10, 12) was synthesized by ultraphonic stirring and lyophilization method.SEM, TEM and XRD results show that the perovskite-type LaFeO_3 was dispersed by rGO to form special porous structure due to the gauze-shaped wrinkles and folds structure of rGO. It was found that the special porous structure can effectively increase the specific surface area and suppress particle aggregation of LaFeO_3, thus improving the electrical conductivity and appreciably enhancing the electrochemical properties of LaFeO_3. As compared with LaFeO_3, the maximum discharge capacity of the composite(x=10) increased from 209.5 mAhg~(–1) to 334.6 mAhg~(–1).The High rate dischargeability at a discharge current density of 1500 mAg~(–1)(HRD1500) and the capacity retention rate after 100 charge/discharge cycles(S100) of the composite increased by 9% and 17%, respectively.  相似文献   

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