Nanoporous Membrane Electrodes with an Ordered Array of Hollow Giant Carbon Nanotubes

This study proposes a next-generation model membrane electrode for fundamental electrochemical research of amorphous-based porous carbon materials. This novel electrode is fabricated by the uniform carbon coating of anodic aluminum oxide formed on an Al substrate and free from a barrier layer. The conformally carbon-coated layer forms vertically aligned giant carbon nanotubes, and their walls comprise low-crystalline stacked graphene sheets. The diameter and the length of the nanopores can be tuned over a broad range of between 10 to 200 nm and 2 to 90 µm, respectively. Moreover, unlike composite electrodes made from other ordered nanoporous carbons, this model electrode exhibits an absence of inter-particle spacing and hence no contact resistance between particles. Thus, this model electrode provides representative nanopores of low-crystalline carbon materials. An atomic-scale structural model of the low-crystalline carbon walls is built with the aid of an in-house temperature-programmed desorption system to enable theoretical simulations to be performed. Using this model electrode, the electrical conductivity of low-crystalline carbon walls and mass transportation in an electric double-layer system are elucidated. This representative model electrode is expected to help clarify the complex electrochemical processes in porous carbon electrodes.     

不同孔结构碳电极材料亲电解质性改性及电化学性能研究

碳电极材料良好的亲电解质性能够促进电解质离子在其表面吸附/脱附,从而提高其电化学性能.为了探究亲电解质性对不同孔结构碳电极材料电化学性能的影响,采用悬浮聚合、可逆加成断裂链转移活性聚合和超浓乳液聚合分别制备碳微球、介孔碳和分级多孔碳,并将具有良好亲水性的聚乙二醇(PEG)分子刷接枝在三种碳材料的表面改善它们的亲水系电解...     

三电极碳纳米管传感器的极间距优化

三电极碳纳米管传感器各电极之间的间距大小是影响检测精度的关键因素之一。在用传感器阵列检测多组分气体混合物时,各传感器的极间距很难确定。为三电极碳纳米管气体传感器提出一种基于粒子群算法(PSO)的极间距优化方法。该方法包括设计极间距、组建由不同极间距的多个传感器组成的传感器阵列、建立包括极间距及检测离子电流的数据库、建立混合气体定量分析模型及极间距优化等步骤。采用多组由不同极间距的三个碳纳米管传感器构成的传感器阵列对NO和SO2 混合气体进行测量,其中各传感器的极间距均采用上述方法优化。实验结果显示,上述极间距优化方法能够有效地选择电极之间的最佳间距,优化极间距后的传感器也获得了更高的检测灵敏度。     

碳纳米管-氢氧化镍复合电极电化学电容器

采用催化裂解法制备了碳纳米管并进一步制备了碳纳米管薄膜电极。基于该种材料的超电容器电极比容量为36 F/g。研究了在碳纳米管薄膜基体上使用电化学方法沉积氢氧化镍的新工艺,制备出碳纳米管/氢氧化镍复合电极。伏安特性曲线以及直流充放电实验证明复合电极的单电极比容量达到63 F/g,交流阻抗谱证明复合电极具有优良的阻抗特性。     

有机双电层电容器用活性炭电极的修饰

利用石墨、炭黑、碳纳米管三种导电碳材料,对高比表面积活性炭进行掺杂修饰,制备有机电解液双电层电容器用薄膜电极。经电化学测试发现,在 1 mol/L 的 LiPF6/EC-DEC(体积比 1∶1)溶液中,经不同导电材料修饰后的活性炭电极,其单电极比容量和大电流充放电性能均有较大改善。其中,掺杂 10%(质量分数)碳纳米管的活性炭电极,在 330 mA/g 电流密度下的单电极比容量可达 81 F/g,比未掺杂活性炭电极 60 F/g 的比容量提高了 35%;电流密度从 60 mA/g 增至 330 mA/g,该电极的容量保持率为 79.4%。     

Radiotransparent carbon electrode for ECG recordings in thecatheterization laboratory

The electrical properties of a radiotransparent carbon electrode were evaluated and compared with those of a high-quality Ag/AgCl electrode. In order to approach clinical electrocardiographic (ECG) recording conditions, special experimental arrangements for the determination of impedance, phase angle, and noise characteristics were used. It is shown that the carbon electrode provides precordial ECG signals of excellent quality during catheterizations and allows simultaneous use of X-ray examination     

分段圆型碳纳米管阴极结构的三极FED制作

利用钠钙平板玻璃形成阴极板;结合丝网印刷技术在阴极板上制作了分段圆型碳纳米管阴极结构。烧结固化的银浆层用于分别构成矩形底电极和圆型底电极,其良好的导电性能确保阴极电势能够被顺利传导给碳纳米管。对矩形底电极采取了分段条形电极形式,多个分段条形电极整体排列在阴极板表面,形成分段条形电极矩阵,改进的矩形底电极能够有效降低整体显示器的无效电压降;而制作的圆型碳纳米管层和圆型底电极用于提高碳纳米管的场发射性能。结合分段圆型碳纳米管阴极,研制了三极结构的场致发射显示器。该显示器具有良好的场致发射特性和高的图像发光亮度,能够正确显示简单的字符图像,其开启场强为2.16 V/μm。     

超电容器活性炭/炭黑复合电极电容特性研究

为制备实用化的超电容器,对活性炭材料进行了表征,详细描述了活性炭/炭黑复合电极的制备工艺。通过循环伏安法和恒电流充电法,对活性炭/炭黑复合电极在水系电解液中的电容行为进行了研究。结果表明:活性炭的BET比表面积达1 654 m2/g,具有合理的孔径分布,主要在2 nm附近。添加高比表面积、高导电性纳米级炭黑制备的活性炭/炭黑复合电极具有优良的电容行为和较好的功率特性,复合电极的比容量达到102.4 F/g。此外还对孔径分布与电容的关系进行了阐述。     

超级电容器碳电极工艺研究

为了进一步完善电容器性能，研究了不同导电剂、粘结剂和电极制作工艺对压片式泡沫镍碳电极性能的影响，确定了制作高性能泡沫镍碳电极的优选方案。     

Self‐Adhesive Macroporous Carbon Electrodes for Efficient and Stable Perovskite Solar Cells

Carbon electrode are a low‐cost and great potential strategy for stable perovskite solar cells (PSCs). However, the efficiency of carbon‐based PSCs lags far behind compared with that of state‐of‐the‐art PSCs. The poor interface contact between the carbon electrode and the underlying layer dominates the performance loss of the reported carbon‐based PSCs. In this respect, a sort of self‐adhesive macroporous carbon film is developed as counter electrode by a room‐temperature solvent‐exchange method. Via a simple press transfer technique, the carbon film can form excellent interface contact with the underlying hole transporting layer, remarkably beneficial to interface charge transfer. A power conversion efficiency of up to 19.2% is obtained for mesoporous‐structure PSCs, which is the best achieved for carbon‐based PSCs. Moreover, the device exhibits greatly improved long‐term stability. It retains over 95% of the initial efficiency after 1000 h storage under ambient atmosphere. Furthermore, after aging for 80 h under illumination and maximum power point in nitrogen atmosphere, the carbon‐based PSC retains over 94% of its initial performance.     

High‐Performance Carbon‐LiMnPO4 Nanocomposite Cathode for Lithium Batteries

A cathode material of an electrically conducting carbon‐LiMnPO₄ nanocomposite is synthesized by ultrasonic spray pyrolysis followed by ball milling. The effect of the carbon content on the physicochemical and electrochemical properties of this material is extensively studied. A LiMnPO₄ electrode with 30 wt% acetylene black (AB) carbon exhibits an excellent rate capability and good cycle life in cell tests at 55 and 25 °C. This electrode delivers a discharge capacity of 158 mAh g^?1 at 1/20 C, 126 mAh g^?1 at 1 C, and 107 mAh g^?1 at 2 C rate, which are the highest capacities reported so far for this type of electrode. Transmission electron microscopy and Mn dissolution results confirm that the carbon particles surrounding the LiMnPO₄ protect the electrode from HF attack, and thus lead to a reduction of the Mn dissolution that usually occurs with this electrode. The improved electrochemical properties of the C‐LiMnPO₄ electrode are also verified by electrochemical impedance spectroscopy.     

电泳淀积三极管结构的碳纳米管场发射显示阴极

本研究探索了一种电泳选域组装碳纳米管发射器到正栅极结构的衬底中作为三极管结构的场发射显示阴极的工艺.在这个工艺中,悬浊液中的碳纳米管在施加于栅极电极和阴极电极的电压的作用下移向并淀积到三极管结构的衬底中.同时,这个栅极电极的正电压能够排斥悬浊的碳纳米管,使栅极电极不吸附碳纳米管.实验结果表明,碳纳米管选域组装到栅极孔洞中去,并且每一个孔洞中碳纳米管具有相同的组装密度.该工艺成本低、可实现大面积阴极的制备,是一种在制备三极管型碳纳米管场发射显示阴极中可供选择的工艺.     

活性炭前处理对双电层电容器性能的影响

制备了沥青焦基活性炭双电层电容器用电极材料,将其分别经水洗、酸洗以及超音速气流粉碎处理。在1 mol/L(C2H5)4NBF4/碳酸丙烯酯电解液体系中进行电化学测试,对比评价了各活性炭前处理方法对电容器电化学性能的影响。结果表明,酸洗后活性炭电极比电容提高7%达到163 F/g,高功率放电性能明显改善,当电流密度由70 mA/g增加到1 A/g时,其电极比电容保持率为88%;活性炭进行超细粉碎后不利于电化学性能的提高。     

隧道带间耦合级联新型激光器扩展电流的优化

隧道带间耦合级联激光器采用C掺杂生长隧道结,由于高浓度C掺杂层在激光器多个有源区之间分布形成了高电导层,增加了注入电流的横向扩展,使激光器的性能不能充分发挥出来。我们利用双面电极新型结构可以很好地克服横向电流扩展,使级联的激光器保证充分的光输出功率,具体是在常规激光器背面衬底做完全与正面电极相同而对中的电极,当加入电场后,使电场完全集中在这两个相对中的电极之间,使激光器注入的电流从正面电极完全不扩展地流入到背面衬底电极,保证每个有源区都注入相同的电流而保证每个有源区充分的光输出。对4个有源区级联的激光器光输出功率较常规电极提高70%以上,输出光功率从1.6W提高到2.4W,斜率效率提高70%以上。     

A Simple Electrode‐Level Chemical Presodiation Route by Solution Spraying to Improve the Energy Density of Sodium‐Ion Batteries

The formation of a solid electrolyte interface (SEI) on the surface of a carbon anode consumes the active sodium ions from the cathode and reduces the energy density of sodium‐ion batteries (SIBs). Herein, a simple electrode‐level presodiation strategy by spraying a sodium naphthaline (Naph‐Na) solution onto a carbon electrode is reported, which compensates the initial sodium loss and improves the energy density of SIBs. After presodiation, an SEI layer is preformed on the surface of carbon anode before battery cycling. It is shown that a large irreversible capacity of 60 mAh g^?1 is replenished and 20% increase of the first‐cycle Coulombic efficiency is achieved for a hard carbon anode using this presodiation strategy, and the energy density of a Na_0.9[Cu_0.22Fe_0.30Mn_0.48]O₂||carbon full cell is increased from 141 to 240 Wh kg^?1 by using the presodiated carbon anode. This simple and scalable electrode‐level chemical presodiation route also shows generality and value for the presodiation of other anodes in SIBs.     

负极性电火花加工时的电极损耗机理及积碳层的减损作用研究

本文基于场致发射理论,对负极性电火花加工时电极材料的损耗情况及极间做功能量进行了研究,设计并分别进行了不同工艺参数下紫铜电极和A3#钢电极单孔负极性电火花加工对比实验.实验研究结果表明:相同工艺参数下,紫铜电极比A3#钢电极加工时的极间放电能量大,加工效率高且电极材料的损耗率低:表面积碳层对紫铜电极材料有着良好的减损作用,而对A3#钢电极则作用甚微;且对紫铜电极而言,在保证有效消电离的情况下,极间有效放电时间比越高,加工效率越高,电极的损耗率越低,而相应的积碳层对电极材料的减损率则减小.     

Next‐Generation Activated Carbon Supercapacitors: A Simple Step in Electrode Processing Leads to Remarkable Gains in Energy Density

The global supercapacitor market has been growing rapidly during the past decade. Today, virtually all commercial devices use activated carbon. In this work, it is shown that laser treatment of activated carbon electrodes results in the formation of microchannels that can connect the internal pores of activated carbon with the surrounding electrolyte. These microchannels serve as electrolyte reservoirs that in turn shorten the ion diffusion distance and enable better interaction between the electrode surfaces and electrolyte ions. The capacitance can be further increased through fast and reversible redox reactions on the electrode surface using a redox‐active electrolyte, enabling the operation of a symmetric device at 2.0 V, much higher than the thermodynamic decompostion voltage of water. This simple approach can alleviate the low energy density of supercapacitors which has limited the widespread use of this technology. This work represents a clear advancement in the processing of activated carbon electrodes toward the next‐generation of low‐cost supercapacitors.     

双电层电容器高比表面积活性炭的研究

以石油焦为原料,KOH和NaOH为活化剂制取双电层电容器用高比表面积活性炭电极材料。考察了活化剂的种类及其与石油焦配比对活性炭比电容的影响,并对KOH和NaOH的混和物在活化过程中金属K和Na的协同作用进行了初步探讨。研究结果表明控制适宜的活化工艺条件可制得比电容高达52.60 F/g的高比表面积活性炭,用它组装成的双电层电容器具有良好的充放电性能。     

Integration of 2D and 3D Thin Film Glassy Carbon Electrode Arrays for Electrochemical Dopamine Sensing in Flexible Neuroelectronic Implants

Here we present the development and characterization of a flexible implantable neural probe with glassy carbon electrode arrays. The use of carbon electrodes allows for these devices to be used as chemical sensors, in addition to their typical use as electrical sensors and stimulators. The devices are fabricated out of polyimide, platinum, titanium, and carbon with standard microfabrication techniques on carrier wafers. The devices are released from the substrate through either chemical or electrochemical dissolution of the underlying substrate material. The glassy carbon electrode arrays are produced through the pyrolysis of SU‐8 pillars at 900 °C as the first process step, as this temperature is incompatible with the other device materials. The process demonstrated here is generally applicable, allowing for the integration of various high temperature materials into flexible devices.     

微波法制备超级电容器用高性能活性炭电极材料

以石油焦为原料,KOH为活化剂,经微波加热活化,制备出了超级电容器用高性能活性炭电极材料。以制得的活性炭制成的电极片为电极,6mol/L的KOH溶液为电解液,组装了模拟电容器。研究了加热时间和碱焦比对活性炭比表面积及电容器性能的影响。研究表明:在KOH与石油焦按3∶1的质量比混合,微波辐射时间为15min时,制备的活性炭比表面积达2683m2/g,模拟电容器单电极比电容量达361F/g。