Organic Materials as Electrodes in Potassium-Ion Batteries

The integrated advantages of organic electrode materials and potassium metal make the organic potassium-ion batteries (OPIBs) promising secondary batteries. This review summarizes the latest research progress on OPIBs according to the different types of electrode materials (namely, organic small molecules compounds, polymers, and frameworks (metal–organic frameworks (MOFs), covalent organic frameworks (COFs)). Additionally, the research prospects and outlook for OPIBs are also provided.     

Electrode Kinetics and Sensitivity of Nanostructured Electrodes from Different Carbon Fiber Precursor Materials

Correlation of properties of common carbon fiber precursor materials, polyacrylonitrile (PAN) and pitch, with kinetics and sensitivity of microdisk electrodes, PAN T650, PAN HCB and Pitch P25, nanostructured by an electrochemical etching method was tested. Sensitivity of PAN electrodes is higher but kinetics are slower than at pitch electrodes due to more defects in PAN. Because of more surface oxides at PAN T650 adsorption of dopamine is greater than at PAN HCB electrodes but for uric acid adsorption is greater at PAN HCB. Uric acid sensitivity is related to high conductivity of PAN fibers, with an inverse relationship observed for dopamine.     

聚对氨基苯磺酸修饰石墨毡电极在全钒液流电池中的应用

通过电聚合和高温碳化的方法在石墨毡电极碳纤维表面修饰对氨基苯苯磺酸。用扫描电镜和电化学工作站分别表征了材料的表面形貌和电化学性质。结果表明:在石墨毡纤维表面均匀的分布着聚对氨基苯磺酸反应位点;电极不仅对V~(3+)/V~(2+)与VO~(2+)/VO_2~+电对具有很好的电催化性能,而且有效抑制了负极析氢过程,该电极在电流密度为180 m A/cm2情况下,能量效率为70%,表现出优异的综合电化学性能。     

Nanostructured Carbon/Antimony Composites as Anode Materials for Lithium‐Ion Batteries with Long Life

A series of nanostructured carbon/antimony composites have been successfully synthesized by a simple sol–gel, high‐temperature carbon thermal reduction process. In the carbon/antimony composites, antimony nanoparticles are homogeneously dispersed in the pyrolyzed nanoporous carbon matrix. As an anode material for lithium‐ion batteries, the C/Sb10 composite displays a high initial discharge capacity of 1214.6 mAh g^?1 and a reversible charge capacity of 595.5 mAh g^?1 with a corresponding coulombic efficiency of 49 % in the first cycle. In addition, it exhibits a high reversible discharge capacity of 466.2 mAh g^?1 at a current density of 100 mA g^?1 after 200 cycles and a high rate discharge capacity of 354.4 mAh g^?1 at a current density of 1000 mA g^?1. The excellent cycling stability and rate discharge performance of the C/Sb10 composite could be due to the uniform dispersion of antimony nanoparticles in the porous carbon matrix, which can buffer the volume expansion and maintain the integrity of the electrode during the charge–discharge cycles.     

氧化镉改性石墨毡作为高性能的钒电池负极

为了提高原始石墨毡(GF)对V3+/V2+氧化还原反应的电催化活性和降低析氢反应对电池性能的影响,本文采用水热法将氧化镉(CdO)纳米颗粒负载于石墨毡表面,制备出改性石墨毡(CdO/GF)作为高性能的钒电池负极。通过扫描电镜(SEM)、X射线衍射分析(XRD)进行表面形貌和物相分析得出:CdO纳米颗粒均匀负载于石墨毡纤维表面;线性扫描伏安法(LSV)、循环伏安测试(CV)、交流阻抗谱测试(EIS)表明:相对于GF,CdO/GF有效抑制了析氢反应的活性,CdO/GF对于V3+/V2+氧化还原反应的电化学活性和可逆性有显著的提高,电荷转移阻抗也有明显的减小;单电池测试中,对比GF,CdO/GF的放电容量衰减速率有显著的下降,在90 mA·cm-2的电流密度下的电压效率和能量效率提高了约5%。在多次充放电循环过程中,CdO/GF的催化性能显示出良好的稳定性。     

全钒液流电池离子导电膜

随着可再生能源技术的不断发展,全钒液流电池作为具有较大发展前景的大规模储能装置,受到了国内外的广泛关注.离子导电膜作为全钒液流电池重要的组成部件之一,对于电池的性能、使用寿命和成本有着关键性的影响.根据国内外的研究报道,本综述详细介绍了全钒液流电池离子导电膜的科研与应用进展以及所面临的技术难题,为高性能、低成本、长寿命...     

全钒氧化还原液流电池用石墨毡电极的分步氧化活化

石墨毡电极是组成钒电池的关键材料,其较低的电化学活性是造成钒电池功率密度较低的关键因素之一. 本论文采用一种简便的石墨毡电极分步氧化活化法,先将石墨毡在高锰酸钾溶液中进行氧化,后置于活化溶液中激发其反应活性. 通过对处理后的石墨毡进行循环伏安、交流阻抗测试、XPS以及SEM表征,发现氧化时间和活化溶液组成是影响电极性能的因素,在本文中,先经过3天氧化时间,后在配比为3:1的活化溶液中处理的电极,较其他方法处理的电极,电荷传递电阻明显降低,其与溶液之间的接触电阻最低,为7.33 Ω·cm ²,氧化还原峰值比更接近于1,有效提高了反应的活性与可逆性,经X射线光电子能谱分析发现性能提高的原因与表面含氧官能团数目增加有关. 单电池性能测试结果进一步证实,利用该方法处理的石墨毡为电极的单电池,较未经处理的电池相比性能更优,有更高的放电容量和能量效率,在100 mA·cm ^-2电流密度下,能量效率较未处理电极高出7.47%. 与热处理法、酸处理法及电化学氧化法相比较,该方法不需要辅助设备,不消耗能源.     

Lead Sensor Using Gold Nanostructured Screen‐Printed Carbon Electrodes as Transducers

Gold nanostructured screen‐printed carbon electrodes are demonstrated to be suitable transducers for the determination of lead using square‐wave voltammetry. Reproducible gold nanostructures have been obtained by direct electrochemical deposition. A calibration plot from 2.5 to 250 μg/L was obtained in acidic solutions of Pb(II) with a reproducibility of 4% (n=10). The detection limit was 0.09 μg/L of lead. The method is then applied to perform a blood lead analysis by adjusting square‐wave parameters in capillary or venous blood with a minimum sample pretreatment and excellent accuracy and reproducibility.     

Self-Assembled Surfactant-Polyoxovanadate Soft Materials as Tuneable Vanadium Oxide Cathode Precursors for Lithium-Ion Batteries

The mixing of [V₁₀O₂₈]⁶⁻ decavanadate anions with a dicationic gemini surfactant ( gem ) leads to the spontaneous self-assembly of surfactant-templated nanostructured arrays of decavanadate clusters. Calcination of the material under air yields highly crystalline, sponge-like V₂O₅ ( gem -V₂O₅ ). In contrast, calcination of the amorphous tetrabutylammonium decavanadate allows isolation of a more agglomerated V₂O₅ consisting of very small crystallites ( TBA -V₂O₅ ). Electrochemical analysis of the materials’ performance as lithium-ion intercalation electrodes highlights the role of morphology in cathode performance. The large crystallites and long-range microstructure of the gem -V₂O₅ cathode deliver higher initial capacity and superior capacity retention than TBA -V₂O₅ . The smaller crystallite size and higher surface area of TBA -V₂O₅ allow faster lithium insertion and superior rate performance to gem -V₂O₅ .     

Novel Nanostructured Electrodes Obtained by Pyrolysis of Composite Polymeric Materials

In this work, we compare pyrolyzed carbon derived from the photoresist SU‐8 alone or in combination with polystyrene and poly(styrene)‐block‐poly(dimethylsiloxane) copolymer (PS‐b‐PDMS), to be used as novel materials for micro‐ and nanoelectrodes. The pyrolyzed carbon films are evaluated with scanning electron microscopy, thermal gravimetric analysis, X‐ray photoelectron spectroscopy, contact angle analysis, and Raman spectroscopy. Furthermore, the standard rate constant for electron transfer is determined from cyclic voltammograms and found to be lower for PS‐b‐PDMS compared to PS and SU‐8 films. This may be related to the lower carbon content of PS‐b‐PDMS, as well as to its higher microstructural disorder.     

钒液流电池用碳纸电极改性的研究

采用红外光谱和扫描电镜等手段研究了浓硫酸处理前、后碳纸的表面结构和形貌的变化。并将这类碳纸用作全钒液流氧化还原电池电极材料,对其电化学性能进行了详细研究。结果表明通过酸处理,碳纸表面有-COOH官能团生成,其电化学活性增强。酸处理后的碳纸电极组装成的电池在电流密度20 mA·cm^-2时有良好充放电性能,平均电流和电压效率达到95%和82%。     

Carbon and Carbon Hybrid Materials as Anodes for Sodium‐Ion Batteries

Sodium‐ion batteries (SIBs) have attracted much attention for application in large‐scale grid energy storage owing to the abundance and low cost of sodium sources. However, low energy density and poor cycling life hinder practical application of SIBs. Recently, substantial efforts have been made to develop electrode materials to push forward large‐scale practical applications. Carbon materials can be directly used as anode materials, and they show excellent sodium storage performance. Additionally, designing and constructing carbon hybrid materials is an effective strategy to obtain high‐performance anodes for SIBs. In this review, we summarize recent research progress on carbon and carbon hybrid materials as anodes for SIBs. Nanostructural design to enhance the sodium storage performance of anode materials is discussed, and we offer some insight into the potential directions of and future high‐performance anode materials for SIBs.     

La and Sr Composite Oxides-modified Graphite Felt for Aqueous Organic Redox Flow Batteries

In this study, aqueous organic redox flow batteries(AORFBs) with NaCl as supporting electrolyte were investigated. In AORFBs, the chlorine evolution reaction should be retarded, not the hydrogen evolution reaction. To enhance the catalytic activity of the graphite felt(GF) electrode, the metal oxides were proposed to decorate on the GF surface. Among the loading oxides, significant enhancement of the mass transfer and reaction activity was obtained by the presence of LaSrO_x nanoparticles. X-Ray photoelectron spectroscopy and contact angle measurements revealed that the content of oxygen-containing groups and the hydrophilicity were remarkably increased. After the electrode assembled in the battery, the LaSrO_x/GF electrode presented huge enhancement of the battery performance, obviously increasing in the battery capacity and efficiency. At a current of 50 Am/cm², the energy efficiency(EE) of the battery increased from 54.76% to 61.37% by the LaSrO_x/GF electrode. Furthermore, the cyclability of the system tested that no obviously fading was observed after 100 cycles, signifying the excellent stability of the LaSrO_x/GF electrode.     

Ultrafast Electrochemical Capacitors with Carbon Related Materials as Electrodes for AC Line Filtering

High-frequency responsive electrochemical capacitors (ECs), which can directly convert alternating current (AC) to direct current (DC), are getting more essential for the rapid development of electronic devices. In order to satisfy the requirements of ECs with fast rate capability and appreciable capacitance density, numerous efforts have been made towards the preparation and design of the electrode material, which is a decisive factor in the performance of ECs. Carbon-related electrode materials have been widely shown to significantly increase the performance of ECs because of their light weight, high strength, and high processability. In this concept, the latest advances in the rational design and controllable fabrication of carbon-related electrode materials, including planar 2D materials, random 3D, and vertical carbon materials are summarized. Moreover, the state of the art of carbon-based ECs is discussed from the viewpoint of the structure of the electrode and performance of ECs. Finally, this concept presents integrated perspectives on the further design and preparation of carbon related ECs.     

全钒液流电池磺化石墨烯/Nafion复合膜的研究

本文通过磺化石墨烯对Nafion膜进行改性,研究了磺化石墨烯/Nafion复合膜（GRS-Nafion复合膜）的吸水率、电阻率和钒离子迁移数. 结果表明,经磺化石墨烯改性之后,GRS-Nafion复合膜的面电阻和钒离子渗透率显著降低. 全钒液流电池的测试结果表明,GRS-Nafion复合膜有着更加优异的电化学性能,展示出GRS-Nafion复合膜在液流电池中的应用潜力.     

锂离子电池锡氧化物基负极材料的湿化学合成与电化学性质

采用新兴的湿化学方法合成了锡氧化物基粉末材料。用X-射线衍射、扫描电镜和电化学方法对材料的微观结构、形貌和电化学性能进行了详细的研究。结果表明，经400 ℃热处理4 h的锡氧化物基材料的颗粒大小均匀，平均粒径约为200 nm。这种材料的可逆充电容量超过570 mAh·g^-1，30次循环后平均每次循环的容量衰减只有0.15%。良好的电化学性能表明锡氧化物基材料有望作为新一代锂离子电池的负极材料。     

锂离子电池正硅酸盐正极材料研究进展

正硅酸盐正极材料因其高理论容量、高安全性能、低成本及环境友好等优点,近几年引起研究者的广泛关注.本文综述了国际上正硅酸盐材料最新研究进展.结合本课题组在该领域的研究,着重从此类材料的合成方法、结构研究、电化学性能及反应机理等方面进行阐述.综合分析正硅酸盐材料各种合成方法的优缺点、结构研究存在的争议以及性能和机理研究上的...     

Surfactant-Mediated and Morphology-Controlled Nanostructured LiFePO4/Carbon Composite as a Promising Cathode Material for Li-Ion Batteries

The synthesis of morphology-controlled carbon-coated nanostructured LiFePO₄ (LFP/Carbon) cathode materials by surfactant-assisted hydrothermal method using block copolymers is reported. The resulting nanocrystalline high surface area materials were coated with carbon and designated as LFP/C123 and LFP/C311. All the materials were systematically characterized by various analytical, spectroscopic and imaging techniques. The reverse structure of the surfactant Pluronic® 31R1 (PPO-PEO-PPO) in comparison to Pluronic® P123 (PEO-PPO-PEO) played a vital role in controlling the particle size and morphology which in turn ameliorate the electrochemical performance in terms of reversible specific capacity (163 mAh g⁻¹ and 140 mAh g⁻¹ at 0.1 C for LFP/C311 and LFP/C123, respectively). In addition, LFP/C311 demonstrated excellent electrochemical performance including lower charge transfer resistance (146.3 Ω) and excellent cycling stability (95 % capacity retention at 1 C after 100 cycles) and high rate capability (163.2 mAh g⁻¹ at 0.1 C; 147.1 mAh g⁻¹ at 1 C). The better performance of the former is attributed to LFP nanoparticles (<50 nm) with a specific spindle-shaped morphology. Further, we have also evaluated the electrode performance with the use of both PVDF and CMC binders employed for the electrode fabrication.