温度对全钒液流电池性能的影响

全钒电池的传热参数优化和电堆温度分布的研究,对提高全钒电池的性能和可靠性起着重要的推进作用。基于对流传热的原理,提出了一个关于全钒液流电池系统的热模型,通过对不同流量和传热系数下全钒液流电池温度分布的研究,得到全钒电池电解液罐温度和电堆温度之间的关系。利用Fluent模拟仿真不同流量下电堆中电解液的温度分布。仿真结果表明,系统的对流换热参数和电解液流量是影响温度分布的重要因素,在该电池配置下电解液流量为90 cm3·s–1时,电堆的温度分布均匀,此时的电池性能较好。     

全钒液流电池发展现状

全钒液流电池是一种新型的高效化学储能电池,在太阳能和风能发电储能系统及其他储能系统和供电领域具有良好的应用前景。简要介绍了全钒液流电池的工作原理和特点,并对钒电池的组成、分类和关键材料进行了简明叙述,分析了国内外钒电池的发展过程和研究现状。     

液流电池可将不稳定输入变为可靠输出

全钒氧化还原液流电池（Vanadium Redox Battery，VRB）通过不同价态的钒离子相互转化实现电能的储存与释放，从原理上避免了正负半电池间不同种类活性物质相互渗透产成的交叉污染，可以满足对持续、稳定、可控的电力能源需求。     

锌空气电池性能影响因素分析

文章根据锌空气电池的工作原理,应用电池电压与电流密度之间的半经验公式,结合电极的反应机理,建立了相应的数学模型,并计算了一定参数条件下的电池性能。计算分析表明,在大电流密度下,扩散层厚度和孔隙率对电池性能的影响最为显著,扩散层厚度增加会降低电池的性能,孔隙率增大,有利于气体的扩散;在较小电流密度下温度升高可以提高电池性能;增加环境的总压力,提高氧气的摩尔分数,增大氧气的分压力,也可以提高电池性能。     

环境温度对VRLA电池性能的影响

主要讨论了环境温度对VRLA（Valve-Regulated Lead Acid）电池容量和寿命的影响。环境温度对电池的容量和寿命都有较大的影响，环境温度高，对电池的容量影响不大，但对电池的寿命影响较大；环境温度低，对电池的容量影响较大，但对电池的寿命影响不大。因此，电池的使用环境温度必须控制在一个合适的范围之内。     

基于主成分分析的液流电池状态估计策略研究

为克服放电后期电压拐点对锌溴液流电池（ZBFB）荷电状态（SOC）辨识精度的影响,研究基于主成分分析（PCA）的锌溴液流电池荷电状态估计方法。以提高锌溴液流电池SOC参数辨识精度为目标,特别是解决锌溴液流电池在放电后期特有的电压拐点非线性特性,在兼顾实际算力限制与运行速率要求的条件下,对锌溴液流电池SOC参数辨识算法进行分析。研究结果表明,所提方法兼顾空间维度特征提取以及系统降维建模,可有效改善电压拐点处的电池SOC的辨识精度,为锌溴液流电池的长时储能应用提供理论与算法分析基础。     

真空退火对氧化钒薄膜的相成分和电学性能的影响

利用真空退火工艺处理p-Si(100)衬底上磁控溅射制备的氧化钒多晶薄膜.利用X射线衍射(XRD)分析、原子力显微镜(AFM)以及四探针测试方法,研究了退火时间对薄膜的相成分和电学性能的影响,并观察分析了氧化钒薄膜的表面形貌.研究结果表明,随着退火时间的变化,薄膜的相成分不断发生变化,钒氧比例不断升高,可以得到多种氧化钒的相.适当的真空退火处理可以改善薄膜的表面质量,并且能有效地降低氧化钒薄膜的室温电阻率达两个数量级.     

CNT/α-MnO_2复合正极对锂空气电池性能的影响研究

作为锂空气电池的关键组成部分之一,正极材料性质对锂空气电池的性能起到重要影响。以CNT为碳载体,以α-MnO_2为催化剂,制备CNT/α-MnO_2复合电极作为电池正极。通过恒流定容充放电测试、深度充放电测试、循环伏安测试、电化学阻抗谱测试和扫描电镜测试,研究CNT/α-MnO_2复合正极材料对锂空气电池性能的影响,并获得最优电极材料配比。研究表明:制备的CNT/α-MnO_2复合电极表现出高循环稳定性和高催化活性,显著提升了锂空气电池的性能;当正极材料中CNT与α-MnO_2的质量比为3∶6时,装备CNT/α-MnO_2复合正极的锂空气电池表现出最佳性能,其循环次数高达170次。     

1MeV电子辐照对硅常规电池性能的影响

本文研究p~+/n硅常规电池受1MeV电子辐照前、后性能参数的变化.实验数据与计算结果均表明,随着电子辐照强度的增加,电池的内部参数S_p/D_n逐渐增大,L_n和L_p逐渐变小,尤其是基区中L_p快速下降,这是导致电池性能衰退的主要原因.     

Revealing the Origin of Highly Efficient Polysulfide Anchoring and Transformation on Anion-Substituted Vanadium Nitride Host

Metal nitrides and quasi-metallic compounds have been extensively employed as sulfur hosts for confining polysulfide shuttling and improving the electronic conductivity. Their electronic structures and surface chemical bonds significantly determine the adsorption and catalytic abilities for polysulfide. However, the surface compositions of the reported metal nitrides and their sulfur anchoring mechanisms are still controversial. Herein, the authors demonstrate the anion-substituted mechanism from vanadium oxide, oxynitride to nitride during ammonia-annealing process and systematically unravel the long-range disorder rock-salt structure of vanadium oxynitride with abundant vanadium (V) and nitrogen (N) vacancies by synchrotron X-ray absorption spectra, atomic pair distribution function, and density functional theory calculation. The defect-rich vanadium oxynitride that is previously considered as vanadium nitride possesses the enhanced electron delocalization of V, N, and oxygen (O) atoms. It strengthens the polar Li N/O and V S bonds, especially near V vacancy, resulting in a strong polar adsorption for polysulfide. Meanwhile, the vanadium oxynitride effectively catalyzes the breaking and conversion of polysulfide, improving the reduction kinetics during discharge process. The bifunctional effects render the excellent cycling and rate performances. This work deeply understands the sulfur redox mechanisms on vanadium oxynitride and nitride and promotes the developments of the quasi-metallic compounds/sulfur cathodes in Lithium-sulfur battery.     

Achieving Synergetic Anion-Cation Redox Chemistry in Freestanding Amorphous Vanadium Oxysulfide Cathodes toward Ultrafast and Stable Aqueous Zinc-Ion Batteries

Flexible aqueous zinc-ion batteries (AZIBs) with high safety and low cost hold great promise for potential applications in wearable electronics, but the strong electrostatic interaction between Zn²⁺ and crystalline structures, and the traditional cathodes with single cationic redox center remain stumbling blocks to developing high-performance AZIBs. Herein, freestanding amorphous vanadium oxysulfide (AVSO) cathodes with abundant defects and auxiliary anionic redox centers are developed via in situ anodic oxidation strategy. The well-designed amorphous AVSO cathodes demonstrate numerous Zn²⁺ isotropic pathways and rapid reaction kinetics, performing a high reversible capacity of 538.7 mAhg^-1 and high-rate capability (237.8 mAhg^-1@40Ag^-1). Experimental results and theoretical simulations reveal that vanadium cations serve as the main redox centers while sulfur anions in AVSO cathode as the supporting redox centers to compensate local electron-transfer ability of active sites. Significantly, the amorphous structure with sulfur chemistry can tolerate volumetric change upon Zn²⁺/H⁺ insertion and weaken electrostatic interaction between Zn²⁺ and host materials. Consequently, the AVSO composites display alleviated structural degradation and exceptional long-term cyclability (89.8% retention after 20 000 cycles at 40 Ag^-1). This work can be generally extended to various freestanding amorphous cathode materials of multiple redox reactions, inspiring development of designing ultrafast and long-life wearable AZIBs.     

Metal and Metal Oxide Electrocatalysts for Redox Flow Batteries

Redox flow batteries (RFBs) are one of the promising technologies for large‐scale energy storage applications. For practical implementation of RFBs, it is of great interest to improve their efficiency and reduce their cost. One of the key components of RFBs that can greatly influence the efficiency and final cost is the electrode. The chemical and structural nature of electrodes can modify the kinetics of redox reactions and the accessibility of the electroactive species to available active sites. The ideal electrocatalyst for RFBs must have good activity for the desirable redox reaction, provide a high surface area, and exhibit sufficient conductivity and durability over repeated use. One strategy is to coat the electrode with metal and metal oxide electrocatalysts. Metal electrocatalysts have the advantage of high conductivity, while metal oxide catalysts are usually less expensive and so more economically attractive. In order to gain a better understanding of the performance of the electrocatalysts in RFBs, a comprehensive review of the progress in the development of metal and metal oxide electrocatalysts for RFBs is provided and a critical comparison of the latest developments is presented. Finally, practical recommendations for advancement of electrocatalysts and effective transfer of knowledge in this field are provided.     

Five-Membered Ring Nitroxide Radical: A New Class of High-Potential,Stable Catholytes for Neutral Aqueous Organic Redox Flow Batteries

The utilization of redox-active and stable cyclic nitroxide radicals (CNRs) holds a great promise in neutral aqueous organic redox flow batteries (AORFBs) for large-scale energy storage. Herein, a new class of CNRs with five-membered ring pyrrolidine and pyrroline motifs for AORFBs is reported. By rational molecular engineering of introducing CC double bond into the pyrrolidine-based molecule, 3-carbamoyl-2,2,5,5-tetramethylpyrroline-1-oxyl (CPL) with a high redox potential of 0.76 V (vs Ag/AgCl) is demonstrated, which is 160 mV higher than the common 2,2,6,6-tetramethylpiperidine 1-oxyl derivatives with a six-membered ring as the core structure. Density functional theory calculations reveal that the much enhanced redox potential for CPL is largely contributed by lowered standard free energy in reduction reaction and charge population sum of N O radical head. When paired with the BTMAP-viologen anolyte, the CPL-based AORFB delivers constant capacity retention of up to 99.96%/cycle over 500 cycles.     

Integrated Saltwater Desalination and Energy Storage through a pH Neutral Aqueous Organic Redox Flow Battery

Here, a pH neutral aqueous organic redox flow battery (AORFB) consisting of three electrolytes channels (i.e., an anolyte channel, a catholyte channel, and a central salt water channel) to achieve integrated energy storage and desalination is reported. Employing a low cost, chemically stable methyl viologen (MV) anolyte, and sodium ferrocyanide catholyte, this desalination AORFB is capable of desalinating simulated seawater (0.56 m NaCl) down to 0.023 m salt concentration at an energy cost of 2.4 W h L^?1 of fresh water—competitive with current reverse osmosis technologies. Simultaneously, the cell delivers stored energy at 79.7% efficiency with a cell voltage of 0.85 V. Furthermore, the cell is also capable of higher current operation up to 15 mA cm^?2, providing 4.55 mL of fresh water per hour. Combining energy storage and water desalination into such a bifunctional device offers the opportunity to address two growing global issues from one hardware installation.     

钒电池系统用控制管理系统关键技术研究

目前,新能源应用比较广泛的就是太阳能和风能,而钒液流储能电池是其中非常重要的组成部分,属于一种蓄电储能装置,而在钒电池系统中,控制管理系统技术占据非常重大的意义,直接关系到整个系统的运行状态。基于这一情况,本文就针对钒电池系统用控制管理系统的关键技术开展研究,为我国的现代化建设提供一定的帮助,也为实现可持续发展奠定坚实的基础。     

Elucidating the Iron-Based Ionic Liquid [C4py][FeCl4]: Structural Insights and Potential for Nonaqueous Redox Flow Batteries

In this study, a low-melting organic-inorganic crystalline ionic liquid compound, N-butyl pyridinium tetrachlorido ferrate (III) is described. The material can easily be synthesized using a one-pot approach in an ionic liquid medium. Single-crystal X-ray diffraction confirms that the basic inorganic block is [FeCl₄]⁻, which is counterbalanced by an N-butyl pyridinium cation. The compound exhibits a melting point of 37.6 °C by differential scanning calorimetry, which is among the lowest values for a pyridinium-based metal-containing ionic liquid. The material shows promising electrochemical behavior at room temperature in both aqueous and nonaqueous solvents, and at elevated temperatures in its pure liquid state. Given its appreciable solubility in both water and acetonitrile, the compound can act as a redox-active species in a supporting electrolyte for redox flow battery applications. These classes of low-melting ionic solids with long-range order and interesting electrochemical applications are potential candidates for a range of green energy storage and harvesting systems.     

Simultaneous Cationic and Anionic Redox Reactions Mechanism Enabling High‐Rate Long‐Life Aqueous Zinc‐Ion Battery

Rechargeable aqueous zinc‐ion batteries hold great promise for potential applications in large‐scale energy storage, but the reversible insertion of bivalent Zn²⁺ and fast reaction kinetics remain elusive goals. Hence, a highly reversible Zn/VN_x O_y battery is developed, which combines the insertion/extraction reaction and pseudo‐capacitance‐liked surface redox reaction mechanism. The energy storage is induced by a simultaneous reversible cationic (V³⁺ ? V²⁺) and anionic (N^3? ? N^2?) redox reaction, which are mainly responsible for the high reversibility and no structural degradation of VN_xO_y. As expected, a superior rate capability of 200 mA h g^?1 at 30 A g^?1 and high cycling stability up to 2000 cycles are achieved. This finding opens new opportunities for the design of high‐performance cathodes with fast Zn²⁺ reaction kinetics for advanced aqueous zinc‐ion batteries.     

Boosting Kinetics of Ce3+/Ce4+ Redox Reaction by Constructing TiC/TiO2 Heterojunction for Cerium-Based Flow Batteries

Cerium, a unique rare earth element, possesses a relatively high abundance, low cost, and high redox voltage, making it an attractive candidate for redox flow batteries. However, the sluggish kinetics and corrosion nature of the Ce³⁺/Ce⁴⁺ electrolyte result in overpotential and degradation of carbon felt (CF) electrodes, which hinders the development of cerium-based flow batteries. Therefore, it is essential to develop an electrode with high catalytic activity and corrosion resistance to the Ce³⁺/Ce⁴⁺ electrolyte. Herein, a TiC/TiO₂ coated carbon felt (TiC/TiO₂-CF) electrode is proposed. Remarkably, the TiC/TiO₂ coating effectively minimizes the exposure of the CF to the highly corrosive cerium electrolyte, consequently enhancing the electrode's corrosion resistance. Additionally, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy characterizations reveal the formation of a heterojunction between TiC and TiO₂, which significantly enhances the redox reaction kinetics of the Ce³⁺/Ce⁴⁺ redox couple. Eventually, the practical application of TiC/TiO₂-CF catalytic electrode in a Ce–Fe flow battery is demonstrated. This study sheds light on the synthesis conditions of the TiC/TiO₂-CF electrode, elucidates its heterojunction structure, and presents a novel Ce–Fe flow battery system.