共查询到17条相似文献,搜索用时 218 毫秒
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钒电池是一种高效储能装置,钒电池电解液直接影响电池性能。本文以V2O3、V2O5和H2SO4为原料,化学合成了用于钒电池的V(Ⅲ)-V(Ⅳ)电解液,研究了无水乙醇与焦磷酸钠作为添加剂对电解液稳定性和电化学活性的影响。实验结果表明,当V2O3/V2O5质量比为7.2∶1时,可以得到V(Ⅲ)/V(Ⅳ)离子浓度比为1.0的电解液;添加剂的加入能提高电解液的稳定性和电化学反应活性。 相似文献
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《化工进展》2017,(1)
以V_2O_5为原料,采用化学还原法制备钒电池电解液。对比草酸、抗坏血酸、酒石酸、柠檬酸、双氧水、甲酸、乙酸制备所得钒电池电解液的转化率、还原率及电化学性能,发现草酸制得的电解液转化率及还原率较高,且其电化学活性明显优于其他还原剂。对草酸制备电解液的反应动力学进行分析,发现该反应为放热反应且在常温下能自发进行。对制备过程中的各项参数进行优化,在n(H_2C_2O_4)∶n(V_2O_5)=1∶1、反应温度90℃、反应时间100min、n(H_2SO_4)∶n(V_2O_5)=5∶1的条件下,电解液的转化率与还原率达到了94.80%和93.55%。草酸和VOSO_4制备的电解液电化学分析结果表明草酸制备的电解液能够抑制析氧副反应的发生,具有较大的扩散系数、交换电流密度、电极反应标准速率常数和较小的极化电阻,对电极反应的传质过程和传荷过程有促进作用,提高了电极反应速率。以草酸为还原剂能够在较低温度下高效地制备具有良好的电化学性能及稳定性的钒电池电解液。 相似文献
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研究了添加剂酒石酸、乙二酸、柠檬酸、葡萄糖对钒电池正极液电化学性能和稳定性的影响,并对其规律和机理进行了探讨。CV研究结果表明:含有多个-OH的有机物葡萄糖能明显提高正极液的阳极峰电流,含有多个-COOH的乙二酸能明显提高正极液的阴极峰电流,而含有多个-OH和多个-COOH的酒石酸对正极液的阴、阳极峰电流均有明显提高。同时,酒石酸(含氧官能团-OH和-COOH)能与5价钒作用,阻碍钒离子聚合,从而提高了5价钒的稳定性。交流阻抗测试表明,正极液中添加酒石酸能大大降低电荷传递电阻和溶液电阻,电解液的性能得到了显著提高。 相似文献
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为了提高钒电池电解液的性能,选取了3种复合添加剂,研究了复合添加剂对钒电池正极电解液稳定性和电化学性能的影响。利用电化学方法制备了2 mol/L的全钒液流电池正极5价钒离子电解液,采用临界胶束浓度法得到复合添加剂的配比为:1% KHSO4+3 mmol/L SDBS(十二烷基苯磺酸钠)、1% KHSO4+2 mmol/L D-山梨醇、1% KHSO4+2 mmol/L CTAB(十六烷基三甲基溴化铵),并考察添加剂加入电解液后的稳定性与电化学性能。通过XRD分析手段,对电解液沉淀物的成分进行了表征。研究表明:添加剂的加入,并不会引起钒离子价态的变化,1% KHSO4+2 mmol/L CTAB加入后,电解液峰电位差减小12 mV,峰电流增加9.8 mA,说明CTAB与KHSO4在合适配比下,能够有效提高正极电解液的稳定性及可逆性,添加剂的引入并未引起电解液沉淀物的物相组成变化,电解液性能显著提高。 相似文献
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Sha Li Kelong Huang Suqin Liu Dong Fang Xiongwei Wu Dan Lu Tao Wu 《Electrochimica acta》2011,(16):5483
Fructose, mannitol, glucose, d-sorbitol are explored as additives in electrolyte for vanadium redox battery (VRB), respectively. The effects of additives on electrolyte are studied by cyclic voltammetry (CV), charge–discharge technique, electrochemical impedance spectroscopy (EIS) and Raman spectroscopy. The results indicate that the vanadium redox cell using the electrolyte with the additive of d-sorbitol exhibits the best electrochemical performance (the energy efficiency 81.8%). The EIS results indicate that the electrochemical activity of the electrolyte is improved by adding d-sorbitol, which can be interpreted as the increase of available (–OH) groups providing active sites for electron transfer. The Raman spectra show that VO2+ ions take part in forming a complex with the d-sorbitol, which not only improve solubility of V(V) electrolyte, but also provide more activity sites for the V(IV)/V(V) redox reaction. 相似文献
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非水系氧化还原液流电池(NARFB)的广泛应用受制于其较低的性能。在电解液中加入一些金属离子添加剂是一种可能的解决方案。实验研究了Sb3+离子对低共熔溶剂(DES)电解液液流电池电化学性能的影响。结果表明,添加Sb3+离子可以强化V(Ⅲ)/V(Ⅱ)氧化还原离子对的电化学反应动力学(最高可达22.6%)过程,钒离子在DES中的扩散系数提高了63.3%,并且电荷转移电阻降低了11.9%。场发射扫描电子显微镜表明,Sb3+离子电沉积在石墨毡的表面,对电化学反应起催化作用,从而改善了电化学性能。考虑增强的动力学和降低的活性比表面积之间的平衡,确定了Sb3+的最佳浓度为15 mmol·L-1。此外,当使用含有Sb3+的负极电解液液流电池时,液流电池的功率密度提高了31.2%,从含原始电解质的3.08 mW·cm-2到含15 mmol·L-1 Sb3+离子的4.04 mW·cm-2。这些结果为改善NARFB的电池性能提供了一个便捷而有前景的方法。 相似文献
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Vanadium redox cell electrolyte optimization studies 总被引:5,自引:0,他引:5
The stability of the positive electrolyte of the vanadium redox cell has been studied at various temperatures and at different solution compositions and solution state-of-charge (SOC). It has been found that at elevated temperatures for extended periods, V(V) can slowly precipitate from solution, the extent and rate of which being dependent on temperature, vanadium and sulphuric acid concentration as well as the SOC of the electrolyte. A H2SO4 concentration of 3–4m has been found to be more suitable than 2m, not only from the point of view of increased stability, but also because of the higher electrolyte conductivity which leads to increased voltage efficiencies during battery cycling. 相似文献
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Kinetics of the Chemical Dissolution of Vanadium Pentoxide in Acidic Bromide Solutions 总被引:2,自引:0,他引:2
A novel vanadium bromide redox flow battery employing a vanadium bromide electrolyte in both half-cells has been proposed.
Preparation of the electrolyte for this redox cell requires the chemical dissolution of vanadium pentoxide powder in the acidic
bromide supporting electrolyte. In this study, the kinetics of the chemical dissolution process were investigated and a second
order surface controlled reaction is reported with rate equation given by: Rate = 5 × 10−4(l mol−1 s−1)[Br−]2 at 25 °C and an activation energy of 37.2 kJ mol−1. 相似文献
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液流电池通常采用对角平推流流场,会形成电解液滞留区,造成电池局部浓差极化大,影响综合性能。鉴于此,提出了一种基于框架设计的流场优化方法,通过设计电极框架,可以得到“蛇形流道”和“平行流道”两类流场。以全钒液流电池为例,通过数学建模,研究了不同流场结构和参数对于多孔电极内电解液流动特性、电化学反应和温度变化特性的影响规律。计算结果与实验结果一致性良好,结果表明:电解液在“平行流场”内的流动均匀性比在“蛇形流场”内好,且不存在滞留区,同时在“平行流场”内浓差极化也较“蛇形流场”低;此外,对于同样的电极面积,在电极内部的“平行流道”越多,电解液的流速分布越均匀,反应特性越好。 相似文献