A Complexing Agent to Enable a Wide-Temperature Range Bromine-Based Flow Battery for Stationary Energy Storage

Bromine-based flow batteries (Br-FBs) are considered one of the most promising energy storage systems due to their features of high energy density and low cost. However, they generally suffer from uncontrolled diffusion of corrosive bromine particularly at high temperatures. That is because the interaction between polybromide anions and the commonly used complexing agent (N–methyl–N–ethyl–pyrrolidinium bromide [MEP]) decreases with increasing temperatures, which causes serious self-discharge and capacity fade. Herein, a novel bromine complexing agent, 1–ethyl–2–methyl–pyridinium bromide (BCA), is introduced in Br-FBs to solve the above problems. It is proven that BCA can combine with polybromide anions very well even at a high temperature of 60 °C. Moreover, the BCA contributes to decreasing the electrochemical polarization of Br⁻/Br₂ couple, which in turn improves their power density. As a result, a zinc–bromine flow battery with BCA as the complexing agent can achieve a high energy efficiency of 84% at 40 mA cm⁻², even at high temperature of 60 °C and it can stably run for more than 400 cycles without obvious performance decay. This paper provides an effective complexing agent to enable a wide temperature range Br-FB.     

将紫外光谱用于溴指数测定方法的选择

对未知组成的样品进行紫外光谱扫描 ,根据扫描结果以及各种溴指数测定方法的适用范围 ,选择测定未知物溴指数的适宜方法 ,以提高测定准确度。     

Fire performance of wood (Pinus radiata) treated with fire retardants and a wood preservative

In this work, we co‐formulated an oil‐borne copper naphthenate/permethrin wood preservative system with synthetic polymer‐based fire‐retardant additives prior to the impregnation of Pinus radiata sapwood. We evaluated what effect, if any, the preservative had upon the fire performance properties of the fire retardants and whether the fire retardants impacted on the fungicidal and termiticidal efficacy of the preservative. The fire retardants included halogenated and phosphorus‐based systems. A mass loss calorimeter, in conjunction with a thermopile, was used to measure the time to ignition and the peak heat release rate (PHRR) from which the fire performance index (FPI) was determined. The preservative properties were evaluated using termite and soil‐block decay bioassays. In summary, we found that the rate of fire growth was reduced when the fire retardants were used in combination with the wood preservative. We also found that the PHRR was a better determinant of fire performance than the FPI. The performance of the wood preservative was enhanced against fungal decay and termite attack when used in combination with the fire retardants. The fire retardants also demonstrated some wood preservative properties of their own. Copyright © 2008 John Wiley & Sons, Ltd.     

氯化溴合成工艺

本文介绍了氯化溴（BrCl）的应用领域及合成工艺。通过对已有工艺的比较与理论分析，可采用低温液相合成。小试结果表明：在所研究的温度范围内，适宜的合成温度在-15℃～-17℃之间，产品中溴的质量分数为69．29％（理论值为69．27％）；在四氯化碳中，吸光度达到最大值时对应的波长为380nm，与文献值吻合。100t／a中试亦取得了预期的结果。与已有工艺相比：本工艺简化了流程，易于操作和控制。中试的成功为产业化奠定了基础。     

我国阻燃剂行业状况

介绍了我国阻燃剂的生产现状、开发前景及相关法律保障。涉及的阻燃剂有十溴二苯醚、十溴二苯乙烷、溴化环氧树脂、四溴双酚A、六溴环十二烷、硅系阻燃剂、磷系阻燃剂、三嗪系阻燃剂和无机阻燃剂等。     

4-(2-溴乙酰基)甲磺酰苯胺的合成工艺研究

以4-乙酰基甲磺酰苯胺与液溴为原料 ,以二氯乙烷为溶剂通过取代反应制备4-(2-溴 乙酰基)甲磺酰苯胺,探讨了合成反应的工艺条件 ,在最佳工艺条件下 ,产品的收率为 93%。     

溴氧化法合成羟基新戊酸反应条件的研究

以羟基新戊醛为原料,以溴为氧化剂制取羟基新戊酸。研究了反应温度、pH、反应物摩尔比、反应物浓度及反应时间与产率、转化率及选择性的关系,并对产品进行了表征。结果表明,溴氧化法合成羟基新戊酸的最佳工艺条件是溴与羟基新戊醛的浓度相等且大于0 1mol/L,pH=0～2,反应温度50℃,反应时间大约2h;最高色谱产率91 0%,分离后化学收率82 4%,选择性可达95%以上。     

Nickel foam and carbon felt applications for sodium polysulfide/bromine redox flow battery electrodes

The first use of nickel foam (NF) as electrocatalytic negative electrode in a polysulfide/bromine battery (PSB) is described. The performance of a PSB employing NF and polyacrylonitrile (PAN)-based carbon felt (CF) as negative and positive electrode materials, respectively, was evaluated by constant current charge-discharge tests in a single cell. Charge/discharge curves of the cell, positive and negative electrodes show that the rapid fall in cell voltage is due to the drop of positive potential caused by depletion of Br₂ dissolved in the catholyte at the end of discharge. Cell voltage efficiency was limited by the relatively high internal ohmic resistance drop (iR drop). Polarization curves indicated that both NF and CF have excellent catalytic activity for the positive and negative redox reactions of PSB. The average energy efficiency of the single cell designed in this work could be as high as 77.2% at 40 mA cm⁻² during 48 charge-discharge cycles.     

The Bromine Electrode. Part I: Adsorption Phenomena at Polycrystalline Platinum Electrodes

A cyclic voltammetric study of the behaviour of Br^– and Br^– ₃ at Pt electrodes, in the potential range between hydrogen and oxygen evolution, is described. Different experiments were carried out, in the presence of Br^– and Br^– ₃, in which the ratio between the species has been kept constant and equal to 1. The halide concentration was varied between 4 × 10^–6 and 1 × 10^–3 and mol dm^–3, at constant ionic strength, in 1 M HclO₄ as well as in 1 M NaClO₄ adjusted to a pH of 2. Underpotential deposition of Br is observed at potentials as low as –0.125 V vs SCE. The adsorption parameters of Br species were determined from the adsorption/desorption peak pair in the hydrogen adsorption/desorption region, and from the oxide reduction peak data. In the absence of oxygen adsorption, a relatively high coverage of the electrode surface is attained. A Langmuir-type adsorption is observed under the different experimental conditions.     

用氨水作溶剂制取溴化锂的工艺研究

本文介绍了用氨水作溶剂制取溴化锂的实验方法和生产工艺。通过正交实验确定了最佳工艺条件。从所用原料的价格和工艺操作角度来看，本文提出的方法优于其它方法。