使用有机阴极材料的可充电电池有望提供高质量的能量密度,因为这些材料每个分子可以经历多次电子氧化还原反应。尽管使用苯醌(BQ)衍生物作为有机阴极活性材料的电池具有较高的理论容量,但其实际容量和循环保持率仍远远不能令人满意。为克服这些问题,合成了基于2,2'-双-对-苯醌(BBQ)骨架的二聚BQ衍生物,并研究了使用BBQs作为正极活性物质制备的电池的充放电行为。与基于BQ单体的电池相比,基于BBQ的电池表现出出色的性能。例如,烧烤室提供了358 A h kg -1的高初始容量(比使用LiCoO 2作为正极活性材料的现有锂离子电池的两倍多)和在50次循环下的198 A h kg -1的高循环保持率。电化学测量和密度泛函理论(DFT)计算表明,烧烤衍生物中通常会发生三个电子氧化还原反应,尽管(OMe)2 -BBQ似乎经历了四电子氧化还原反应。
Substituent effects in the oxidation of 2-alkyl-1,4-dialkoxybenzenes with ceric ammonium nitrate
作者:Brian E. Love、Alexander L. Simmons
DOI:10.1016/j.tetlet.2016.11.042
日期:2016.12
Increased steric size of alkyl groups and the presence of coordinating atoms on alkoxy groups have both been found to contribute to decreasing yields of diquinones upon reaction of 2-alkyl-1,4-dialkoxybenzenes with CAN. The overall hydrophilicity of the substrates does not appear to be a significant factor in determining the diquinone yield for these reactions.
Preparation of a series of substituted diquinones is reported. In most examples, inverse order of addition (addition of a dimethoxybenzene derivative to a CAN solution) has been found to produce higher yields of diquinones than the traditional protocol in which the oxidant is added to the arene.
Effects of reaction conditions on quinone/diquinone product ratios in the oxidation of 1,4-dimethoxybenzene derivatives with ceric ammonium nitrate
作者:Brian E. Love、Brian C. Duffy、Alexander L. Simmons
DOI:10.1016/j.tetlet.2014.02.017
日期:2014.3
Proper choice of reaction conditions allows formation of either the quinone or corresponding diquinone as the major product upon treatment of 2-alkyl-1,4-dimethoxybenzenes with ceric ammonium nitrate. (c) 2014 Elsevier Ltd. All rights reserved.