应用于水相有机液流电池的双电子紫精化合物

由3-氯-1,2-丙二醇与4,4'-联吡啶通过简单的一步反应得到具有双电子特性的1,1'-双(2,3-二羟丙基)-(4,4'-联吡啶)二氯化物(DHPV²⁺Cl^2-), 其理论比容量为142.56 mA·h/g. 电化学测试结果表明, 该材料有利于提升电池容量, 且还原电位低至-0.807 V(vs. Ag/AgCl). 以NaCl为支持电解质、 DHPV²⁺Cl^2-为负极活性物质、 氮氧自由基哌啶醇(4-OH-TEMPO)为正极活性物质的全电池电压高达1.562 V, 且可在10~100 mA/cm²的电流密度下稳定运行. 采用25 mA/cm²的电流密度充放电, 活性物质的有效利用率为70.90%. 循环100次后的放电容量保持率为98.09%, 每次循环的容量平均保持率为99.93%, 表现出较好的循环性能.

Two-Electron Storage Viologen for Aqueous Organic Redox Flow Batteries

A two-electron storage, 1,1'-bis(2,3-dihydroxypropyl)-(4,4'-bipyridine)-1,1'-diium chloride(DHPV²⁺Cl^2-), was synthesized by simply one-step reaction of 3-chloro-1,2-propanediol with 4,4'-bipyridine. The theoretical specific capacity of the viologen anolyte is up to 142.56 mA·h/g in NaCl solution(1.5 mol/L) and the reduction potential is as low as -0.807 V(vs. Ag/AgCl). In full battery testing, with the two-electron storage viologen as anolyte, 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl(4-OH-TEMPO) as catholyte in NaCl supporting electrolyte, the full battery voltage is up to 1.562 V. At the same time, the charge and discharge curves exhibit two-electron storage characteristics of DHPV²⁺Cl^2-. Furthermore, the full battery performance showed that the battery could operate stably at the current density from 10 mA/cm² to 100 mA/cm². The effective utilization rate of the active material is 70.90% at the current density of 25 mA/cm². After 100 cycles, the capacity retention rate of the battery and the capacity average retention rate per cycle are 98.09% and 99.93%, respectively. The DHPV²⁺Cl^2-/4-OH-TEMPO AORFB showed attractive cycle performance. These AORFB materials are built from earth-abundant elements and are environmentally friendly, thus representing a promising choice for safe and sustainable energy storage.