Hydrophilic Organic Redox-Active Polymer Nanoparticles for Higher Energy Density Flow Batteries

Hydrophilic redox-active polymer nanoparticles with different redox potentials and radii were synthesized via the dispersion polymerization to yield their stable dispersion in aqueous electrolyte media as promising catholytes and anolytes in redox flow batteries. Despite the small physical diffusion coefficient (10(-9) cm(2)/s) of the nanosized particles, the sufficiently large coefficient for charge transfer within the polymer particle dispersion (10(-7) cm(2)/s) was observed as a result of the fast electron propagation throughout the polymer particles. Redox flow cells were fabricated using TEMPO-, viologen-, or diazaanthraquinone-substituted polymer nanoparticles as active materials. The reversible charge/discharge over 50 cycles was achieved even at a high concentration of the redox units (1.5 M), which exceeded the limitation of the solubility of the corresponding dissolved species.

通过分散聚合合成了具有不同氧化还原电位和半径的亲水性氧化还原活性聚合物纳米粒子，使其在水性电解质介质中稳定分散，作为氧化还原液流电池中有前景的正极电解液和负极电解液。尽管纳米粒子的物理扩散系数较小（10⁻⁹ cm²/s），但由于电子在聚合物粒子内快速传播，观察到聚合物粒子分散体中电荷转移系数足够大（10⁻⁷ cm²/s）。使用含有TEMPO（2,2,6,6 - 四甲基哌啶 - 1 - 氧基自由基）、紫精或二氮杂蒽醌取代的聚合物纳米粒子作为活性材料制备了氧化还原液流电池。即使在氧化还原单元浓度较高（1.5 M）的情况下，也实现了50次以上的可逆充放电，这超出了相应溶解物质溶解度的限制。