Zhao Feipeng, Wang Yeyun, Xu Xiaona, Liu Yiling, Song Rui, Lu Guang, Li Yanguang
Institute of Functional Nano & Soft Materials (FUNSOM) & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou 215123, China.
ACS Appl Mater Interfaces. 2014 Jul 23;6(14):11007-12. doi: 10.1021/am503375h. Epub 2014 Jul 9.
Although great recent efforts have been invested to improve the performance of supercapacitors, these energy storage devices still fall short of meeting our expectations because of their limited working voltage, insufficient cycle life, and high manufacturing cost. Here, we report the facile preparation of cobalt hexacyanoferrate (CoHCFe) nanoparticles, which have an analogous structure to Prussian blue but with many vacant ferricyanide sites. In 0.5 M Na2SO4, CoHCFe exhibits specific capacitance of >250 F/g, excellent rate capability, and ultrahigh cycling stability with capacitance retention of 93.5% after 5000 cycles. Furthermore, CoHCFe was paired up with a carbon black modified graphene (mRGO) negative electrode to form asymmetric supercapacitors. They deliver a wide working voltage of ∼2.4 V in Na2SO4, large energy density and power density. Given its high electrochemical performance, chemical robustness, environmental benignity, ease of preparation and low cost, CoHCFe as well as other Prussian blue analogues clearly deserve more attention for future energy storage applications.
尽管最近人们付出了巨大努力来提高超级电容器的性能，但由于其工作电压有限、循环寿命不足和制造成本高，这些储能设备仍未达到我们的期望。在此，我们报告了六氰合铁酸钴（CoHCFe）纳米颗粒的简便制备方法，其结构与普鲁士蓝类似，但有许多空位的铁氰化物位点。在0.5 M Na2SO4中，CoHCFe表现出>250 F/g的比电容、优异的倍率性能和超高的循环稳定性，在5000次循环后电容保持率为93.5%。此外，CoHCFe与炭黑改性石墨烯（mRGO）负极配对形成不对称超级电容器。它们在Na2SO4中提供约2.4 V的宽工作电压、高能量密度和功率密度。鉴于其高电化学性能、化学稳定性、环境友好性、易于制备和低成本，CoHCFe以及其他普鲁士蓝类似物显然值得在未来储能应用中得到更多关注。
