Miya Lindobuhle A, Kumari Pooja, Saha Chandan, Ghosh Sarit K, Singh Harishchandra, Mallick Kaushik
Department of Chemical Sciences, University of Johannesburg, Auckland Park, P.O. Box: 524, Johannesburg 2006, South Africa.
Nano and Molecular Systems Research Unit, University of Oulu, Oulu FIN-90014, Finland.
ACS Omega. 2025 Aug 12;10(33):37266-37275. doi: 10.1021/acsomega.5c02598. eCollection 2025 Aug 26.
Supercapacitors have received significant interest as advanced energy storage solutions because of their high value of specific capacitance, power density, and extended cycle life. Cobalt-based compounds are naturally abundant and have good electrical conductivity, which makes them ideal for supercapacitor applications. In this work, ultrafine cobalt-(II) ferrocyanide (CFC) particles were produced using a complexation-mediated synthesis route and analyzed through surface, microscopic, and optical characterization techniques. In a three-electrode setup using CFC as the working electrode, the cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) techniques delivered specific capacitance values of 525 F g at 3 mV s and 435 F g at 6 A g, respectively. Additionally, a hybrid supercapacitor device was built with CFC as the cathode and activated carbon serving as the anode electrodes, respectively, demonstrating specific capacitance values of 44 F g at 3 mV s and 51 F g at 0.5 A g. The device preserved 96% of the initial capacitance with a Coulombic efficiency of 98% after 3000 GCD cycles with a maximum energy and power density of 28 W h kg and 2800 W kg, respectively. Furthermore, two CFC-based hybrid devices, each charged at 1 A g, were linked in series to illuminate a red LED for a duration of 90 s.
超级电容器因其高比电容、功率密度和长循环寿命而作为先进的储能解决方案受到了广泛关注。钴基化合物天然丰富且具有良好的导电性，这使其成为超级电容器应用的理想选择。在这项工作中，采用络合介导的合成路线制备了超细钴（II）亚铁氰化物（CFC）颗粒，并通过表面、微观和光学表征技术进行了分析。在以CFC作为工作电极的三电极装置中，循环伏安法（CV）和恒电流充放电（GCD）技术分别在3 mV s时提供了525 F g的比电容值，在6 A g时提供了435 F g的比电容值。此外，构建了一种混合超级电容器装置，分别以CFC作为阴极和活性炭作为阳极电极，在3 mV s时比电容值为44 F g，在0.5 A g时为51 F g。该装置在3000次GCD循环后保留了96%的初始电容，库仑效率为98%，最大能量密度和功率密度分别为28 W h kg和2800 W kg。此外，两个以CFC为基础的混合装置，每个以1 A g充电，串联连接以点亮一个红色发光二极管90秒。
