Käärik Maike, Arulepp Mati, Perkson Anti, Leis Jaan
Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia.
Skeleton Technologies, Sepise 7, 11415 Tallinn, Estonia.
Molecules. 2023 Oct 20;28(20):7191. doi: 10.3390/molecules28207191.
This study investigates three carbide-derived carbon (CDC) materials (TiC, NbC, and MoC) characterized by uni-, bi-, and tri-modal pore sizes, respectively, for energy storage in both neat and acetonitrile-diluted 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. A distribution of micro- and mesopores was studied through low-temperature N and CO adsorption. To elucidate the relationships between porosity and the electrochemical properties of carbon materials, cyclic voltammetry, galvanostatic cycling, and electrochemical impedance spectroscopy measurements were conducted using three-electrode test cells. The ultramicroporous TiC-derived carbon is characterized by a high packing density of 0.85 g cm, resulting in superior cathodic and anodic capacitances for both neat ionic liquid (IL) and a 1.9 M IL/acetonitrile electrolyte (93.6 and 75.8 F cm, respectively, in the dilute IL). However, the bi-modal pore-sized microporous NbC-derived carbon, with slightly lower cathodic and anodic capacitances (i.e., 85.0 and 73.7 F cm in the dilute IL, respectively), has a lower pore resistance, making it more suitable for real-world applications. A symmetric two-electrode capacitor incorporating microporous CDC-NbC electrodes revealed an acceptable cycle life. After 10,000 cycles, the cell retained approximately 75% of its original capacitance, while the equivalent series resistance (ESR) only increased by 13%.
本研究考察了三种碳化物衍生碳（CDC）材料（TiC、NbC和MoC），其特征分别为具有单峰、双峰和三峰孔径，用于在纯的和乙腈稀释的1-乙基-3-甲基咪唑双（三氟甲基磺酰）亚胺中进行能量存储。通过低温N和CO吸附研究了微孔和介孔的分布。为了阐明孔隙率与碳材料电化学性能之间的关系，使用三电极测试池进行了循环伏安法、恒电流循环和电化学阻抗谱测量。由超微孔TiC衍生的碳的特征在于具有0.85 g/cm的高堆积密度，这使得其在纯离子液体（IL）和1.9 M IL/乙腈电解质中均具有优异的阴极和阳极电容（在稀释的IL中分别为93.6和75.8 F/cm）。然而，具有双峰孔径的微孔NbC衍生的碳，其阴极和阳极电容略低（即在稀释的IL中分别为85.0和73.7 F/cm），具有较低的孔电阻，使其更适合实际应用。包含微孔CDC-NbC电极的对称双电极电容器显示出可接受的循环寿命。在10000次循环后，电池保留了其原始电容的约75%，而等效串联电阻（ESR）仅增加了13%。
