Bello A, Dangbegnon J, Momodu D Y, Ochai-Ejeh F O, Oyedotun K O, Manyala N
Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja Nigeria
Department of Physics, Institute of Applied Materials, SARCHI Chair in Carbon Technology and Materials, University of Pretoria Pretoria 0028 South Africa +27 (0)12 420 2516 +27 (0)12 420 3549.
RSC Adv. 2018 Dec 6;8(71):40950-40961. doi: 10.1039/c8ra08534j. eCollection 2018 Dec 4.
Porous carbon nanostructures have long been studied because of their importance in many natural phenomena and their use in numerous applications. A more recent development is the ability to produce porous carbon materials with tuneable properties for electrochemical applications, which has enabled new research directions towards the production of suitable carbon materials for energy storage applications. Thus, this work explores the activation of carbon from polyaniline (PANI) using a less-corrosive potassium carbonate (KCO) salt, with different mass ratios of PANI and the activating agent (KCO as compared to commonly used KOH). The obtained activated carbon exhibits a specific surface area (SSA) of up to ∼1700 m g for a carbon derived PANI : KCO ratio of 1 : 6. Moreover, the prepared samples were tested as electrode materials for supercapacitors with the results showing excellent electrical double layer capacitor behavior. Charge storage was still excellent for scan rates of up to 2000 mV s, and a capacitance retention of 70% at a very high specific current of 50 A g was observed. Furthermore, the fabricated device can deliver an energy density of 25 W h kg at a specific current of 0.625 A g and a power density of 260 W kg in 1-ethyl-3-methylimidazolium bistrifluorosulfonylimide (EMIM-TFSI) ionic liquid, with excellent rate capability after cycling for 16 000 cycles at 3.0 V with ∼98% efficiency. These results are promising and demonstrate the electrode's potential for energy storage, leading to the conclusion that KCO is a very good alternative to corrosive activation agents such as KOH in order to achieve high electrochemical performance.
多孔碳纳米结构因其在许多自然现象中的重要性以及在众多应用中的用途而长期受到研究。最近的一项进展是能够生产出具有可调节性能的多孔碳材料用于电化学应用，这为生产适用于储能应用的碳材料开辟了新的研究方向。因此，本工作探索了使用腐蚀性较小的碳酸钾（KCO）盐对聚苯胺（PANI）进行碳化，研究了PANI与活化剂（与常用的KOH相比的KCO）的不同质量比。对于PANI:KCO比例为1:6的碳，所获得的活性炭的比表面积（SSA）高达约1700 m²/g。此外，将制备的样品作为超级电容器的电极材料进行测试，结果显示出优异的双电层电容器性能。在高达2000 mV/s的扫描速率下，电荷存储性能仍然优异，并且在50 A/g的非常高的比电流下观察到电容保持率为70%。此外，在1-乙基-3-甲基咪唑鎓双三氟甲磺酰亚胺（EMIM-TFSI）离子液体中，所制造的器件在0.625 A/g的比电流和260 W/kg的功率密度下可提供25 W h/kg的能量密度，在3.0 V下循环16000次后具有优异的倍率性能，效率约为98%。这些结果很有前景，证明了该电极在储能方面的潜力，得出的结论是，为了实现高电化学性能，KCO是KOH等腐蚀性活化剂的一个非常好的替代品。
