Ali Gomaa A M, Divyashree A, Supriya S, Chong Kwok Feng, Ethiraj Anita S, Reddy M V, Algarni H, Hegde Gurumurthy
Faculty of Industrial Sciences & Technology, Universiti Malaysia Pahang, Gambang, 26300, Kuantan, Malaysia.
Dalton Trans. 2017 Oct 17;46(40):14034-14044. doi: 10.1039/c7dt02392h.
Carbon nanospheres derived from a natural source using a green approach were reported. Lablab purpureus seeds were pyrolyzed at different temperatures to produce carbon nanospheres for supercapacitor electrode materials. The synthesized carbon nanospheres were analyzed using SEM, TEM, FTIR, TGA, Raman spectroscopy, BET and XRD. They were later fabricated into electrodes for cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy testing. The specific capacitances were found to be 300, 265 and 175 F g in 5 M KOH electrolyte for carbon nanospheres synthesized at 800, 700 and 500 °C, respectively. These are on a par with those of prior electrodes made of biologically derived carbon nanospheres but the cycle lives were remarkably higher than those of any previous efforts. The electrodes showed 94% capacitance retention even after 5200 charge/discharge cycles entailing excellent recycling durability. In addition, the practical symmetrical supercapacitor showed good electrochemical behaviour under a potential window up to 1.7 V. This brings us one step closer to fabricating a commercial green electrode which exhibits high performance for supercapacitors. This is also a waste to wealth approach based carbon material for cost effective supercapacitors with high performance for power storage devices.
报道了采用绿色方法从天然来源制备的碳纳米球。对菜豆种子在不同温度下进行热解，以制备用于超级电容器电极材料的碳纳米球。使用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、傅里叶变换红外光谱（FTIR）、热重分析（TGA）、拉曼光谱、比表面积分析仪（BET）和X射线衍射仪（XRD）对合成的碳纳米球进行了分析。随后将它们制成电极，用于循环伏安法、恒电流充放电和电化学阻抗谱测试。在5M氢氧化钾电解液中，800℃、700℃和500℃合成的碳纳米球的比电容分别为300F/g、265F/g和175F/g。这些与先前由生物衍生碳纳米球制成的电极相当，但循环寿命明显高于以往的任何研究。即使在5200次充放电循环后，电极仍保持94%的电容保持率，具有出色的循环耐久性。此外，实际的对称超级电容器在高达1.7V的电位窗口下表现出良好的电化学性能。这使我们离制造出一种用于超级电容器的高性能商业绿色电极又近了一步。这也是一种变废为宝的方法，基于碳材料制造的超级电容器具有成本效益且性能高，可用于储能设备。
