From dead leaves to high energy density supercapacitors
From dead leaves to high energy density supercapacitors
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DOI：
10.1039/c3ee22325f
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发表时间：
2013-04-01
影响因子：
32.5
通讯作者：
Ogale, Satishchandra
中科院分区：
文献类型：
--
作者：
Biswal, Mandakini;Banerjee, Abhik;Ogale, Satishchandra
以植物枯叶(干垃圾、粉末状)为原料，采用一步热解法制备了比表面积约为1230m(2)g(-1)的功能微孔导电碳，并对其在超级电容器中的应用进行了研究。我们认为，这种激活是由叶中由软有机物和金属组成的自然成分提供的。虽然在此进行和报告的详细研究是针对印属植物枯叶进行的，但这一过程显然是通用的，适用于大多数形式的枯叶。事实上，我们还审查了阿育王树叶枯死的情况。通过印尼叶和阿育卡叶的比较，揭示了生物源的组成和组成在碳形成的性质和性质中的重要性。我们还对绿叶和未磨死叶的热解情况与磨碎死叶粉的热解情况进行了详细的讨论和比较。我们在碳质材料中实现的同时具有高电导率和微孔率是高能超级电容器应用的关键。事实上，我们合成的功能碳在1M H_2SO_4溶液中表现出很高的比电容400Fg(-1)和55W h kg(-1)的能量密度，电流密度为0.5Ag(-1)。死植物叶碳(CDDPL)的面积电容值也很高(32muF cm(-2))。在有机电解液中，当电流密度为2Ag(-1)时，材料的比电容为88Fg(-1)。
Functional microporous conducting carbon with a high surface area of about 1230m(2) g(-1) is synthesized by single-step pyrolysis of dead plant leaves (dry waste, ground powder) without any activation and studied for supercapacitor application. We suggest that the activation is provided by the natural constituents in the leaves composed of soft organics and metals. Although the detailed study performed and reported here is on dead Neem leaves (Azadirachta indica), the process is clearly generic and applicable to most forms of dead leaves. Indeed we have examined the case of dead Ashoka leaves as well. The comparison between the Neem and Ashoka leaves brings out the importance of the constitution and composition of the bio-source in the nature of carbon formed and its properties. We also discuss and compare the cases of pyrolysis of green leaves as well as un-ground dead leaves with that of ground dead leaf powder studied in full detail. The concurrent high conductivity and microporosity realized in our carbonaceous materials are key to the high energy supercapacitor application. Indeed, our synthesized functional carbon exhibits a very high specific capacitance of 400 F g(-1) and an energy density of 55 W h kg(-1) at a current density of 0.5 A g(-1) in aqueous 1 M H2SO4. The areal capacitance value of the carbon derived from dead (Neem) plant leaves (CDDPL) is also significantly high (32 mu F cm(-2)). In an organic electrolyte the material shows a specific capacitance of 88 F g(-1) at a current density of 2 A g(-1).