High-capacity disordered carbons derived from peanut shells as lithium-intercalating anode materials
High-capacity disordered carbons derived from peanut shells as lithium-intercalating anode materials
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DOI：
10.1016/s0379-6779(03)00082-1
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发表时间：
2003-08-08
期刊：
影响因子：
4.4
通讯作者：
Kumar, TP
中科院分区：
文献类型：
--
作者：
Fey, GTK;Lee, DC;Kumar, TP
我们首次报道了热解碳质材料的初始锂吸收容量，远远超过了金属锂的理论值。以花生壳为原料，在氩气保护下进行热解，合成了含碳材料。优化了热解条件，以获得具有良好电化学性能的材料。花生壳经过两步碳化，发生在300至600摄氏度之间。这些贝壳还被一种专有的致孔剂处理，目的是改变热解产物的孔结构和表面积。未经处理和致孔剂处理的贝壳都产生了结晶度较差的碳，尽管后者的表面积和孔径分别比前者增加了66倍和2倍。这两种碳都具有非平行单层碳的优势，这取决于它们的R因子的值。充放电研究表明，尽管未经处理的壳层中碳的容量随H/C比的不同而不同，但通常可以合理地将高初始容量(在某些情况下高达4765mAh/g)与无组织单层碳的额外表面积和造孔器产生的纳米孔洞相关联。人们还认为，额外的容量可能来自于锂与表面基团的相互作用，以及碳表面的锂电镀和随后的钝化。(C)2003 Elsevier Science B.V.保留所有权利。
We report for the first time initial lithium intake capacities for pyrolytic carbonaceous materials far exceeding even the theoretical value for metallic lithium. The carbonaceous materials were synthesized by pyrolysis of peanut shells under argon. Thermal conditions for the pyrolysis were optimized in order to obtain materials with desirable electrochemical properties. Peanut shells carbonized in a two-step process that occurred between 300 and 600 degreesC. The shells were also treated with a proprietary porogenic agent with the goal of altering the pore structure and surface area of the pyrolysis products. Both the untreated and the porogen-treated shells yielded carbons with poor crystallinity, although the surface area and the pore diameter of the latter registered a 66-fold and two-fold increase, respectively, over the former. Both the carbons had a predominance of non-parallel single sheets of carbons, as determined by the values of their R factors. Charge-discharge studies showed that although the capacities registered with carbons from the untreated shells varied with the H/C ratio, it was generally reasonable to relate the high initial capacities (in some cases as much as 4765 mAh/g) to the extra surface area of unorganized single layers of carbon and nanoscopic cavities generated by the pore-former. It is also believed that the 'extra' capacity may stem from lithium interaction with surface groups and from lithium plating on the carbon surface and subsequent passivation. (C) 2003 Elsevier Science B.V. All rights reserved.