Electrochemically Driven Transformation of Amorphous Carbons to Crystalline Graphite Nanoflakes: A Facile and Mild Graphitization Method

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• 作者：Dr. Junjun Peng ; Nanqing Chen ; Rui He ; Dr. Zhiyong Wang ; Prof. Sheng Dai and Prof. Xianbo Jin
• 刊名：Angewandte Chemie
• 出版年：2017
• 出版时间：February 6, 2017
• 年：2017
• 卷：129
• 期：7
• 页码：1777-1781
• 全文大小：3554K
• ISSN：1521-3757

文摘

Although, in the carbon family, graphite is the most thermodynamically stable allotrope, conversion of other carbon allotropes, even amorphous carbons, into graphite is extremely hard. We report a simple electrochemical route for the graphitization of amorphous carbons through cathodic polarization in molten CaCl₂ at temperatures of about 1100 K, which generates porous graphite comprising petaloid nanoflakes. This nanostructured graphite allows fast and reversible intercalation/deintercalation of anions, promising a superior cathode material for batteries. In a Pyr₁₄TFSI ionic liquid, it exhibits a specific discharge capacity of 65 and 116 mAh g⁻¹ at a rate of 1800 mA g⁻¹ when charged to 5.0 and 5.25 V vs. Li/Li⁺, respectively. The capacity remains fairly stable during cycling and decreases by only about 8 % when the charge/discharge rate is increased to 10000 mA g⁻¹ during cycling between 2.25 and 5.0 V.