单壁碳纳米管提升正极复合材料杯[4]醌/介孔炭CMK-3储锂性能

将杯[4]醌(Calix[4]quinone,C4Q)通过灌注法与有序介孔炭CMK-3制备成纳米复合材料,可抑制其在常规有机电解液中的溶解。为了进一步提升其电化学性能,本文在C4Q/CMK-3复合材料中加入单壁碳纳米管(SWCNTs),减少了CMK-3的用量,并代替导电炭黑Super-P作为导电剂,通过脱泡搅拌法制备了C4Q/CMK-3/SWCNTs复合材料。研究表明,当m(C4Q)∶m(CMK-3)∶m(SWCNTs)为1∶1∶1时,电化学性能最佳,0. 1 C电流密度下循环100圈后,电池的容量保持为238. 7 m A·h/g,当电流密度增大到1 C时,放电容量仍有260 m A·h/g,这是由于SWCNTs在复合材料C4Q/CMK-3中构建了三维导电网络,增强了电极的稳定性,降低了电池内阻,从而提升了电池的循环性能与倍率性能。

Single-Walled Carbon Nanotubes Enhanced Electrochemical Performance of High-Capacity Organic Cathode Composites Calix[4]quinone/Mesporous Carbon CMK-3 for Li-Ion Batteries

The dissolution of calix[4]quinone(C4Q) in electrolytes can be inhibited by the C4Q/CMK-3(mesoporous carbon) nanocomposites prepared through perfusion method, but the electrochemical performance of the nanocomposites needs to be further improved. We prepared a serious of C4Q/CMK-3/SWCNTs(single-walled carbon nanotubes) composites with different ratio by deaerating-stirring method. In these composites, SWCNTs substituted conductive carbon blacks Super-P of the original C4Q/CMK-3 composites, which also reduced the content of CMK-3. SEM and electrochemical tests are conducted to investigate the relation of the morphology and electrochemical performance that cased by SWCNTs. The results show that the optimum mass ratio was m(C4Q)：m(CMK-3)：m(SWCNTs)=(1：1：1), which shows a capacity retention of 55% after 100 cycles at 0.1 C. Even at 1 C, the discharge capacity is still 260 mA·h/g. The significant improvement in the electrochemical performance could be ascribed to the formation of three-dimensional conductive network by SWCNTs.