Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
ACS Nano. 2011 Nov 22;5(11):8552-61. doi: 10.1021/nn2029617. Epub 2011 Oct 20.
Thin film electrodes of polyaniline (PANi) nanofibers and functionalized multiwall carbon nanotubes (MWNTs) are created by layer-by-layer (LbL) assembly for microbatteries or -electrochemical capacitors. Highly stable cationic PANi nanofibers, synthesized from the rapid aqueous phase polymerization of aniline, are assembled with carboxylic acid functionalized MWNT into LbL films. The pH-dependent surface charge of PANi nanofibers and MWNTs allows the system to behave like weak polyelectrolytes with controllable LbL film thickness and morphology by varying the number of bilayers. The LbL-PANi/MWNT films consist of a nanoscale interpenetrating network structure with well developed nanopores that yield excellent electrochemical performance for energy storage applications. These LbL-PANi/MWNT films in lithium cell can store high volumetric capacitance (238 ± 32 F/cm(3)) and high volumetric capacity (210 mAh/cm(3)). In addition, rate-dependent galvanostatic tests show LbL-PANi/MWNT films can deliver both high power and high energy density (~220 Wh/L(electrode) at ~100 kW/L(electrode)) and could be promising positive electrode materials for thin film microbatteries or electrochemical capacitors.
通过层层自组装（LbL）技术制备聚（苯胺）纳米纤维和功能化多壁碳纳米管（MWNTs）的薄膜电极，用于微型电池或电化学电容器。通过苯胺的快速水相聚合合成的高度稳定的阳离子聚（苯胺）纳米纤维与羧酸功能化的 MWNTs 组装成 LbL 薄膜。PANi 纳米纤维和 MWNTs 的表面电荷随 pH 值变化，使得该体系可以像弱聚电解质一样行为，通过改变层的数量来控制 LbL 薄膜的厚度和形态。LbL-PANi/MWNT 薄膜由纳米级互穿网络结构组成，具有发达的纳米孔，为储能应用提供了优异的电化学性能。这些在锂离子电池中的 LbL-PANi/MWNT 薄膜可以储存高体积电容（238 ± 32 F/cm³）和高体积容量（210 mAh/cm³）。此外，电流依赖的恒流测试表明，LbL-PANi/MWNT 薄膜可以提供高功率和高能量密度（220 Wh/L（电极）在100 kW/L（电极）），并且可能是用于薄膜微型电池或电化学电容器的有前途的正极材料。
