Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States.
ACS Nano. 2012 Sep 25;6(9):7948-55. doi: 10.1021/nn302417x. Epub 2012 Aug 15.
A multiwall carbon nanotube (MWCNT) sponge network, coated by ALD V(2)O(5), presents the key characteristics needed to serve as a high-performance cathode in Li-ion batteries, exploiting (1) the highly electron-conductive nature of MWCNT, (2) unprecedented uniformity of ALD thin film coatings, and (3) high surface area and porosity of the MWCNT sponge material for ion transport. The core/shell MWCNT/V(2)O(5) sponge delivers a stable high areal capacity of 816 μAh/cm(2) for 2 Li/V(2)O(5) (voltage range 4.0-2.1 V) at 1C rate (1.1 mA/cm(2)), 450 times that of a planar V(2)O(5) thin film cathode. At much higher current (50×), the areal capacity of 155 μAh/cm(2) provides a high power density of 21.7 mW/cm(2). The compressed sponge nanoarchitecture thus demonstrates exceptional robustness and energy-power characteristics for thin film cathode structures for electrochemical energy storage.
多壁碳纳米管 (MWCNT) 海绵网络经原子层沉积 (ALD) V(2)O(5) 涂层处理后，呈现出作为锂离子电池高性能阴极所需的关键特性，充分利用了 (1) MWCNT 的高导电性、(2) ALD 薄膜涂层前所未有的均匀性，以及 (3) MWCNT 海绵材料的高表面积和孔隙率以利于离子传输。核壳 MWCNT/V(2)O(5) 海绵在 1C 速率（1.1 mA/cm(2)）下，在 4.0-2.1 V 的电压范围内，每 2 Li/V(2)O(5) 可稳定提供 816 μAh/cm(2) 的高面积容量，是平面 V(2)O(5) 薄膜阴极的 450 倍。在更高的电流 (50×) 下，155 μAh/cm(2) 的面积容量提供了 21.7 mW/cm(2) 的高功率密度。压缩海绵纳米结构因此展示了电化学储能用薄膜阴极结构的出色的坚固性和能量-功率特性。
