MWCNT/V_2O_5 Core/Shell Sponge for High Areal Capacity and Power Density Li-Ion Cathodes

摘要

A multlwall carbon nanotube (MWCNI) sponge network, coated by ALD V_2O_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_2O_5 sponge delivers a stable high areal capacity of 816 μAh/ cm~2 for 2 Li/V_2O_5 (voltage range 4.0-2.1 V) at 1C rate (1.1 mA/cm~2), 450 times that of a planar V_2O_5 thin film cathode. At much higher current (50 x), 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.