Wednesday, September 16, 2015

ALD of Co9S8 and Its Application for Supercapacitors

Vapor-Phase Atomic Layer Deposition of Co9S8 and Its Application for Supercapacitors

Hao Li, Yuanhong Gao, Youdong Shao, Yantao Su, and Xinwei Wang
School of Advanced Materials, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
Nano Lett., Article ASAP
Publication Date (Web): August 27, 2015

Atomic layer deposition (ALD) of cobalt sulfide (Co9S8) is reported. The deposition process uses bis(N,N′-diisopropylacetamidinato)cobalt(II) and H2S as the reactants and is able to produce high-quality Co9S8 films with an ideal layer-by-layer ALD growth behavior. The Co9S8films can also be conformally deposited into deep narrow trenches with aspect ratio of 10:1, which demonstrates the high promise of this ALD process for conformally coating Co9S8 on high-aspect-ratio 3D nanostructures. As Co9S8 is a highly promising electrochemical active material for energy devices, we further explore its electrochemical performance by depositing Co9S8 on porous nickel foams for supercapacitor electrodes. Benefited from the merits of ALD for making high-quality uniform thin films, the ALD-prepared electrodes exhibit remarkable electrochemical performance, with high specific capacitance, great rate performance, and long-term cyclibility, which highlights the broad and promising applications of this ALD process for energy-related electrochemical devices, as well as for fabricating complex 3D nanodevices in general.