The effect of Co–Co3O4 coating on the electrochemical properties of Si as an anode material for Li ion battery

Autor: Sang-Min Lee, Joon-Sup Kim, Yong-Mook Kang, Goojin Jeong, Min-Seok Sung, Sung-Soo Kim
Rok vydání: 2006
Předmět:
Zdroj: Electrochimica Acta. 52:450-454
ISSN: 0013-4686
DOI: 10.1016/j.electacta.2006.05.026
Popis: In order to improve the electrochemical performance of Si as an anode material for Li ion secondary batteries, a biphasic layer composed of Co and Co 3 O 4 was coated on Si particles by sol–gel method. Compared to Si, Co–Co 3 O 4 coated Si showed the drastic improvement in several electrochemical properties, such as initial coulombic efficiency (55% → 88%), cyclic efficiency and cycle life. The comparison between Co–Co 3 O 4 coated Si and heat-treated Si without the coating let us know that the improvement of electrochemical properties only results from Co–Co 3 O 4 coating layer. Little changed cyclic properties (cyclic efficiency and cycle life) of Co–Co 3 O 4 coated Si even at a higher charge–discharge rate insinuated that Co–Co 3 O 4 coating layer plays a crucial role in maintaining the electronic contacts between particles and conducting parts. When trying to measure a thickness variation of the electrodes each containing Si and Co–Co 3 O 4 coated Si as active materials, it was notified that Co–Co 3 O 4 coating layer can accommodate the volume expansion of Si during Li + insertion, which has its original thickness almost recovered after Li + extraction.
Databáze: OpenAIRE
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