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Indexed by:期刊论文

Date of Publication:2014-04-15

Journal:CHEMELECTROCHEM

Included Journals:SCIE、EI、Scopus

Volume:1

Issue:4

Page Number:733-740

ISSN No.:2196-0216

Key Words:carbon; copper sulfide; lithium-ion batteries; mesoporous materials; reaction mechanisms

Abstract:An effective strategy is explored for the in situ generation of a Cu2S/tubular mesoporous carbon composite by exploiting the charge-discharge processes of a S/C composite on a copper-foil current collector. By studying the reaction mechanism, we discover that the dissolved polysulfide ions (from the reaction of pristine sulfur) and inserted Li+ are firmly anchored by the copper ions released from the copper foil, which forms insoluble CuxS intermediates in the mesopore channels of the carbon matrix. Moreover, the new electrochemically active CuxS intermediates are gradually converted to the final product, Cu2S, during subsequent cycles. The as-prepared Cu2S nanoparticles are highly dispersed throughout the tubular mesoporous carbon, and the Cu2S/C composite exhibits a high reversible capacity of 270 mAhg(-1) at 0.2 C over 300 cycles, with the negligible capacity loss, when used as a cathode material for a lithium-ion battery. Furthermore, the composite shows an outstanding rate capability with a reversible capacity of 225 mAhg(-1) under a high rate of 10 C. This work provides a convenient platform for the controlled synthesis of metal sulfides for lithium-storage applications.