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Title: In situ X-ray study of the electrochemical reaction of Li with {eta}{prime}-Cu{sub 6}Sn{sub 5}

Abstract

The electrochemical reaction of lithium with crystalline intermetallic {eta}{prime}-Cu{sub 6}Sn{sub 5} has been studied by means of in situ X-ray diffraction. The reaction of Li with Cu{sub 6}Sn{sub 5} proceeds in two distinct steps. A first discharge plateau at approximately 0.4 V vs. Li is attributed to the coexistence of Cu{sub 6}Sn{sub 5} and a ternary Li{sub 2}-CuSn-type phase. Upon further reaction Li{sub 2}CuSn coexists with a Li-rich tin phase (Li{sub 4.4}Sn) and metallic Cu at a potential below 0.1 V. During the charge, the initial intermetallic is reformed in a multistep reaction. First, some Li can be removed from Li{sub 4.4}Sn making Li{sub 4.4{minus}x}Sn with the same structure. As Li is removed from Li{sub 4.4}{minus}xSn it reacts with the available Cu to make Li{sub 2}CuSn. Then, lithium can be removed from Li{sub 2}CuSn, making vacancies in the structure to form Li{sub 2{minus}x}CuSn. The 0.8 V plateau during the charge of Li/Cu{sub 6}Sn{sub 5} cells is associated with this coexistence of Li{sub 2{minus}x}CuSn and Cu{sub 6}Sn{sub 5}. The in situ experiments show that both the Li{sub 4.4}Sn and the Li{sub 2}CuSn phases can exhibit a range of Li stoichiometries, especially as Li is removed from their structures. When Li/Cu{sub 6}Sn{submore » 5} cells are charged and discharged above the lower plateau, to prevent the continual expulsion and reincorporation of Cu from the cathode grains, better cycling is obtained than when cycling includes the lower plateau where metallic copper is formed.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Dalhousie Univ., Halifax, Nova Scotia (CA)
OSTI Identifier:
20080559
Resource Type:
Journal Article
Journal Name:
Journal of the Electrochemical Society
Additional Journal Information:
Journal Volume: 147; Journal Issue: 5; Other Information: PBD: May 2000; Journal ID: ISSN 0013-4651
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 25 ENERGY STORAGE; LITHIUM; COPPER ALLOYS; TIN ALLOYS; ELECTROCHEMISTRY; PHASE STUDIES; ELECTRICAL PROPERTIES; METAL-NONMETAL BATTERIES; ANODES

Citation Formats

Larcher, D., Beaulieu, L.Y., MacNeil, D.D., and Dahn, J.R. In situ X-ray study of the electrochemical reaction of Li with {eta}{prime}-Cu{sub 6}Sn{sub 5}. United States: N. p., 2000. Web. doi:10.1149/1.1393413.
Larcher, D., Beaulieu, L.Y., MacNeil, D.D., & Dahn, J.R. In situ X-ray study of the electrochemical reaction of Li with {eta}{prime}-Cu{sub 6}Sn{sub 5}. United States. doi:10.1149/1.1393413.
Larcher, D., Beaulieu, L.Y., MacNeil, D.D., and Dahn, J.R. Mon . "In situ X-ray study of the electrochemical reaction of Li with {eta}{prime}-Cu{sub 6}Sn{sub 5}". United States. doi:10.1149/1.1393413.
@article{osti_20080559,
title = {In situ X-ray study of the electrochemical reaction of Li with {eta}{prime}-Cu{sub 6}Sn{sub 5}},
author = {Larcher, D. and Beaulieu, L.Y. and MacNeil, D.D. and Dahn, J.R.},
abstractNote = {The electrochemical reaction of lithium with crystalline intermetallic {eta}{prime}-Cu{sub 6}Sn{sub 5} has been studied by means of in situ X-ray diffraction. The reaction of Li with Cu{sub 6}Sn{sub 5} proceeds in two distinct steps. A first discharge plateau at approximately 0.4 V vs. Li is attributed to the coexistence of Cu{sub 6}Sn{sub 5} and a ternary Li{sub 2}-CuSn-type phase. Upon further reaction Li{sub 2}CuSn coexists with a Li-rich tin phase (Li{sub 4.4}Sn) and metallic Cu at a potential below 0.1 V. During the charge, the initial intermetallic is reformed in a multistep reaction. First, some Li can be removed from Li{sub 4.4}Sn making Li{sub 4.4{minus}x}Sn with the same structure. As Li is removed from Li{sub 4.4}{minus}xSn it reacts with the available Cu to make Li{sub 2}CuSn. Then, lithium can be removed from Li{sub 2}CuSn, making vacancies in the structure to form Li{sub 2{minus}x}CuSn. The 0.8 V plateau during the charge of Li/Cu{sub 6}Sn{sub 5} cells is associated with this coexistence of Li{sub 2{minus}x}CuSn and Cu{sub 6}Sn{sub 5}. The in situ experiments show that both the Li{sub 4.4}Sn and the Li{sub 2}CuSn phases can exhibit a range of Li stoichiometries, especially as Li is removed from their structures. When Li/Cu{sub 6}Sn{sub 5} cells are charged and discharged above the lower plateau, to prevent the continual expulsion and reincorporation of Cu from the cathode grains, better cycling is obtained than when cycling includes the lower plateau where metallic copper is formed.},
doi = {10.1149/1.1393413},
journal = {Journal of the Electrochemical Society},
issn = {0013-4651},
number = 5,
volume = 147,
place = {United States},
year = {2000},
month = {5}
}