Stress-strain relationships of LixSn alloys for lithium ion batteries

Tin with a theoretical capacity of 993 mAh g(-1) is considered as a promising anode material for lithium ion batteries (LIBs). However, under the intercalated-Li+ state, large volume deformation in tin active materials may result in cracks and flakes that seriously affect the cycle stability of LIBs. In this paper, the indentation load-displacement behaviors of LixSn (0 < x < 4.4) alloys with various charge states are tested to determine their hardness, elastic modulus, yield strength and hardening exponent. In conjunction with finite element modeling and dimensional analysis, the stress-strain relationships of LixSn alloys are obtained by using a power-law hardening model. Furthermore, the evolution of stress-strain relationships is investigated as the change of charge states. (C) 2016 Elsevier B.V. All rights reserved.