Effect of Compressive Stress on Electrochemical Performance of Silicon Anodes

In this study, we report on the effect that an externally applied compressive stress has on the electrochemical performance of Si anodes. Using the compression of an all-solid-state cell as a convenient format for simulating volume confinement, the electrochemical performance of Si anodes as a function of externally applied compressive stress has been systematically investigated. We verify that the extent of Si lithiation is limited by confining the free volume expansion of nano-Si particles. Volume confinement of Si particles is manifested as an overpotential and results in a stable anode for lithium-ion batteries. These results are foundational and lead to the best understanding to date of the complex electrochemomechanics of a Si-based anode. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.064301jes] All rights reserved.