Decrepitation Model For Capacity Loss During Cycling of Alloys in Rechargeable Electrochemical Systems

Mechanisms that are involved in the loss of capacity upon the cycling of electrochemical cells are discussed. The inherent instability of the electrochemical interface and the resultant geometrical changes are characteristic of electrodes in which the reactant is a pure element. On the other hand, decrepitation can play an important role in the case of polyphase electrodes in which significant changes in specific volume occur. A simple one-dimensional model is presented that shows the mechanism and the important parameters that are involved in particle fracture. It predicts that decrepitation will lead to a terminal particle size, as is found experimentally.