Effects of physical constraints on Li cyclability

Mechanical pressure is shown to have a large effect on lithium plating morphology, lithium cyclability and the propensity to form dendritic shunts. In situ examination of lithium growth during cycling was carried out using a special force-displacement instrumented apparatus. Lithium growth is found to strongly depend on electrode stack pressure. The build up of electrode stack pressure in constant volume cells is examined in terms of cell design, component thickness and component compressibility. Methods of obtaining optimum lithium cyclability in a constant volume cell with respect to electrode stack pressure are discussed and illustrated.