Phase field simulation of effect of ceramic composite separator on the growth of lithium dendrites

Abstract

The uncontrollable growth of lithium dendrites has a huge impact on the practical application of lithium metal batteries. The separator is an integral element of the battery and fulfils two functions: firstly, it ensures the normal operation of the battery, and secondly, it is effective in inhibiting the growth of lithium dendrites. The present paper proposes the establishment of a two-dimensional phase field model, with the objective of investigating the effects of the ceramic composite diaphragm phase and the PE separator diaphragm phase on lithium dendrite growth. This investigation is conducted under conditions of stress and temperature fields. It has been shown that the elastic modulus of ceramic particles is greater than that of lithium metal. Therefore, the ceramic separator can effectively prevent the growth of lithium dendrites under stress-coupled conditions. In addition, at higher temperatures, it is beneficial to the transport of lithium ions and increases the deposition of lithium dendrites in the tip and non-tip regions, thereby reducing the length of lithium dendrites at high temperatures. This study reveals the important influence of the ceramic separator on inhibiting the growth of lithium dendrites under the conditions of stress field and temperature field.