摘要
The instability of the lithium and electrolyte interface as well as the lithium dendrite growth could be the major issues for the practical application of lithium metal batteries. This work provides an effective solution to the issues with employing a crosslinked polyimide for preparation of thermally-stable separators. The effect of porous morphology of the separators from various porous membrane-formation methods on their electrochemical properties and the corresponding cell performance has been examined and discussed. The separator made with the non-solvent-induced phase separation (NIPS) has an asymmetric structure possessing a macro-void matrix and a relatively dense layer containing nanoscale pores. This top layer plays as a barrier to prevent the lithium dendrite growth and penetration into the separator. The nanoscale pores in the top layer allows ion migration to ensure the high ionic conductivities. The cells employing the prepared separators are capable of operating at high C rate (10C) and show high stability in cycle tests. A straightforward approach for thermally-stable separators with self-protective layers and inhibition of lithium dendrite growth has been demonstrated.