Enhanced ion transport in PVDF-HFP gel polymer electrolyte containing PDA@BN for lithium ion batteries

Boron nitride nanosheet (BN) modified by polymerized dopamine (PDA@BN) was incorporated into PVDF-HFP gel polymer electrolyte (GPE) by solution casting method. PDA@BN can improve the ionic conductivity (2.26 x 10(-3) S cm(-1) at 30 degrees C), the electrochemical stability of GPE (electrochemical window is 5.0 V) and effectively inhibit the growth of lithium dendrites because of barrier effect of two-dimensional BN. The cell prepared with 3PVDF-HFP/5[EMIM][TFSI]/2LiTFSI+6%PDA@BN (3P5E2L+6%PDA@BN) GPE presents excellent cycle performance. The LiFePO4/3P5E2L + 6%PDA@BN/Li cells exhibited more than 99% columbic efficiency and the initial discharge capacity reached the maximum of 162.9 mAh/g, capacity retention was about 85% after 80 cycles at 0.1C. The excellent performance of this GPE implies that it can be applied to high-safety and long-cycle life lithium metal batteries. (C) 2020 Elsevier B.V. All rights reserved.