Preparation of self-standing lithium iron phosphate electrodes by 3D printing method
摘要
The self-standing electrodes attract widespread attention because of the rapid development of flexible micro energy storage devices in recent years. In this study, the self-standing lithium iron phosphate electrodes containing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) are prepared by 3D printing. The effects of different LiTFSI contents on electrode are investigated, and the electrochemical performance of the self-standing electrodes is analyzed and discussed. The results show that as the printing needle diameter is 0.16 ± 0.02 mm and an air pressure is 0.65 MPa, the printing slurry of self-standing electrodes exhibits an apparent viscosity of 4.77 Pa s at shear rate of 198.1 s−1, which is suitable for 3D gel printing. Electrochemical tests show that the self-standing electrodes maintain a stable voltage plateau and rate capability during charge–discharge processes after undergoing 500 cycles for 90° bending. After 300 charge–discharge cycles at 0.5C, the specific capacities of the self-standing electrode and the electrode after bending are 102 mAh g−1 and 99 mAh g−1, with capacity retentions of 90.9% and 91.6%, respectively. The prepared self-standing electrodes exhibit high electrochemical stability cycling performance, which provides a reference for 3D printing of self-standing electrodes.