Effect of lithium bis(trifluoromethanesulfonyl)imide on 3D-printed lithium iron phosphate electrodes

With the rapid advancement of microelectronic devices, 3D printed batteries hold significant potential for development in the battery fields. In this study, the network-structured lithium iron phosphate (LFP) electrodes containing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were prepared by 3D gel printing (3DGP) technology and the effect of different LiTFSI content on 3D-printed LFP electrodes was investigated. With increasing the LiTFSI content from 0 to 10 wt%, the apparent viscosity of the 3D printing slurry showed a gradual increase. The printing slurry of 3 wt% LiTFSI showed an apparent viscosity of 9.43 Pa s at a shear rate of 129 s −1 with the 0.16 mm inner diameter printing needle and 0.60 MPa air pressure, and the 3 wt% LiTFSI electrode printed maintained the intact network structure and the printing lines were uniform. The LFP electrodes with LiTFSI contents of 0 wt%, 3 wt%, 6 wt% and 10 wt% showed respectively specific capacities of 147 mAh g −1 , 142 mAh g −1 , 139 mAh g −1 and 127 mAh g −1 at 0.1C. After 0.5C and 300 charge-discharge cycles, the specific capacities of the electrodes were respectively 108.6 mAh g −1 , 104.7 mAh g −1 , 101.6 mAh g −1 and 99 mAh g −1 , and the capacity retention are respectively 87 %, 85 %, 85 % and 88 %, which indicates that these electrodes are cyclically stable and provide some reference for printing composite electrodes.