Fabrication and Characterization of 3D-Printed Highly-Porous 3D LiFePO4 Electrodes by Low Temperature Direct Writing Process

Abstract

LiFePO4 (LFP) is a promising cathode material for lithium-ion batteries. In this study, low temperature direct writing (LTDW)-based 3D printing was used to fabricate three-dimensional (3D) LFP electrodes for the first time. LFP inks were deposited into a low temperature chamber and solidified to maintain the shape and mechanical integrity of the printed features. The printed LFP electrodes were then freeze-dried to remove the solvents so that highly-porous architectures in the electrodes were obtained. LFP inks capable of freezing at low temperature was developed by adding 1,4 dioxane as a freezing agent. The rheological behavior of the prepared LFP inks was measured and appropriate compositions and ratios were selected. A LTDW machine was developed to print the electrodes. The printing parameters were optimized and the printing accuracy was characterized. Results showed that LTDW can effectively maintain the shape and mechanical integrity during the printing process. The microstructure, pore size and distribution of the printed LFP electrodes was characterized. In comparison with conventional room temperature direct ink writing process, improved pore volume and porosity can be obtained using the LTDW process. The electrochemical performance of LTDW-fabricated LFP electrodes and conventional roller-coated electrodes were conducted and compared. Results showed that the porous structure that existed in the printed electrodes can greatly improve the rate performance of LFP electrodes.

Low-Temperature Deposition Manufacturing: A Versatile Material Extrusion-Based 3D Printing Technology for Fabricating Hierarchically Porous Materials

“…Therefore, we speculate that LTDM can be used to fabricate thick electrodes with effective 3D carbon conductive network and porous network to achieve efficient ion and electron transport simultaneously. Liu [63]. Pore size and distribution measured by mercury porosimetry indicated that hierarchically porous structures were obtained with the porosity of over 60%.…”

“…Origin and principle of low-temperature deposition manufacturing. (a) Temperature-composition phase diagram for TIPS, (b) conventional material extrusion-based 3D printing process, (c) principle of LTDM process, (d) schematic of LTDM machine, and (e) LTDM machine[63].…”

Additive Manufacturing of Batteries

“…Li 4 Ti 5 O 12 and LiFePO 4 are the most commonly used anode and cathode materials in 3D‐printed batteries, exhibiting a minimal volumetric expansion, high rate capability, high stability, and security. In recent years, an increasing number of studies on the 3D printing of LTO/LFP‐based electrodes have been reported . The first 3D‐interdigitated microbattery architectures (3D‐IMA) with LTO/LFP materials were developed by the Lewis Group .…”

Direct Ink Writing Technology (3D Printing) of Graphene-Based Ceramic Nanocomposites: A Review

“…Thanks to the flexibility and simplicity of DIW, other scientists have been able to implement this technology for the fabrication of parts with periodic structures [26,161], for electrodes for lithium-ion (Li-ion) batteries [162,163] and, in recent years, the manufacture of bioceramic implants [19,164,165]. The last is the prominent application thanks to/as a result of the porosities that appear in the part after sintering.…”