Preparation and properties of highly loaded SnO2-based porous electrodes by DLP 3D printing

Abstract

In this study, highly loaded tin oxide-based (SnO2-based) porous electrodes were prepared by digital light processing (DLP) 3D printing technology. Firstly, the SnO2 light-cured slurry was prepared. The curing process and heat treatment process were analyzed and optimized. Then the best process parameters were obtained. Antimony oxide (Sb2O3) was selected as the conductive agent to improve the electrical conductivity of the SnO2-based electrode. Through the characterization of resistivity, SEM and XRD, the optimum doping amount of conductive agent Sb2O3 was determined to be 6 wt. %. Three kinds of porous electrodes with different shapes were prepared by DLP 3D printing, and the printing accuracy and mechanical properties were characterized. The results showed that the forming dimension error was about 1.7 % in the X and Y direction, 2.3 % in the Z direction. And the average compressive strength was 18.1 MPa, which effectively ensured the shape integrity and mechanical stability of the printed parts. Then the electrochemical properties of DLP 3D printed SnO2-based electrode and conventional coated electrode were tested and compared. The results showed that the 3D printed porous electrode showed lower charge transfer impedance and higher ion diffusion efficiency, and the maximum charge transfer impedance could be reduced to 1/25 of the traditional electrode; At the same time, it showed better cycle performance and rate performance, and the capacity retention of the 3D printed porous electrode could be improved by about 29.0 % compared with the traditional electrode. This work shows that high-performance high-load porous electrodes can be accurately prepared by DLP 3D printing, which provides a new strategy for the future development of high-load thick electrodes.