Design of 3D-Printable Conductive Composites for 3D-Printed Battery

In this research, a biocompatible nano-composite is designed for the application of 3D printed battery. The nano-composite paste is composed of an electrically conductive silver nanowire (AgNW) filler within a thixotropic carboxymethyl cellulose (CMC) matrix. Experimental demonstration and computational simulations on nano-composites with various filler fractions are performed to find the electrical percolation threshold of the nano-composite. The percolation threshold as 0.7 vol. % of AgNWs is predicted by computer simulations as well as by experiments. Also, maximum electronic conductivity is obtained as 1.19×102 S/cm from a nano-composite with 1.9 vol. % of AgNWs. Also, newly designed paste 3D printing apparatus is built by integrating a commercially available delta 3D printer with a paste extruder.Finally, the 3D printable battery facilitated by the conductive composite is demonstrated. Cathode and anode materials are formulated by addition of cathode and anode active materials to the nano-composite of AgNW and CMC. Rheology study of the cathode and anode paste is carried out and thixotropic (shear-thinning) behavior is observed which is an essential characteristic of the 3D printable paste [1], [2]. Lastly, the performance demonstration on the fabricated 3D printed battery is carried out. The 3D printable conductive paste is expected to contribute in additive manufacturing process for printable electronics.