Development of a processing route for the fabrication of thin hierarchically porous copper self-standing structure using direct ink writing and sintering for electrochemical energy storage application

Abstract

The present study aims to develop a systematic processing route using direct ink writing (DIW) and pressureless sintering for fabricating hierarchically porous Cu (HP-Cu) electrodes. A 3D printable high particle loading Cu ink >95wt% with polylactic acid as a binder was prepared. Green Cu samples using optimum value of Cu loading, nozzle diameter, layer height, and printing speed as 97 wt%, 0.2 mm, 70% and 10 mm/s respectively were fabricated and subsequently sintered. A proper inter-particle bonding with 91% relative density and 215 Mpa ultimate compressive strength was achieved. Finally, a proof-of-concept study targeting the fabrication of thin HP-Cu current collector was performed and the pore size of 154 ± 10 µm with a thickness of 200 µm was achieved successfully. Moreover, the prepared sample exhibited the highest coulombic efficiency of 95.86% for more than 400 h at 1 mAcm-2 making it a potential candidate for energy storage applications. Graphical abstract: (Figure presented.) © The Author(s), under exclusive licence to The Materials Research Society 2024.