Fabrication of manganese-tin electrodes for sodium-ion battery and supercapacitor applications via laser ablation, laser texturing, and inkjet printing

Manganese exhibits pseudocapacitive and stabilising effects while tin has strong battery behaviour but suffers stability issues, making these materials strong candidates for sodium-ion battery (SIB) technologies. Inkjet printing of Mn and Sn nanoparticle (NP) inks enhances performance due to its precision and high surface area, enabling the fabrication of high-precision micro-batteries. However, two key challenges exist: (1) poor ink properties, such as oversized particles, incorrect viscosity, and (2) poor ink adhesion due to the hydrophobic and low-roughness surface of copper foils current collectors. Herein, these challenges are addressed by controlling ink properties via pulsed laser ablation in liquid with real-time monitoring using dynamic light scattering for particle size distribution and viscosity measurement. Surface adhesion is improved through laser texturing (50–70 µm track spacing at 10–20 kHz) using an Nd:YAG laser, which increased roughness by 367 % (up to 2.1 µm), enabling successful inkjet printing. Mn and Sn printing was conducted on copper foils at 50 °C. The Mn ink had a mean spherical NP size of 64 nm, a viscosity of 2.9 mPa·s, and a specific surface area of 67 m²/cm³. Cyclic voltammetry confirmed pseudocapacitive behaviour for Mn, and battery behaviour for Mn-Na-Sn electrodes in half-cell sodium-ion experiments.