2D metal patterns transformed from 3D printed stamps for flexible Zn//MnO₂ in-plane micro-batteries

Patterned 2D metal conductors have been frequently employed as interconnectors and electrodes in flexible and wearable electronics due to their high conductivity and low cost. However, many patterned technologies have shortcomings including conventional photolithography and emerging printing technologies (inkjet, screen, microcontact printing, et al.). Herein, a new alternative printing strategy, transform printing, is put forward to print metal patterns and construct Zn//MnO₂ in-plane micro-batteries (IMBs) by combining 3D printing with stamping of metal films. As printed metal patterns on paper show very high-precision (<2% diffusion) and low sheet-resistance (75.0 mΩ/□). Using these metal patterns, Zn//MnO₂ IMBs are constructed based on aqueous and gel electrolytes. The devices display an outstanding energy density (168 μWh cm⁻², corresponding to 336 mAh g⁻¹)/power density (4.5 mW cm⁻²) outperforming the flexible and rechargeable Zn//MnO₂ IMBs previously reported and most of the micro-supercapacitors, show long-term cycle stability (84.3% of capacity retention after 2000 cycles at 5 A g⁻¹) and excellent mechanical flexibility. Owing to the simple, rapid, and low-cost fabrication of metal conductors and MBs with excellent properties, this printing strategy provides a new idea for the exploration of next-generation flexible and wearable electronics.