A 3D-Printed ZnO/CNTs Mesh@Cu Composite Electrode for Dendrite-Free and Ultra-Stable Lean-Lithium Metal Batteries

Abstract

Lean-lithium metal batteries address Li excess in conventional lithium metal batteries and improve the energy density and safety, yet still face challenges including Li dendrite growth and volume expansion that cause low coulombic efficiency and rapid capacity degradation. To address these challenges, a three-dimensional-printed (3DP) composite anode was engineered via direct ink writing technology, synergistically integrating lithophilic ZnO nanoparticles, conductive muti-walled carbon nanotubes (CNTs), and an architected 3D mesh framework. The ZnO nanoparticles induce uniform Li+ flux and homogeneous nucleation at the electrode-electrolyte interface, fundamentally suppressing dendrite initiation through lithiophilic interfacial control. Concurrently, the percolating CNTs network creates rapid 3D electron pathways, lowering impedance and homogenizing current distribution to eliminate localized hotspots. The porous mesh structure dynamically accommodates volume fluctuations during Li plating/stripping, mitigating mechanical stress while enhancing electrolyte infiltration to stabilize ion transport. Consequently, the 3DP ZnO/CNTs Mesh@Cu symmetric cell maintains ultra-stable cycling for 3200 h at 1 mA cm-2/0.5 mAh cm-2 with only 95 mV overpotential, even after prior cycling at different areal capacities (0.1-4 mAh cm-2). Additionally, the full-cell assembled with high-loading LiNi0.8Co0.1Mn0.1O2 (NCM811, 3.82 mAh cm-2) achieves a capacity retention of 89.7% and a coulombic efficiency close to 100% after 100 cycles at 0.2 C. Furthermore, 3DP ZnO/CNTs Mesh@Cu was assembled into an anode-free pouch cell with 3DP LiFePO4 Mesh, demonstrating the promising application of 3D printing technology in electrochemical energy storage systems.