3D-Printed Carbon Scaffold for Structural Lithium Metal Batteries

Focus on advancement of energy storage has now turned to curbing carbon emissions in the transportation sector by adopting electric vehicles (EVs). Technological advancements in lithium-ion batteries (LIBs), valued for their lightweight and high capacity, are critical to making this switch a reality. Integrating structurally enhanced LIBs directly into vehicular design tackles two EV limitations: vehicle range and weight. In this study, 3D-carbon (3D-C) lattices, prepared with an inexpensive stereolithography-type 3D printer followed by carbonization, are proposed as scaffolds for Li metal anodes for structural LIBs. Mechanical stability tests revealed that the 3D-C lattice can withstand a maximum stress of 5.15 ± 0.15 MPa, which makes 3D-C lattices an ideal candidate for structural battery electrodes. Symmetric cell tests show the superior cycling stability of 3D-C scaffolds compared to conventional bare Cu foil current collectors. When 3D-C scaffolds are used, a small overpotential (≈0.075 V) is retained over 100 cycles at 1 mA cm^-2 for 3 mAh cm^-2, while the overpotential of a bare Cu symmetric cell is unstable and increased to 0.74 V at the 96th cycle. The precisely oriented internal pores of the 3D-C lattice confine lithium metal deposits within the 3D scaffold, effectively preventing short circuits.