Extrusion 3D Printing of Patterned Cu Current Collectors for Advanced Lithium Metal Anodes

3D-printed copper current collectors for Li metal anodes were produced a) by material extrusion (MEX) and evaluated their electrochemical performances. The three-dimensional network favours homogeneous lithium nucleation due to b) larger electroactive surface area. No signs of dendrite growth were found even after c) 330 hours of Li stripping and plating. The Li@3DCu anode in a LiFePO₄-based full cell shows very good rate performance.

Abstract

Lithium (Li) metal is the most attractive anode material for the next generation Li batteries. However, crucial open challenges still limit its applicability at large scale, such as the low coulombic efficiency, unstable electrodeposition, and dendrite propagation with severe safety concerns. One strategy to address these drawbacks is the rational design of innovative current collectors for the Li anode. Here, we report on a simple, low-cost, and easily scalable process based on Additive Manufacturing technology via extrusion 3D printing to produce Cu current collectors with different and tuneable patterned structures. The current collectors are characterized by means of X-ray diffractometry, electron microscopy, profilometry and galvanostatic cycling. We show that the three-dimensional network can significantly stabilize the electrodeposition of Li, thanks to an enhanced electroactive surface area that enables a better Li accommodation without uncontrollable dendrite growth. Contrary to the planar current collector, the Li anode supported by the 3D current collectors exhibits stable and low voltage hysteresis at different current densities and can run for at least 330 hours without short-circuiting. Moreover, the evaluation of Li@3DCu anode in a LiFePO₄-based full cell by galvanostatic cycling reveals excellent rate performances, achieving specific capacity exceeding 100 mAh g⁻¹ at 1 C and coulombic efficiency higher than 99 %. These results show that the material extrusion 3D printing approach is a versatile strategy to develop new and safer anodes with a long lifespan and reduced amount of Li metal.

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