Electrochemical Dealloying-Enabled 3D Hierarchical Porous Cu Current Collector of Lithium Metal Anodes for Dendrite Growth Inhibition

Abstract

Lithium metal anodes are the most attractive for high-energy-density batteries because of their high theoretical capacity of 3860 mA h g −1 . However, their practical application is hindered by many challenges such as lithium dendrite growth, volume change of anodes, unstable anode/electrolyte interphase, and so on. Here, we demonstrate a three-dimensional hierarchical porous copper (3DHP Cu) current collector derived using a highly efficient electrochemical dealloying method that can suppress lithium dendrite growth during cycling. The micropores on the surface of the porous copper facilitate the insertion/extraction of lithium ions, which accelerates fast electrochemical reaction kinetics, and the interconnected copper network within the porous copper holds the volume change during lithium plating/ stripping. Moreover, the nanopores on the surface further enable a high surface area and even current distribution. Symmetric cells assembled with the 3DHP Cu exhibit stable cycling over 850 h at 1 mA cm −2 with a low voltage hysteresis of 33 mV. In addition, compared with a full cell using a planar Cu foil, a Li@3DHP Cu||LiFePO 4 full cell exhibits better cycle stability that results in 110.2 mA h g −1 at 1C after 150 cycles. Our work paves the way for developing safe and longevous lithium metal anodes with a porous Cu current collector derived using a highly efficient electrochemical dealloying strategy.

Porous Nb2O5 Formed by Anodic Oxidation as the Sulfur Host for Enhanced Performance Lithium-Sulfur Batteries

“…The promoted rate capability of the P-Nb 2 O 5 could be attributed to the porous nature, fast charge transfer, and rapid transport capabilities. When the rate returned to 0.2 C, the specific capacities of the batteries with the P-Nb 2 O 5 , G-Nb 2 O 5 , and CNT forms were 958.85, 655.01, and 870.70 mAh·g −1 , respectively [ 30 ]. Electrochemical impedance spectroscopy on the batteries with the G-Nb 2 O 5 and P-Nb 2 O 5 electrodes was carried out, and the differences in the internal resistance were investigated, as shown in Figure 5 f. The two Nyquist diagrams of the batteries in Figure 5 f have the same shape, including a semicircle involving the charge transfer resistance (Rct) and a sloping line associated with the Li diffusion.…”

Rational Design of Three‐Dimensional Self‐Supporting Structure for Advanced Lithium Metal Anode

“…Li et al constructed 3D hierarchical porous Cu(3DHP Cu) by controlled electrochemical etching of CuÀ Zn alloy. [15] Under the condition of 1 mA cm À 2 , the configured symmetrical batteries (Li@3DHP Cu j j Li@ 3DHP Cu) can stably cycle for 850 h. CuS/Cu 2 S nanosheets were formed by dropping sulfurcontaining solution on the surface of Cu foil at 60 °C, which were converted into porous Cu through oxidation reaction, and finally, the porous Cu with ant nest shape was obtained after hydrogen reduction (Figure 1a). [16] Due to the rich pores and unique geometric morphology, large-capacity lithium deposition (10 mAh cm À 2 ) has been realized.…”

Advances in research on the inhibitory effect of 3D current collector structures for lithium dendrites

“…Luan et al obtained 3D current collectors with graded porous structures by electroplating-roll bonding-annealing-electrochemical dealloying. 112 In the process of electrochemical dealloying, owing to the different diffusion rates of copper atoms, the larger diffusion rate on the surface can form micrometer-sized pores and coarse ligaments, and the incomplete aggregation of copper atoms on ligaments can form micrometer-sized pores, which results in a graded porous structure with nanometer-sized (500–800 nm) and micrometer-sized (1 μm) structures. 3D-graded porous current collectors can be stably cycled for about 250 h with a very low voltage hysteresis (84 mV) in a symmetric cell at 3 mA cm −2 and 1 mA h cm −2 .…”