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• 3D Cu current collectors were gained by painting-alloying-dealloying and annealing. • The porous structure of 3D Cu was regulated by altering Ga mass and annealing. • The relationships between porous layer depth and performance were explored. • The Li deposition behaviors on 3D/2D Cu were clarified. Lithium metal anode has shown great potentials for achieving high energy density due to its high theoretical capacity and low redox potential, but its application is impeded by the dendrite proliferation and unstable solid electrolyte interface. Herein, three-dimensional (3D) porous Cu current collectors were fabricated via the combination of painting-alloying-dealloying with subsequent annealing, where the depth and length scale of the porous layer can be facilely regulated by controlling the alloying and annealing processes. In lithium metal batteries, the relationship between the Li deposition behavior and the porous layer depth was explored in detail via electrochemical measurements and ex-situ scanning electron microscopy. Notably, the A-3D Cu-14 current collector with the porous layer depth of around 34.5 µm exhibits long lifespan over 430 h at 1 mA cm−2 and low voltage hysteresis, in comparison with the pristine Cu foil and the porous Cu with thinner porous layers. The superior electrochemical performance of A-3D Cu-14 can be attributed to the enhanced suppression effect upon the Li dendrite deriving from the more accommodation capability of its thick porous layer, as well as the better homogenization of the Li+ ion flux caused by the porous structure. Furthermore, the Li@A-3D Cu-14 | LiFePO 4 full cell shows excellent cycling stability and rate capability in full battery tests. Dealloying-induced modulation upon porous layer depth of three-dimensional copper current collector to stabilize the lithium batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

• Nanoporous NiSb (np-NiSb) alloy was fabricated by a facile dealloying strategy. • The np-NiSb anode exhibits good cycling stability and superior rate capability. • Operando XRD reveals the sodiation/desodiation mechanism of the np-NiSb anode. • On-line DEMS verifies the gas release of half cells with NiSb anode during cycling. Engineering Sb-based anode materials is the key to enhance their electrochemical performance for sodium ion batteries (SIBs) by solving the issues of the rapid capacity decay and poor rate capability. In this work, a nanoporous NiSb alloy (np-NiSb) with a three-dimensionally interconnected ligament-channel structure was synthesized by a facile dealloying strategy. As an anode for SIBs, the np-NiSb alloy exhibits excellent cycling performance, rate capability and stability with a reversible capacity of 334.6 mAh g −1 at 0.2 A g −1 after 100 cycles, 155.6 mAh g −1 at 20 A g −1 and a capacity retention rate of 97% after 100 cycles at 1 A g −1. The nanoporous structure and the introduction of inactive Ni effectively tolerate the dramatic volume changes during the charge/discharge processes, restraining the pulverization of np-NiSb. The unique ligament-channel network structure with an average size of about 30 nm significantly shortens the ion transmission distance, ensuring the fast charge transfer at high rates. Operando X-ray diffraction reveals the sodiation/desodiation mechanism of the np-NiSb anode during the discharge/charge processes. In addition, on-line differential electrochemical mass spectrometry further explores the reaction mechanism of np-NiSb. This work highlights constructing nanoporous Sb-based alloys as an effective strategy to improve the performance of SIBs. [Display omitted] As an anode for SIBs, the np-NiSb alloy with bicontinuous ligament-channel structure exhibits good cycling stability with capacity retention rate of 97% over 100 cycles at 1 A g −1 (279.7 mAh g −1). [ABSTRACT FROM AUTHOR]