Synergistic design of 3D porous lithiophilic Cu-Sn alloy current collectors for high-rate and stable graphite anodes

Conventional planar copper (Cu) current collectors severely limit the rate capability and cycle life of lithium-ion batteries. To overcome this, we report a three-dimensional (3D) porous Cu-Sn alloy architecture fabricated via scalable, cyanide-free electrodeposition and chemical dealloying methods. Its core innovation lies in the synergistic benefits of the porous structure and Cu-Sn alloying: the interconnected pores facilitate rapid Li⁺ transport and buffer graphite's volume expansion, while the intrinsic lithiophilicity of Sn ensures a stable, low-impedance interface. Consequently, an anode using the optimized porous collector delivers a remarkable specific capacity of 120.3 mAh g⁻¹ at 5C, representing a nearly five-fold enhancement in high-rate capacity retention over conventional Cu foil. The collector also confers exceptional cycling stability, enabling a 57.2 % capacity increase over 200 cycles, in stark contrast to the decay observed with standard foil. Electrochemical analysis confirms that the porous design drastically reduces electrode impedance while maintaining structural integrity. This work validates that engineering the current collector architecture is a powerful and effective strategy for developing high-performance, fast-charging batteries.