Integration of Si in a metal foam current collector for stable electrochemical cycling in Li-ion batteries

Abstract

Here we designed and fabricated an integrated Li-ion battery electrode by trapping electrochemically active materials inside a three-dimensional (3D) metal current collector. Silicon microparticles have been sealed into a compressed 3D Cu foam matrix, which has interconnected pores for electrolyte wetting and also for providing enough empty space for the volume expansion of Si during lithiation. Such an electrode design can effectively trap the active materials inside the metal framework during dynamic electrochemical cycles, preventing particle escape from the current collector. Having these advantages, the electrode exhibits greatly improved electrochemical stability. The initial capacity reaches 2500 mA h g⁻¹ and remains more than 1000 mA h g⁻¹ over 200 cycles. While setting a constant charge capacity by 500 mA h g⁻¹, the capacity does not reduce after 600 cycles.