High-Energy-Heavy-Ion Engineering Low-Tortuosity and High-Porosity 3D Metallic Electrodes for Long-Life Lithium Anodes

Lithium metal anodes are the most hopeful candidate for new-generation energy storage batteries because of their high energy-density and low electrochemical redox potential. However, the sluggish ion diffusion and nonuniform electric field in lithium anodes hinder their high rate properties and long-life performance with deep capacities. Here, a highly interconnected 3D metallic Cu&CuAu_x matrix with both low-tortuosity (1.3) and ultrahigh porosity (81.5%) is fabricated by using a high energy heavy ion-tracking method. As a consequence, the 3D metallic Cu&CuAu_x matrix can highly accelerate the transfer of Li⁺ and reduce the Li nucleation barrier during the Li deposition process due to its low-tortuosity and ultrahigh porosity. Furthermore, finite element simulation reveals that the unique 3D Cu&CuAu_x structure can highly homogenize the electric field and Li-ion flux as well as decrease the lithium-ion concentration gradient in Li anodes. As a result, the composite 3D Cu&CuAu_x-Li anodes exhibit ultrahigh cycle life more than 2000 h and high rate capabilities. Full cells consisting of the 3D Cu&CuAu_x-Li anodes and LiFePO₄ cathodes also demonstrate a good capability and stable cycle life up to 200 cycles.