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

Abstract 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 LiFePO 4 cathodes also demonstrate a good capability and stable cycle life up to 200 cycles.