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

摘要

Lithium metal anodes are the most hopeful candidate for new-generationenergy storage batteries because of their high energy-density and lowelectrochemical redox potential. However, the sluggish ion diffusion andnonuniform electric field in lithium anodes hinder their high rate propertiesand long-life performance with deep capacities. Here, a highly interconnected3D metallic Cu&CuAux matrix with both low-tortuosity (1.3) and ultrahighporosity (81.5%) is fabricated by using a high energy heavy ion-trackingmethod. As a consequence, the 3D metallic Cu&CuAux matrix can highlyaccelerate the transfer of Li+ and reduce the Li nucleation barrier during the Lideposition process due to its low-tortuosity and ultrahigh porosity.Furthermore, finite element simulation reveals that the unique 3D Cu&CuAuxstructure can highly homogenize the electric field and Li-ion flux as well asdecrease the lithium-ion concentration gradient in Li anodes. As a result, thecomposite 3D Cu&CuAux-Li anodes exhibit ultrahigh cycle life more than2000 h and high rate capabilities. Full cells consisting of the 3D Cu&CuAux-Lianodes and LiFePO_4 cathodes also demonstrate a good capability and stablecycle life up to 200 cycles.