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.
We develop a metric-torsion theory for chiral structures by using a generalized framework of transformation optics. We show that the chirality is uniquely determined by a metric with the local rotational degree of freedom. In analogy to the dislocation continuum, the chirality can be alternatively interpreted as the torsion tensor of a Riemann-Cartan space, which is mimicked by the anholonomy of the orthonormal basis. As a demonstration, we reveal the equivalence of typical three-dimensional chiral metamaterials in the continuum limit. Our theory provides an analytical recipe to design optical chirality.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.