Lithiation and Delithiation Behavior of Porous Li-Cu Anode in Li-ion Battery Systems

Li-metal anodes exhibit the potential to increase the efficiencies of Li-ion battery systems. However, the commercialization of Li metal is hindered by several inherent challenges, such as the formation of inhomogeneous Li dendrites and considerable volume expansion during deposition and dissolution. Fabrication of 3D porous structures is a promising technique that resolves these problems, however, no attempts to replace graphite anodes with porous Li-Cu anodes in Li-ion secondary battery systems are reported. Moreover, the charging/discharging behaviors of porous Li-Cu anodes are not yet completely understood. In this study, the changes in a porous Li-Cu anode in a symmetric cell during lithiation and delithiation are investigated. The porous Li-Cu anode suppresses dendrite growth and volume changes via the filling and evacuation of the pores around the Li particles within and on the surface of the anode, and thus, the higher porosity results in a larger capacity. The Li-Cu anode displays a stable cyclability at 1 mA cm –2 with a capacity of 1 mA h cm –2 over 700 h. The porous Li-Cu anode exhibits promise in replacing graphite in Li-ion secondary battery systems.