Electrical Conductivity Gradient Based on Heterofibrous Scaffolds for Stable Lithium‐Metal Batteries
Sang‐Ho Hong, Dae‐Han Jung, Jung‐Hwan Kim, Yong‐Hyeok Lee, Sung‐Ju Cho, Sang Hoon Joo, Hyun‐Wook Lee, Ki‐Suk Lee, Sang‐Young Lee
Abstract
Abstract The inability to guide the nucleation locations of electrochemically deposited Li has long been considered the main factor limiting the utilization of high‐energy‐density Li‐metal batteries. In this study, an electrical conductivity gradient interfacial host comprising 1D high conductivity copper nanowires and nanocellulose insulating layers is used in stable Li‐metal anodes. The conductivity gradient system guides the nucleation sites of Li‐metal to be directed during electrochemical plating. Additionally, the controlled parameter of the intermediate layer affects the highly stable Li‐metal plating. The electrochemical behavior is confirmed through experiments associated with the COMSOL Multiphysics simulation data. The distributed Li‐ion reaction flux resulting from the controlled electrical conductivity enables stable cycling for more than 250 cycles at 1 mA cm −2 . The gradient system effectively suppresses dendrite growth even at a high current density of 5 mA cm −2 and ensures Li plating and stripping with ultra‐long‐term stability. To demonstrate the high‐energy‐density full‐cell application of the developed anode, it is paired with the LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode. The cells demonstrate a high capacity retention of 90% with an extremely high Coulombic efficiency of 99.8% over 100 cycles. These results shed light on the formidable challenges involved in exploiting the engineering aspects of high‐energy‐density Li‐metal batteries.