Outstanding Low‐Temperature Performance of Structure‐Controlled Graphene Anode Based on Surface‐Controlled Charge Storage Mechanism
Michael J. Lee, Kyungbin Lee, Jeonghoon Lim, Mochen Li, Suguru Noda, Seok Joon Kwon, Brianne DeMattia, Byeongyong Lee, Seung Woo Lee
Abstract
Abstract The energy and power performance of lithium (Li)‐ion batteries is significantly reduced at low‐temperature conditions, which is mainly due to the slow diffusion of Li‐ions in graphite anode. Here, it is demonstrated that the effective utilization of the surface‐controlled charge storage mechanism through the transition from layered graphite to 3D crumpled graphene (CG) dramatically improves the Li‐ion charge storage kinetics and structural stability at low‐temperature conditions. The structure‐controlled CG anode prepared via a one‐step aerosol drying process shows a remarkable rate‐capability by delivering ≈206 mAh g –1 at a high current density of 10 A g –1 at room temperature. At an extremely low temperature of −40 °C, CG anode still exhibits a high capacity of ≈154 mAh g –1 at 0.01 A g –1 with excellent rate‐capability and cycling stability. A combination of electrochemical studies and density functional theory (DFT) reveals that the superior performance of CG anode stems from the dominant surface‐controlled charge storage mechanism at various defect sites. This study establishes the effective utilization of the surface‐controlled charge storage mechanism through structure‐controlled graphene as a promising strategy to improve the charge storage kinetics and stability under low‐temperature conditions.