Large-Scale Electric-Field Confined Silicon with Optimized Charge-Transfer Kinetics and Structural Stability for High-Rate Lithium-Ion Batteries
Tao Meng, Bo Li, Qiushi Wang, Junnan Hao, Binbin Huang, Feng Gu, Huimin Xu, Peng Liu, Yexiang Tong
Abstract
The stereospecific design of the interface effects can optimize the electron/Li-ion migration kinetics for energy-storage materials. In this study, an electric field was introduced to silicon-based materials (C-SiOx@Si/rGO) through the rational construction of multi-heterostructures. This was achieved by manipulating the physicochemical properties at the atomic level of advanced Li-ion batteries (LIBs). The experimental and density functional theory calculations showed that the unbalanced charge distribution generated a large potential difference, which in turn induced a large-scale electric-field response with a boosted interfacial charge transfer in the composite. The as-prepared C-SiOx@Si/rGO anode showed advanced rate capability (i.e., 1579.0 and 906.5 mAh g–1 at 1000 and 8000 mA g–1, respectively) when the migration paths of the Li-ion/electrons hierarchically optimized the large electric field. Furthermore, the C-SiOx@Si/rGO composite with a high SiOx@Si mass ratio (73.5 wt %) demonstrated a significantly enhanced structural stability with a 40% volume expansion. Additionally, when coupled with the LiNi0.8Co0.1Mn0.1O2 (NCM) cathode, the NCM//C-SiOx@Si/rGO full cell delivers superior Li-ion storage properties with high reversible capacities of 157.6 and 101.4 mAh g–1 at 500 and 4000 mA g–1, respectively. Therefore, the electric-field introduction using optimized electrochemical reaction kinetics can assist in the construction of other high-performance LIB materials.