Controllable Design Coupled with Finite Element Analysis of Low-Tortuosity Electrode Architecture for Advanced Sodium-Ion Batteries with Ultra-High Mass Loading

摘要

Electrode design enabling more active materials makes it possible to improve the energy density for sodium-ion batteries (SIBs) on the device level, yet suffer from sluggish ion transport. Herein, a low-tortuosity Na3V2(PO4)(3)-based cathode is demonstrated based on a nonsolvent-induced phase separation method. The targeted low-tortuosity morphology can be achieved by thermodynamic and kinetic modulation. Benefiting from the structural advantages, the electrode with an ultra-high mass loading (60 mg cm(-2)) and areal capacity (4.0 mAh cm(-2)) is successfully achieved. Even at a high rate of 10 C, the areal capacity remains 1.0 mAh cm(-2). Comprehensive understanding on the effects of low-tortuosity architecture to the spatial and temporal distribution of the multi-physical field parameters has been elucidated by the finite element method. A homogeneous Na+ distribution, gentle and uniform local current density, and polarization inside the electrode are illustrated. Combining numerical simulations and experiments, it reveals that the low-tortuosity architecture can contribute to an impressive ion transport capability and consequently significant improvements in electrochemical performance. This study exhibits a prospective solution for the design and optimization of the low-tortuosity electrodes with ultra-high mass loading, which opens a new door for developing advanced SIBs with high energy/power density.