Ionic Polarization‐Driven Defect Engineering in Na <sub>4</sub> Fe <sub>3</sub> (PO <sub>4</sub> ) <sub>2</sub> (P <sub>2</sub> O <sub>7</sub> ) Cathode: Fast Charging and Ultra‐Long Cycle Life of Sodium‐Ion Batteries
Abstract
Abstract The Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) (NFPP) cathode material faces the challenge of coordinating the improvement of high‐rate performance and long‐cycle stability for sodium‐ion batteries (SIBs). This study proposes an ionic polarization‐driven defect engineering strategy, which regulates the electronic structure and Na + transmission dynamics of NFPP through Bi 3+ doping. Experimental results and theoretical calculations show that Bi 3+ with (18 + 2) electron configuration significantly enhances the crystal structure stability of NFPP by strengthening the covalency of Bi─O bonds. Meanwhile, the heterovalent Bi 3+ doping optimizes the bandgap of the material (from 3.29 to 0.16 eV) and promotes Na + diffusion, while introducing lattice defects to provide additional sodium storage sites. The optimized 0.02Bi‐NFPP cathode exhibits excellent electrochemical performance as the half‐cell only takes 31.6 min to charge to 80% at a rate of 1 C, and the capacity decay is only 0.000495 mA h g −1 per cycle (86.9% capacity retention) over 20,000 cycles at 20 C. The full battery based on hard carbon anode maintains 95.5% capacity retention after 200 cycles at 1 C. This study reveals the synergistic mechanism between ion polarization effect and lattice defects, and provides a new strategy for designing SIBs cathode materials with both fast charging/discharging capabilities and ultra‐long life.
Article Details
Authors (9)
Yu‐Jie Wang
School of Chemical Engineering ocean and life science Dalian University of Technology Panjin Liaoning 124221 P.R. China
Zhen‐Yi Gu
MOE Key Laboratory For UV Light‐Emitting Materials and Technology Northeast Normal University Changchun Jilin P. R. China
Dong‐Sheng Bai
School of Chemical Engineering ocean and life science Dalian University of Technology Panjin Liaoning 124221 P.R. China
Ze‐Lin Hao
State Key Laboratory of Integrated Optoelectronics, and MOE Key Laboratory for UV Light‐Emitting Materials and Technology, Department of Physics Northeast Normal University Changchun China
Han‐Wei Huang
School of Chemical Engineering ocean and life science Dalian University of Technology Panjin Liaoning 124221 P.R. China
Yang Yan
Department of Cardiovascular Surgery, Med-X Institute, the First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China.
Cheng‐Jie Li
Shandong Peninsula Blue Economy and Engineering Research Institute Weifang University of Science and Technology Weifang 262700 P.R. China
An‐Min Liu
School of Chemical Engineering ocean and life science Dalian University of Technology Panjin Liaoning 124221 P.R. China
Xing‐Long Wu
MOE Key Laboratory For UV Light‐Emitting Materials and Technology Northeast Normal University Changchun Jilin P. R. China