Tailoring Unconventional Cyanogen Defect in High‐Entropy Prussian Blue Cathode Material for Advanced Sodium‐Ion Batteries
Tailoring Unconventional Cyanogen Defect in High‐Entropy Prussian Blue Cathode Material for Advanced Sodium‐Ion Batteries
研究概述
通过植酸辅助共沉淀，在高熵普鲁士蓝正极中精准引入CN⁻空位，形成柔性配位位点和局域电子离域，抑制Jahn–Teller效应及复杂相变，实现近零应变固溶储钠。初始比容量117.6 mAh/g，循环超过6000次；准固态全电池能量密度338.0 Wh/kg，循环超过4000次。
谱图与表征信息
FIGURE 1 Structure characterization. a) Rietveld refinement XRD patterns of HE-Cu, HE-Cu-PA, and HE-Ti-PA. b) ε calculated using Williamson– Hall analysis. c) EPR spectra. d) Crystal structure diagram of high-entropy PBA containing cyanide defect. e) EXAFS spectra and f) wavelet transform spectra of HE-Cu-PA. g) Bond length range difference of HE-Cu and HE-Cu-PA. h) EDS mapping images of HE-Cu-PA.
FIGURE 4 Charge compensation mechanism of HE-Cu-PA. a) Ex situ XANES and b) EXAFS spectra at Mn, Fe, Co, and Cu K-edge during the charge-discharge process. Wavelet transform of c) Fe and d) Cu K-edge EXAFS spectra. e) Debye–Waller factors and bond length of TM-N collected by the fitting EXAFS spectra. f) In situ Raman intensity contour plots during the charge–discharge process.