Table 7 Na-ion battery impedance analysis of a-VOx films
Film | State | Rsf (Ω) | Rct (Ω) | Rb (Ω) | CPEsf (μF) | CPEdl (μF) | CPEb (μF) | Ci (mF) |
|---|---|---|---|---|---|---|---|---|
a-VOx-6 Pa | OCV | 311 | 280.4 | 7769 | 99.1 | 175.3 | 293.4 | 0.002 |
1.5 V | – | 522.3 | 12,446 | – | 5.2 | 75.3 | 0.57 | |
4.0 V | – | 209.1 | 12,520 | – | 5.8 | 100.5 | 0.54 | |
a-VOx-13 Pa | OCV | – | 106.8 | – | – | 11.8 | – | 0.21 |
1.5 V | – | 111.7 | 4622 | – | 26.4 | 542.1 | 1.41 | |
4.0 V | – | 111.9 | 4621 | – | 26.3 | 542.0 | 1.42 | |
a-VOx-30 Pa | OCV | – | 297.8 | – | – | 7.3 | – | 8.2 |
1.5 V | – | 450.0 | – | – | 28.8 | – | 15.8 | |
4.0 V | – | 273.3 | – | – | 7.6 | – | 4.6 |