Table 1 Comparison of electrochemical performances for different layered Na_xMO₂ electrodes (M, transition metal)

Monoclinic-NaMnO₂ (unknown)

2.0–3.8

185 mAh g⁻¹ at 0.1 C

132 mAh g⁻¹ after 20 cycles at 0.1 C

ref. ⁷

β-NaMnO₂ (4–5)

2.0–4.2

90 mAh g⁻¹ at 10 C

65 mAh g⁻¹ after 100 cycles at 10 C

ref. ⁸

Bir-Na_0.71MnO₂·0.25H₂O (1.1)

1.85–3.65

89 mAh g⁻¹ at 8/3 C

105 mAh g⁻¹ after 100 cycles at 0.4 C

ref. ¹⁰

NaMn₃O₅ (~1.95)

1.5–4.7

115 mAh g⁻¹ at 5 C

153 mAh g⁻¹ after 20 cycles at 0.1 C

ref. ³⁴

P2/O′3-NaMnTi_0.1Ni_0.1O₂ (~1.3)

1.5–4.2

103 mAh g⁻¹ at 10 C

97 mAh g⁻¹ after 500 cycles at 5 C

ref. ³⁵

O3-Na_0.9[Cu_0.22Fe_0.30Mn_0.48]O₂ (3–5)

2.5–4.05

59 mAh g⁻¹ at 5 C

95 mAh g⁻¹ after 100 cycles at 0.1 C

ref. ³⁶

O3-NaNi_0.5Mn_0.2Ti_0.3O₂ (3–5)

2.0–4.0

135 mAh g⁻¹ at 1 C

115 mAh g⁻¹ after 200 cycles at 1 C

ref. ³⁷

P2-Na_0.6[Cr_0.6Ti_0.4]O₂ (unknown)

2.5–3.85

61 mAh g⁻¹ at 2 C

60 mAh g⁻¹ after 200 cycles at 1 C

ref. ³⁸

O3-NaNi_0.45Cu_0.05Mn_0.4Ti_0.1O₂ (3)

2.0–4.0

81 mAh g⁻¹ at 10 C

84 mAh g⁻¹ after 500 cycles at 1 C

ref. ³⁹

C-NaCrO₂ (3.5)

2.0–3.6

106 mAh g⁻¹ at 50 C

109 mAh g⁻¹ after 300 cycles at 0.5 C

ref. ⁴⁰

P2-Na_0.7CoO₂ (~1.4)

2.0–3.8

64 mAh g⁻¹ at 16 C

84 mAh g⁻¹ after 300 cycles at 4 C

ref. ⁴¹

NaMnO_2−y−δ(OH)_2y (2–3)

2.0–4.0

156 mAh g⁻¹ at 50 C

174 mAh g⁻¹ after 1000 cycles at 10 C

This work