A layered sodium-ion battery cathode, O3/P3/P2-type NaNi1/3Mn1/3Fe1/3O2, has been systematically investigated by first-principles density functional theory to explore the detailed structural and Na-ion diffusion behavior during desodiation. Our results suggest that the (NaO6) spacing is greatest in the P3 phase and lowest in the O3 phase, with the P2 phase exhibiting intermediate spacing. During desodiation, the intermediate stages have a greater (NaO6) spacing than the initial and final stages. The great (NaO6) spacing facilitates the formation of the P3 phase, resulting in the structural evolution of NaxNi1/3Mn1/3Fe1/3O2 from the O3 to the P3 phase at x ≈ 0.59, finally reaching the O3 structure again at x ≈ 0.12. The electronic structure clearly proves that both Ni and Fe are active in O3/P3/P2-type NaxNi1/3Mn1/3Fe1/3O2. Ni2+ is oxidized to Ni3+ as Na content decreases from x = 1 to x = 0.66, then further oxidized to Ni4+ at x = 0.33, and finally, Fe3+ → Fe4+ oxidation occurs at x = 0. In the Na ion diffusion behavior, the order of the barrier is O3 (0.82 eV) > P2 (0.53 eV) > P3 (0.35 eV) at the initial stage, whereas it is O3 (0.53 eV) > P3 (0.21 eV) > P2 (0.16 eV) at a highly desodiated stage. The former can be traced back to the (NaO6) spacing, but the latter is related to the different Na sites. Our results thus provide a factor of the structural evolution and Na ion diffusion barrier by considering (NaO6) width and Na site changes during desodiation.

1.
M.
Winter
,
B.
Barnett
, and
K.
Xu
,
Chem. Rev.
118
,
11433
(
2018
).
2.
4.
C.
Vaalma
et al,
Nat. Rev. Mater.
3
,
18013
(
2018
).
5.
6.
J.
Wang
et al,
J. Power Sources
461
,
228129
(
2020
).
7.
V.
Palomares
et al,
Energy Environ. Sci.
5
,
5884
(
2012
).
9.
J.
Wang
et al,
ACS Appl. Mater. Interface
12
,
5017
(
2020
).
10.
R.
Usiskin
et al,
Nat. Rev. Mater.
6
,
1020
(
2021
).
11.
Y.
Arinicheva
et al,
Advanced Ceramics for Energy Conversion and Storage
(
Elsevier
,
2020
), p.
549
.
12.
N.
Yabuuchi
et al,
Nat. Mater.
11
,
512
(
2012
).
13.
W.
Zheng
et al,
Energy Storage Mater.
28
,
300
(
2020
).
14.
15.
S.
Xu
et al,
Adv. Energy Mater.
5
,
1501156
(
2015
).
16.
L.
Liu
et al,
Adv. Energy Mater.
5
,
1500944
(
2015
).
18.
F.
Ding
et al,
Adv. Funct. Mater.
31
,
2101475
(
2021
).
19.
M.
Jeong
et al,
J. Power Sources
439
,
227064
(
2019
).
20.
D.
Kim
et al,
Electrochem. Commun.
18
,
66
(
2012
).
21.
E.
Talaie
et al,
Energy Environ. Sci.
8
,
2512
(
2015
).
22.
Y.
Xie
et al,
Adv. Energy Mater.
6
,
1601306
(
2016
).
23.
D.
Zhou
et al,
J. Power Sources
473
,
228557
(
2020
).
24.
X.
Xia
and
J. R.
Dahn
,
J. Electrochem. Soc.
159
,
A1048
(
2012
).
25.
H.
Wang
et al,
J. Electrochem. Soc.
163
,
A565
(
2016
).
26.
C.
Delmas
,
C.
Fouassier
, and
P.
Hagenmuller
,
Physica B+C
99
,
81
(
1980
).
28.
G.
Kresse
and
J.
Furthmuller
,
Phys. Rev. B
54
,
11169
(
1996
).
29.
30.
J. P.
Perdew
,
K.
Burke
, and
M.
Ernzerhof
,
Phys. Rev. Lett.
77
,
3865
(
1996
).
31.
J. P.
Perdew
,
M.
Ernzerhof
, and
K.
Burke
,
J. Chem. Phys.
105
,
9982
(
1996
).
32.
V. I.
Anisimov
,
J.
Zaanen
, and
O. K.
Andersen
,
Phys. Rev. B
44
,
943
(
1991
).
33.
34.
H. J.
Monkhorst
and
J. D.
Pack
,
Phys. Rev. B
13
,
5188
(
1976
).
35.
G.
Henkelman
and
H.
Jónsson
,
J. Chem. Phys.
113
,
9978
(
2000
).
36.
K.
Okhotnikov
,
T.
Charpentier
, and
S.
Cadars
,
J. Cheminf.
8
,
17
(
2016
).
37.
38.
39.
N. A.
Katcho
et al,
Adv. Energy Mater.
7
,
1601477
(
2017
).
40.
E.
Goikolea
et al,
Adv. Energy Mater.
10
,
2002055
(
2020
).
41.
Z.
Liang
et al,
Inorg. Chem. Front.
10
,
7187
(
2023
).
42.
T.-Y.
Yu
et al,
J. Mater. Chem. A
8
,
13776
(
2020
).
43.
F.
Ding
et al,
Energy Storage Mater.
30
,
420
(
2020
).
44.
C.
Zhao
et al,
Angew Chem. Int. Ed. Engl.
59
,
264
(
2020
).
45.

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