Graphene Electrolyte Gated Field Effect Transistors for Biosensing
Effect of Concentrated Electrolyte on High Voltage Aqueous...
Transcript of Effect of Concentrated Electrolyte on High Voltage Aqueous...
Kosuke Nakamoto, Ayuko Kitajou*, Masato Ito* and Shigeto Okada* (IGSES, Kyushu University, *IMCE, Kyushu University)
Effect of Concentrated Electrolyte on High Voltage Aqueous Sodium-ion Battery
Oct 6. (Thu) A01-0134
Introduction
This study Advantage
/disadvantage
Aqueous sodium-ion Non-inflammability, Cost, Power! Energy density
Post LIB Aqueous lithium-ion Sodium-ion
Electrolyte Aqueous Organic Solid
Commercial Nickel metal hydride Lithium-ion Sodium sulfur
Commercialized secondary batteries and post lithium-ion batteries
Components Lithium-ion Aqueous sodium-ion
Electrolyte solvent Organic WaterElectrolyte salt LiPF6, LiTFSI Na2SO4, NaClO4
Separator Polypropylene porous Nonwoven fabric
Anode current collector Cu Fe
Cathode active material Co, Ni Fe, Mn
Electrode slurry thickness ~ 100 µm ~ 20,000 µm
Primary requirement to the large scale energy storage system is the cost (Wh/$), rather than specific energy density (Wh/kg).
Hybrid capacitor (Aquion Energy)
Operation voltage ~ 4 V ~ 2 V
Electrode materials for aqueous lithium-ion battery
Very recent aqueous lithium-ion battery with highly concentrated electrolyterealized high voltage operation exceeding 1.23 V theoretical stability window.
-3
-2
-1
0
1
2 5
4
3
2
1
0
E (V
) vs.
Na/
Na+
E (V
) vs. Li/Li +E
(V) v
s. N
HE
E
(V) vs. A
g/AgC
l
E = 1.23 – 0.059pH O2↑
H2↑ E = – 0.059pH
Theoretical stability window of water
0 7 14 pH
LiNi0.5Mn1.5O4
Li4Ti5O12
LiTi2(PO4)3
LiCoO2
TiO2
LiMn2O4
4
3
2
1
0 -3
-2
-1
0
1
Extended practical stability window of aqueous lithium-ion electrolyte
Mo6S8
Polyimide
LiFePO4
VO2
LiV3O8
LiMn2O4 LiNi0.5Mn1.5O4
Mo6S8
Cathode Anode ElectrolyteVoltag
e /V
Discharge capacity /mAh g-1 Ref.
LiMn2O4 VO2 5 mol/l LiNO3 aq. 1.5 50 (electrodes) 1
LiNi0.81Co0.19O2 LiV3O8 1 mol/l Li2SO4 aq. 0.9 20 (electrodes) 2
LiMn2O4 LiTi2(PO4)3 1 mol/l Li2SO4 aq. 1.5 40 (electrodes) 3
LiFePO4 LiTi2(PO4)3 1 mol/l Li2SO4 aq. 0.9 55 (electrodes) 4
LiCoO2 Polyimide 5 mol/l LiNO3 aq. 1.1 71 (electrodes) 5
LiMn2O4 Mo6S8 21 mol/kg LiTFSI aq. 2.0 47 (electrodes) 6
LiMn2O4 TiO2
21 mol/kg LiTFSI + 7 mol/kg LiOTf aq.
2.1 48 (electrodes) 7
LiCoO2 Li4Ti5O12
20 mol/kg LiTFSI + 8 mol/kg LiBETI aq.
2.4 55 (electrodes)8
LiNi0.5Mn1.5O4 3.0 30 (electrodes)
Estimated cost of recent aqueous lithium-ion chemistries is still high.
Aqueous lithium-ion batteries
[1] W. Li, et al., Science, 264 (1994) 1115. [2] J. Köhler, et al., Electrochim. Acta, 46 (2000) 59.[3] J.Y. Luo, et al., Adv. Funct. Mater., 17 (2007) 3877. [4] J. Luo, et al., Nat. Chem., 2 (2010) 76 [5] H. Qin, et al., J. Power Sources, 249 (2014) 367. [6] L. Suo, et al., Science, 350 (2015) 938.[7] L. Suo, et al., Angew. Chemie., 85287 (2016) 7136. [8] Y. Yamada, et al., Nat. Energy, 1 (2016) 16129.
Cathode Anode ElectrolyteVoltage
/V Discharge capacity
/mAh g-1 Ref.
λ-MnO2 Active Carbon 1 mol/l Na2SO4 aq. 1.2 50 (electrolyte) 9
NaVPO4F Polyimide 5 mol/l NaNO3 aq. 1.1 40 (electrodes) 5
Na3V2O(PO4)2F NaTi2(PO4)3 *10 mol/l NaClO4 aq. 1.4 40 (cathode) 10
Na4Mn9O18 NaTi2(PO4)3 1 mol/l Na2SO4 aq. 1.0 100 (anode) 11
Na2FeP2O7 NaTi2(PO4)3 4 mol/l NaClO4 aq. 0.9 48 (cathode) 12
Na2Ni[Fe(CN)6] NaTi2(PO4)3 1 mol/l Na2SO4 aq. 1.3 100 (anode) 13
Na2Cu[Fe(CN)6] NaTi2(PO4)3 1 mol/l Na2SO4 aq. 1.4 102 (anode) 14
NaCr[Mn(CN)6] Na2Mn[Mn(CN)6] *10 mol/l NaClO4 aq. 1.0 28 (electrodes) 15
Na2Co[Fe(CN)6] NaTi2(PO4)3 1 mol/l Na2SO4 aq. 1.6 120 (cathode) 16
NaFe[Fe(CN)6] (Active Carbon) 1 mol/l Na2SO4 aq. (> 1.5) 60 (cathode) 17
We focus on rocking-chair aqueous sodium-ion batteries (not capacitors). Active materials should be low cost & yield high voltage output to maximize the cost performance index.
Aqueous sodium-ion batteries
[9] J.F. Whitacre, et al., J. Power Sources, 213 (2012) 255. [10] P.R. Kumar, et al., Mater. Chem. A, 3 (2015) 6271. [11] W. Wu, et al., J. Electrochem. Soc., 162 (2015) A803. [12] K. Nakamoto, et al., J. Power Sources, 327 (2016) 327. [13] X. Wu, et al., Electrochem. Commun., 31 (2013) 145. [14] X. Wu, et al., ChemSusChem, 7 (2014) 407. [15] M. Pasta, et al., Nat. Commun., 5 (2014) 3007. [16] X. Wu, et al., ChemNanoMat., 1 (2015) 188. [17] X. Wu, et al., Nano Energy, 13 (2015) 117.
*10 M NaClO4 aq. ≒ 17 m NaClO4 aq.
M Ni Cu Co Fe
Initial C/D capacity /mAh g-1
74/65 71/59 142/128 102/122
E/V vs. Ag/AgCl 0.5 0.6 0.9
0.4 1.0 0.2
Electrolyte 1 mol/l Na2SO4 aq. 1 mol/l Na2SO4 aq. 1 mol/l Na2SO4 aq. 1 mol/l Na2SO4 aq.
Upper redox Inactive Inactive [Fe(CN)6]4-/3- Fe2+/3+
Lower redox [Fe(CN)6]4-/3- [Fe(CN)6]4-/3- Co2+/3+ [Fe(CN)6]4-/3-
Weak point
Low capacity Expensive
Low capacity Expensive Expensive Low initial capacity
Air-stability
Sodium metal hexacyanoferrates Na2M[Fe(CN)6], M = Ni, Cu, Fe, Co, Mn
0.5
1.0
0.0E[V
] vs.
Ag/
AgC
l After Wu [13] After Wu [14] After Wu [16] After Wu [17]
Na2Mn[Fe(CN)6] is low cost and was reported high voltage operation in non-aqueous electrolyte but has never been realized in aqueous electrolyte.
Capacity [mAh/g] 1501500 150 150
O2↑
Capacity [mAh/g] Capacity [mAh/g] Capacity [mAh/g]
Sodium metal hexacyanoferrates Na2M[Fe(CN)6], M = Ni, Cu, Fe, Co, Mn
M Mn (in Non-aq.) Co (in Aq.) Fe (in Aq.)
Morph.
Property Round particle with defects
Cubic without defects
Cubic without defects
After Wu [16] After Wu [17]
Na2Mn[Fe(CN)6] is attractive because of 2 redox-active sites. However, the round particles with defects may dissolve and cannot suppress water decomposition in diluted electrolyte.
E [V
] vs.
Na/
Na+
After Song [18]
3.5
4.0
3.0
→Other methods should be considered as suppressing dissolution and water decomposition.
After Song [18] After Wu [16] After Wu [17]
Capacity [mAh/g]Capacity [mAh/g]
0.5
1.0
0.0
0.5
1.0
0.0
E [V
] vs. Ag/A
gCl
O2↑
E [V
] vs.
Ag/
AgC
l
1500 50 100 150 0 50 100 0 50 100
Capacity [mAh/g]
Approx. saturated concentration [mol/kg]
Cation Weak points Ref.
Li+ Na+
Anion
Cl- 18 6 Anodic oxidation & gas evolution - OH- 5 32 Prussian blue decomposition in alkali 19 NO3
- 13 10 Ti based NASICON corrosion 11 SO4
2- 3 2 Low solubility - N(SO2CF3)2
- 21 9 High cost TFSI- 6
SO2CF3- 22 9 High cost OTf- 7
N(SO2C2F5)2- ND ND High cost BETI- 8
ClO4- 6 17 Explosive -
Highly concentrated NaClO4 aqueous electrolyte will suppress dissolution or side reaction and support high voltage operation.
Electrolyte selection for aqueous sodium-ion battery
[6] L. Suo, et al., Science, 350 (2015) 938. [7] L. Suo, et al., Angew. Chemie., 85287 (2016) 7136. [8] Y. Yamada, et al., Nat. Energy, 1 (2016) 16129. [11] W. Wu, et al., J. Electrochem. Soc., 162 (2015) A803. [19] R. Koncki, et al., Anal. Chem., 70 (1998) 2544.
17
Cathode Electrolyte Anode Na2Mn[Fe(CN)6]
(NMHCF) 17 mol/kg NaClO4 aq. NaTi2(PO4)3 (NTP)
Experiment
Synthesis of NaxMn[Fe(CN)6]y・zH2O
Stir (in H2O + EtOH) @ RT
Na4[Fe(CN)6] aq.
Green blue NaxMn[Fe(CN)6]y・zH2O
Filter & Wash (H2O + EtOH)
NaCl aq.
Light green precipitation
MnCl2 aq.
Vacuum dry @100 ℃ (over night)
[18] J. Song, et al., J. Am. Chem. Soc., 137 (2015) 2658.
Conventional co-precipitation method [18]
Green blue NaxMn[Fe(CN)6]y・zH2O
Morphological & structural properties of NMHCF
(100
)
(110
)
(200
)
(210
) (2
11)
(220
)
(310
) (3
00)
Na2MnFe(CN)6 Pm-3m Cubic
ICSD #75-4637
2θ/degree
Inte
nsity
/a. u
.
200 nm
NMHCF powder was identified as cubic with Pm-3m diffraction pattern consistent with Na2Mn[Fe(CN)6]. Approx. 200 nm sized round particles not nano-cubes were observed.
XRD SEM
Na Mn Fe H2O 1.24 1 0.81 1.28
By ICP-AES & TGA
As-prepared NMHCF
605040302010
[20] Y. Morimoto, et al., Energies, 8 (2015) 9486.
[20]
Na1.24Mn[Fe(CN)6]0.81·1.28H2O
(AB : Acetylene black, PTFE : Polytetrafluoroethylene)
WE Ti mesh
CE Ti mesh
WE pellet (~ 2 mg)
CE pellet (~ 3 mg)
Ion-type cell Na2Mn[Fe(CN)6] + NaTi2(PO4)3 ⇄ Mn[Fe(CN)6] + Na3Ti2(PO4)3
Electrochemical cell
Beaker-type cell
RE
Na2MnFe(CN)6//NaTi2(PO4)3
Working electrode (WE)
Electrolyte (EL)
Reference electrode (RE)
Counter electrode (CE)
Na2Mn[Fe(CN)6]:AB:PTFE =70:25:5 (wt%)
1 or 17 mol/kg
NaClO4 aq.Silver-silver chloride
(Ag/AgCl) in sat. KCl aq.NaTi2(PO4)3:AB:PTFE
=70:25:5 (wt%)
EL
Prussian blue analogues [21] Na2Mn[Fe(CN)6] NMHCF Sodium manganese hexacyanoferrate
NASICON-type NaTi2(PO4)3 NTP
Sodium titanium phosphate
[21] T. Tojo, et al., Electrochem. Acta, 207 (2016) 22.
Result & discussion
1 & 17 mol/kg NaClO4 aqueous electrolyte had 1.9 V & 2.7 V practical stability windows, respectively. The windows were larger than 1.23 V theoretical stability window of water.
Cyclic voltammetry on Ti current collector & active materials
43214321
Voltage/V vs. Ag/AgCl
Voltage/V vs. Na/Na+
Cur
rent
/mA
0.5
-0.5
0.0
Cur
rent
den
sity
/A g
-1
0.5
-0.5
0.0
-2 -1 0 1 2
-2
-1
0
1
2
-2
-1
0
1
2
-2 -1 0 1 2
NMHCF
NTP
NMHCF
NTP
1 mol/kg NaClO4 aq.
17 mol/kg NaClO4 aq.
1 mol/kg NaClO4 aq.
17 mol/kg NaClO4 aq.
Theoretical 1.23 V pH = 7
Practical 1.9 V
Practical 2.7 V
O2↑
H2↑
H2↑
O2↑ O2
↑
H2↑
Theoretical 1.23 V pH = 6
Na1.24Mn[Fe(CN)6]0.81·1.28H2O & NaTi2(PO4)3 half cells
17 mol/kg electrolyte suppressed both of O2/H2 evolution and supported the reversible operation. In contrast, 1 mol/kg electrolyte does not allow cycling.
Volta
ge/V
vs.
Ag/
AgC
l
Specific capacity/mAh g-1-anode
NMHCF
Voltage/V vs. N
a/Na
+
Specific capacity/mAh g-1-anode
Specific capacity/mAh g-1-cathode Specific capacity/mAh g-1-cathode
NTP NTP
NMHCF 4
3
2
1
1.3 V cut1.2 V cut
1 mol/kg NaClO4 aq. 2.0 mA cm-2
17 mol/kg NaClO4 aq. 2.0 mA cm-2
150100500
150100500
1st 2nd
-2
-1
0
1
24003002001000
1st 2nd
150100500
40302010
Ex-situ XRD patterns of NMHCF cathode in charge/discharge process
403020102θ/degree
1.5 1.0 0.5 0.0
300
250
200
150
100
50
0
-50
Voltage/V vs. Ag/AgCl
Cap
acity
/mA
h g-
1
2θ/degree 1.5 1.0 0.5 0.0
400
300
200
100
0
Cap
acity
/mA
h g-
1
Voltage/V vs. Ag/AgCl
1 mol/kg NaClO4 aq. NMHCF
XRD intensities of NMHCF in 1 mol/kg electrolyte were weakened at higher voltage range, and some small peaks were observed again at 0.2 V indicating some deposition.
Inte
nsity
/a. u
.
Inte
nsity
/a. u
.
0.2 V
0.7 V
1.3 V
1.2 V
0.9 V
OCV
0.2 V
0.7 V
1.3 V
0.9 V
OCV
0.2 V
0.7 V
1.3 V
1.2 V
0.9 V
OCV
0.2 V
0.7 V
1.3 V
0.9 V
OCV
Deposition
17 mol/kg NaClO4 aq. NMHCF
NMHCF cathode deterioration in 1 mol/kg NaClO4 (color, pH, metal ion ICP)
1.51.0
0.50.0
300
250
200
150
100500
-50
Volta
ge/V
vs.
Ag/
AgC
l
Capacity/mAh g-1
17 mol/kg NaClO4 aq.
1.51.0
0.50.0
400
300
200
1000
Capacity/mAh g-1Vo
ltage
/V v
s. A
g/A
gCl
1 mol/kg NaClO4 aq.
Voltage/V Prep. Ini. 0.9 1.3 0.7 0.2
pH 6 5 5 0.5 0.8 0.8
Prep. Ini. 0.9 1.2 1.3 0.7 0.2
7 6 4 2 2 2 2
Fe/mol% 0.0 0.0 0.0 0.0 0.0 0.0
Mn/mol% 0.0 0.0 0.0 0.0 0.0 0.0
Ti/mol% 0.0 0.0 0.0 0.0 0.0 0.0
0.0 4.0 6.8 28 27 26 15
0.0 7.3 8.0 0.0 0.0 0.0 0.0
0.0 0.0 0.0 0.0 0.0 0.0 0.0
In 1 mol/kg electrolyte, NMHCF dissolved as [Fe(CN)6]4- at lower, [Fe(CN)6]3- at higher voltage, and MnO precipitating accompanied with Mn2+ dissolution on the cathode and OH- generated on NTP.
[Fe(CN)6]4-
dissolution
[Fe(CN)6]3-
dissolution
MnO precipitation
[Fe(CN)6]α- deposition
H3O+ extraction Partially O2↑
[Fe(CN)6]4-
dissolution [Fe(CN)6]3- dissolution
MnO precipitation No dissolution or no precipitation
Strong acidic Mild acidic
deposition
Deterioration process in 1 mol/kg NaClO4 aq.
Volta
ge/V
vs.
Ag/
AgC
l
Specific capacity/mAh g-1-anode
NMHCF
Voltage/V vs. N
a/Na
+
Specific capacity/mAh g-1-anode
Specific capacity/mAh g-1-cathode Specific capacity/mAh g-1-cathode
NTP NTP
NMHCF 4
3
2
1
1.3 V cut1.2 V cut
1 mol/kg NaClO4 aq. 2.0 mA cm-2
17 mol/kg NaClO4 aq. 2.0 mA cm-2
150100500
150100500
1st 2nd
-2
-1
0
1
24003002001000
1st 2nd
150100500
Deterioration process in 1 mol/kg NaClO4 aq.
Water decomposition 2H2O + 2e- → H2↑ + 2OH-
Cathode decomposition Na2-xMn[Fe(CN)6] + 2NaOH → Na4-x[Fe(CN)6] + MnO↓ + H2O
2H2O + 2e- → H2↑ + 2OH-
100
50
010080604020
100
50
010080604020
Electrolyte concentration & rate dependences on cyclability of NMHCF cathode
Better cycle performances of NMHCF cathode were obtained in more concentrated electrolytes and at larger current densities.
Cycle number
Dis
char
ge c
apac
ity/m
Ah
g-1
Fe2+/Fe3+ + Mn2+/Mn3+
Fe2+/Fe3+
Dis
char
ge c
apac
ity re
tent
ion/
%
Cycle number
Concentration dependence at const. 2.0 mA cm-2
Rate dependence in const.17 mol/kg electrolyte
17 mol/kg
14 mol/kg
10 mol/kg
7 mol/kg
1 mol/kg
5.0 mA cm-2
2.0 mA cm-2
Binding energy/eV Binding energy/eV730 720 710 700
NMHCF cathode operation (structural & metal ion valence changes)
1.5 1.0 0.5 0.0
300
250
200
150
100
50
0
-50
Voltage/V vs. Ag/AgCl
Cap
acity
/mA
h g-
1
XPS of Fe XPS of Mn XRDC/D profile of NMHCF in 17 mol/kg NaClO4 aq.
NMHCF cathode worked with Fe2+/Fe3+ redox, partial Mn2+/Mn3+ redox and Na ion extraction/insertion in highly concentrated 17 mol/kg NaClO4 aq.
181716660 650 6402θ/degree
Calc. valence
state
Fe2+
/Mn2+
Fe3+
/Mn2+
Fe3+
/Mn2.43+
Fe3+
/Mn2+
Fe2+
/Mn2+
Calc. Na
amount
1.24
0.42
0
0.42
1.24
monoclinic
monoclinic
cubic
cubic
tetragonal
100
50
020151050
1.00.50.02.5
2.0
1.5
1.0
0.5
0.0150100500
1.51.00.50.0
1st 2nd
x in Na1.24-xMn[Fe(CN)6]0.81·1.28H2O
Capacity/mAh g-1–cathode
Volta
ge/V
vs.
NaT
i 2(P
O4)
3
2.0 mA cm-2
0.5 ~ 2.0 V
100806040200
5040302010
Ret
entio
n/%
Cycle number
Current density/mA cm-2D
isch
arge
cap
acity
/mA
h g-
1 cat
hode
Cathode: 20 mg cm-2, 200 µm
Anode: 30 mg cm-2, 200 µm
High voltage aqueous sodium-ion battery of NMHCF/17 m NaClO4 aq./NTP
Na1.24Mn[Fe(CN)6]0.81/17 mol/kg NaClO4 aq./NaTi2(PO4)3 operates at 1.3, 1.5 & 1.8 V. The cell exhibited initial discharge capacity of 117 mAh g-1, good cycle & rate performances.
Current density/A g-1-cathode
0.5 ~ 2.0 V
Conclusions
Conclusion
Electrodes selection
Na2MnFe(CN)6 cathode & NaTi2(PO4)3 anode were selected because of high voltage combination and low cost of the materials.
Electrolyte selection
Low cost NaClO4 salt can realize highly concentrated aqueous electrolyte, which suppresses water decomposition.
Effect of concentrated electrolyte
Concentrated 17 mol/kg electrolyte suppressed the water decomposition and dissolution of NMHCF cathode compared to diluted 1 mol/kg electrolyte.
Factor of cathode deterioration in 1 mol/kg electrolyte
Prussian blue analogue cathode was decomposed by hydroxide ion occurred on the anode because of the small practical stability window of 1 mol/kg electrolyte.
High voltage aqueous sodium-ion battery
Na1.24Mn[Fe(CN)6]0.81/17 mol/kg NaClO4 aq./NaTi2(PO4)3 operates over 1.2 V. The cell delivered initial discharge capacity of 117 mAh g-1, good cycle & rate performances.
Thank you for your attention
Acknowledgement
This research was financially supported by ESICB, Elements Strategy Initiative for Catalysts and Batteries
Project, MEXT, Japan.