Supporting Information to the manuscript entitled
An Electrochemical Cell for Selective Lithium
Capture from Seawater
Joo-Seong Kim,†,‡,# Yong-Hee Lee,†,‡,# Seungyeon Choi,†,‡ Jaeho Shin,§ Hung-Cuong
Dinh,⊥,‖ and Jang Wook Choi *,†,‡
†
Graduate School of Energy, Environment, Water, and Sustainability (EEWS), ‡Center for
Nature-inspired Technology (CNiT) in KAIST Institute NanoCentury, and §Department of
Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and
Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-338, Republic of Korea
⊥Laboratory
for Materials and Engineering of Fibre Optics, Institute of Materials Science
(IMS), Vietnamese Academy of Science and Technology (VAST), 18 Hoang Quoc Viet road,
Cau Giay District, Hanoi, Vietnam
‖
#
International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for
Materials Science (NIMS), 1-1 Namiki, Tsukuba 305-0044, Japan
These authors contributed equally.
*
Corresponding author
Phone: +82-42-350-1719;
fax: +82-42-350-2248;
Number of pages : 8
Number of tables : 4
Number of figures : 5
S1
e-mail: [email protected]
Standard mean chemical composition
Metal ion
[Unit: mg(Metal)/kg(Seawater)]
[Unit: mmol/kg(Seawater)]
Na+
10781.45
468.9674
Mg2+
1283.72
52.8171
Ca2+
412.08
10.2821
K+
399.10
10.2077
Sr2+
7.95
0.0907
Li+
0.183
0.0264
Table S1. The mass and mole fractions of various cations in seawater.
Alkali
metal ion
Crystal ionic
Radius
Alkaline earth
metal ion
Unit: pm
Crystal ionic
radius
Li+
90
Mg2+
86
Na+
116
Ca2+
114
K+
152
Sr2+
132
Table S2. Ionic radii of alkali metal and alkaline earth metal ions.
S2
Unit: g/100g H2O @ 20 °C
Alkali metal
(bi)carbonate
Solubility
Alkaline earth
metal carbonate
Solubility
Li2CO3
1.33
MgCO3
0.039
Na2CO3
21.5
K2CO3
Aragonite
: 0.0007753,
111
CaCO3
LiHCO3
5.74
NaHCO3
9.6
KHCO3
33.7
Calcite
: 0.0006170
SrCO3
0.0011
Table S3. The solubility of alkali metal and alkaline earth metal ions at 20 °C.
Unit: kJ/mol
Alkali
metal ion
-ΔH°hyd (expt.)
Alkaline earth
metal ion
-ΔH°hyd (expt.)
Li+
519
Mg2+
1921
Na+
409
Ca2+
1577
K+
322
Sr2+
1443
Table S4. Hydration enthalpy of alkali metal and alkaline earth metal ions.
S3
Figure S1. The effect of polydopamine (pD) coating on c-FP (pD-c-FP). (a-b) The first and
(c-d) the fifth Li capture-release profiles measured under the 3-electrode configuration.
Platinum mesh and Ag/AgCl were used as the other electrode and RE, respectively. The red
and black lines represent the samples with and without pD coating.
S4
Figure S2. Structural characteristics of olivine and maricite. (a) Atomic-level lattice changes
of FP upon Li or Na ion insertion. (b) Structural energy difference between olivine (NaFePO4)
and maricite (FeNaPO4). (c) A single particle level phase transition upon Li/Na ion insertion.
S5
Figure S3. (a) Li/Na ion preference tests by simple dipping c-FP powder. Briefly, the c-FP
powder was dipped into 0.5 M of LiI (left) and NaI (right) acetonitrile solutions. After 5 min
dipping the powder, the final solution was collected in each vial. The more brownish color in
the LiI case indicates more pronounced oxidation reaction from 3I- to I3-, which is
accompanied with a higher extent of alkali ion insertion into c-FP. Reversible Li capture
system in the (b) initial, (c) Li capture, and (d) Li release states. The I-/I3- redox couple, 5%
pD-c-FP electrode, and Ag/AgCl were used as the working, counter, and reference electrodes,
respectively. The Li release was achieved by reversing the current direction compared to that
of the Li capture.
S6
Figure S4. Contact angle images of prepared electrodes by varying the amount of pD coating.
(a) Pristine c-FP, (b) 5% pD-c-FP, (c) 10% pD-c-FP, (d) 20% pD-c-FP, and (e) 50% pD-c-FP
electrodes. (f) Changes in contact angle of the c-FPs electrodes with different pD contents.
All the measurements were conducted for the electrodes that contain c-FP, denka black, and
PVDF in a weight ratio of 8:1:1.
S7
Figure S5. Stable potential profiles during Li capture processes under the constant current
mode.
S8