ars.els-cdn.com · Web viewThe reaction mixture was kept under reflux at 200 C for 6 hours. The...
Transcript of ars.els-cdn.com · Web viewThe reaction mixture was kept under reflux at 200 C for 6 hours. The...
Decreasing redox voltage of terephthalate-based electrode
material for Li-ion battery using substituent effect
A. E. Lakraychi,a-d F. Dolhem,b-d F. Djedaïni-Pilard,b-d A. Thiam, a,c,d C. Frayret, a,c,d M.
Becuwe*a,c,d
(a) Laboratoire de Réactivité et Chimie des Solides (LRCS), UMR CNRS 7314, Université de
Picardie Jules Verne (UPJV), Amiens, 33 rue Saint-leu, 80039 Amiens, France
(b) Laboratoire de Glycochimie, des Antimicrobiens et des Agroressources (LG2A), UMR CNRS
7378, Université de Picardie Jules Verne (UPJV), Amiens, 33 rue Saint-leu, 80039 Amiens, France
(c) Institut de Chimie de Picardie (ICP), FR 3085, 33 rue Saint-leu, 80039 Amiens, France
(d) Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, France
Synthesis details
Synthesis of the 2,5-dimethyl terephthalic acid 1:
CH3
CH3
Br
Br
CH3
CH3
CN
NC
CH3
CH3
OO
OH
OH
CuCN, NMP
200°C/6h
H2SO4/H2O
160°C/24h
LiOH.H2O
MeOH/90°C16h
40% 92% 97%
To prepare the dimethylterephthalate acid (DMT), 2.78 g (30,3 mmole) of CuCN was dissolved in 50
mL of N-methylpyrrolidone (NMP) followed by the addition of 2 g (7.56 mmole) of dibromo-p-xylene
1. The reaction mixture was kept under reflux at 200 °C for 6 hours. The mixture was precipitated in
ammonia solution 38% and was washed with an aqueous solution of Ethylene diamine tetraacetic acid
tetrasodium salt (EDTA) to obtain 1.7 g of 1,4-dicyano-2,5-dimethylbenzene 2 (40%) corresponding
1
to a brown solid. The 1,4-dicyano-2,5-dimethylbenzene 2 was hydrolyzed with H2SO4 acid in
deionized water under reflux at 160 °C for one day. The mixture was precipitated and washed several
times with water to give dimethylterephthalic acid 3 (DMT), a light brown solid.
CH3
CH3
Br
Br
CH3
CH3
CN
NC
CH3
CH3
CO2H
HO2C
Synthesis of dilithium 2,5-dimethyl-terephthalate 2:
The synthesis of dimethylterephthalate dilithium salt (Li2-DMT) was adapted from a procedure by
Ogihara et al.2. Briefly, 0.455 g (10.8 mmol, 2.1 eq) of lithium hydroxide monohydrate (LiOH.H2O)
and 1 g (5.1 mmol, 1 eq) of dimethyl terephthalic acid were ground together in a mortar and then
dissolved in 30 mL of methanol. The solution initially remained clear, with a white precipitate forming
over the course of 30 min; the obtained suspension was stirred under reflux for one night. The solid
obtained after centrifugation was washed with methanol several times and dried under vacuum at 120
°C for one day. The retrieved powder exhibits a light brown color (1 g, 98% yield).
1H liquid NMR δH (400 MHz; D2O; Me4Si) : 7.03 ( 1H, s), 2.19 ( 1H, s)
Further characterization and electrochemical tests
2
Powder X-Rays Diffraction patterns (XRPD) were acquired using a Bruker D8 diffractometer
equipped with a Cu target (Kα radiation, operating at 40kV–40mA). Patterns were collected in the 2θ
range of 10–60° with a step size of 0.03. Crystal structure resolution was not possible owing to
preferential orientation.
10 µm
Scattering angle 2θ ( � )-CoKα
Inte
nsity
(a.u
.)
Li2-DMTDMT
Figure S1: Evolution of X-rays diffraction patterns before (blue curve) and after lithiation (red curve)
C = 2.02 mg/l
0
0,1
0,2
0,3
0,4
0,5
0,6
0 0,5 1 1,5 2 2,5 3 3,5
Abso
rban
ce
Concentration (ppm)
LA107_Li2-DMT
Figure S2: Estimation of lithium stoichiometry using atomic absorption spectrometry
3
% and type of Carbon
MillingTime
1st discharge capacity(x e-/mAh.g-1)
1st charge capacity(x e-/mAh.g-1)
2nd discharge capacity(x e-/mAh.g-1)
2nd charge capacity (x e-/mAh.g-1)
20th discharge capacity(x e-/mAh.g-1)/% Cth
Capacity retentionafter 20 cycles
Planetaryball mill
30% of Csp 5 h 0 Li / 0 mAh.g-1 0 Li / 0 mAh.g-1 0 Li / 0 mAh.g-1 0 Li / 0 mAh.g-1 0 mAh.g-1 -
20% of Csp +10% of SFG-44 5 h 1.6 Li / 208 mAh.g-1 0.5 Li / 65 mAh.g-1 0.5 Li / 65 mAh.g-1 0.5 Li / 65 mAh.g-1 65 mAh.g-1
31 %
10% of Csp +20% of SFG-44 5 h
1.7 Li / 221 mAh.g-1 0.8 Li / 104 mAh.g-1 0.8 Li / 104 mAh.g-1 0.8 Li / 104 mAh.g-1 104 mAh.g-1 47 %
5% of Csp +25% of SFG-44 5 h 1.7 Li / 221 mAh.g-1 0.8 Li / 104 mAh.g-1 0.8 Li / 104 mAh.g-1 0.8 Li / 104 mAh.g-1 104 mAh.g-1 47 %
Laboratoryball mill
40% of SFG-44 10min 1.7 Li / 221 mAh.g-1 0.7 Li / 91 mAh.g-1 0.7 Li / 91 mAh.g-1 0.7 Li / 91 mAh.g-1 91 mAh.g-1/35% 41 %
40% of SFG-44 30min 2.5 Li / 325 mAh.g-1 1.1 Li / 143 mAh.g-1 1.1 Li / 143 mAh.g-1 1.1 Li / 143 mAh.g-1 143 mAh.g-1/55% 44 %
40% of SFG-44 1h 2.7 Li / 351 mAh.g-1 1.1 Li / 143 mAh.g-1 1.1 Li / 143 mAh.g-1 1.1 Li / 143 mAh.g-1 143 mAh.g-1/55% 41%
30% of SFG-44 30min 2.2 Li / 286 mAh.g-1 1.1 Li / 143 mAh.g-1 1.1 Li / 143 mAh.g-1 1.1 Li / 143 mAh.g-1 143 mAh.g-1/55% 50 %
30% of SFG-44 45min 1.6 Li / 208 mAh.g-1 0.8 Li / 113 mAh.g-1 0.8 Li / 113 mAh.g-1 0.8 Li / 113 mAh.g-1 113 mAh.g-1/43% 54 %
30% of SFG-44 1h 1.8 Li / 234 mAh.g-1 0.4 Li / 52 mAh.g-1 0.4 Li / 52 mAh.g-1 0.4 Li / 52 mAh.g-1 52 mAh.g-1/20% 22 %
25% of SFG-44 1h 1.4 Li / 182 mAh.g-1 0.6 Li / 78 mAh.g-1 0.6 Li / 78 mAh.g-1 0.6 Li / 78 mAh.g-1 78 mAh.g-1/30% 43 %
20% of SFG-44 1 h 1.7 Li / 221 mAh.g-1 0.7 Li / 91 mAh.g-1 0.7 Li / 91 mAh.g-1 0.7 Li / 91 mAh.g-1 91 mAh.g-1/35% 41 %
20% of SFG-44 30 min 2.1 Li / 273 mAh.g-1 1.2 Li / 160 mAh.g-1 1.2 Li / 160 mAh.g-1 1.2 Li / 160 mAh.g-1 160 mAh.g-1/61% 58 %
20% of SFG-44 20 min 2.1 Li / 273 mAh.g-1 1.2 Li / 160 mAh.g-1 1.2 Li / 160 mAh.g-1 1.2 Li / 160 mAh.g-1 160 mAh.g-1/61% 58 %
20% of SFG-44 10 min 1.5 Li / 195 mAh.g-1 0.5 Li / 65 mAh.g-1 0.5 Li / 65 mAh.g-1 0.5 Li / 65 mAh.g-1 65 mAh.g-1/25% 33 %
Figure S3: Optimization of electrode composition and electrochemical performances
5µm
Li2-DMT + Super Pcomposite
Figure S4: Material’ and composite morphologies determined using Scanning Electron Microscopy
4
18
Pote
ntia
l(V)
vs.
Li+ /L
i0
Pote
ntia
l(V)
vs.
Li+ /L
i0
Pote
ntia
l(V)
vs.
Li+ /L
i0
Pote
ntia
l(V)
vs.
Li+ /L
i0
X in Li2-DMTX in Li2-DMT
X in Li2-DMTX in Li2-DMT
1 C C/5
C/10 C/30
Figure S5: Electrochemical curve obtained for Li2-DMT composite (20% of SFG-44) at different current
rate
Figure S 6 : Electrochemical curve obtained for pure Graphite (SFG-44)
5
Positive Electrode
NegativeElectrode
Voltage output
[VLi]
Capacitynegative[mAh.g-1]
Capacitypositive
[mAh.g-1]
Energynegative[Wh.Kg-1]
EnergyPositive
[Wh.Kg-1]
Energy Cell(Wh.Kg-1)
LiFePO4 Graphite 3.2 372 170 1190 540 373
LiFePO4 Li4Ti5O12 1.9 175 170 333 323 166
LiFePO4 Li2-DMT 2.8 260 170 728 476 288
LiFePO4 Li2-DMT 2.8 160* 170 448 476 230
LiFePO4 Li2-DMT 2.8 128* 170 358 476 204
* Gravimetric capacity per gram of active material* Gravimetric capacity per gram of electrode
Figure S7: Comparison of Li2-DMT with leading contender (LTO and graphite) in term of gravimetric
energy density using LiFePO4 as positive electrode material on the basis of calculation and assumption
described in the literature.3
References:
1 H. Huang, Q. He, H. Lin, F. Bai, Z. Sun and Q. Li, Polym. Adv. Technol., 2004, 15, 84–88.
2 N. Ogihara, T. Yasuda, Y. Kishida, T. Ohsuna, K. Miyamoto and N. Ohba, Angew. Chemie Int.
Ed., 2014, 53, 11467–11472.
3 Y.-C. Lu, B. M. Gallant, D. G. Kwabi, J. R. Harding, R. R. Mitchell, M. S. Whittingham and
Y. Shao-Horn, Energy Environ. Sci., 2013, 1–9.
6