The document describes research on developing asymmetric hybrid supercapacitors based on lithium-ion intercalated compounds. Specifically, it discusses synthesizing cathode materials of pure LiCoO2 and LiCo1-xAlxO2 with varying amounts of aluminum doping (x=0, 0.2, 0.4, 0.6). The materials were characterized using techniques like thermal analysis, X-ray diffraction, and Fourier transform infrared spectroscopy. Electrochemical characterization of the materials was also performed through cyclic voltammetry and charge/discharge testing to evaluate their performance in supercapacitors.

1. DEVELOPMENT OF NON-AQUEOUS
ASYMMETRIC HYBRID SUPERCAPACITORS
BASED ON Li-ION INTERCALATED COMPOUNDS
GUIDE
Dr.D.KALPANA, SCIENTIST, BY
EEC DIVISION, NAKKIRAN.A,
CECRI,
KARAIKUDI.

2. An overview of previous
presentations
 Introduction
 Hybrid supercapacitors
 Synthesis of LiMn2O4 and the same multidoped with
Ni, Co and Cu
 Physical characterization - XRD, SEM, FTIR
 Cell Fabrication
 Electrochemical characterizations
 Comparison of their performances

3. Study of supercapacitors
 Having LiCo1-xAlxO2 as cathodes
(where x=0,0.2,0.4 and 0.6)

4. Lithium Cobaltate(LiCoO2)
 Commercially successful
 The layered structure of
LiCoO2 enables easy
diffusion of Li-ions in
and out of the structure

5. Why Aluminum
 There has recently been considerable interest in Al-
doping of lithium intercalation oxides.
 Al substitution of the transition-metal cation has been
shown theoretically and experimentally to increase the
cell voltage.
 Some other advantages of Al are that it is light, non-
toxic, and inexpensive

6. Advantage
 The similarity of Al and Co ions in these
lithium metal oxides makes Al an attractive
choice for doping
 The end members, a-LiAlO2 and LiCoO2, have
the same crystal structure, layered a-NaFeO2
and the metal ions are close in size.
 These similarities remove the complications of
phase transitions and lattice strain when
varying doping content.

7. Synthesis Of Cathode Material
 Two cathode materials synthesized are,
i) Pure LiCoO2
ii) LiCoO2 doped with Al - LiCo1-xAlxO2 ( x = 0.2, 0.4,0.6 )
 The cathode material was synthesized by soft combustion method
 Compositions were taken on a stoichometric ratio based on
following equations,
LiNO3 + Co(NO3)2.6H2O LiCoO2 (for pure substance)
LiNO3 + (1-x) Co(NO3)2.6H2O + xAl(NO3)2.9H2O LiCo1-xAlxO2
(for doped substance)

8. Composition of precursors
required for synthesis
Basis : 0.2 moles of product
Weight of the material
Precursor
X=0 X=0.2 X=0.4 X=0.6
LiNO3 13.8g 13.8 g 13.8g 13.8
Al(NO3)2.9H2O - 15 g 30g 45g
Co(NO3)2.6H2O 58.2g 46.56 g 34.92g 23.28g
Glycine(C2H5NO2) 30g 30 g 30g 30g
Distilled Water 100ml 100 ml 100ml 100ml
X= Fraction of Aluminium

9. The Soft Combustion Process
Weighing of required chemicals
Dissolve in 100ml distilled water
Stir well at 600C
Heat the mixture at 1000C for 8 hours
Product is formed following a soft
combustion

10. Physical Characterization
 Thermal Analysis
 X-Ray Diffraction
 FTIR

11. Thermal Analysis
 TGA is used to find the optimum temperature ranges
for drying a sample to remove the moisture and
impurities from it.
 In DTA phase transitions or chemical reactions are
followed through observation of heat absorbed or
liberated.

12. TGA Curves
1.0
0.9
Weight fraction
0.8
0.7
0.6
LiCoO2
LiCo0.8Al0.2O2
0.5
LiCo0.6Al0.4O2
LiCo0.4Al0.6O2
0.4
0 200 400 600 800 1000 1200 1400
0
Temperature ( C)

13. DTA Curves
2.0
1.5
Temperature difference( C)
0
1.0
0.5
0.0
-0.5
LiCoO2
-1.0 LiCo0.8Al0.2O2
LiCo0.6Al0.4O2
-1.5 LiCo0.4Al0.6O2
-2.0
0 200 400 600 800 1000 1200
0
Temperature( C)

14. TGA Curves
 The initial weight drop from 300C-1500C is due to
moisture removal from the sample.
 the subsequent weight loss from 1500C to
3000Ccorresponds to elimination of organic
compounds from samples.
 Next weight drop in the temperature range of
3000C-5000C is formed as a result of the reaction of
unreacted precursors to give the final product.
 The stabilization temperature for these samples
mostly lay after 8000C.
 So the samples are heated at 8000C for 4 hours.

15. FTIR Curves
100
80
60
% Transmittance
40 LiCoO2
LiCo0.8Al0.2O2
LiCo0.6Al0.4O2
20 LiCo0.4Al0.6O2
0
500 1000 1500 2000 2500 3000 3500
-1
Wave numbers(cm )

16.  These are the FTIR spectroscopes of
LiCoO2, LiCo0.8Al0.2O2, LiCo0.6Al0.4O2, and LiCo0.4Al0.6O2
respectively
 For high level of Al substitution, the broadening of
the infrared peaks can be interpreted as an increase
in CoO6 distortion due to the incorporation of Al3+ in
the Co3+ site.

17. XRD Patterns
(003)
(104)
(006)
LiCo0.4Al0.6O2
(101)
(012)
(107)
(108)
(105)
(110)
(113)
(201)
LiCo0.6Al0.4O2
LiCo0.8Al0.2O2
LiCoO2
10 20 30 40 50 60 70 80 90 100
2 theta

18.  All samples are single phase and have the α-NaFeO2
structure (space group R3m).
 Miller indices (hkl) are indexed in the hexagonal
setting.
 No impurity phase was detected in the XRD patterns
of LiAlyCo1−yO2
 On Al doping, the (108) peak shifts towards lower 2θ
and the (110) peak shifts towards higher 2θ value

19. XRD Patterns
(108)
(110)
LiCo0.4Al0.6O2
LiCo0.6Al0.4O2
LiCo0.8Al0.2O2
LiCoO2
64 66 68

20. Electrochemical
Characterizations
 Cyclic Voltammetry
 Electrochemical Impedance Spectroscopy
 Galvanostatic Charge/Discharge

21. CV of LiCoO2/CNF before
cycles
0.0004
0.0002
0.0000
Current(A)
-0.0002
-0.0004
-0.0006
1mV/s
2mV/s
-0.0008
5mV/s
2000 1000 0 -1000 -2000
Voltage(mV)

22. CV of LiCoO2/CNF after 500
cycles
0.0002
0.0000
Current(A)
-0.0002
1mV/s
-0.0004 2mV/s
5mV/s
1500 1000 500 0 -500 -1000 -1500
Voltage(mV)

23. CV of LiCo0.8Al0.2O2/CNF before
cycles
0.0004
0.0002
Current(A)
0.0000
-0.0002
-0.0004 1mV/s
2mV/s
5mV/s
-0.0006
1500 1000 500 0 -500 -1000 -1500
Voltage(mV)

24. CV of LiCo0.8Al0.2O2/CNF after
500 cycles
0.0002
0.0001
Current(A)
0.0000
-0.0001
1mV/s
2mV/s
5mV/s
-0.0002
1500 1000 500 0 -500 -1000 -1500
Voltage(mV)

25. CV of LiCo0.6Al0.4O2/CNF before
cycles
0.00015
0.00010
0.00005
Current(A)
0.00000
-0.00005
-0.00010 1mV/s
2mV/s
5mV/s
-0.00015
1500 1000 500 0 -500 -1000 -1500
Voltage(mV)

26. CV of LiCo0.6Al0.4O2/CNF after
500 cycles
0.0006
0.0004
0.0002
Current(A)
0.0000
-0.0002
1mV/s
-0.0004 2mV/s
5mV/s
-0.0006
2000 1000 0 -1000 -2000
Voltage(mV)

27. CV of LiCo0.4Al0.6O2/CNF before
cycles
0.0004
0.0002
Current(A)
0.0000
-0.0002
1mV/s
2mV/s
-0.0004 5mV/s
1500 1000 500 0 -500 -1000 -1500
Voltage(mV)

28. CV of LiCo0.4Al0.6O2/CNF after
500 cycles
0.00010
0.00005
Current(A)
0.00000
-0.00005
1mV/s
2mV/s
-0.00010
1500 1000 500 0 -500 -1000 -1500
Voltage(mV)

29. Specific capacitance (F/g)
from CV
Scan rate
Composition
5mV/s 2mV/s 1mV/s
0 15.93 18.75 20.09
0.2 11.6 15.25 16.3
Before cycles
0.4 21.74 26.93 27.61
0.6 6.1 7.63 8.3
0 4.113 5.29 11.95
0.2 8.274 10.33 12.93
After cycles
0.4 16.225 19.74 21.51
0.6 - 5.1 6.4

30. Impedance Spectroscopy –
Before Cycles
-80
LiCoO2
LiCo0.8Al0.2O2
LiCo0.6Al0.4O2
-60 LiCo0.4Al0.6O2
ZIm(Ohm)
-40
-20
0
0 20 40 60 80 100
ZRe(Ohm)

31. Impedance Spectroscopy – After
500 Cycles
-250
LiCoO2
LiCo0.8Al0.2O2
-200 LiCo0.6Al0.4O2
LiCo0.4Al0.6O2
-150
ZIm(Ohm)
-100
-50
0
0 50 100 150 200 250
ZRe(Ohm)

32. Results of Impedance
Spectroscopy
Property Rs Cdl
x
Ohm mF
0 3.747 0.6194
0.2 2.392 0.5518
Before cycles
0.4 4.551 0.5491
0.6 5.649 0.6328
0 4.721 0.6567
0.2 6.253 0.5778
After cycles
0.4 4.782 0.621
0.6 6.211 0.711

33. Galvanostatic Charge-Discharge
behaviour of LiCoO2/CNF
2.1
2.0
1.6
1.4
Voltage(V)
Voltage(V)
1.2
0.8
0.7
0.4
0.0 0.0
350 400 450 500 550 600 5600 5610 5620 5630 5640 5650
Time(s) Time(s)
First cycle 500th cycle

34. Galvanostatic Charge-Discharge
behaviour of LiCo0.8Al0.2O2/CNF
2.0
1.6 1.6
Voltage(V)
Voltage(V)
1.2
0.8
0.8
0.4
0.0
26 28 30 32 34 36 38 40 42 0.0
1337 1338 1339 1340 1341 1342 1343 1344
Time(s)
Time(s)
First cycle 500th cycle

35. Galvanostatic Charge-Discharge
behaviour of LiCo0.6Al0.4O2/CNF
2.0
2.0
1.6
1.6
Voltage(V)
Voltage(v)
1.2
1.2
0.8
0.8
0.4 0.4
0.0 0.0
600 650 700 750 800 850 900 9120 9140 9160 9180 9200
Time(s) Time(s)
First cycle 500th cycle

36. Galvanostatic Charge-Discharge
behaviour of LiCo0.4Al0.6O2/CNF
2.0 2.0
1.6 1.6
Voltage(V)
Voltage(V)
1.2 1.2
0.8 0.8
0.4 0.4
0.0 0.0
105 110 115 120 125 130 135 140 145 11732 11736 11740 11744 11748 11752
Time(s) Time(s)
First cycle 500th cycle

37. Results of Galvanostatic
Charge-Discharge Analysis
Properties
Composition
Specific
Power density Energy density
capacitance
(kW/kg) (kWh/kg)
(F/g)
0 11.17 312.5 12.41
0.2 0.415 303.03 0.44
Before cycles
0.4 11.41 333.3 12.68
0.6 1.53 322.58 1.075
0 1.8 312.5 2.01
0.2 0.303 303.03 0.336
After cycles
0.4 3.83 333.33 4.25
0.6 0.88 322.58 0.986

38. Conclusion
 LiCoO2 is a good cathode material for hybrid
supercapacitor since it is having specific capacitance of
11 F/g.
 In the doped cathode materials, LiCo0.6Al0.4O2 is having
good capacitance and cycle behaviour.

39. Thank You

40. Queries?