Arcangelo Celeste, Vittorio Pellegrini, Sergio Brutti, Laura Silvestri
Lithium Rich Transition Metal Oxides as high capacity positive
electrode materials in Li-ion cells
Nanoinnovation, Roma17th September 2020
IntroductionLithium Ion Batteries
Nanoinnovation, Roma17th September 2020
IntroductionLi-rich Transition Metals Layered Oxides
Nanoinnovation, Roma17th September 2020
Lithium
Cobalt
Nickel
Manganese
Lithium Cobalt Oxide(LCO)
Low Specific Capacity
Structural Change
Cobalt is toxic and expensive
Lithium Nickel Manganese Cobalt Oxide
(NMC)More Eco-Friendly
Poor Rate Capability
Low Specific Capacity
Lithium-Rich Nickel Manganese Cobalt Oxide
(LR-NMC)
𝑳𝒊𝟏+𝒙 𝑵𝒊𝑪𝒐𝑴𝒏 𝟏−𝒙𝑶𝟐⇆ 𝒛𝑳𝒊+ + 𝒛𝒆− + 𝑳𝒊(𝟏+𝒙−𝒛) 𝑵𝒊𝑪𝒐𝑴𝒏 𝟏−𝒙𝑶𝟐
High SpecificCapacity
High SpecificEnergy
Cheap
Nanoinnovation, Roma17th September 2020
IntroductionLi-rich Transition Metals Layered Oxides
Nanoinnovation, Roma17th September 2020
• Synthesis of Li1.2Ni0.13Co0.13Mn0.54O2
• X-Ray Diffracion and Rietveld• Scanning Electron Microscope, Energy-
Dispersive X-Ray Spectroscopy• Galvanostatic Cycling• Cyclic Voltammentry• Li-ion Battery test
Outline
Sol-Gel Synthesis of Li1.2Ni0.13Co0.13Mn0.54O2
• Stoichiometric Ratio C2H2O4 : M = 1.5:1• pH value was controlled with ammonia
Nanoinnovation, Roma17th September 2020
Monoclinic
Scatt
ere
d In
ten
sity
LiMO2 ICSD 98-017-3137
10 20 30 40 50 60 70 80 90
2q Degree
Li2MnO3 ICSD 98-020-2639
Rhombohedral
Structural AnalysisSynchrotron Diffraction Pattern
Ref
eren
ce
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Elettra MCX beamline, wavelength 1.2 Å (10 KeV)10° ≤ 2𝜃 ≤ 90°
Structural AnalysisRietveld Refinement
Stoichiometry wR(%)
Li1.2Mn0.54Ni0.13Co0.13O2 4.55
Structural
Model
Cell
Parameters
Atoms Wyckoff
Position
Atomic
Coordinates
Occupancies
R-3m𝐚 = 𝟐. 𝟖𝟓𝟒
𝐛 = 𝟏𝟒. 𝟐𝟑𝟗
Li/Ni
Mn/Co/Ni/Li
O
3b
3a
6c
0, 0, 0.5
0, 0, 0
0, 0, 0.739
0.99/0.01
0.54/0.13/0.12/0.21
1.0
10 20 30 40 50 60 70 80
Sca
tte
red
In
tensity
2q
Obs
Calculated Profile
Bkg
Difference Line
Nanoinnovation, Roma17th September 2020
Elettra MCX beamline, wavelength 1.2 Å (10 KeV)5° ≤ 2𝜃 ≤ 90°
Morphological AnalysisScanning Electron Microscope –
Energy-dispersive X-ray spectroscopy
Mn
Co
Ni
Electrochemical PerformancesGalvanostatic Cycling
0 20 40 60 80 100 120 1400
40
80
120
160
200
240
280
320
360
400
Sp
ecific
Ca
pa
city (
mA
h/g
)
Cycle Number
Charge
Discharge
0
50
100
150
200
250
300
350
400
Cu
rre
nt
(mA
/g)
0 50 100 150 200 250 300 350 400 450 5000
40
80
120
160
200
240
280
320
360
400
Sp
ecific
Ca
pa
city (
mA
h/g
)
Cycle Number
Charge
Discharge• Specific Capacity over 220 mAh/g.
• LR-NMC is able to substain high currents.
• Capacity Retention is 62% after 500 cycles.
Li/LP30 (1M LiPF6 in EC:DMC)/LR-NMC 2-4.8V
Current density = 377 mA/g
0 20 40 60 80 100 120 140 160 180 2000
40
80
120
160
200
240
280
320
360
400
Sp
ecific
Ca
pa
city (
mA
h/g
)
Cycle Number
Charge
Discharge
50
60
70
80
90
100
Co
ulo
mb
ic E
ffic
ien
cy (
%)
Current density = 37.7 mA/g
Nanoinnovation, Roma17th September 2020
2.0 2.5 3.0 3.5 4.0 4.5 5.0-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Curr
ent D
ensity (
mA
/cm
2)
Potential (V vs Li)
Cycle 1
Cycle 2
Cycle 3
Cycle 4
Cycle 5
Electrochemical BehaviorCyclic Voltammetry
FIRST ANODIC SCAN
FIRST CATHODIC SCAN
Li/LP30 (1M LiPF6 in EC:DMC)/LR-NMC2-5 VScan rate: 0.5 mV/s
𝐿𝑖 𝑀 𝑂2 ↔ 𝑧𝐿𝑖+ + 𝑧𝑒− + 𝐿𝑖 1−𝑧 𝑀 𝑂2
𝐿𝑖2𝑀𝑛𝑂3 ↔ 𝑧𝐿𝑖+ + 𝑧𝑒− + 𝐿𝑖 2−𝑧 𝑀𝑛𝑂2 + 𝑂2−
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0 50 100 150 200 250 300 350 4002.0
2.5
3.0
3.5
4.0
4.5
Ce
ll P
ote
ntia
l (V
vs L
i)
Specific Capacity (mAh/g)
Cycle 1
Cycle 2
Cycle 10
Cycle 30
Cycle 50
Cycle 100
Cycle 150
Cycle 200
Electrochemical BehaviorGalvanostatic Cycling
Li/LP30 (1M LiPF6 in EC:DMC)/LR-NMC2-4.8 VCurrent Density: 37.7 mAh/g
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0 20 40 60 80 100 120 140 160 180 2002.8
3.0
3.2
3.4
3.6
3.8
Avera
ge D
ischarg
e P
ote
ntial (V
)
Cycle Number
0 20 40 60 80 100 120 140 160 180 2000.0
0.2
0.4
0.6
0.8
1.0
Pote
ntial H
yste
resis
Cycle Number
VOLTAGE DECAY
INCREASE IN POTENTIAL HYSTERESIS
0 50 100 150 2000
50
100
150
200
250
300
350
Specific
Cap
acity (
mA
h/g
)
Cycle Number
Charge
Discharge
Performances in Li-ion batteryGalvanostatic Cycling
LR-NMC/LP30/Graphite (Pi-Kem)• Potential range: 2.2-4.7V.• C-rate: 1C (230 mA/g)
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0 50 100 150 200 250 300 350
2.5
3.0
3.5
4.0
4.5
Cell
Pote
ntial (V
)
Specific Capacity (mAh/g)
Cycle 1
Cycle 100
Cycle 200
Conclusions
• A simple Sol-Gel synthesis is used to synthetizeLi1.2Ni0.13Co0.13Mn0.54O2
• XRD and Rietveld showed a complex structure.
• Li1.2Ni0.13Co0.13Mn0.54O2 has a very highelectrochemical perfomances.
• Several drawbacks, such as voltage decay andhysteresis increase.
Nanoinnovation, Roma17th September 2020
Thank you for your attention!
Nanoinnovation, Roma17th September 2020
