Phosphate for high rate application - Phostech Lithium inc.

Amperex Technology Limited / Phostech Lithium Inc.
Phosphate for high rate application
Presented at:
THE 25TH INTERNATIONAL BATTERY SEMINAR & EXHIBIT
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Outline
LiFePO 4 characteristics
LiFePO 4 /C powder by Phostech
ATL IFR18650 performance
• Cell information
• Continuous discharge at different rate
• Temperature rise at different rate
• Ragone plot
• 1C discharge at different temperature
• 4A/6C cycle performance
Conclusion
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LiFePO 4 characteristics
Thermal stability of FePO 4
phase after full
charge
• Covalent P-O bonding makes the skeleton of
LiFePO 4 and shows less effects by Li ions.
• No O 2 release for overcharge and overheat,
much safer than other commercial cathode
materials.
• Possibility to decrease costs associated to
external safety devices
Good electrochemical characteristics
• Long Calendar Life for the stable olivine
structure
• High tolerance to high and low-voltage abuse
• Lower thickness change of full cell during
charge and discharge provides stable
performance for negative swelling rate of
cathode.
Abundant resource of basic elements
• Fe and P are common components
Environmentally friendly
• No toxic elements
Compound a(Å) b(Å) c(Å) V (Å 3 )
LiFePO 4
10.3449 6.0137 4.6990 292.33
FePO 4
9.8213 5.7927 4.7886 272.43
Charge
Discharge
The olivine structure is stable during Liions
insertion and extraction.
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LiFePO 4 characteristics
Some physical parameters of cathode materials
• Cathode Electric conductivity Solid diffusion co-efficient
• LiCoO 2 10 -3 ~10 -4 S/cm 10 -7 ~10 -9 cm 2 /s
• LiMn 2 O 4 10 -5 ~10 -6 S/cm 10 -9 ~10 -12 cm 2 /s
• LiFePO 4 10 -9 ~10 -10 S/cm 10 -12 ~10 -14 cm 2 /s
Pure LiFePO 4, shows lower conductivity for the one-dimensional model of Li + diffusion
among 3D structure. Lower solid diffusion co-efficient and electron conductivity, are
major problems before it can be applied in power cell.
How to improve conductivity and rate performance
Phostech C-LiFePO
• Carbon coating
4 , P2
Drs. M.Armand and N. Ravet, of University de Montréal
Introduced and patented nano-painting of LiFePO 4 with
a Carbon electronic conductor in 1998
• Nano-structured
Decrease the distance of Li + insertion/extraction in particle
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ATL IFR18650 performance
Cell information
ATL-IFR18650
Cathode material
Nominal voltage
Nominal discharge capacity at 1C
Nominal Impedance
Cell weight
Maximum continuous discharge current
Energy density
Power density
Phostech P2
LiFePO 4
3.2V
1.2Ah
20m!
39±1g
30A
100Wh/kg
240Wh/L
1800W/Kg
3800W/L
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ATL IFR18650 performance
Continuous discharge at different rate
Charge: 1C CC to3.65V,CV to 60mA
4.0
High Rate Discharge
Continuous discharge at 23 3.65V-2.0V,1C=1.2A
Voltage (V)
3.5
3.0
2.5
2.0
1C
10C
15C
20C
25C
1.5
1.0
0 300 600 900 1200 1500
Capacity (mAh)
Rate
1C
10C
15C
20C
25C
Power (W)
3.84
34.6
49.5
62.9
73.5
Energy (Wh)
4.03
3.69
3.47
3.14
2.46
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ATL-IFR18650 performance
Ragone plot
Ragone plot
1000
Energy density(Wh/L)
100
10
100 1000 10000
Pow er density(W/L)
• Increase in power density hasn't led to obvious
decrease in energy density.
Amperex Technology Limited
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ATL IFR18650 performance
Temperature rise at different rate
Charge: 1C CC to3.65V,CV to 60mA
70
Temperature rise
Continuous discharge at 23 3.65V-2.0V,1C=1.2A
Temperature rise()
60
50
40
30
20
10
1C
10C
15C
20C
25C
0
0 300 600 900 1200 1500
Capacity(mAh)
• Temperature rise is below 60 ºC even after 25C continuous
discharge to 2.0V
Amperex Technology Limited
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ATL-IFR18650 performance
1C discharge at different temperature
Charge: 23℃, 1C CC to3.65V,CV to 60mA
4.0
H/L Temp Performance
Continuous discharge 3.65V-2.0V/1C
Voltage(V)
3.5
3.0
2.5
60
25
0
-10
-15
-20
2.0
1.5
0% 20% 40% 60% 80% 100% 120%
Discharge Rate(%)
• 80% capacity retention even at -15ºC
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ATL-IFR18650 performance
4A/6C cycle
Charge: 4A CC to 3.65V,CV to 60mA, Discharge:6C to 2.0V.
1600
Capacity Retention vs. Cycle_Index
23 4A/6C, 2.0-3.65V
1400
Capacity Retention (%)
1200
1000
800
600
400
200
0
0 500 1000 1500 2000 2500 3000 3500 4000
Cycle
• Excellent 4A/6C cycle performance
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Conclusion
LiFePO 4 as one promising cathode material displays
significant advantages of low cost, environmentally
benign and reliability. The limitation of poor rate
performance has been solved by carbon coating and
nano-structured in Phostech P2 Powder.
ATL IFR18650 with Phostech LiFePO 4 demonstrates
excellent rate performance and reliability, which has
been employed in power tools.
Amperex Technology Limited
Surpassing customer’s expectation