Performance and Safety Testing of Panasonic 2.9 Ah Li-ion NCR
18650 Cells
Jon S. Read ESCG/NASA- JSC, Judith Jeeverajan Ph. D./NASA-JSC, Pranav Patel ESCG/NASA- JSC, Joe Bytella BAE
Systems , and Symmetry Resources Inc.
Nov. 2009 Jon S. Read ESCG/NASA-
JSC
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Outline • Cell Characteristics • Performance • Safety
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Panasonic NCR Cell Characteristics
• Voltage :3.6 V • Capacity :2.9 Ah • Dimensions : • Height: 65 mm • Diameter: 18 mm • Mass: 44.0g
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Rate Capability
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Rate Capability
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Rate Capability
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Rate Capability
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Rate Capability
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Rate Capability
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Charge Dischar
ge Cycle Capacity Energy Change in Energy
Density
Rate Rate Number (Ah) Density (Wh/
kg) From 1 to 200 Cycles
(Wh/kg) C/5 C/10 1 2.917 241.91
200 2.792 231.28 10.63 C/5 C/5 1 2.899 239.06
200 2.676 219.69 19.37 C/5 C/2 1 2.827 228.25
200 2.622 210.50 17.75 C/5 C 1 2.817 221.75
200 2.493 194.51 27.24 C/10 C/10 1 2.914 242.34
200 2.781 230.88 11.46 C C 1 2.812 222.15
200 1.195 88.97 133.19
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Rate Capability
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Rate Capability
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1.5
2
2.5
3
3.5
0 20 40 60 80 100 120 140 160 180 200
C/10 charge C/10 discharge C/10 charge C discharge C/5 charge C discharge C/2 charge C discharge C charge C discharge
Cap
acity
(A
h)
Cycle Number
Capacity Fade Over 200 Cycles Due to Charging at Different Rates and then Discharging at C at Room Temperature
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Performance Capability at Different Temperatures
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0 5 10 15 20 25 30
Cap
acity
Del
iver
ed (A
h)
Cycle Number
PERFORMANCE CAPABILITY AT DIFFERENT TEMPERATURES (Protocol B.2)
Nominal Capacity = 2.900 Ah
Capacity Delivered versus cycle Number for Panasonic NCR18650
0 °C at C/2 rate
3 cells per test
23 °C at C/2 rate 40 °C
0 °C at C/10 rate
-10 °C at C/2 rate
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Internal Resistance
0
20
40
60
80
100
120
140
160
180
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
0 20 40 60 80 100
Inte
rnal
Res
ista
nce
(moh
m)
Volta
ge (V
)
% Depth of Discharge
INTERNAL RESISTANCE (Protocol B.3) Voltage and Internal Resistance versus Depth of Discharge (%)
Voltage
Internal resistance
3 cells tested
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Overcharge
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Overdischarge –
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Overdischarge –
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Short Circuit, External
•
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Short Circuit, Internal
•
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Short Circuit, Internal
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Heat to Vent
Before
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After
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Summary
• The cell capacity degrades significantly over the course of 200 cycles especially at the C charge and discharge rates at room temperature. This capacity degradation is exacerbated at lower temperatures (-10oC)
• No potentially hazardous events were observed during the overcharge, overdischarge, or external short circuit tests. Extreme heat and fire were observed in most of the internal short circuit and heat-to-vent tests.
• Only the external short circuit test cells were functional after testing. The overcharged cells were open circuited, the overdischarged into reversal test cells were short circuited, and all cells from both the internal short circuit and the heat-to-vent tests suffered extreme thermal damage and loss of cell containment integrity. Jon. S. Read ESCG/NASA-JSC
