MOFA Post-launch Battery – Increased Performance...

An advanced weapon and space systems company

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ATK OS Power Sources CenterATK OS Power Sources CenterATK Thiokol PropulsionATK Thiokol Propulsion

49th Annual NDIA Fuze ConferenceSeattle, WA

5-7 April 2005

MOFA Post-launch Battery – Increased Performance Reliability Through Electrolyte Changes

Authors:Paul F. Schisselbauer, ATK OS Power Sources CenterChuck Kelly, P.E. ATK OS Power Sources CenterEldon Bott, ATK ThiokolSeung Kee Min, Ph.D ATK ThiokolMarvin Hawkins, Ph.D ATK Thiokol


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MOFA BatteryPresentation Outline

• Introduction

• Battery Description

• Problem Background

• Investigation

• Design Improvements

• Performance Data

• Electrolyte Compatibility & Stability

• Accomplishments

MOFA Post-launch Battery


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MOFA BatteryIntroduction

• The MOFA Post-launch Battery is a reserve, g-activated, lithium thionyl chloride (Li/SOCl2) primary unit designed to power fuze functions.

• Throughout development and 1st year production, this battery met all fuze requirements. During multiyear production, improvements in test equipment capabilities revealed some performance marginality not seen using earlier test methods.

• The battery’s performance reliability was increased through rigorous scientific investigation, finding the root cause, making design improvements and demonstrating, and exhaustively supporting the changes via laboratory analyses.


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Multi-Option Fuze for Artillery (MOFA)

Post-launch Battery(Device No. G3158B2)

PerformanceVoltage (V): 5.6 to 12.0Current (mA): 325Rated Capacity (mAh): 30Activation Time (ms): < 100Initiation Approach: Setback Initiated at

> 3,000 G’s & 3,600 RPMOperating Temp. Range (°F): -45 to +145Storage Temp. Range (°F): -60 to +160

Physical CharacteristicsChemistry: Moderate Power Li/SOCl2Size: 1.50” Dia. by 0.66” LengthWeight (g): 70

EnvironmentalMIL-STD-331 EnvironmentsAcceleration (G): 30,000 max.Spin (RPM): 30,000 max.

MOFA Battery Description

Focus of Performance

Improvement


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Problem Background

Background

• In production, changes were made to enhance battery producibility. Ultimately these changes led to a decrease in battery capacity to the point of being marginal with respect to the tactical usage of the fuze.

• Improvements in ARL’s airgun test capability revealed a performance shift (degradation) in the production battery which was not observed under earlier lower-spin test conditions.

• Batteries retained from the earlier EMD effort were tested and did not exhibit the same performance deterioration observed from the production hardware.

• An investigation was initiated to identify the cause of the problem and make corrective action.


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Problem Background

0

0.5

1

1.5

2

2.5

3

3.5

4

-100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300

Ti m e ( s )

1.87

767 Cat hode

Gore Cat hode

P lat eau

Cut off Volt age

Laboratory Cell Comparison of Discharge Profiles

Lab Cell

Vendor-supplied Production Cathode

ATK Cathode

Plateau

Cutoff Voltage

Background


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InvestigationTeam

• An Integrated Product Team (IPT) approach was used in the investigation to ensure success.

• The IPT had participation from the following organizations: PM CAS, ARDEC, ARL, ATK Thiokol, ATK Ordnance Systems, and PowerCell Technologies.

PowerCell TechnologiesATK Thiokol

Power Sources Center


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Investigation

Tools• Fault Tree analysis

• Airgun Tests

• Post-test Teardown Analyses

• Laboratory Cell Tests

• Ballistic Tests

• Review of Quality Records & Certifications

• Analytical Tests: BET Analysis, SEM dot mapping, Polarization Resistance, Cyclic Polarization, Microcalorimetry, RAMAN Spectroscopy, ICP/OES, and Metallurgical Examination.


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Investigation

Conclusions

Root Cause: Specific capacity variation of the production cathode matrix material.

Proof: ATK produced cathode matrix material does not exhibit this performance variation.

Why Missed During Production Start Up

• Even though the purchased cathode matrix material had been evaluated and characterized before incorporation into the battery, the test equipment used in its validation did not stress the battery enough to reveal this deficiency.


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Design Improvements

Cathode Material Change

• A straight-forward change of the cathode matrix material was not possible because:

• The automated production equipment had been designed around its use.

• The vendor considered their manufacturing process to be intellectual property. Making constructive changes to an un-identified process would be a long and expensive path.


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Design Improvements

Work-around Solution

• Instead a path was chosen to work around the cathode matrix materials deficiency electrochemically.

• The cathode matrix materials behavior was characterized and a theory was developed as to why it exhibited variations in its specific capacity under dynamic discharge conditions.

• The electrochemical approach was supported via laboratory testing and the most advantageous work around solution (changing electrolyte) was evaluated in detail.


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Design Improvements

Producibility Aspects• In addition to the performance benefits, the No.7 electrolyte also

offers manufacturing benefits. Some are:• Reduces fill volume variability through its lower vapor

pressure.• Can be analyzed for contamination after formulating to ensure

its quality.• Is a less complex formulation which reduces the risk of

formulation errors.• Is easier to handle in production and offers lower risk in lab

glassware, i.e., improved handling safety.• Offers improved overall battery safety by helping ensure the

battery’s complete discharge during test.

Cost Savings

Improved Quality

Improved Quality

Improved Safety

Improved Safety


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Performance Data

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100

200

300

400

500

600

Prod. No.7 Elect. Prod. No.7 Elect. Prod. No.7 Elect.Description

Life

(Sec

onds

)

MINAVERAGEMAX

Cold Temperature(-45F)

Ambient Temperature(70F)

Hot Temperature(+160F)

Airgun Results

Electrolyte No.7 Meets Capacity & Risetime Objectives Across the Full Temperature Range with Margin.

Mean Voltage Risetime (ms)Temperature Baseline

ElectrolyteNew (No.7) Electrolyte

Cold (-45F) 36.9 49

RT (70F) 22.9 23

Hot (+145F) 21 16

Battery Voltage Risetime

Battery Life

Army Research Laboratory 300RPS Air Gun


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Performance Data

Group Qty Weapon Proj / Ctg (Zone) Temp (F) Test Mode Results P/F Comments4 16 M109A5 M107 / M3A1 (3) -45 PD 15 pass / 1 fail Target test (1 dud)

5 8 M109A5 M107 / M4A2 (6) 70 Delay 8 pass / 0 fail Target test

7 24 M119A1 M913 HERA / M229 (8) 145 Prox 24 pass / 0 fail

6 16 M109A5 M107 / M3A1 (3) -45 Time 15 pass / 1 fail 1 dud - TM heard (TOF 111 sec)8 24 M109A5 M549A1 HERA / M203A1 (8) -45 Time 23 pass / 1 fail 1 dud - TM heard (63 sec)9 32 M109A5 M549A1 HERA / M203A1 (8) 145 Time 32 pass / 0 fail

120

Comments: - Both duds in Time mode did broadcast Telemetry (TM) and attempted to issue a fire signal.

M782 MOFA Electrolyte # 7 Ballistic Qualification Test (Lot ATF04C001S001, 120 units)Test Dates: 7 - 9 July 2004 (Yuma Proving Grounds)

• 120 fuzes were ballistically testedwith batteries using electrolyte No.7.

• The fuzes provided acceptable performance.

Ballistic Results 0 failures / 120 testswith the incorporation of the new electrolyte


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Electrolyte Compatibility & Stability

Analytical Tests

Polarization Resistance

(General Corrosion)

Cyclic Polarization

(Pitting Corrosion)

ICP /OES

(Trace Metals)

Microcalorimetry

(Reaction Heat Flows)

FT-RAMAN Spectroscopy

(Identifies Molecules)

Metallurgical Analyses

(Direct Observation)

Compatibility & Stability

of Electrolyte


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Worst Case Polarization Resistance Tests at 160 °F (304L SS in No. 7, MOFA, and Neutral Electrolytes)

0.0E+00

5.0E-05

1.0E-04

1.5E-04

2.0E-04

2.5E-04

0 30 60 90Immersion Time (days)

Cor

rosi

on R

ate

(inch

/yr)

Test 2A (304L SS in No. 7 Elect.)Test 2B (304L SS in MOFA Elect.)Test 2C (304L SS in Neutral Elect.)

Linear Corrosion Rate Threshold for 20-yr

Survivabilty of the Reservoir

Average Corrosion Rate of 304L SS in 160°F Elect. No. 7 after 25-day

Immersion: 1.8E-04 inch/yr

Average Corrosion Rates at Cold and Ambient Temperatures are Significantly Lower, I.e., Less Than 8.4E-06 inch/yr


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Isothermal Microcalorimetry of Batteries at 73 Deg C(Baseline Subtracted)

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20

40

60

80

100

120

0 10 20 30 40 50 60 70 80

Time at 73 Deg C (Hours)

Hea

t Flo

w (u

W)

Cell 1 - MOFA Electrolyte, Total Heat = + 5.81 Joules

Cell 2 - XJammer Electrolyte, Total Heat = + 3.36 Joules

Cell 3 - #7 Electrolyte, Total Heat = + 3.39 Joules

Microcalorimetry Test – No long term reactions observed, supporting ability to meet 20-

year shelf life. Exot

herm

ic

Endo

ther

mic


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196.

47

285.

68

345.

1349

1.21

1229

.95

X-JAM FROM RESERVOIR, FT-RAMAN, B00294.101

0

5

10

15

20

Int

196.

97

285.

92

345.

4349

1.73

1229

.69

THIONYL CHLORIDE, SAMPLE J-3, FT-RAMAN, RUN #1, LWR B00294.001

0

1

2

3

4

5

6

Int

500 1000 1500 2000 2500 3000 3500 Raman shift (cm-1)

• EXJAM Battery Tear-down Analysis • Thionyl Chloride Evaluation

Raman Vibrational Spectroscopy – Laser excitation

No degradation products identified after 18 years of “Real

Time” storage in battery indicating the EXJAM

electrolytes chemical stability.


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ICP-OES Trace Metal Analysis

• Inductively Coupled Plasma with Optical Emission Spectroscopy identification.

Perkins Elmer Optima 4300DV Optical Emission Spectrometer Inductively Coupled Plasma

Identified Insignificant levels of contamination supporting

20-year storage life.

Aluminum Chromium Silicon Zinc Calcium Copper Manganese Iron Magnesium Nickel Cobalt Vanadium Molybdenum(ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm)

# 7 42904 1.83 1.39 N/D 1.36 N/D N/D 1.84 3.87 0.175 N/D N/D N/D# 7 GLASS 46120 1.38 12.9 N/D 2.97 N/D N/D 10.7 3.33 N/D N/D N/D N/D

SAMPLE ID:


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Accomplishments

Accomplishments/Reliability Benefits• Demonstrated significant capacity margins across the full temperature

range.• Demonstrated acceptable risetimes across the full temperature range.• Demonstrated acceptable fuze performance across multiple test

regimes.• Demonstrated the electrolyte’s compatibility:

• No significant corrosion at cold & nominal temperatures• Very low, acceptable corrosion rates under worst case

conditions• Electrolyte No.7 offers improved safety and producibility over the

baseline MOFA electrolyte formulation.• Analytical laboratory work demonstrated the electrolyte’s stability

supporting the 20-year shelf life requirement.


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MOFA Battery

Acknowledgements• The authors would like to thank the U.S. Army PM Combat

Ammunition Systems, and the Armament Research, Development and Engineering Center, Picatinny Arsenal, New Jersey, for theirsponsorship of the MOFA Program and the U.S. Army Research Laboratory, Electro-Chemistry Branch, Adelphi, Maryland, for their contributions in battery technology.

MOFA Post-launch Battery – Increased Performance...

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