7 - Battery and Cap Review.pdf

David Delafuente and Martin Martinez

June 17, 2024

Overview of Crew Space Flight Battery and Capacitor Requirements

Agenda

• Battery Fire Risks

• JSC 20793 Rev D

• NASA test requirements and verification program

• COTS battery

• Capacitors requirements and future changes

• IHS Battery Templates Introduction

• Medium and High Templates

• COTS and CubeSat’s

• Test requirements

• Capacitors

General Risk of a Li-ion Battery

• Likelihood of cell going into thermal runaway causing a fire is estimated at 1 in 1M to 1 in 10M

• Significantly more likely to have a random battery fire than winning the lottery (Mega Millions/Powerball)

• Li-ion cell contains all the components necessary to initiate and support a fire

• In general Batteries are recalled when failure rates drop below ~1:1M

• Samsung Note 7 was down to ~1:40k when the second battery recall was initiated

• Every year major brands recall batteries in the US and Canada

• HP, Dell, Toshiba, Sony, Panasonic… Samsung Note 7 first recall

Li-ion Battery Fire Video

4https://www.youtube.com/watch?v=hm18s-NYLZU https://www.youtube.com/watch?v=hm18s-NYLZU

JSC 20793, Crewed Space Vehicle Battery Safety Requirements

• Basic – September 1985 (Battery Safety Handbook)

• Revision A – January 2005

• Revised to update battery chemistries, hazards, and controls.

• Changed from a handbook/guideline to a requirements document.

• Revision B – April 2006

• Revised to clarify sentences and requirements for each chemistry; added new section for vibration requirements.

• Revision C – January 2014

• Not baselined into the ISS Program Requirements due to configuration management issues

• Revised to clarify all requirements, specifically, lithium-ion battery chemistry

• Added new sections for lithium-sulfur and thermal battery chemistries, as well as super capacitors

• Significant reformat to aid in readability and identification of requirements vs. best practice

• Added thermal runaway propagation evaluation, as well as other lessons learned from 2013 lithium-ion battery incidents

• Revision D – March 2017

• Baselined into the ISS Program in August 2017

• Included risk characterization methodology and consolidated non-critical criteria

• Non-critical batteries: increased threshold from 300 to 1000 mAhr, removed vacuum leak checks

• Defined cell DPA quantities, updated document references to Appendix A and incorporated alkaline shelf life (EP-11-042)

• Incorporated recommended changes from ISS CR 014210, “Revise JSC 20793 to Revision D”:

• Updated applicable document references, corrected reference to obsolete Form 1230, corrected qualification test vacuum pressure limit, clarified lot testing requirements, extended vendor configuration control authority to International Partners, added computer based control requirements and verification references, clarified toxicology assessment description, removed legacy voltage limit on electrical short requirement, included functional test definition, added unique Hazard Report requirement, clarified transport requirements for lithium sulfur cells, and updated safety review requirement reference.

JSC 20793

• JSC 20793, Crewed Space Vehicle Battery Safety Requirements contains the detailed design information for all batteries on crewed spacecraft, including vehicle, payload, and crew equipment batteries

• Separate sections include:

• Section 4, General Battery Requirements: Basic requirements for all battery designs and applications

• Section 5, General Battery Hazards and Controls: Description of hazards and controls and also includes requirements

• Section 6, Safety Relevant to Specific Battery Chemistries: Chemistry-specific information. No requirements appear in this section, only best practices.

JSC 20793.D Key Requirements

• All batteries must be tested for each application

• There are no “approved” batteries for payload providers to utilize

• A new lot of cells requires testing to validate the cell/battery lot (includes COTS)

• Suggest program lifetime buy with cold storage if available

• Each system is unique and the battery has to be verified to operate with the specific system

• CMC does have some cells/battery available which do not need to be tested (list in later slide)

• NASA approval IS required along with completed UHR and battery description form (BDF)

• All batteries over 80Wh are required to be passively propagation resistant (PPR)

• Testing is required to validate the design will not propagate

• EP-19-001 Interpretation Memo provides more information on how to meet the PPR requirements

Battery Shipping and Disposal

• JSC 63322 Rev B Packaging Requirements for Launch, On-Orbit Storage, and Disposal of Batteries

• Packaging of batteries for launch, on-orbit storage and landing or disposal is an important aspect in the safe handling of batteries

• Batteries are typically not launched inside equipment and form part of the accessories kit

• Packaging them for safe launch and landing is critical

• Proper bagging and labeling of batteries and cells for containment of electrolyte and reduce potential for external shorts

• Packaging should prevent movement during launch

• Electrically isolated from each other

• Two levels of containment against leakage of electrolyte

• Acceptance testing based on JSC 20793

• Batteries should be stored in controlled environments

• Environmental conditions such as extreme temperatures can contribute to catastrophic failures

• Cold storage should be used for increased life

• Store batteries at low states of charge for increased life and safety

• Fire bags are now available on ISS to store multiple batteries safely to limit the battery-to-battery propagation

• Fire bags are contained within a CTB and can hold up to 175Wh of batteries per bag Improper Storage of Batteries

PROPULSION & POWER DIVISION

NASA Johnson Space Center, Houston, Texas

Cell and Battery Testing

Why Test?

• All batteries are inherently hazardous

• Some have greater hazard potential/consequences then others

• If untested the likelihood of having a hazardous battery increases

• Industry is not infallible in their battery designs and generally not directly suitable for space flight

• Prevent batteries from being abused

• Mechanically/Physically

• Electrically

• Thermally

• Validation of hazard controls are necessary

• Determine if battery/cells are healthy to fly

Causes leading to a Li-ion Battery Fire

Wang, Q.; Mao, B.; Stoliarov, S.I.; Sun, J. A review of lithium ion battery failure mechanisms and fire prevention strategies. Prog. Energy Combust. Sci. 2019, 73, 95–131 11

Internal Cell Short

• There are no controls for internal cell shorts while all other hazards can be controlled (overcharge, external short…)

• Initial NASA philosophy was with good screening all cell potential internal shorts could be removed

• Even with extensive screening protocols latent defects can be missed

• There have been several recalls which appear to be from latent defects

• Every year major brands recall batteries in the US and

Canada: HP, Dell, Toshiba, Sony, Panasonic…

• Current methodology is to reduce the consequence of a cell thermal runaway by designing the battery to be Passively Propagation Resistant (PPR)

Testing Introduction

• Cell and Battery Testing

• Initial receiving inspection

• Cell lot testing

• Safety testing

• Qualification testing at the EDU battery level

• Acceptance testing at the flight battery level

• Serialization and Initial inspection

• Cells must be serialized and inspected once received from the vendor

• Inspection includes removal of the battery shrink sleeve and insulating washer for proper visual inspection to expose hidden defects

• Corrosion

• Evidence of leakage

• Anomalous seal ring condition

• Bulging

• Physical surface damage (dents, cuts, scratches)

• New shrink wrap can be added if desired, but bare cells are preferred

• After visual inspection is completed temporarily replace the insulating sleeve and washer

• Mass and dimensional measurements must be taken

• Initial Electrochemical test (OCV, AC imp and internal resistance)

• Statement of Work (SOW)

• Detailed battery SOW describing flight acceptance and qualification testing must be reviewed with the NASA Battery Group for

Safety and Advanced Technology prior to CDR

REMOVE SLEEVE & WASHER

Corrosion

Cell Lot Testing

• Cell Lot Testing assesses manufacturing quality

• Quantity of cells to be tested must be coordinated with NASA Battery Group

• Internal Shorts Vibration Test

• Eliminates cells that develop internal shorts as a result of vibration

• Qualification vibe profile: (there is also the acceptance vibe for all cells/batteries)

• Vent-to-Burst Test

• To determine the cell vents before burst

• Header disassembly

• Vent and burst pressures are as expected

• CT Scan and Destructive Physical Analysis (DPA)

• To find manufacturing issues within the cells

• Examples of problems

• Lithium deposits on the Anode

• Crimp seal corrosion pitting

• Foreign Object Debris (FOD) in a cell

FREQ (Hz) ASD (G2/Hz) dB/OCT Grms

20.00 0.057600 * *

40.00 0.057600 0.00 1.07

70.00 0.144000 4.93 2.02

700.00 0.144000 0.00 9.74

2000.00 0.037440 -3.86 13.65

Battery Safety (Abuse) Testing

• To verify design meets minimum safety requirements for manned spacecraft

• Overcharge Control Verification

• Overcharge inhibit test

• Charger cannot overcharge battery

• Over-discharge Control Verification

• Discharge into reversal

• Overdischarge protocol

• Low voltage cut-offs

• External Short Circuit Verification

• Cell response to external short

• Cell bundle response to external short

• Cell vent-burst

• External short on the battery bypassing the safeties

• Thermal Runaway Severity Assessment

• If battery pack energy capacity exceeds 80 W-hr

• Demonstrate that no propagation occurs from fire/explosion of a single cell failure

• CT Scan (optional) and DPA of Cells from COTS battery (required) EP-WI-034

• To determine manufacturing issues with battery

Battery Qualification Testing

• Perform qualification tests at the cells or battery level (whichever is the flight configuration).

• Testing at the higher levels could damage the battery

• Do not use for flight after testing at these levels

• Physical and Electrochemical Characteristics

• Mass and dimensional Measurements

• Electrochemical test (OCV, CCV, AC imp, internal resistance)

• Vacuum Leak Test with post vacuum physical and electromechanical test

• Thermal Cycling or Thermal Vacuum/Cycling with post-test physical and electromechanical test

• Internal Shorts Vibration Test with post vibration physical and electromechanical test

Yes

Battery Acceptance Testing

• Tests at lower levels that will not damage the battery

• Physical and Electrochemical Characteristics

• Mass and dimensional Measurements

• Electrochemical test (OCV, CCV, AC imp, internal resistance)

• Vacuum Leak test with post vacuum physical and electromechanical test

• Thermal Cycling with post-thermal physical and electromechanical test

No

Yes Pass

Fly

No

Need info

Good

Fail

Need changes

Good

Gate 1 Gate 2

Clear Pass/Fail criteria reviewed.

Verification testing did not damage test hardware

Hazard Report Review

EP5 Safety Battery Lead works with

Hardware owner on another battery solution or waiver

ReportTest Test Plan

Approved?

Hardware Owner Approval

EP5 Safety Battery Lead

Review

Test Org Review of

Requirements

ATP?

Generate SOW

Hazard Report Start

Hardware Owner Needs Battery (Test

Request)

Battery Hazards and Risk

Battery Classifications

JSC 20793 SSP 51721 Definition

Non-Critical Low BRC • Lowest level of hazard control that is reserved for low energy cells and battery designs for which standard emergency procedures are written and practiced

Critical Medium BRC • Typically manufactured in high volumes for the consumer

• Have commonly available means to help determine the reliability and safety of the products.

• Due the consequence of a failure, these End Items will follow a comprehensive test and validation plan

Catastrophic High BRC • Typically custom, high energy, or high power designs

• Due to the extreme consequence of a failure, these End Items will follow a comprehensive test and validation plan that includes testing to determine the result of single cell thermal runaway

• Analysis of the thermal runaway can lead to a redesign of the battery to mitigate the consequence.

• BRC – “Battery Risk Classification” is defined in the JWI 8705.3 and SSP 51721 along with JSC 20793 Revision E and any future updates to battery procedures and guidelines

• The terms “non-critical”, “critical” and “catastrophic” described above differs in context and are not to be confused with the ISRP hazard severity definitions as defined within SSP 30599, SSP 50021, and SSP 51700

Important: Battery classification should be correctly identified as soon as possible to determine necessary testing!

Low BRC Batteries

• Lowest level of hazard control that is reserved for low energy cells and battery designs for which standard emergency procedures are written and practiced

• Batteries within this ‘Low BRC’ or “Non-critical” classification shall be:

✓ Low energy < 4 Watt-Hours (Wh) per battery pack where each battery is thermally and electrically isolated (or < 60Wh for Alkaline Primary Batteries) where Wh = Cell Capacity (Ah) × Cell Voltage (V), and

✓ Rated with a Toxicity Hazard Level (THL) of 1 or 2, and

✓ Contained within a not intentionally sealed compartment, and

✓ Meet one of the following criteria based on battery chemistry:

• Alkaline Primary Batteries (meets all five):

• Non-rechargeable cells in sizes D or smaller and,

• Maximum of 12 V and/or 60 Wh and,

• Cells either all in series or all in parallel and,

• No potential charging source and,

• Cells located in a vented compartment

• Note: Silver oxide cells are also considered alkaline chemistry.

• Lithium-ion Secondary Batteries – COTS (rechargeable) lithium-ion button, cylindrical, or pouch batteries of up to 1000 mAh capacity.

• Lithium Primary Batteries – COTS (non-rechargeable) lithium button cells (i.e., Li-MnO2, Li-CFX and LiFeS2) of up to 1000 mAh capacity.

• Nickel Cadmium Batteries – Nickel-cadmium (rechargeable) batteries and cells of up to 1000 mAh capacity.

• Nickel-Metal Hydride Batteries – Nickel-metal hydride (rechargeable) batteries and cells of up to 1000 mAh capacity.

• Silver-Zinc Batteries – Silver-zinc (rechargeable) batteries and cells of up to 1000 mAh capacity.

• Zinc-Air Primary Batteries – Zinc-air (non-rechargeable) batteries and cells of up to 1000 mAh capacity.

• Note: For primary cells, rated cell capacity is defined as the maximum stated capacity per cell product data sheet

Low BRC Battery Hazard Reports

• Requirement: Low BRC Batteries shall meet manufacturer’s specifications

• Low BRC incorporated into Standard HR in ISS

• This template is intended to be used for cells/batteries that are considered "non-critical"* per JSC 20793, Rev. D.

The Battery Risk Classification (BRC) per JWI 8705.3 and SSP 51721 is "low."

• Cause: Battery Leakage/Rupture Due to Improper Workmanship

• Cause Description: Poor quality control of the cell manufacturing process that can result in electrolyte leakage, fire, and thermal runaway.

• Cause Remarks:

• Controls/verification methods noted within "Ctl-1" or "Ctl-2" (either approach is sufficient; only one control approach required) are to be used for cells/batteries procured/provided by the provider directly.

• Control/verification method noted in "Ctl-3" is to be used for cells/batteries provided by the ISS Program (ex: "ISS Pantry" batteries) provided as Contractor Furnished Equipment (CFE) by the CMC-2 contract.

• Controls:

• Ctl-1: Provider Supplied/Procured Cells/Batteries: UL Certification using Battery Regulations

• Ctl-2: Provider Supplied/Procured Cells/Batteries: Flight Acceptance Testing

• Ctl-3: ISS Program Provided Cells/Batteries: Use of Contractor Furnished Equipment (CFE) Within Certified Limits/Application

• HR Battery Description Form

• Shall be completed and attached to the HR

• Available as an attachment in the HR template

• Intermediate level of risk classification requiring single fault tolerance typical of commercial devices manufactured in high volumes for the global consumer

• Batteries within this “Medium BRC” or “Critical” classification do not meet the ‘Non-Critical’ classification and shall be:

✓ Energy levels < 80 Wh per battery pack where each battery is thermally and electrically isolated (or > 60Wh for

Alkaline Primary Batteries) where Wh = Cell Capacity × Cell Voltage, and

✓ Rated with a THL of 1 or 2, and

✓ Contained within a not intentionally sealed compartment, and

✓ Meet one of the following criteria based on battery chemistry:

• Alkaline Primary Batteries (meets all five):

• Non-rechargeable cells in sizes D or smaller and,

• Greater than 12 V and/or 60 Wh and,

• Cells either all in series or all in parallel and,

• No potential charging source and,

• Cells located in a vented compartment

• Note: Silver oxide cells are considered alkaline chemistry.

• Lithium-ion Secondary Batteries – COTS (rechargeable) lithium-ion button, cylindrical, or pouch batteries > 1000 mAh capacity and ≤ 20 V.

• Lithium Primary Batteries – COTS (non-rechargeable) lithium button cells (i.e., Li-MnO2, Li-CFX and LiFeS2) > 1000 mAh capacity and ≤ 20 V.

• Nickel Cadmium Batteries – Nickel-cadmium (rechargeable) batteries and cells > 1000 mAh capacity.

• Nickel-Metal Hydride Batteries – Nickel-metal hydride (rechargeable) batteries and cells > 1000 mAh capacity.

• Silver-Zinc Batteries – Silver-zinc (rechargeable) batteries and cells > 1000 mAh capacity.

• Zinc-Air Primary Batteries – Zinc-air (non-rechargeable) batteries and cells > 1000 mAh capacity.

Medium BRC Batteries

Medium BRC Battery Hazard Reports

• Requirement: Medium and High BRC Batteries shall be designed to prevent internal cell pressures that result in cell/battery failure in the worst-case flight environments with margin

• Use Medium and High BRC Template HR (IHS# 28907)

• Causes:

1. Battery Leakage/Rupture Due to External Short Circuit

• Improper battery design or operations error/mishandling allows for an external short circuit and subsequent leakage or battery rupture causing a loss of life and/or vehicle.

• Controls include cell seal integrity, energized component separation, and external short tolerance

2. Battery Leakage/Rupture Due to Cell Internal Shorts (includes Workmanship)

• Catastrophic internal shorts are generally rare events but can be very violent and damaging

• Demonstrating tolerance to all external shorts does not imply achieving tolerance to all internal shorts

• There are no tests that fully screen for the possibility or the severity of outcome for an internal short circuit of an individual cell

• Controls include cell acceptance test, cell lot qualification test, battery qualification test, battery acceptance test, and single cell failure propagation mitigation

3. Battery Leakage/Rupture Due to Inadvertent Charging of Primary Cells/Batteries

• Devices, controls and procedures to prevent inadvertent charging

4. Battery Leakage/Rupture Due to Improper Charging (includes Overcharge) of Secondary Cells/Batteries

• Improper or overcharging of battery assembly can cause internal cell pressure build-up that leads to electrolyte leakage, venting, fire, or thermal runaway with potential injury to the crew or damage to surrounding equipment, the ISS, or transport vehicles

• Controls include designated charger compatibility, charger protocols, overcharge tolerance and battery overcharge controls 23

Medium BRC Battery Hazard Reports

• Medium and High BRC Template HR (IHS# 28907) continued

• Causes (con’t):

5. Battery Leakage/Rupture Due to Overdischarge (includes Reversal)

• Overdischarge can lead to electrolyte leakage, venting, fire, or thermal runaway with potential injury to the crew or damage to surrounding equipment, the ISS, or transport vehicles

• Controls include tolerance to 100% reversal, low voltage cut-off, low voltage limit for charge by charger, and overdischarge protocol by charger

6. Battery Leakage/Rupture Due to Thermal Extremes

• Exposure to thermal extremes leads to electrolyte leakage, venting, fire, or thermal runaway with potential injury to the crew or damage to surrounding equipment, the ISS, or transport vehicles

• Controls include operational temperature range

• Verifications:

• There are one to many verifications to choose from for each control and other controls may be added to the HR depending on the design of the battery and/or charger hardware

• Verifications stating to "Verify Once" should be performed each lot of cells and/or batteries.

• Verifications stating to "Verify Each Flight" will be performed on each flight battery and/or cell.

• HR Battery Description Form will be attached to the unique HR and is available as an attachment to the template 24

• Batteries within this classification do not meet the Low and Medium BRC classification and are typically custom, high energy, or high power designs

• Use Medium and High BRC Template HR (IHS# 28907)

• Requirement addition to Medium BRC Batteries

• 5.1.5.1 – Thermal Runaway Propagation

a. For battery designs greater than a 80-Wh energy employing high specific energy cells (greater than 80 watt-hours/kg, for example, lithium-ion chemistries) with catastrophic failure modes, the battery shall be evaluated to ascertain the severity of a worst-case single-cell thermal runaway event and the propensity of the design to demonstrate cell-to-cell propagation in the intended application and environment.

b. The evaluation shall include all necessary analysis and test to quantify the severity (consequence) of the event in the intended application and environment as well as to identify design modifications to the battery or the system that could appreciably reduce that severity.

• Verification - High BRC End Item Thermal Runaway

• Verification is considered successful when a Thermal Runaway Assessment with no propagation can be substantiated by:

A and (B and/or C)

A. Analysis is performed to determine whether thermal runaway with propagation can be substantiated (A)

B. Analysis to quantify the magnitude (consequence) of the event in the intended application and environment (A)

C. Test to quantify the magnitude (consequence) of the event in the intended application and environment (T)

• HR Battery Description Form will be attached to the unique HR and is available as an attachment to the template

High BRC Batteries

Medium and High BRC IHS 28907

Linked Here (https://hazard.iss.nasa.gov/show_bug.cgi?id=28907&preview_template=1) https://hazard.iss.nasa.gov/show_bug.cgi?id=28907&preview_template=1 https://hazard.iss.nasa.gov/show_bug.cgi?id=28907&preview_template=1

Key Drivers for Med/High BRC

• Multiple controls with each of the controls have multiple verifications

• Not all controls and verifications are required, generally two or more are needed to demonstrate sufficient level of controls for a catastrophic hazard

• There are no direct controls for internal shorts and testing is required to validate a short isn’t currently present

• Testing will not always determine if the cell has a latent defect

• For over 80WH propagation testing is required to reduce the consequence of an internal short

• Validation of controls is generally a mix of testing and analysis

Tailored Testing for COTS and CubeSats

COTS Batteries

• Commercial Off-the-Shelf (COTS) Cells and Batteries

• The manufacturing process of industrial COTS batteries are not suitable for manned space application

• Therefore, attention must be payed to identify cell manufacturing defects that could create safety hazards or create performance issues

• Testing must be performed at the cell level and battery level

• Battery Definition

• One cell or a packaged or unpackaged assembly of two or more cells that provide stored electrical energy. Specific design and verification requirements for a battery are dependent upon:

• Chemistry, capacity, complexity, charging, environment, and application

• Variety of battery chemistries available, combined with the variety of battery-powered applications, results in each battery application having specific, unique requirements pertinent to the specific battery application.

COTS Test List

CubeSat Testing

• All CubeSats utilize the NanoRack deployer

Not required for batteries that do not charge on ISS

Capacitors

• POC for capacitors is Martin Martinez (martin.d.martinez@nasa.gov)

• Capacitors with non-solid/liquid electrolyte capacitors and Electrolytic Capacitors (EC) are the only capacitors currently requiring testing and validation

• Electrolytic capacitor is a generic term for: (1) Aluminum electrolytic capacitors, (2) Tantalum electrolytic capacitors, and (3) Niobium electrolytic capacitors. Super- and Ultra-capacitors are included in ECs

• Capacitors hazard are leaking of tox-2 hazard not all capacitors are considered tox-2

• Require levels of containments and testing to fly wet capacitors

• Inspection

• Vacuum leak check

• Vibration

• Burn-in testing

• EP-18-113 Memo provided updated test 32

Low CRC

Risk Classification Individual Capacitor

Volume Vent Verification

Low CRC ≤ 4000 [mm3] Yes or No

• All wet electrolytic capacitors demonstrated to be ≤ 4000 [mm3] case volume based on external dimensions

• Successful functional test

• Vent refers to opening in hardware enclosure for air flow

• Information in the form of a manufacturer’s datasheet, analysis, measurement, etc. must be provided as verification documentation of the case size of the largest enclosed wet electrolytic capacitor

• Low CRC End-Items must successfully perform various functions as defined by provider

• Functional test procedure is subject to EP review and acceptance

• The intent is for the capacitors to be energized

• Therefore, it is recommended that it be attached to the Hazard Report

Medium CRC Hardware

Risk Classification Individual Capacitor

Volume Vent Verification

Medium CRC

> 4000 [mm3] OR unable to determine volume

No

• 3 continuous hours of capacitor-screening test at room/lab ambient temperature

• Successful post capacitor-screening functional test

• Minimum 5 on/off cycles

• System-level capacitor-screening test

• Tested at worse case, steady state DC power quality levels per SSP 52051

• If it receives 28 VDC from ISS bus → test at 32 VDC

• If it receives 120 VDC from ISS bus → test at 126 VDC

• Hardware that accepts AC input via ISS Inverter: wall power acceptable

• Either Capacitor-screening procedure or functional test procedure should be representative of hardware’s on-orbit concept of operations (subject to EP review)

• Power cycles can be performed either in the screening or the functional test

• Success criteria for post capacitor-screening functional test:

• Nominal operation of hardware

• For hardware that can be inspected:

• All capacitors shall have no visible signs of deterioration

• For hardware that cannot be inspected:

• End-item must be actively monitored during the test to demonstrate there is no evidence of capacitor failure from the electronic assembly enclosure

High CRC Hardware

Risk Classification Individual Capacitor

Volume Vent Verification

High CRC

> 4000 [mm3] OR unable to determine volume

Yes

• 100 hours capacitor-screening* at room/lab ambient temperature

• Successful post capacitor-screening functional test

OR

• Proper use of capacitor by design:

• Voltage and temperature de-rating (60% or project required value)

• Review of design for proper polarity

• Inspection of as-built end item for proper installation polarity or CoC

• 20 hours capacitor-screening* at room/lab ambient temperature

• Successful post capacitor-screening functional test

• Same criteria as Medium CRC plus HMST

Contact Information

Battery POC:

• David Delafuente, david.a.delafuente@nasa.gov

• John Gafford, john.r.gafford@nasa.gov

Capacitor POC:

• Martin Martinez, martin.d.martinez@nasa.gov

• John Gafford, john.r.gafford@nasa.gov mailto:david.a.delafuente@nasa.gov mailto:john.r.gafford@nasa.gov mailto:martin.d.martinez@nasa.gov mailto:john.r.gafford@nasa.gov

Backup

Recalls of Li-ion Batteries: 2012-2019

~ 5M total products recalled in seven years due to battery failures

U.S. Consumer Product Safety Commission, Lithium-ion Battery Safety Standards for Consumer Product Import in the United States, 2020 Update

Commercial Product Failures Lithium Batteries & Lithium Battery-powered Devices

FAA Battery Incident Chart as of 5/22/2019

19 incidents in 2019 reported as of May 22

Events Involving Smoke, Fire, Extreme Heat or Explosion

Vehicle Recalls

• 2021 recall numbers do not include December

• Chevy has had 3 recall of the Bolt totaling ~144,000 vehicles and 16 confirmed battery fires

• Root cause determined to be cell manufacturing issues (LG)

• GM redesigns batteries and assembly process

• BMW, Chrysler, Ford, Hyundai/Kia, Mitsubishi, and

Tesla have all issued EV fire-related recalls

Battery Design Overview

Battery Basics

• Battery Failure Prevention in Li-ion Cells

• PTC (Positive Temperature Coefficient)

• Chokes off the current at temperatures over 130°C

• Reversible when fault is removed and the temperature lowers below 130°C

• CID (Current Interrupt Device)

• Cathode additive generates CO2 gas when overcharging above 4.3 V

• Mechanical contact disconnects at a pressure of ~10 bar and safety vent which triggers at ~12 bar

• Both of these are irreversible and do not allow the cell to function if either of these protectors are triggered

Primary Cells (Non-rechargeable)

1.5 or 9 V Alkaline Cells 1.5-3.6 V Lithium Cells

1.4 V Zinc/Air Cells

Secondary Cells (Rechargeable)

1.2 V Nickel/Cadmium (NiCd)

1.2 V Nickel/Metal Hydride (NiMH)

1.28 V Nickel Hydrogen (NiH2)

3.2-3.8 V Li-ion/Li-polymer

Li-ion Cutaway

Common Cell Voltages (No matter what size it is)

Battery Design Considerations

• Batteries alone are not certified!

• Applications or systems that use batteries are certified!

• Chapter 6 of JSC 20793 discusses hazard and best practices for all chemistries

• Two failure tolerance is required for all catastrophic hazards and vary based on cell chemistry

• Battery hazards that must be controlled

• Overcharge (or charging of a primary battery)

• Overdischarge (or recharge of an overdischarged battery)

• External Short (reversal)

• Internal Short

• Temperature extremes

• Controls must be verified via test when applicable

• 100% Acceptance Testing is required at the cell and battery level

• Qualification Testing is required

• Safety (Abuse) Tests

• Vacuum, Vibration and Thermal Tests

• Requirements can be adjusted by NASA, based on battery and application design as needed to meet the intent of JSC 20793

Thermal Runaway Propagation

• Passively Propagation Resistant (PPR) Battery Designs

• Design Driving Factors for Reducing Hazard Severity from a Single Cell TR

• The “Big 5” design rules for PPR:

1. Prevent side wall can ruptures from causing propagation

• Without structural support most high energy density (>660 Wh/L) designs are very likely to experience side wall ruptures during TR

• Battery should minimize constrictions on cell TR pressure relief

2. Provide adequate cell spacing

• Direct contact between cells nearly assures propagation

• Spacing required is inversely proportional to effectiveness of heat dissipation path

3. Individually fuse parallel cells

• TR cell becomes an external short to adjacent parallel cells and heats them up

4. Protect the adjacent cells from the hot TR cell ejecta (solids, liquids, and gases)

• TR ejecta is electrically conductive and can cause circulating currents

5. Prevent flames and sparks from exiting the battery enclosure

• Provide tortuous path for the TR ejecta before hitting battery vent ports equipped flame arresting screens

General Battery Hazards

• Battery hazards are caused by

• Buildup or venting of flammable gases or electrolyte

• Corrosive or toxic gasses and reaction products

• Expulsion of electrolyte

• Failure modes of over-temperature, internal and external shorts, reverse current, cell reversal, leakage, and overpressure

• Electrical, mechanical or environmental abuse could cause internal cell pressure build-up that leads to rupture of battery, leakage of electrolyte, venting, fire or explosion with potential injury to the crew, or damage to equipment, ISS or other crewed space environment.

Risk by Type of Cells/Batteries

• Alkaline Primary Batteries

• Electrolyte leakage: KOH can corrode aluminum and is a caustic electrolyte that can cause skin damage and permanent eye damage, therefore considered THL 2 (catastrophic)

• High temperatures can be produced when short circuited

• Lithium Primary Batteries

• Electrolyte leakage: Corrosive and considered THL 2 (catastrophic)

• Flammable electrolyte

• NiMH Secondary Batteries

• Electrolyte leakage: KOH can corrode aluminum and is a caustic electrolyte that can cause skin damage and permanent eye damage, therefore considered THL 2 (catastrophic)

• Catastrophic event could occur with the accumulation of combustible gas mixtures

• Note that internal short is not a catastrophic hazard

• NiH2 Secondary Batteries

• Same hazards as NiMH and has the added risk of pressure vessel rupture

• Li-ion Secondary Batteries

• Electrolyte leakage: Corrosive and considered THL 2 (catastrophic)

• Flammable electrolyte

• Catastrophic events are triggered by overcharge, internal short, high temperature, external shorts and overdischarge

• Pouch cells have no integral CID or PTC and are completely dependent on external protection circuits

Mitigation of Battery Hazard Risk

• Cell and Battery Lot Testing

• Every new lot of cells or batteries must be tested

• Performance testing of all cells

• Abuse testing verifies critical safety controls

• Test for failure modes with specific attention to cell versus module/battery level safety tests

• Cell and Battery Qualification Testing

• Test with margin to required environments for performance

• CT Scanning and DPAs to assess quality of manufacturing

• Thermal runaway hazard assessment driving mitigation measures

• Battery Flight Acceptance Testing

• 100% of flight batteries

• Vacuum leak check and vibration

• Functional checks (OCV, CCV and capacity) before and after each test

• Charge/discharge cycles for post-vibration capacity check

• Testing can be the major cost and long lead schedule item for any project using batteries

New Document 51721

• Often refers back to JSC 20793 for additional detail but contains the requirements for ISS

• Has the requirements but lacks the how to meet requirements

• Implements the BRC (low, medium, and high) officially and will be updated in JSC 20793 in the next revision to Rev E.

• Provides the verifications necessary via test, analysis, or inspection

• 51721 did not generate new requirements separate from JSC 20793 but summarizes the shalls without all the supporting information

Work Instructions to support

JSC 20793

• JWI 8705.3 - Battery Processing for Crewed Space Vehicle Applications

• Guidelines for safe handling of cells or batteries from the manufacturing and acceptance stages through disposal

• Procedures for design, evaluation, approval, and processing

• Pre-flight, on-orbit, post-flight; on-ground

• EP-WI-037 - Specification for Acceptance Testing of Commercial Lithium Ion Cell Lots

• Defines how a lot of commercial Li-ion cells are acceptance tested for use in batteries for NASA’s crewed spacecraft in a manner compliant to JSC 20793

• Acceptance tests are non-destructive testing that enables assessment of manufacturing and performance quality

• Applicability of this specification is determined by the customer of the flight battery for which these commercial cells are the building block

• Deviations from the requirements herein to customize it for a specific application or cell design shall be detailed in the authorization document (statement of work (SOW), test preparation sheet (TPS), or Test Request) that references this specification

• EP-WI-036 - Specification for Cell Lot Certification Testing of Commercial Lithium Ion Cell Lots

• Defines how a lot of commercial Li-ion cells shall be destructively sampled to assess if its design performance, quality, and safety are acceptable for use in batteries for NASA’s crewed spacecraft in a manner compliant to JSC 20793

• Applicability of this specification is determined by the customer of the flight battery for which these commercial cells are the building block

• Deviations from the requirements herein to customize it for a specific application or cell design shall be detailed in the authorization document (statement of work (SOW), test preparation sheet (TPS), or Test Request) that references this specification

Counterfeit Cells

• Counterfeit: A suspect battery or cell that is a copy or substitute without legal right or authority to do so or one whose material, performance, or characteristics are knowingly misrepresented by a supplier in the supply chain.

• Parts which do not contain the proper internal construction consistent with the ordered part

• Parts which have been used, refurbished or reclaimed, but represented as new product

• Parts which have different package style or surface plating/finish than the ordered parts

• Parts which have not successfully completed the Original Component

Manufacturer’s (OCMs) full production and test flow, but are represented as completed product

• Parts sold as upscreened parts, which have not successfully completed upscreening

• Parts sold with modified labeling or markings intended to misrepresent the part’s form, fit, function, or grade

• Why we test?

• Increased risk of catastrophic failures

• Removed/not included safety features (Vent, CID, and/or PTC)

• Counterfeit cells/batteries are more common than you think

• Mass, capacity, labeling, impedance, CT scan, and DPA are good tools for detection of counterfeit cells 49