Determination and Assessment of the Large Format Lithium Ion (Li-ion) Cell Thermal Runaway Initiation Methods

1. Purpose/Objective The objective of this Request for Information (RFI) is to seek input from lithium ion cell manufacturers/suppliers as potential collaborators in order to identify Thermal Runaway (TR) initiation methods that 1) are suitable for large format Li-ion cells, 2) most accurately reflect worst case TR events caused by internal shorting that might occur in the field, and 3) can be readily implemented in a test program of battery level designs as a means to trigger a cell into TR for the purposes of assessing severity. This severity assessment would be in unmitigated designs or to ensure TR mitigated designs do not propagate thermal runaway to cells neighboring the trigger cells and thus reducing the severity of the TR event. This RFI references tasks designed to evaluate the technical feasibility of novel TR trigger methods for large format Li-ion cell designs. 2. Background Previous NASA activities have trail blazed design methods for building TR propagation resistant Li-ion batteries comprised of large numbers of 18650 format cells in an array/matrix. These efforts have been very successful and NASA, having trail-blazed design approaches for small form factor cells battery builds, is moving to require this level of safety (i.e., TR passive propagation resistance) in a number of its applications. The application of these design/test approaches (e.g. patch heaters for trigger cell initiation) have not been successful in large form factor cell tests. Given there are NASA missions that benefit from the high cycle life large cell designs, NASA is seeking to begin the process of trailblazing similar methods for large cell based designs. NASA has previously conducted testing to better understand the consequence of single-cell TR on a flight-like International Space Station (ISS) Li-ion main battery. These tests, which attempted to use penetration as the initiation method, showed that ejection of the initiation (trigger) cell contents during TR may have removed the high-energy thermal mass typically responsible for single-cell TR propagation from the close proximity of neighboring cells. These results were not observed in previous ISS Li-ion main battery single-cell safety testing and were not considered when battery thermal analyses where conducted. Further evaluation indicated that ejection of the trigger cell contents was not a worst-case test from a thermal runaway propagation standpoint, and therefore an orbitable replacement unit (i.e. a single on flight battery enclosure) level TR under-test condition was postulated. The most likely cause of the ejection was the test configuration, and the TR trigger method may not have produced internal shorts bounding the worst case results of an actual field failure. In summary, NASA's efforts to trail blaze a test methodology for large cell battery designs have been unsuccessful or have carried unacceptable levels of uncertainty in outcome. As a result, as new NASA missions are designed, particularly those involving crewed flight due to their safety requirements, large cell battery designs are at a disadvantage during architecture formulation. The goal of this RFI is to identify potential collaboration opportunities with large cell battery manufacturers for the development of a suitable test methodology and provide a path for large cell designs to be testable against NASA's emerging thermal runaway related requirements. The cell manufacturers should suggest methods best suited to trigger a thermal runaway event in the trigger cell within an aerospace battery design compromised of large capacity cells. The NASA team has discussed potential options such as implantable internal short circuit devices and conventional methods (e.g. nail penetration, external shorting, and others). NASA will look to cell manufacturers for their recommendations and can envision a manufacturer recommending more than one method. A bounding worst case single cell TR condition with largest energy release to neighboring cells is desired even if this considered conservative and if the catalyst (e.g. internal short circuit) that creates this condition is considered unlikely. 3. Response Details NASA envisions a collaboration to accomplish the following task list and the purpose of the RFI is to determine the level of interest/capability in industry and the extent to which collaboration is possible. NASA will consider all technical and cost collaboration opportunities (both domestic and international organizations) and acquisition strategies available to develop this test approach. Through this RFI, NASA is seeking strategic information, collaboration opportunities and technical inputs required to assist in the formulation of an acquisition strategy that includes determining the most desirable methods for performing collaborative development, including technical/cost sharing with industry via cooperative agreements, FAR-based contracts, and other agreements. The tasks envisioned by NASA in this future collaboration activity would include: TASK 1 - Determine potential initiation methods and their attributes, provide comparative data Develop a matrix summarizing potential methods, their characteristics, and pros and cons. Include notional description of how such a method could be used to evaluate NASA battery designs as we assess the propensity of TR. Provide any data available to characterize analytically or experimentally the viability of the method and the likelihood of generating a single cell thermal runaway. TASK 2 - Develop proposed test plan Develop a test plan to evaluate and compare test methods that includes temperature measurements around the test cell, cell voltage, and means to evaluate total energy released from TR event apportioning total liberated energy between 2 categories a) vented products and then b) heat retained with the cell case. If the manufacturer does not have a means to conduct the testing, NASA can conduct the testing within a calorimeter it has designed for this purpose. TASK 3 - Cell selection and acceptance test cells planned for testing in the comparative initiation test matrix developed in TASK 2 Choose cell type in collaboration with NASA team. Cells should be large form factor custom designs most suited to space flight applications. Develop a cell worthiness acceptance test plan in partnership with the NASA team and execute test plan on no less than 10 cells that will be subjected to each TR initiation method. If the manufacturer chooses to use them, on-demand implantable internal short circuit (ISC) devices activated by heating the cells (to ~60 - C) and procedures for test cell implantation will be supplied by NASA. Test cell manufacturing and acceptance test data shall be delivered to the NASA team in Microsoft Excel or other approved format. TASK 4 - Conduct comparative initiation testing documenting temperature, voltage and energy data for each method and characterize differences in data and results. Reevaluate pros and cons and develop a test report along with narrative outlining recommended ignition methods along with pros and cons. 4. RFI Response Instructions NASA seeks responses to the questions in Appendix A, included below. Partial responses are welcome. Responses will be used to aid NASA in planning and prioritizing future research. NASA has no intention to publicly disclose Respondents' proprietary information obtained in response to this RFI. Proprietary and export controlled information should be marked appropriately in any response to this RFI. To the full extent that it is protected pursuant to the Freedom of Information Act and other laws and regulations, information identified by a Respondent as "Proprietary or Confidential" will be kept confidential. NO CLASSIFIED INFORMATION SHOULD BE INCLUDED IN ANY RFI RESPONSE. It is emphasized that this RFI is NOT a Request for Proposal, Quotation, or Invitation for Bid. This RFI is for information and planning purposes only, subject to FAR Clause 52.215-3 titled "Request for Information or Solicitation for Planning Purposes," and is NOT to be construed as a commitment by the Government to enter into a contractual and/or binding agreement, nor will the Government pay for information solicited. The Government may request follow-on discussion with one or more respondents, at the Government's discretion, to obtain clarification or additional detail of the material submitted. Respondents will not be notified of the results of the evaluation. No solicitation exists; therefore, do not request a copy of the solicitation. If a solicitation is released, it will be synopsized in the FedBizOpps website. It is the responsibility of any potential offerors/bidders to monitor these sites for the release of any solicitation or synopsis. The Point of Contact (POC) for questions regarding this RFI is: Connie Snapp Email address: c.snapp@nasa.gov 5. Schedule All responses to this RFI may be submitted via e-mail to c.snapp@nasa.gov by close-of-business (COB) June 10, 2019. Files may be submitted in MS Word, PDF, or RTF format. Paper submissions will not be accepted. All responses should be no more than ten (10) pages including questions, graphs, charts, tables, illustrations, and other figures. A page is defined as one (1) sheet 8 - x 11 inches using a minimum of 12-point font size for text. Appendix A RFI Questionnaire Please answer as many questions as possible (10-page limit). 1. Information about your organization a. Company Name b. Ownership status - US/Foreign/Multi-National c. Name, title, and Point of Contact Information for a U.S. Person (i.e. U.S. citizen or U.S. permanent resident/Green Card holder) Representing the Company d. Address/Location e. Size of business (large, small, small disadvantaged, 8(a), veteran-owned, service disabled veteran-owned and/or women owned or HUBZone, etc.) f. Years in business 2. Collaborative Work a. Does your organization agree with NASA's stated goals and notional tasks described in this future activity? If you agree, please provide a brief statement that addresses how the outcomes align with your organization's strategy. If not, please provide a brief statement on what other near-term objectives, themes, challenges and/or prioritizations your organization recommends that NASA should consider. b. Describe any modifications to the proposed task plan based on refinements provided in item 2a above. c. Given the responses in items 2 a and b above, how would your organization propose the division of activities in the collaborative effort outlined in this RFI and your responses 3. Cost a. Provide what resources (funds, facilities, labor, and/or assets) NASA should provide against each item in the respondent revised task list. b. Provide the same listing but with respect to contractor provided resources. i. Your Rough Order of Magnitude (ROM) information WILL NOT be made public, shared with incumbent contractor workforce, or shared outside of NASA. 4. Collaboration Interest NASA anticipates this effort, which will trail blaze battery level design techniques for large form factor cells, is viewed as mutually beneficial by cell suppliers and hence can be a collaborative effort. To the greatest extent possible, all measurements made by NASA will be published openly. If you are interested in collaborating with NASA, please describe the proposed activity, including any concerns/issues you have regarding the collaboration.