OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Directed Energy (DE); Renewable Energy Generation and Storage
OBJECTIVE: Develop shipboard containment for embedded lithium batteries in standard containment dimensions, to support the integration of large batteries that scale up to the megawatt (MW), and up to MW-hour (MWh) scales. The batteries have interfaces up to 1000VDC, and containment must account for protection from shock, vibration, internal/external fire, overpressure, managing battery gas release, kinetic effects, etc. The containment system should provide a modular construct to enable a level of isolation between battery modules of different form factors, inside of the container so that propagation potential is minimized.
DESCRIPTION: Energy storage systems, comprised of high power and energy-density batteries, offer the potential for numerous benefits as applied to power systems of different types. However, high density storage systems, which may present electrical, chemical, and flammability/explosive hazards, must be able to be simply and effectively installed in locations which can be populated by personnel and sensitive equipment. Because of this, robust and rugged enclosures must be designed that are capable of overcoming effects related to temperature, pressure and internal/external effects, at the same time.
Battery systems will need to be enclosed in containment structures that protect from internal (e.g., other failing modules) and external (e.g., fires, weapons effects, moisture) threats. Containment should not be tied to a specific cell size or chemistry, nor to a specific battery module design or form factor, as it is likely that battery technology approaches and designs will change in time. Thus, containment approaches that are universally useful (e.g., standard containment rack widths or designs that can intrinsically be adapted to various battery designs) are recommended. However, the approaches must provide substantial innovation because the effects upon size and weight due the enclosure and containment cannot substantially adversely affect the power and energy density of the storage systems. Innovative R & D to support the creation of compact, lightweight, and high performance enclosure structures should support the evaluation of means of enclosing and isolating energy storage systems from the surrounding environment.
The overall structural approaches should be amenable to large shipboard-embedded systems. Approaches must be considerate of the conditions of release, including MW thermal flux from failed components, overpressures, and flame effects. The system should include a directed ventilation approach to allow gasses generated to escape into a specific, acceptable location or direction. The enclosure shall not require substantial volume above that already taken by the storage system itself, thus an enclosure system will not expand the volume by more than 10% of the racked storage components. Ultimately the design should ensure strength of the shelving and resilience to shock, vibration and environmental effects as defined in the MIL specifications provided in the References. Any design should be able to support devices enclosed with voltages up to 1000VDC (including arcs and plasmas) and power capabilities up to 1MW, and provide penetrations to allow cabling sufficient for moving energy in and out of the enclosure. Cooling may also be assumed to be available, but no colder than 40 degrees Celsius at a flow rate proportional to the volume of the box. It should not be assumed that copious quantities of cooling liquid are available to cool the enclosure itself, but rather the items placed inside. However, small amounts could be utilized by the enclosure itself to support internal environmental characteristics. Aspects of packaging of components internal to the enclosure could be manipulated to support the overall requirements of the enclosure system; however, the design must be flexible and adaptable to specific components or combinations of components inside.
PHASE I: Perform advanced modeling and analysis to define the energetic characteristics of cascading battery failure conditions, where it is assumed that a device fails on the order of one per minute continuously. The basis of the analysis will utilize the thermal and inertial effects from released gas and ejecta from cells. The evaluations will be utilized to determine the requirements for scalable architectures which create minimal impact on device density. Utilizing this information, a conceptual design will be provided with traceable simulation basis to demonstrate performance. If possible, validation of simulated performance parameters will be provided prior to the Option phase. This work will be used to help define a containment volume of sufficient dimensions to be considered a standard rack, with dimensions of ca. 25”W x 48”D x 72”H.
PHASE II: Scale any conceptual enclosure design artifacts and material selections produced under Phase I and its Option period, if exercised, to relevant size, which provides dense rack-mount capability and serviceability aspects. All input and output interface points will be defined and performance simulations evaluated with a greater level of detail. An interface Control Document (ICD) will be created to define clearly all connection points, types, dimensions, model numbers, etc. The complete containment equipment will be built to the designs produced, and validation of the performance aspects (inertial, mechanical, thermal, chemical resilience) will be demonstrated via failure of Li-ion batteries.
PHASE III DUAL USE APPLICATIONS: Design and build full-scale flexible rack-mount enclosures for a particular military application, with the internal modular structure built to a specific battery. The containment will be designed to the intent of meeting appropriate MIL-SPEC operational requirements, and a combination of detailed analytical evaluations and specific test events will be performed.
A scalable, cost-effective enclosure scheme that provides local isolation from energetic release will enable lighter, more compact energy storage to be implemented onto a greater number of platforms and operational equipment.
Dual use applications are anticipated for commercial marine large scale battery applications.
- “Maritime Risk Focus: Lithium-ion batteries fire risks and loss prevention measures in shipping”, 3/21/2023, https://maritimecyprus.com/2023/03/21/maritime-risk-focus-lithium-ion-batteries-fire-risks-and-loss-prevention-measures-in-shipping/
- NAVSEA S9310-AQ-SAF-010, Technical Manual for Batteries, Navy Lithium Safety Program Responsibilities and Procedures, http://everyspec.com/USN/NAVSEA/NAVSEA_S9310-AQ-SAF-010_4137/
KEYWORDS: Battery, Thermal Runaway, Containment, Enclosure, Fire