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Compact and/or MEMS-based gas-sampling sensors for analysis of battery offgassing
Navy SBIR 2010.1 - Topic N101-056 NAVSEA - Mr. Dean Putnam - [email protected] Opens: December 10, 2009 - Closes: January 13, 2010 N101-056 TITLE: Compact and/or MEMS-based gas-sampling sensors for analysis of battery offgassing TECHNOLOGY AREAS: Sensors ACQUISITION PROGRAM: PMS 399 OBJECTIVE: Design and demonstrate highly compact (possibly MEMS-based) sensor devices, suitable for robust, reliable monitoring and sensing of gases indicative of battery degradation and release, and/or offgassing due to typical operation. The device is designed to observe the release of electrolyte from a damaged or compromised lithium-ion battery, but would also be usable to monitor offgassing of other battery technologies due to the desired species which the device should be able to determine. The device should have good dynamic range of operation, and be suitable for mounting in tight places with minimal accessibility and power requirements. The devices should also offer long life with minimal interface required, and be available at relatively low cost so that they can be utilized in high volume. DESCRIPTION: Energy storage is becoming more and more critical to the enabling of advanced electrical architectures on ships, and is also of very high utility for use in combination with other high-efficiency systems such as fuel cells. Advanced lithium-ion batteries offer significant benefits in terms of capacity, discharge characteristics, and volumetric and gravimetric power and energy densities. However, lithium-ion batteries, like most other energy storage systems, have a variety of safety concerns, particularly if placed in an enclosed space in a means that cannot readily be removed, disposed, etc. As a means of risk mitigation, it is critical to be aware of battery breakage, leakage and other means of degradation or compromise, through multiple, redundant means to ensure safety. A critical aspect of the redundant, interlocked safety analysis is that of monitoring the atmosphere around the units, which may or may not include lithium-ion , lead acid, silver-zinc and other battery types, to determine the presence and concentration of gases of interest, including VOCs, CH4, CO/CO2, HF, hydrogen, H2S/SO2 etc., in air that is typically between 40-140F and ambient pressure. Typically, sensor systems for environmental monitoring and specialty analysis of such gases have been large, especially if hardened and militarized for diverse applications. The typical set of devices also is generally based upon chromatographic and/or spectroscopic technologies which are relatively large in size. Recent systems, while tunable to be sensitive to the gas sets desired, still are of a size and architecture that does not enable highly redundant sensing and on-location determination of the content and concentrations of interest. The combination of a gas sampling device coupled to the sensor, data bus, processing and data analysis, energy storage, etc. creates a system that is too large for broadly distributed application throughout a cabinet or set of cabinets or similar installation. Recent developments in advanced sensor technology and MEMS device design and operation make it potentially possible to have extremely small, low power draw devices that can exist at relatively low cost compared to traditional technology. Additionally, with miniaturization and "sensor on a chip" technologies advancing quickly, it provides the opportunity to perform multiple applications in a tiny package, further increasing redundancy and distributed safety analysis. As a result, the compact or MEMS sensor should not take up a space larger than 36in^3, and no larger than six inches in any one dimension. It is preferable for a smaller package to be provided, to whatever minimal scale is possible, should technology permit. Of key interest to this effort is the ability to operate and detect trace levels of the gases described, while maintaining good dynamic range, reliability and calibration for durations in excess of one year. This minimizes the labor and upkeep costs, while also ensuring that these sensors, which may be placed in very tight, difficult spaces, are not a liability to the safety system operation. Also, because of potential placement and desired minimization of interfacing and requirements, the system should be relatively self-contained, and require no outside utilities or equipment (e.g. air, water, vials, syringes) that it cannot self contain for the duration. An ultimate sensor device should be rugged and robust in design, capable of existing in wet environments with salt air. General specifications are as follows: PHASE I: Demonstrate proof of concept for sensing the gases described above. The device need not sense all gases on one chip/unit, but it is preferable to demonstrate multiple gases determined from a single unit. Proof of concept should be from moderate ppb range (e.g. 250ppb) through low ppm range (e.g. 25ppm), or higher. The device can operate with whatever power source is required for a prototype, but should ultimately be designed for 24 or 48VDC input. PHASE II: Develop an integrated prototype device that offers multiple sensor technologies on one chip/unit, and operates via a standard interface, such as LabView (with a more advanced interface designed under an option phase). The device itself should have a self-contained indicator of operation, and an indicator of conditions or presence of specific gases. The integrated device should show a good linear range of at least that shown in Phase I, preferably wider, with increased sensitivity to low-levels of the gases desired. The sensor operational characteristics shall be demonstrated in a controlled environment consisting of a lead-acid battery under charge (with release of hydrogen), with controlled input of a variety of low-level test gases including HF and VOCs relevant to the compromise of a lithium-ion battery. PHASE III: Advanced sensors are in increasingly high need for a wide variety of applications, and it is anticipated that these sensors will be of use for monitoring release and atmosphere as lithium-ion batteries are utilized for applications such as hybrid vehicles and distributed grid-tied energy storage. Phase III should focus on militarization of the system, and providing compatible interfaces, including a self-contained indicator system, as well as a compact communication means via CAN bus. The sensors should be demonstrated in its final form in a controlled atmosphere as described in phase II, as well as in conjunction with a platform which routinely handles charging of batteries which are known to offgas hydrogen. PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Sensors to monitor the release of batteries have applicability for applications ranging from hybrid cars to battery backup for telecommunications and grid stabilization. The products potentially released from batteries as they degrade, as well as from some battery varieties simply as they undergo charge, etc. is of high importance for monitoring and health/operation assessment, as well as safety. REFERENCES: 2. Charles J. Scuilla, The Commercialization of Lithium Battery Technology, S9310-AQ-SAF-010. KEYWORDS: Sensor; MEMS; Battery; Safety; Gas; Vapor
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