1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
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4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J2983_201212 SURFACE VEHICLE RECOMMENDED PRACTICE J2983 DEC2012 Issued 2012-12 Re
5、commended Practice for Determining Material Properties of Li-Battery Separator RATIONALE As the market for Li-battery continues to grow, due to the evolution of motive and stationary power applications, new separator concepts are being proposed for incorporation into the batteries. There are a varie
6、ty of properties that could be measured and a variety of methodologies to perform testing. This Recommended Practice (RP) provides a set of test methods for the characterization of the Li-battery separators properties, which if used consistently across different materials, will facilitate the compar
7、ison of the properties of Li-battery separator. TABLE OF CONTENTS 1. SCOPE 2 2. REFERENCES 2 2.1 Applicable Document 2 3. DEFINITIONS . 4 4. SAMPLE PREPARATION . 4 5. MANUFACTURING PARAMETERS . 4 5.1 Thickness (g80m) . 4 5.2 Air Permeability (measure of time required for 100mL of air to pass through
8、 film). 5 5.3 Porosity . 5 6. CHEMISTRY/CUSTOMER SPECIFIC PARAMETERS 7 6.1 Pore size . 7 6.2 Tensile strength . 7 6.3 Shrinkage 8 6.4 Shutdown 9 6.5 Resilience to puncture during cell manufacturing . 10 6.6 Separator wetting 10 6.7 Chemical Stability 11 6.8 Skew 12 6.9 Melt Integrity 13 6.10 Melt Te
9、mperature (DSC method) 14 6.11 Impact of separator on Ion Conductivity/Electrical Resistance . 14 6.12 HiPotential (HiPot) insulation resistance/Dielectric breakdown . 16 SAE J2983 Issued DEC2012 Page 2 of 19 7. R Telephone: 03-3588-8002; Fax: 03-3583-0462; http:/www.jsa.or.jp/default_english.asp JI
10、S P 8117 Paper and board - Determination of air permeance and air resistance (medium range) - Gurley method 2.1.4 United States Publications NASA/TM-2010-216099: “Battery Separator Characterization and Evaluation Procedures for NASAs Advanced Lithium-ion batteries”, May 2010. USABC “Procedure for de
11、termining shutdown temperature of battery separators” (http:/www.uscar.org/guest/article_view.php?articles_id=86) UL2591, “Investigation for Battery Separator”, Issue 2, March 2009 ORNL/TM-2012/247 (“Standard Test Method for Fatigue Evaluation of Polymeric Separators for Li-ion Cells”, E. Lara-Curzi
12、o and T.M. Trejo, 2011 is recommended SAE J2983 Issued DEC2012 Page 4 of 19 3. DEFINITIONS Except as noted below, all definitions are in accordance with SAE J1715. 4. SAMPLE PREPARATION Except where indicated, the tests in this recommended practice are to be performed at standard laboratory atmosphe
13、re, defined in ASTM D618-00 (Standard practice for Conditioning Plastics for Testing, Section 3). Some of the test techniques discussed in the following section require preparation of samples with an accurate surface area. Preparation of such a sample is described in ASTM D6287-09 (Standard Practice
14、 for Cutting Film and Sheeting Test specimens) In all cases, samples should be conditioned (e.g., dried) using the manufacturers recommended practice Except where indicated, the tests of this recommended practice are to be performed on a dry separator. It is possible that the addition of a solvent o
15、r electrolyte impact the performance of the separator. Users of this RP are urged to consider the interaction of the separator and solvent and perform tests on wet separators when deemed necessary, such as when a significant change in behavior is suspected to occur. The safety issues related with ha
16、ndling of electrolytes should be considered before doing the tests. 5. MANUFACTURING PARAMETERS 5.1 Thickness (g80m) In order to accurately and repeatedly measure thickness, some degree of pressure is applied to the film. The acceptable pressure to be applied to the film during thickness measurement
17、 is determined by the films porosity, composition and compressibility. NOTE: Compression modulus of the material should be taken under consideration when selecting the pressure to be applied when measuring thickness. The pressure which yields the smallest degree of film compression is to be selected
18、. Thickness measurements are described in 2 separate ASTM documents, whose main difference is the pressure to be applied: ASTM D5947-06: Standard Test Methods for Physical Dimensions of Solid Plastic Specimens ASTM D2103-08: Standard Specifications for Polyethylene Film and Sheeting The user is task
19、ed with selecting the best method based on the criteria described above. SAE J2983 Issued DEC2012 Page 5 of 19 Basis Weight (grams / cm2) Sample preparation: Preparation of the sample area is critical to accurate determination of the basis weight - repeatable surface area is necessary. A sufficient
20、amount of sample needs to be prepared to yield a recordable value on the balance. Equipment specification: Balance accurate to 4 decimal places ( 1mg) Sample size: Surface area of at least 225 cm2(equivalent of 15 x 15 cm) Measurement environment: standard laboratory atmosphere (see Section 3) Measu
21、rement frequency: measure each sample 3 times, and then average. Number of samples: g116 3 5.2 Air Permeability (measure of time required for 100mL of air to pass through film). The method as described in JIS P 8117 (“Paper and board Determination of air permeance and air resistance (medium range) -
22、 Gurley method”, 2009), is recommended with the following clarification g120 for rapid elution times, the head fitting may need to change to a smaller footprint (0.645cm2= 0.1 sq inch). This smaller head fitting increases elution time to improve measurement resolution. g120 normal head = 1 sq inch (
23、= 6.45 cm2) In the event that the user does not have equipment to perform Gurley measurement, the alternative burette method, as described in ASTM D726 - 94 (“Standard Test Method for Resistance of Nonporous Paper to Passage of Air“) may be used, with the following clarification g120 The user must b
24、e able to transform the burette method result into an equivalent Gurley measurement result. The user is encouraged to measure Gurley and empirically determine the correlation factor. 5.3 Porosity 5.3.1 Calculated porosity Requirements: Thickness (3.2), basis weight (3.3) and specific gravity (sg). %
25、100*1(%)g184g184g185g183g168g168g169g167g16g32avitySpecificGrThicknesstBasisWeighPorosity 5.3.2 Absorption method NOTE: This method is recommended for materials of composite compositions where density is not known. Absoprtion techniques will measure porosity from blind pores and through pores. SAE J
26、2983 Issued DEC2012 Page 6 of 19 Method: g120 The sample is to be conditioned per manufacturers recommendation. g120 A liquid capable of wetting the substrate is to be used, preferably an oil or an alcohol, although the latter is more susceptible to evaporation g120 Cut (minimum dimension of 10cm x
27、10cm or equivalent) and weigh the sample (mdry_sep). g120 Immerse the sample in the liquid for a minimum of 5 minutes. Remove the sample from the liquid. g120 Fold the sample multiple times so that the exterior surface represents 90o. g120 Water intrusion is preferred since the solvent is innocuous.
28、 However it may not be possible to use water since not all separator materials are hydrophobic. g120 Mercury intrusion: method as specified in ASTM D 2873 94 is recommended. o The user is cautioned that there is anecdotal evidence that mercury may chelate with polyolefin; reaction of the mercury wit
29、h silicates. The user is encouraged to investigate further before choosing this method. o There is also a possibility that the pore structure is damaged during the mercury intrusion method as high pressures are used for the measurement. The user is encouraged to investigate further before choosing t
30、he method. SAE J2983 Issued DEC2012 Page 7 of 19 o NOTE: o Mercury intrusion porosimetry will give volume in cc/g. A specific gravity is still required to obtain a porosity unless bulk density and skeletal density measurements are also taken o Since mercury intrusion porosimetry is a volume based te
31、chnique, multiple layers of separator are likely to be required. The gap between the layers will then be measured as a pore size and this factor should be eliminated from all calculations. g120 Some equipment which is known to perform the testing as described above: o Water Intrusion porosimeter (Aq
32、uapore) (http:/ o Mercury intrusion porosimeter (http:/ 6. CHEMISTRY/CUSTOMER SPECIFIC PARAMETERS All of the tests described in the following sections include a recommendation on the key property to be measured after testing. However, in some cases, the test conditions may result in unintended chang
33、es in the separator. To fully comprehend the impact of a test on the separator, the user is encouraged to consider how best to evaluate the separators performance. 6.1 Pore size 6.1.1 Intrusion techniques Intrusion techniques are recommended. Refer to 4.4.3 for more information on intrusion methods
34、Intrusion techniques measure a distribution of both through and blind pores based on volume. 6.1.2 Porometer/capillary flow porometry NOTE: this technique measures only the through pores in the sample A Porometer is to be used. The pores in the sample are spontaneously filled with a wetting liquid.
35、Pressure of a non-reacting gas on one side of the sample is slowly increased to remove liquid from the pores and permit gas flow through the pores. Measured differential pressures and flow rates of gas through wet and dry conditions of the sample are used to compute maximum and median pore size, por
36、e size distribution. Determination of the minimum pore size depends on the maximum pressure that can be applied by the instrument. (Refer to equipment manufacturers manual for information on how the pore diameters are computed). g120 The solvent must wet the sample g120 Some equipment which is known
37、 to perform the testing as described above g120 Porous Materials Capillary flow porometer (http:/ Measurement environment: per instrument guidelines Number of samples: g116 5 6.2 Tensile strength Tensile properties of the material should be determined using the methods described in ASTM D882 09: Sta
38、ndard Test Method for Tensile Properties of Thin Plastic Sheeting. SAE J2983 Issued DEC2012 Page 8 of 19 6.3 Shrinkage 6.3.1 Unrestrained Shrinkage NOTE: material should be conditioned per the manufacturers recommendation. 6.3.1.1 Oven method Generally, the methods as described in ASTM D1204-08: “St
39、andard test method for linear dimensional changes on non-rigid thermoplastic sheeting or film at elevated temperature”, are recommended with the following exceptions Equipment specification: g120 Oven should be suitable for controlling test temperatures within +/-1 C in the temperature range of 80 C
40、 to 260 C. g120 Thermometer/thermocouple should be graduated in 0.5 C increments and suitable for the test temperature used. Sample preparation: g120 Measure sample dimensions g120 Samples may be hung in the oven (no paper necessary), in which case the separator should not be exposed to temperatures
41、 near the melting point. g120 If samples are placed in paper, samples should be mounted in silicone paper (Griff Paper and Film, Item No. 03313-001, Rolls: 8 inch wide, Description: 42#S2S Release Liner), not just heavy paper sheets. Talc is not recommended Measurement conditions: g120 Test temperat
42、ure should be the manufacturers recommended drying temperature or temperature specified by the battery manufacturer. g120 Conditioning time at test temperature and post-test cooling are to be determined in conjunction with the manufacturer. Conditioning time is affected by sample composition. g120 A
43、dditional tests at temperatures at least 20% above the manufacturers recommendation are recommended to determine the tolerance of the material to fluctuation in the process Compare the dimensions to the initial values. Number of samples: g116 3 6.3.1.2 DMA method Generally, the methods as described
44、in NASA/TM-2010-216099: “Battery Separator Characterization and Evaluation Procedures for NASAs Advanced Lithium-ion batteries”, May 2010, 3.3, are recommended with the following exceptions: g120 The pre-load force is equipment and separator material dependent. Users should use the minimum pre-load.
45、 The 0.001N pre-load force, per the NASA method, may be appropriate but higher force may be needed to keep the separator taut and/or to get repeatable results. g120 The force on the sample should be maintained at the pre-load level during testing (in the NASA document, the force increases) g120 The
46、isotherm temperature and duration are customer and application specific. The temperature and duration set by the NASA procedure are considered to be a good starting point. SAE J2983 Issued DEC2012 Page 9 of 19 Number of samples: g116 3 6.3.2 Restrained Shrinkage 6.3.2.1 DMA with load Generally, the
47、methods as described in NASA/TM-2010-216099: “Battery Separator Characterization and Evaluation Procedures for NASAs Advanced Lithium-ion batteries”, May 2010, 3.3, are recommended with the following exceptions: g120 The pre-load force is equipment and separator material dependent. (NOTE: 0.001N, pe
48、r NASA may be appropriate, but higher force may also be needed to keep separator taut and/or to get repeatable results). g120 The force to be applied during the temperature sweep is dependent on the material under test. The 0.01N force specified in the NASA procedure is considered a good starting point. 6.3.2.2 Dimensional stability NOTE: The objective of this test is to evaluate the propensity of the separator to crack/tear when confined, as the separator would be in a cell, and exposed to elevated temperature. The method, as describe
