ASTM_D_7148_-_19a.pdf

Designation:D714819aAn American National StandardStandard Test Method forDetermining the Ionic Resistivity(ER)of Alkaline BatterySeparator Using a Carbon Electrode in an Electrolyte BathMeasuring System1This standard is issued under the fixed designation D7148;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the pretreatment,testconditions,apparatus,and procedure to determine the ionicresistivity,commonly referred to in the battery industry aselectrical resistance(ER)of an alkaline battery separatorimmersed in an electrolyte of 40%potassium hydroxide(KOH).1.2 The values stated in SI units are to be regarded as thestandard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1711 Terminology Relating to Electrical InsulationE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE2935 Practice for Conducting Equivalence Testing inLaboratory Applications2.2 Battery Council International:Standard Test Method for Determining the Electrical Resis-tance of a Battery Separator Using a Palico MeasuringSystem,Section 3.3b33.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 barrier resistance(RB),nthe resistance of the bathwith a solid,nonporous sheet of alkaline resistant,electricalinsulation that separates the electrodes.3.1.2 bath resistance(RC),nthe resistance of the bathwithout the specimen(separator).3.1.3 bath resistance(RT),nthe total electrical resistanceof the bath and a separator specimen.3.1.4 battery separator,nan ion-permeable,nonconduc-tive material that prevents electrical contact between electrodesof opposite polarity.3.1.5 electrolyte,na 40%potassium hydroxide solution.3.1.6 ionic resisitivity(ER),nthe product of a change inelectrical resistance times an area.3.1.6.1 DiscussionThe area is the aperture area divided bythe number of separators between the electrodes.The change inresistance is the difference,in ohms,of the electrical resistancewith and without the seperator(s).The SI units for ER areohms-metre2but the customary practice in the battery industryis to report the ER in units of ohms-cm2.This terminology isnot in conflict with Terminology D1711.3.2 Symbols:3.2.1 ERa symbol,peculiar to the battery industry,denot-ing that characteristic of a sheet material that is related to therate of transfer of ions through the interstices of a porous sheetimmersed between two carbon electrodes in an aqueouselectroyte.4.Summary of Test Method4.1 This test method detects small changes in ohmic resis-tance between carbon electrodes immersed in an alkalineelectrolyte with and without separator material between thecarbon electrodes.This change is related to the rate of transfer1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.01 on Electrical Insulating Products.Current edition approved Nov.1,2019.Published November 2019.Last previousedition approved in 2019 as D7148 19.DOI:10.1520/D7148-19A.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from Battery Council International,330 N.Wabash Ave.,Ste.2000,Chicago,IL 60611.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 of ions through a separator material.The ER is calculated fromthe fixed aperture area.The sensitivity and resolution of theapparatus detects electrical resistance changes of 60.1%.5.Significance and Use5.1 The ER of a battery separator is a standard measurementused by separator and battery manufactur