概括單體蓄電池充放電的平均壽命

概括單體蓄電池充放電的平均壽命鑒于相同原材料、同批次的單體電池，容量、內(nèi)阻、壽命等性能參數(shù)符合正態(tài)分布并且離散程度有限；鑒于在相同的電流激勵條件下，單體電池電壓變化過程的一致性漸進逼近其它性能參數(shù)的一致性,其中最重要的參數(shù)是荷電程度;鑒于電池在未曾歷經(jīng)過過充、過放的損害，在其生命期里不容易提前失效，可以推斷,如果在充放電過程中通過能量變換的辦法實施電池組中單體電壓的均衡控制,使單體電壓趨于一致,以單體電池為動力源如移動通訊，電源管理技術(shù)已經(jīng)十分完善，但在蓄電池組中,單體之間的差異總是存在的,以容量為例,其差異性永不會趨于消失，而是逐步惡化的。組中流過同樣電流，相對而言,容量大者總是處于小電流淺充淺放、趨于容量衰減緩慢、壽命延長，而容量小者總是處于大電流過充過放、趨于容量衰減加快、壽命縮短,兩者之間性能參數(shù)差異越來越大，形成正反饋特性，小容量提前失效,組壽命縮短。Asrawmaterials,withthesamebatchofmonomerbattery,thecapacity,internalresistance,servicelifeandotherperformanceparametersconformtonormaldistributionanddiscretedegreeislimited;Givenundertheconditionofsamecurrentincentive,ofmonomerbatteryvoltagechangeprocessconsistency,graduallyapproachingotherperformanceparametersofthedegreeofoneofthemostimportantparameteristhecharged;Lightneverafterhavethechargerandabatterydamage,initslifetimeisnoteasytoearlyfailure,canbeconcludedthatifintheprocessofcharginganddischargingthroughthewayofenergyconversionimplementationofmonomerinthebatterypackvoltagebalancingcontrol,leadtotheagreementmonomervoltage,monomerbatteryaspowersource,suchasmobilecommunications,powermanagementtechnologyhasbeenveryperfect,butinthebattery,alwaysexistdifferencesbetweenmonomer,capacity,forexample,thedifferenceswillnevertendtodisappear,butgraduallydeteriorating.Groupthroughthesamecurrent,incontrast,capacityisalwaysinsmallcurrentshallowfilllightput,capacityofslowattenuation,longevity,andsmallbreastsarelargecurrentchargedischargecapacity,capacityattenuationspeed,shortentheservicelife,performanceparametersofthedifferencesbetweenthetwoismoreandmorebig,theformationofthepositivefeedbackfeatures,smallcapacityfailureaheadoftime,groupshortenedlifespan.2、蓄電池組的充電過程thebatterychargingprocess2.1、充電2.1,charging目前充電主要是限壓限流法,初期恒流(cc)充電,電池接受能力最強，主要為吸熱反應(yīng)，但溫度過低時，材料活性降低，可能提前進入恒流階段,因此在北方冬天低溫時,充電前把電池預(yù)熱可以改善充電效果。隨著充電過程不斷進行,極化作用加強，溫升加劇,伴隨析氣，電極過電位增高，電壓上升，當(dāng)荷電達到約70~80%時，電壓達到最高充電限制電壓，轉(zhuǎn)入恒壓(cv)階段。理論上并不存在客觀的過充電壓閾值，若理解為析氣、升溫就意味著過充，則在恒流階段末期總是發(fā)生不同程度的過充，溫升達到40~50攝氏度，殼體形變?nèi)菀赘袦y，部分逸出氣體還可以復(fù)合,另一些就作為不可逆反應(yīng)的結(jié)果，損失了容量，這可以看作電流強度超出電池接受能力。在恒壓階段,有稱涓流充電,大約花費30%的時間充入10%的電量，電流強度減小，析氣、溫升不再增加，并反方向變化。Chargingatpresentismainlypressurelimitingcurrentlimitmethod,theinitialconstantcurrent(cc)charging,thebatterytoacceptabilityisstrongest,mainlyfortheendothermicreaction,butthetemperatureistoolow,materialactivitydecreased,maybeinadvanceintotheconstantcurrentphase,socoldinwinterinthenorth,thebatterybeforechargingpreheatimprovesthechargingeffect.Withconstantchargingprocess,thepolarizationeffectstrengthen,temperaturerise,alongwithgaschromatography,electrodeoverpotentialincreases,thevoltagerise,whenchargedtoabout7080%,reachedthehighestvoltagelimitingvoltage,chargingintoconstantvoltage(CV)phase.Intheorythereisnoobjectiveofchargingvoltagethreshold,ifunderstoodasanalysis,gasheatingmeansovercharge,theendalwayshappenduringtheconstantcurrentphasevaryingdegreesofovercharge,4050degreesCelsiustemperature,sensorshelldeformationeasily,partoftheescapinggascanalsobecompound,theotherisasaresultofirreversiblereaction,lossofcapacity,itcanbeseenascurrentstrengththanbatterycapacities.Atconstantpressurestage,hassaidatricklecharge,thecostabout30%into10%ofthetime,currentintensitydecreases,gasanalysis,temperaturenolongerincreases,andchangesintheoppositedirection.2.2過充電2.2aftercharging上述過程考慮電池組總電壓或平均電壓控制，其實總有單體電壓較高者，相對組內(nèi)其它電池已經(jīng)進入過充電階段。過充電時，若在恒流階段發(fā)生,由于電流強度大,電壓、溫升、內(nèi)壓持續(xù)升高，若繼續(xù)過充，氣閥打開、溫升繼續(xù)升高、不可逆反應(yīng)加劇。恒壓階段，電流強度較小，過充癥狀不如恒流階段顯著。釀酒設(shè)備只要溫升、內(nèi)壓過高,就伴隨副反應(yīng),電池容量就會減少,而副反應(yīng)具有慣性，發(fā)展到一定程度，可能在充電中也可能在充電結(jié)束后的短時間里使電池內(nèi)部物質(zhì)燃燒,導(dǎo)致電池扌報廢。過充電加速電池容量衰減、導(dǎo)致電池失效，百害而無一利。Consideringaboveaveragetotalbatteryvoltageorvoltagecontrol,actuallythereisalwaysamonomervoltagehigh,relativetoothercellsinthegrouphasenteredthestageofcharging.Beforecharging,exceptintheconstantcurrentphase,duetothecurrentintensity,voltage,temperature,innerpressurecontinuedtorise,ifcontinuetoovercharge,thevalveopens,andirreversiblereactiontemperaturecontinuestorise.Constantpressurestage,thecurrentstrengthissmall,overchargesymptomsthanconstantcurrentphaseisremarkable.Aslongasthetemperaturerise,highinternalpressure,isassociatedwithsideeffects,batterycapacitywillbereduced,andtheadverseeventhasinertia,developmenttoacertainextent,mayinchargemayalsobeinchargeofthebatteryinashorttimeafterthematterinsideburning,leadtodeadbatteries.Chargingspeedbatterycapacityattenuation,leadtobatteryfailure,vileindeed.3、蓄電池組的放電過程thebatterydischargeprocess3.1放電3.1discharge導(dǎo)線電阻和觸點電阻，電壓繼續(xù)下降，經(jīng)過一段時間以后,到達新的電化學(xué)平衡,進入放電平臺期,電壓變化不明顯，放熱反應(yīng)加電阻釋熱使電池溫升較高。放電電壓曲線近似單體放電曲線,持續(xù)放電,電壓曲線進入馬尾下降階段，極化阻抗增大，輸出效率降低,熱耗增大,接近終止電壓時停止放電。Wireresistanceandcontactresistance,voltagecontinuestofall,afteraperiodoftime,reachnewelectrochemicalbalance,intothedischargeplateau,voltagechangeisnotobvious,theexothermicreactionandresistanceheatreleasethebatterytemperatureriseishigher.Dischargevoltagecurveapproximationmonomerdischargecurve,continuetodischarge,thevoltagecurveintohorsetaildeclinephase,polarizationimpedanceincreases,theoutputefficiencyisreduced,heatconsumptionincreases,closetotheendstopdischargevoltage.3.2過放電3.2afterdischarge考慮組內(nèi)單體電池，必有相對的過放電情況。在放電后期，電壓接近馬尾曲線，組中單體容量正態(tài)分布，電壓分布很復(fù)雜,容量最小的單體電壓跌落得也就最早、最快，若這時其它電池電壓降低不是很明顯，小容量單體電壓跌落情況被掩蓋,已經(jīng)被過度放電。Considersinglecellsinthegroup,therewillbeaturnhadrelativedischargecondition.Lateinthedischarge,thevoltageisclosetomaweicurve,singlecapacityofnormaldistribution,thevoltagedistributioniscomplex,thesmallestcapacitymonomervoltagesagsaretheearliest,thefastest,ifthebatteryvoltageislowerwhentheotherisnotveryobvious,monomervoltagedropwerehidesmallcapacity,hasbeenexcessivedischarge.觀察單體過放情況，進入馬尾曲線以后，若電流持續(xù)較大，電壓迅速降低,并很快反向，這時電池被反方向充電,或稱被動放電,活性物質(zhì)結(jié)構(gòu)被破壞,另一種副反應(yīng)很快發(fā)生,過一段時間，電池活性材料接近全部喪失，等效為一個無源電阻,電壓為負值,數(shù)值上等于反充電流在等效電阻上產(chǎn)生的壓降，停止放電后,原電池電動勢消失，電壓不能恢復(fù)，因此，一次反充電足以使電池報廢。Observemonomerthroughput,toenterafterhorsetailcurve,ifcontinuedlargecurrent,thevoltagedecreaserapidly,andquicklyreversed,theoppositedirectionofthebatteryischarging,dischargeorpassive,activematerialstructureisbroken,anothersideeffectshappenquickly,overaperiodoftime,batterylossofactivematerialisclosetofull,equivalenttoapassiveresistance,voltageisnegative,thevalueisequaltoreversechargeflowonequivalentresistanceofpressuredropandstopafterdischarge,batteryelectromotiveforcedisappears,thevoltagecan'trecovery,therefore,arevers