Reasons for depth analysis of lithium ion batteries

Umbhali :Iflowpower-UMboneleli weSikhululo saMandla esiphathwayo

Ngenxa yobomi bayo obuphezulu, ibhetri ye-lithium-ion isetyenziswa ngokubanzi, kunye nokwandiswa kwexesha lokusetyenziswa, ingxaki yokuqhuma, ukhuseleko lokusebenza alufanelekanga kwaye ukujikeleza kwe-attenuation kunzulu kakhulu, kubangela uhlalutyo kunye nokunyanzeliswa kwebhetri ye-lithium. . Ngokutsho kophando lovavanyo kunye namava ophuhliso, umbhali uhlula izizathu zeebhetri ze-lithium zibe ziindidi ezimbini, enye i-bulging ebangelwa ubukhulu bebhetri (okwesibini, ngenxa yokunyuka kwe-electrolytic liquid oxidation). Kwiinkqubo ezahlukeneyo zebhetri, ezona zinto zilawula ubukhulu bebhetri zahlukile.

Ngokomzekelo, kwi-lithium titanate ibhetri ye-electrode negative, izinto eziphambili ze-bulging ziyi-drum; kwinkqubo ye-electrode negative yegraphite, ukutyeba kobunzima bepali kunye nokugqabhuka koMthetho wonikezelo lwegesi. Okokuqala, ubukhulu bepali ye-electrode buyatshintshwa xa kusetyenziswa iibhetri ze-lithium, kwaye ubukhulu bepali ye-electrode inokutshintsha kobunzima, ngakumbi i-electrode negative yegraphite. Ngokutsho kwedatha ekhoyo, ibhetri ye-lithium igqithise ukugcinwa kobushushu obuphezulu kunye nokujikeleza, ethandwa kakhulu kwi-drumming, kunye neqondo lokukhula kobunzima malunga ne-6% ukuya kwi-20%, apho umlinganiselo wokwandiswa kwe-polar yi-4% kuphela, kunye ne-negative. Umlinganiselo wokwandisa ngama-20%.

Ingcambu yesizathu sokugquma kobunzima bokutshintsha kwebhetri ye-lithium ichaphazeleka ngundoqo wegraphite. I-electrode negative graphite yenza i-LICX (LIC24, i-LiC12 kunye ne-LIC6, njl.), kunye nokutshintsha kwesithuba somgca, okubangelwa ukubunjwa koxinzelelo lwe-microscopic yangaphakathi, okubangelwa i-electrode engalunganga Yandisa.

Lo mzobo ungezantsi yitshathi yolwakhiwo lweskimu yesakhiwo sepleyiti yegraphite negative electrode endaweni kunye nentlawulo kunye nokukhupha. Ukwandiswa kwe-electrode engalunganga yegraphite kubangelwa ikakhulu kukwandiswa okungenakusebenza. Le nxalenye yokwandiswa ikakhulu ihambelana nesakhiwo sobukhulu be-particle size, i-adhesive agent kunye ne-pole sheet.

Ukwandiswa kwe-electrode engalunganga ibangela ukuba undoqo wonakele, kwaye i-electrode yenziwe phakathi kwe-diaphragm, kwaye amasuntswana e-electrode angalunganga enza i-microcrack, ifilimu eqinileyo ye-electrolyte phase interface (SEI) yaphukile kwaye iphinda isebenze, idla i-electrolyte, kwaye icociwe. ukusebenza okujikelezayo. Kukho izinto ezininzi ezichaphazela izibonda ze-electrode ezingalunganga, kwaye ubume be-adhesive kunye neeparitha zesakhiwo sephepha le-polar zimbini zibaluleke kakhulu. I-adhesive edla ngokusetyenziswa kwi-graphite negative electrode yi-SBR, i-adhesive elastic modulus eyahlukeneyo, amandla omatshini ahlukeneyo, kunye neziphumo ezahlukeneyo kubunzima bepleyiti.

Amandla okuqengqeleka emva kokugqiba ukutyabeka nawo achatshazelwa bubunzima bepleyiti ye-electrode engalunganga kwibhetri. Ngaphantsi koxinzelelo olufanayo, inkulu i-elastic modulus ye-adhesive, encinci i-polarity physical shelving, xa itshaja, ngenxa yokufakela i-Li +, ukwandiswa kwe-lattice yegraphite; ngelo xesha, ngenxa ye-deformation ye-electrode particles negative kunye ne-SBR, uxinzelelo lwangaphakathi lukhululwe ngokupheleleyo , Yenza izinga lokunyuka elibi likhuphuke ngokukhawuleza, i-SBR ikwinqanaba lokuguqulwa kweplastiki. Le nxalenye yomlinganiselo wokwandisa inxulumene nemodyuli e-elastic ye-SBR, ekhokelela kwimodyuli enkulu kunye namandla e-SBR, kunye nokwandiswa kokunyuka okungenakuguqulwa.

Xa inani le-SBR lingahambelani, uxinzelelo luyahluka xa i-polar roller icinezelekile, kwaye ukuhlukana koxinzelelo kubangela ukuba uxinzelelo olushiyekileyo oluveliswa yi-pole, lukhulu luxinzelelo olushiyekileyo, olukhokelela ekwandisweni kwe-shelving pre-physical, umbane ogcweleyo kunye. Umlinganiselo ongenanto wokwandisa amandla; isiqulatho esincinci se-SBR, incinci yoxinzelelo lokuqengqeleka, iishelufu zomzimba ezingaphantsi, umlinganiselo wokwandiswa kombane wangaphambili kunye ne-electrocositis engenanto, okuncinci ukwandiswa okungalunganga kubangela ukuba undoqo ukhubazeke, uchaphazele okubi Inqanaba le-lithium i-lithium kunye ne-Li + isantya sokusasazwa, ngaloo ndlela ivelisa impembelelo enkulu ekusebenzeni komjikelo webhetri. Okwesibini, ukungena kwerhasi yangaphakathi yebhetri eninzi ebangelwa yigesi yebhetri sesinye isizathu esibalulekileyo esibangela ukuqhuma kwebhetri, nokuba ngumjikelo wobushushu bebhetri, umjikelo wobushushu obuphezulu, ishelving ephezulu yobushushu, ivelisa amanqanaba ahlukeneyo erhasi. Ngokweziphumo zophando lwangoku, undoqo wokudumba kombane kubangelwa kukubola kwe-electrolyte.

Kukho iimeko ezimbini zokubola kwe-electrolyte, enye kukungahlambuluki kwe-electrolyte, njengokufuma kunye nokungcola kwesinyithi ukubola ulwelo lwe-electrolytic, kwaye enye iphantsi kakhulu kulwelo lwe-electrolytic, olubangela ukubola ngexesha lokutshaja, nakwi-electrolyte. I-solvents ezifana ne-EC, i-DEC ziveliswa emva kokufumana i-electron, kunye nemiphumo ethe ngqo ye-radical reactions yamahhala i-hydrocarbons, i-esters, i-ethers kunye ne-CO2, njl. Emva kokuba indibano yebhetri ye-lithium igqityiwe, ixabiso elincinci legesi lenziwa ngexesha lenkqubo enqunywe kwangaphambili. , kwaye ezi gesi zingenakuphepheka, kwaye into ebizwa ngokuba ngumbane ongundoqo ongenakuguqulwa umthombo wokulahlekelwa kwamandla. Ngethuba lokuqala lokuhlawula kunye nenkqubo yokukhupha, ii-electron zifikelela kwisisombululo se-electrolytic kunye nesisombululo se-electrolytic ye-electrode embi emva kwesiphaluka sangaphandle, senza igesi.

Kule nkqubo, i-SEI yenziwe kumphezulu we-graphite negative electrode, kunye nobukhulu bokunyuka kwe-SEI, ii-electron azikwazi ukungena kwi-oxidation eqhubekayo ye-electrolyte. Ngethuba lobomi bebhetri, umthamo wegesi wangaphakathi uya kunyuka ngokuthe ngcembe, ngenxa yesizathu sokungcola okanye umswakama kwi-electrolyte okanye kwi-electrolyte. Ubukho be-electrolyte bufuna ukungabandakanyi kakhulu, kwaye ulawulo lokufuma alukho ngqongqo.

Isisombululo se-electrolytic ngokwaso asingqongqo, kwaye ipakethe yebhetri ayifakwanga ngokungqongqo emanzini, ukuchithwa kwe-angular kubangelwa, kwaye ukugqithisa kwebhetri kuya kukhawulezisa ukuveliswa kwegesi yebhetri. Isantya, kubangela ukusilela kwebhetri. Kwiinkqubo ezahlukeneyo, inani lemveliso yebhetri lihlukile.

Kwi-graphite negative electrode battery, unobangela wokuveliswa kwegesi ikakhulu ngenxa yokwenziwa kwefilimu ye-SEI, ukufuma kwibhetri kugqithisiwe, kunye nokuhamba kweekhemikhali akuqhelekanga, iphakheji imbi, kunye ne-betri florescent ratio kwi-lithium titanate. Inkqubo yebhetri yeNCM kufuneka ibe nzulu ngakumbi. Ukongeza kwizinto ezingcolileyo, umswakama kunye neenkqubo kwi-electrolyte, omnye umehluko ovela kwi-graphite negative electrode kukuba i-lithium titanate ayikwazi ukufana ne-graphite negative electrode battery, eyenza ifilimu ye-SEI ebusweni bayo, inqanda ukusabela kwayo kwe-Electrolyte. I-electrolyte isoloko idibana ngokuthe ngqo nobuso be-Li4Ti5O12 ngexesha lokuhlawula kunye nokukhutshwa, okubangela ukunciphisa okuqhubekayo kwendawo ye-Li4Ti5O12 yezinto eziphathekayo, ezinokuthi zibe yimbangela ye-Li4Ti5o12 ibhetri flatulence.

Izinto eziphambili zegesi ziyi-H2, i-CO2, i-CO, i-CH4, i-C2H6, i-C2H4, i-C3H8, njl. Xa i-lithium titanate ifakwe ngokwahlukileyo kwi-electrolyte, kuphela i-CO2 iveliswa, kwaye emva kokulungiselela ibhetri nge-NCM impahla, iigesi eziveliswayo ziquka i-H2, i-CO2, i-CO, kunye nenani elincinci le-hydrocarbons ye-gaseous, kwaye emva kwebhetri, kuphela kumjikelezo Xa utshaja kunye nokukhutshwa, i-H2 yenziwe, kwaye kwi-gesi eyenziwe, umxholo we-H2 udlula i-50%. Oku kubonisa ukuba i-H2 kunye ne-CO igesi iya kuveliswa ngexesha lokuhlawula kunye nokukhutshwa.

I-LIPF6 ikhona kwi-electrolyte: PF5 yi-asidi eyomeleleyo, elula ukubangela ukubola kwe-carbonate, kunye nokwandisa inani le-PF5 ngokunyuka kobushushu. I-PF5 incedisa ukubola kwe-electrolyte, ukuvelisa i-CO2, i-CO kunye ne-CXHY igesi. Ngokophando olufanelekileyo, ukuveliswa kwe-H2 kuthathwa kumanzi okulandelela kwi-electrolyte, kodwa umxholo wamanzi kwi-electrolyte jikelele malunga ne-20 ¡Á 10-6, ephantsi kakhulu kwiSivuno se-H2.

Uvavanyo lweWu Kai lweYunivesithi yaseShanghai Jiaotong lusetyenziswe njengebhetri yegraphite / NCM111. Isiphelo sagqiba ukuba umthombo we-H2 kukuchithwa kwe-carbonate phantsi kombane ophezulu. Okwangoku, kukho izisombululo ezintathu zokucinezelwa kweebhetri ze-lithium titanate.

, Inkqubo yokunyibilikisa; okwesithathu, ukuphucula iteknoloji inkqubo yebhetri.