Umthamo uyimpahla yokuqala yebhethri,lithium battery cellumthamo ophansi ubuye ube yinkinga evame ukuhlangana namasampula, ukukhiqizwa kwenqwaba, indlela yokuhlaziya ngokushesha izimbangela zezinkinga zomthamo ophansi ezihlangatshezwane nazo, namuhla ukwethula kini ukuthi yiziphi izimbangela zomthamo ophansi webhethri ye-lithium cell?
Ukumataniswa kwezinto, ikakhulukazi phakathi kwe-cathode ne-electrolyte, kunomthelela omkhulu kumthamo weseli.Nge-cathode entsha noma i-electrolyte entsha, uma ukuhlolwa okuphindaphindiwe kuveza umthamo ophansi we-lithium precipitation njalo lapho iseli lihlolwa, khona-ke kungenzeka kakhulu ukuthi izinto ngokwazo azifani.Ukungafani kungase kube ngenxa yokuthi ifilimu ye-SEI eyakhiwe ngesikhathi sokubunjwa yayingaminyene ngokwanele, iminyene kakhulu noma ingazinzi, noma i-PC eku-electrolyte eyenza ungqimba lwe-graphite lukhumuke, noma ukwakheka kweseli ukungakwazi ukuzivumelanisa nokushaja okukhulu/ amazinga okukhishwa ngenxa yokuminyana ngokweqile kwendawo.
Ama-diaphragms nawo ayisici esinomthelela esingabangela umthamo ophansi.Sithole ukuthi ama-diaphragm enxeba lesandla akhiqiza imibimbi ekuqondeni kwe-longitudinal phakathi kwesendlalelo ngasinye, lapho i-lithium ingagxiliwe ngokwanele ku-electrode engalungile futhi ngaleyo ndlela ithinte umthamo weseli cishe ngo-3%.Nakuba amanye amamodeli amabili esebenzisa i-semi-automatic winding lapho ukushwabana kwe-diaphragm kuncane kakhulu futhi umthelela kumthamo ungu-1% kuphela, akusona isisekelo sokuyeka ukusebenzisa i-diaphragm.
Imingcele yokuklama umthamo onganele ingase futhi ibangele umthamo ophansi.Ngenxa yomthelela we-electrode enhle nengalungile, iphutha lesihlukanisi samandla kanye nomthelela we-adhesive kumthamo, kubalulekile ukuvumela inani elithile lomkhawulo womthamo lapho uklama.Lapho uklama imajini yomthamo, kungenzeka ukushiya imali enqwabelene ngemva kokubala umthamo womongo nazo zonke izinqubo emugqeni ophakathi nendawo, noma ukubala imali enqwabelene ngemva kokuba zonke izici ezithinta umthamo zenzeke emkhawulweni ophansi.Ukuze uthole izinto ezintsha, ukuhlolwa okunembile kwegram play ye-cathode kuleyo sistimu kubalulekile.Isiphindaphindi samandla ngokwengxenye, amandla okunqamula inkokhiso, isiphindaphindi seshaja/ukukhipha, uhlobo lwe-electrolyte, njll., konke kuthinta ukudlala kwegramu ye-cathode.Uma inani ledizayini yokusebenza kwegremu ephozithivu liphezulu ngokuzenzisa ukuze kufinyelelwe umthamo oqondiwe, lokhu futhi kulingana nomthamo wedizayini onganele.Akukho lutho olungalungile ngesixhumi esibonakalayo seseli, futhi akukho lutho olungalungile ngedatha yenqubo iyonke, kodwa umthamo weseli uphansi.Ngakho-ke, izinto ezintsha kufanele zihlolwe ukuze kutholwe i-cathode grammage enembile, ngoba i-cathode efanayo ngeke ibe ne-grammage njenganoma iyiphi i-cathode noma i-electrolyte.
I-electrode engemihle eyeqile ingase futhi ithinte ukusebenza kwe-electrode enhle ngokwezinga elithile, ngaleyo ndlela ithinte umthamo weseli.Ukulayisha ngokweqile okungekuhle akuwona "inqobo nje uma ingekho imvula ye-lithium".Uma ukulayishwa okungalungile kwenyuswa kufinyelele emkhawulweni ophansi wokugcwala kwemvula okungeyona i-lithium, kuzoba nokwenyuka okungu-1% kuya ku-2% ekusebenzeni kahle kwegram, kodwa noma ngabe kunyusiwe, ukugcwala okungekuhle kusanele ukuqinisekisa ukuthi umthamo wokukhipha amandla uphezulu ngangokunokwenzeka.Lapho i-electrode engemihle ngokweqile iphezulu kakhulu, i-electrode enhle izodlala indima ephansi ngoba i-lithium engenakuhlehliswa iyadingeka kukhemistry, kodwa ngokuqinisekile amathuba okuba lokhu kwenzeke cishe awekho.
Uma umthamo womjovo owuketshezi uphansi, ivolumu yokugcinwa koketshezi ehambisanayo nayo izoba phansi.Uma umthamo wokugcina uketshezi weseli uphansi, khona-ke umphumela wokushumeka kwe-lithium ion kanye nokushumeka kuma-electrode aqondile noma angalungile azothinteka, ngaleyo ndlela kucuphe umthamo ophansi.Nakuba kuzoba nengcindezi encane ezindlekweni nasezinkambisweni ezinomthamo ophansi womjovo, isisekelo sokwehlisa umthamo womjovo kumele kube ukuthi akuthinti ukusebenza kweseli.Yebo, ukwehlisa izinga lokugcwalisa kuzokhuphula kuphela amathuba okuba namandla aphansi ngenxa yokugcinwa koketshezi okwanele kuseli, kodwa akuwona umphumela ongenakugwemeka.Ngesikhathi esifanayo, lapho kunzima kakhulu ukumunca uketshezi, kufanele kube khona i-electrolyte eyengeziwe ukuze kuqinisekiswe ukuthintana okungcono ne-electrode ngesikhathi sokumanzisa i-electrolyte.Ukugcinwa kweseli okunganele kuzoholela ekutheni ama-electrode ahle noma angabibikho ome kanye nongqimba oluncane lwemvula ye-lithium phezu kwe-electrode engalungile, okungaba isici samandla aphansi ngenxa yokugcinwa okungalungile.
I-electrode eboshwe kancane eqondile noma engalungile ingabangela ngokuqondile umthamo ophansi womthamo.Uma i-electrode ephozithivu iboshwe kancane, isixhumi esibonakalayo sikamongo oshajwe ngokugcwele ngeke sibe esingajwayelekile.I-electrode engeyinhle, njengomamukeli we-lithium ion, kufanele inikeze inombolo enkulu yezikhundla ze-lithium ezishumekiwe kunenombolo yemithombo ye-lithium enikezwe i-electrode ephozithivu, ngaphandle kwalokho i-lithium eningi izokwehla phezu kwe-electrode engeyinhle, kuphumele ungqimba oluncane. yemvula efanayo ye-lithium.Njengoba kushiwo ngaphambili, ngoba isisindo esingalungile se-electrode asikwazi ukuthathwa ngokuqondile esisindweni sokubhaka sama-cores, ngakho-ke umuntu angenza olunye ucwaningo ukuze athole ingxenye yenzuzo yesisindo se-electrode engalungile ukuze athole isisindo sokumboza ngesisindo sokubhaka se-negative. ama-electrode cores.Uma i-electrode eyinegethivu yengqikithi yomthamo ophansi inongqimba oluncane lwe-lithium precipitation, amathuba okuba ne-electrode engalungile enganele aphezulu.Ngaphezu kwalokho, i-cathode noma i-electrode negative enamathela ohlangothini lwe-cathode nayo ingabangela umthamo ophansi, futhi i-electrode engemihle ohlangothini olulodwa enamathela ngokuyinhloko ukukhanya, ngoba ngisho noma i-electrode enamathela enesisindo esindayo, nakuba ukudlala kwegram kuzoncishiswa, kodwa umthamo ophelele uzokwehla. zinganciphisi kodwa zingaze zande.Uma i-electrode engalungile iboshwe endaweni engafanele, ukuqhathaniswa okuqondile kwezilinganiso zesisindo esihlobene zezinhlangothi ezilodwa nezikabili ngemva kokubhaka, inqobo nje uma idatha ifana nohlangothi luka-A ilula ngo-6% kune-B side coating. ngokuyisisekelo nquma inkinga, yebo, uma inkinga yomthamo ophansi inzima kakhulu, kuyadingeka ukuqhubeka uhlehlisa ukuminyana kwangempela kwendawo yohlangothi lwe-A/B.Uma inkinga yamandla aphansi ibucayi, kuyadingeka ukuthi uqhubeke unciphise ukuminyana kwangempela kohlangothi lwe-A/B.Ukugoqa kubhubhisa ukwakheka kwezinto, okubuye kuthinte umthamo.Isakhiwo samangqamuzana noma se-athomu sento ebalulekile isizathu esiyisisekelo sokuthi kungani inezindawo ezifana nomthamo, i-voltage, njll. Uma ukuminyana kwamaroli e-electrode ephozithivu kudlula inani lenqubo, i-electrode ephozithivu izokhanya kakhulu lapho umgogodla uhlakazwa.Uma i-electrode compaction enhle inkulu kakhulu, ucezu oluhle lwe-electrode kulula ukuphuka ngemva kokuvunguza, okuzophinde kubangele umthamo ophansi.Kodwa-ke, njengoba i-electrode compaction enhle izobangela ukuba ucezu lwesigxobo luphuke ngokushesha nje lapho lugoqiwe, umshini wokucindezela i-electrode roller oqondile udinga ukucindezela okukhulu, ngakho-ke imvamisa yokuhlangana ne-electrode compaction enhle iphansi kakhulu kune-electrode compaction engalungile.Lapho i-electrode eyinegethivu ihlanganiswa, umucu noma ibhulokhi ye-lithium precipitation izokwakheka ebusweni be-electrode eyinegethivu, futhi inani loketshezi olugcinwe kumongo lizoncishiswa kakhulu.
Umthamo ophansi nawo ungabangelwa ubuningi bamanzi amaningi.I-Capacitance ephansi ingenzeka lapho okuqukethwe kwamanzi e-electrode ngaphambi kokugcwalisa, iphuzu lamazolo ebhokisi leglavu ngaphambi kokugcwalisa, okuqukethwe kwamanzi e-electrolyte kudlula izinga, noma lapho umswakama ungeniswa uphawu lwesibili lwe-de-aerated.Ukulandelela amanani wamanzi adingekayo ukuze kwakhiwe umgogodla, kodwa lapho amanzi edlula inani elithile, amanzi amaningi azolimaza ifilimu ye-SEI futhi adle usawoti we-lithium ku-electrolyte, ngaleyo ndlela anciphise umthamo womgogodla.Okuqukethwe kwamanzi kudlula indinganiso ye-cell full charge course negative ucezu oluncane olunsundu ngokumnyama.
Isikhathi sokuthumela: Aug-16-2022