Ukuphepha Kwebhethri Lithium

Amabhethri e-lithium anezinzuzo zokuphatheka nokushaja ngokushesha, kungani-ke amabhethri e-lead-acid namanye amabhethri esibili asazungeza emakethe?
Ngaphezu kwezinkinga zezindleko nezinkambu ezihlukene zohlelo lokusebenza, esinye isizathu ukuphepha.
I-Lithium iyinsimbi esebenza kakhulu emhlabeni.Ngenxa yokuthi izici zayo zamakhemikhali zisebenza kakhulu, lapho insimbi ye-lithium ivezwa emoyeni, izoba nokusabela okuqinile kwe-oxidation nge-oksijeni, ngakho-ke ijwayele ukuqhuma, ukuvutha kanye nezinye izenzakalo.Ngaphezu kwalokho, ukusabela kwe-redox nakho kuzokwenzeka ngaphakathi kwebhethri ye-lithium ngesikhathi sokushaja nokukhipha.Ukuqhuma nokuvutha okuzenzakalelayo kubangelwa ikakhulukazi ukunqwabelana, ukusabalalisa nokukhululwa kwebhethri ye-lithium ngemva kokushisa.Ngamafuphi, amabhethri e-lithium azokhiqiza ukushisa okukhulu ngesikhathi sokushaja nokukhipha inqubo, okuzoholela ekukhuphukeni kokushisa kwangaphakathi kwebhethri nokushisa okungalingani phakathi kwamabhethri ngamanye, ngaleyo ndlela kubangele ukusebenza okungazinzile kwebhethri.
Ukuziphatha okungaphephile kwebhethri le-lithium-ion elibalekayo elishisayo (okuhlanganisa ukushajwa kwebhethri nokuchichima ngokweqile, ukushaja okusheshayo nokukhipha, isifunda esifushane, izimo zokuhlukumeza ngomshini, izinga lokushisa eliphezulu ukushaqeka kokushisa, njll.) kungenzeka kubangele ukusabela okuyingozi ohlangothini ngaphakathi kwebhethri futhi kubangele ukushisa, ukulimaza ngokuqondile ifilimu ye-passive ku-electrode engalungile kanye nendawo ye-electrode enhle.
Kunezizathu eziningi zokubangela izingozi ezishisayo ezibalekayo zamabhethri e-lithium ion.Ngokwezici zokubangela, kungahlukaniswa ukucupha ukuhlukunyezwa kwemishini, ukuhlukunyezwa kukagesi kanye nokuqala ukuhlukumeza okushisayo.Ukuhlukumeza ngemishini: kubhekise ekutshoni, ukucwiliswa kanye nomthelela wezinto ezinzima ezibangelwa ukushayisana kwemoto;Ukusebenzisa kabi ugesi: ngokuvamile okubangelwa ukuphathwa okungafanele kwamandla kagesi noma ukwehluleka kwengxenye kagesi, okuhlanganisa isifunda esifushane, ukushajwa ngokweqile kanye nokukhipha ngokweqile;Ukushisa ukuhlukunyezwa: okubangelwa ukushisa ngokweqile okubangelwa ukuphathwa okungafanele kwezinga lokushisa.

Lezi zindlela ezintathu zokuqalisa zihlobene.Ukusetshenziswa kabi kwemishini ngokuvamile kuzodala ukuguquguquka noma ukuphuka kwe-diaphragm yebhethri, okuholela ekuthintwaneni okuqondile phakathi kwezigxobo eziphozithivu nezingezinhle zebhethri kanye nesekhethi efushane, okuholela ekusebenziseni kabi ugesi;Kodwa-ke, ngaphansi kwesimo sokusetshenziswa kabi kukagesi, isizukulwane sokushisa esifana nokushisa kwe-Joule siyenyuka, okwenza izinga lokushisa lebhethri likhuphuke, okuholela ekusetshenzisweni kabi kokushisa, okuqhubekisela phambili ukusabela kohlangothi lweketango lokukhiqiza ukushisa ngaphakathi kwebhethri, futhi ekugcineni kuholele esenzeka. ukubaleka kokushisa kwebhethri.
Ukushisa okushisayo kwebhethri kubangelwa ukuthi izinga lokukhiqiza ukushisa kwebhethri liphezulu kakhulu kunezinga lokukhipha ukushisa, futhi ukushisa kunqwabelana ngenani elikhulu kodwa akuhlakazwa ngesikhathi.Empeleni, "i-thermal runaway" iyinqubo yomjikelezo wempendulo yamandla amahle: izinga lokushisa elikhulayo lizokwenza ukuthi uhlelo lushise, futhi izinga lokushisa lizokhuphuka ngemva kokuba uhlelo kushisa, okuzokwenza ukuthi uhlelo lushise.
Inqubo yokubaleka okushisayo: lapho izinga lokushisa langaphakathi lebhethri likhuphuka, ifilimu ye-SEI ebusweni befilimu ye-SEI ibola ngaphansi kwezinga lokushisa eliphezulu, i-lithium ion eshumekwe ku-graphite izosabela nge-electrolyte kanye ne-binder, iqhubekisele phambili izinga lokushisa lebhethri phezulu. ukuya ku-150 ℃, futhi ukusabela okusha kwe-exothermic okunamandla kuzokwenzeka kuleli zinga lokushisa.Lapho izinga lokushisa lebhethri lifinyelela ngaphezu kuka-200 ℃, impahla ye-cathode iyabola, ikhiphe inani elikhulu lokushisa negesi, futhi ibhethri iqala ukuqhuma futhi ifudumale ngokuqhubekayo.I-anode eshumekiwe ye-lithium yaqala ukusabela nge-electrolyte ku-250-350 ℃.I-cathode ene-charged material iqala ukusabela ngokubola okunodlame, futhi i-electrolyte ibhekana nokusabela kwe-oxidation enobudlova, ikhiphe inani elikhulu lokushisa, ikhiqize izinga lokushisa eliphezulu nenani elikhulu legesi, okubangela ukuvutha nokuqhuma kwebhethri.
Inkinga yemvula ye-lithium dendrite ngesikhathi sokushajwa ngokweqile: Ngemva kokuba ibhethri ye-lithium cobalate ishajwe ngokugcwele, inani elikhulu lama-ion e-lithium lihlala ku-electrode ephozithivu.Okusho ukuthi, i-cathode ayikwazi ukubamba i-lithium ion eyengeziwe exhunywe ku-cathode, kodwa esimweni sokukhokhiswa ngokweqile, i-lithium ion eyengeziwe ku-cathode isazobhukuda iye ku-cathode.Ngenxa yokuthi azikwazi ukuqukethwe ngokugcwele, i-lithium yensimbi izokwakhiwa ku-cathode.Njengoba le lithium yensimbi iyikristalu ye-dendritic, ibizwa ngokuthi i-dendrite.Uma i-dendrite iyinde kakhulu, kulula ukubhoboza i-diaphragm, okubangela ukujikeleza okufushane kwangaphakathi.Njengoba ingxenye eyinhloko ye-electrolyte i-carbonate, indawo yayo yokuthungela nendawo yokubilisa iphansi, ngakho-ke izoshisa noma iqhume ekushiseni okuphezulu.

Uma kuyibhethri ye-lithium ye-polymer, i-electrolyte i-colloidal, ejwayele ukuvutha ngobudlova.Ukuze baxazulule le nkinga, ososayensi bazama ukufaka esikhundleni sezinto eziphephile ze-cathode.Izinto zebhethri ze-lithium manganenate zinezinzuzo ezithile.Ingaqinisekisa ukuthi i-ion ye-lithium ye-electrode eqondile ingashumeka ngokuphelele emgodini wekhabhoni we-electrode engafanele ngaphansi kwesimo sokushaja esigcwele, esikhundleni sokuba nezinsalela ezithile ku-electrode enhle njenge-lithium cobalate, okuthi ngokwezinga elithile igweme ukukhiqizwa ama-dendrites.Isakhiwo esizinzile se-lithium manganate senza ukusebenza kwayo kwe-oxidation kube phansi kakhulu kunalokho kwe-lithium cobalate.Ngisho noma kukhona isifunda esifushane sangaphandle (kunokuba isifunda esifushane sangaphakathi), ngokuyisisekelo singagwema ukusha nokuqhuma okubangelwa imvula yensimbi ye-lithium.I-lithium iron phosphate inokusimama okushisayo okuphezulu kanye namandla aphansi we-oxidation we-electrolyte, ngakho inokuphepha okuphezulu.
Ukunciphisa ukuguga kwebhethri ye-lithium ion kubonakala ngokuncishiswa kwamandla kanye nokukhuphuka kokumelana kwangaphakathi, futhi indlela yayo yangaphakathi yokunciphisa ukuguga ihlanganisa ukulahlekelwa kwezinto ezisebenzayo ezisebenzayo nezingalungile kanye nokulahlekelwa kwe-lithium ion etholakalayo.Lapho impahla ye-cathode igugile futhi ibolile, futhi amandla e-cathode ayanele, ingozi yokuguquguquka kwe-lithium kusuka ku-cathode kungenzeka kakhulu.Ngaphansi kwesimo sokuphuma ngokweqile, amandla e-cathode ku-lithium azokhuphukela ngaphezu kwe-3V, ephakeme kunamandla okuhlakazeka ethusi, okubangela ukuhlakazeka komqoqi wethusi.Ama-ion e-copper ancibilikisiwe azokwehla endaweni ye-cathode futhi akhe ama-dendrite ethusi.Ama-dendrite e-Copper azodlula ku-diaphragm, abangele ukujikeleza okufushane kwangaphakathi, okuthinta kabi ukusebenza kokuphepha kwebhethri.
Ngaphezu kwalokho, ukumelana nokushajwa ngokweqile kwamabhethri aguga kuzokwehla ngezinga elithile, ikakhulukazi ngenxa yokwanda kokuphikiswa kwangaphakathi kanye nokuncipha kwezinto ezisebenzayo ezinhle nezingezinhle, okuholela ekwandeni kokushisa kwe-joule phakathi nenqubo yokushajwa ngokweqile kwamabhethri.Ngaphansi kokushajwa ngokweqile, ukusabela okuseceleni kungase kucushwe, kubangele ukubaleka kwamabhethri.Ngokuphathelene nokuzinza kokushisa, i-lithium evolution evela ku-cathode izoholela ekwehleni okubukhali ekuzinzeni kokushisa kwebhethri.
Ngamafuphi nje, ukusebenza kokuphepha kwebhethri elikhulile kuzoncipha kakhulu, okuzobeka engcupheni ukuphepha kwebhethri.Isixazululo esivame kakhulu ukuhlomisa isistimu yokugcina amandla ebhethri ngohlelo lokuphatha ibhethri (BMS).Isibonelo, amabhethri angu-8000 18650 asetshenziswa ku-Tesla Model S angakwazi ukubona ukuqapha kwesikhathi sangempela kwamapharamitha ahlukahlukene aphathekayo ebhethri, ahlole isimo sokusetshenziswa kwebhethri, futhi enze ukuxilonga ku-inthanethi kanye nesixwayiso kusenesikhathi ngohlelo lwayo lokuphatha ibhethri.Ngesikhathi esifanayo, ingakwazi futhi ukwenza ukulawula kokukhipha kanye nokulawula ukushajwa kwangaphambili, ukuphathwa kwebhalansi yebhethri nokuphathwa kokushisa.