Ngokwezidingo zabangane beqembu, khuluma ngokuqonda ukushaja okusheshayo kwebhethri ye-lithium:

Isithombe

Sebenzisa lo mdwebo ukukhombisa inqubo yokushajwa kwebhethri. I-abscissa yisikhathi futhi i-ordinate i-voltage. Esigabeni sokuqala sokushaja sebhethri ye-lithium, kuzoba nenqubo encane yamanje yokushaja kwangaphambili, okuyi-CC pre-charge, ehlose ukuzinzisa izinto ze-anode ne-cathode. Ngemva kwalokho, ibhethri ingashintshwa ukuze Ishaje enamandla amanje, okuyi-CC Fast Charge, ngemva kokuba ibhethri isizinzile. Ekugcineni, ingena kumodi yokushaja i-voltage engaguquki (CV). Ngebhethri ye-lithium, isistimu iqala imodi yokushaja i-voltage njalo lapho i-voltage ifinyelela ku-4.2V, futhi amandla okushaja ayancipha kancane kancane kuze kuphele ukushaja lapho i-voltage ingaphansi kwenani elithile.

Phakathi nayo yonke inqubo, kukhona ukushaja okujwayelekile okujwayelekile kwamabhethri ahlukene. Isibonelo, emikhiqizweni ye-3C, ukushaja okujwayelekile kwamanje kungu-0.1C-0.5C, kanti kumabhethri anamandla amakhulu, ukushajwa okujwayelekile kuvamise ukuba ngu-1C. Ukushaja okuphansi kwamandla nakho kucatshangelwa ukuphepha kwebhethri. Ngakho-ke, ake sithi ngezikhathi ezijwayelekile ukushaja okusheshayo, kuwukukhomba izikhathi ezimbalwa eziphakeme kunezindleko ezijwayelekile zamanje ukuya ezikhathini eziyishumi.

Abanye abantu bathi ukushaja amabhethri e-lithium kufana nokuthela ubhiya, ngokushesha nokugcwalisa ubhiya ngokushesha, kodwa ngegwebu eliningi. Uyanensa, uyacotha, kodwa ubhiya omningi, uqinile. Ukushaja okusheshayo akugcini nje ngokugcina isikhathi sokushaja, kodwa futhi kulimaza ibhethri ngokwalo. Ngenxa yesimo se-polarization ebhethrini, umthamo omkhulu wamanje wokushaja engawamukela uzokwehla ngokunyuka kokushaja nomjikelezo wokukhipha. Uma ukushaja okuqhubekayo namandla okushaja kukukhulu, ukugxiliswa kwe-ion ku-electrode kuyakhula futhi i-polarization iba namandla, futhi i-voltage yetheminali yebhethri ayikwazi ukuhambisana ngokuqondile nokushajwa/amandla ngengxenye yomugqa. Ngesikhathi esifanayo, ukushaja okuphezulu kwamanje, ukwanda kokumelana kwangaphakathi kuzoholela ekushiseni okunamandla kwe-Joule (Q=I2Rt), okuletha ukusabela okuhlangene, njengokubola kokusabela kwe-electrolyte, ukukhiqizwa kwegesi kanye nochungechunge lwezinkinga, isici esiyingozi. inyuka kungazelelwe, inomthelela ekuphepheni kwebhethri, impilo yebhethri elingewona amandla izofushaniswa kakhulu.

01

Impahla ye-anode

Inqubo yokushaja esheshayo yebhethri ye-lithium ukufuduka okusheshayo nokushumeka kwe-Li+ kokokusebenza kwe-anode. Usayizi wezinhlayiyana zezinto ze-cathode zingathinta isikhathi sokuphendula kanye nendlela yokusabalalisa yama-ion kunqubo ye-electrochemical yebhethri. Ngokocwaningo, i-diffusion coefficient ye-lithium ion iyanda ngokuncipha kosayizi wokusanhlamvu bento. Kodwa-ke, ngokuncipha kosayizi wezinhlayiya ezibonakalayo, kuzoba nokuhlangana okukhulu kwezinhlayiya ekukhiqizeni i-pulping, okuholela ekuhlakazweni okungalingani. Ngesikhathi esifanayo, ama-nanoparticles azonciphisa ukuminyana kokuhlanganiswa kweshidi le-electrode, futhi andise indawo yokuxhumana ne-electrolyte inqubo yokushaja nokukhipha ukusabela ohlangothini, okuthinta ukusebenza kwebhethri.

Indlela enokwethenjelwa kakhudlwana iwukuba ulungise izinto electrode positive by enamathela. Isibonelo, ukuqhutshwa kwe-LFP ngokwayo akukuhle kakhulu. Ukumboza ingaphezulu le-LFP ngezinto zekhabhoni noma ezinye izinto kungathuthukisa ukusebenza kwayo, okulungele ukuthuthukisa ukusebenza kokushaja okusheshayo kwebhethri.

02

Izinto ze-anode

Ukushaja okusheshayo kwebhethri ye-lithium kusho ukuthi i-lithium ion ingaphuma ngokushesha futhi “ibhukude” iye ku-electrode engalungile, okudinga impahla ye-cathode ukuze ibe nekhono lokushumeka ngokushesha i-lithium. Izinto ze-anode ezisetshenziselwa ukushaja okusheshayo kwebhethri ye-lithium zifaka i-carbon material, i-lithium titanate nezinye izinto ezintsha.

Okwezinto zekhabhoni, ama-ion e-lithium ashumekwa ku-graphite ngaphansi kwesimo sokushaja okuvamile ngoba amandla okushumeka kwe-lithium afana nalawo emvula ye-lithium. Kodwa-ke, ngaphansi kwesimo sokushaja okusheshayo noma izinga lokushisa eliphansi, i-lithium ion ingase igibele phezulu futhi yakhe i-dendrite lithium. Lapho i-dendrite lithium ibhoboza i-SEI, ukulahlekelwa kwesibili kwe-Li+ kwabangelwa futhi nomthamo webhethri wehla. Lapho insimbi ye-lithium ifinyelela izinga elithile, izokhula isuka ku-electrode engeyinhle iye kudiaphragm, okubangela ubungozi bokujikeleza kwebhethri.

Ngokuqondene ne-LTO, iyingxenye ye-“zero strain” ene-oxygen-containing anode material, engakhiqizi i-SEI ngesikhathi sokusebenza kwebhethri, futhi inekhono eliqinile lokubopha nge-lithium ion, engahlangabezana nezidingo zokushaja okusheshayo nokukhululwa. Ngesikhathi esifanayo, ngenxa yokuthi i-SEI ayikwazi ukwakhiwa, impahla ye-anode izothintana ngokuqondile ne-electrolyte, ekhuthaza ukuvela kokusabela ohlangothini. Inkinga yokukhiqiza igesi yebhethri ye-LTO ayikwazi ukuxazululwa, futhi ingadanjiswa kuphela ukuguqulwa kwendawo.

03

Electrode liquid

Njengoba kushiwo ngenhla, ngenqubo yokushaja okusheshayo, ngenxa yokungavumelani kwesilinganiso sokufuduka kwe-lithium ion kanye nesilinganiso sokudlulisa i-electron, ibhethri izoba ne-polarization enkulu. Ngakho-ke ukuze kuncishiswe ukusabela okungekuhle okubangelwa ukuhlukaniswa kwebhethri, amaphuzu amathathu alandelayo ayadingeka ukuze kuthuthukiswe i-electrolyte: 1, usawoti we-electrolyte wokuhlukaniswa okuphezulu; 2, i-solvent composite – i-viscosity ephansi; 3, isilawuli esibonakalayo – i-membrane impedance ephansi.

04

Ubudlelwano phakathi kobuchwepheshe bokukhiqiza nokugcwalisa ngokushesha

Ngaphambili, izidingo kanye nemithelela yokugcwalisa ngokushesha kwahlaziywa kusuka ezintweni ezintathu ezibalulekile, njengezinto ezinhle nezimbi zama-electrode kanye noketshezi lwe-electrode. Okulandelayo ukwakheka kwenqubo okunomthelela omkhulu uma kuqhathaniswa. Imingcele yezobuchwepheshe yokukhiqiza ibhethri ithinta ngokuqondile ukumelana nokufuduka kwe-lithium ion engxenyeni ngayinye yebhethri ngaphambi nangemva kokwenziwa kusebenze kwebhethri, ngakho imingcele yobuchwepheshe yokulungiswa kwebhethri inethonya elibalulekile ekusebenzeni kwebhethri ye-lithium ion.

(1) udaka

Ngezakhiwo ze-slurry, ngakolunye uhlangothi, kuyadingeka ukugcina i-agent conductive ihlakazekile ngokulinganayo. Ngenxa yokuthi i-agent conductive isatshalaliswa ngokulinganayo phakathi kwezinhlayiya zento esebenzayo, inethiwekhi ye-conductive efanayo ingakhiwa phakathi kwento esebenzayo kanye nento esebenzayo kanye ne-collector fluid, enomsebenzi wokuqoqa i-micro current, ukunciphisa ukumelana nokuxhumana, futhi ingathuthukisa izinga lokunyakaza kwama-electron. Ngakolunye uhlangothi ukuvimbela ukuhlakazeka ngokweqile kwe-agent conductive. Enqubweni yokushaja nokukhipha, ukwakheka kwekristalu kwezinto ze-anode ne-cathode kuzoshintsha, okungase kubangele ukuxebuka kwe-ejenti eqhubayo, kwandise ukumelana kwangaphakathi kwebhethri, futhi kuthinte ukusebenza.

(2) Ukuminyana ngokwengxenye ngokwedlulele

Ngokombono, amabhethri aphindaphindayo namabhethri amakhulu kakhulu akuhambisani. Uma ukuminyana kwe-polarization kwama-electrode aqondile noma angalungile iphansi, isivinini sokusabalalisa se-lithium ion singanyuswa, futhi ukumelana nokufuduka kwe-ion kanye ne-electron kungancishiswa. I-Density ebusweni ephansi iwukuthi, i-electrode encane kakhulu, futhi ukuguqulwa kwesakhiwo se-electrode okubangelwa ukufakwa okuqhubekayo nokukhululwa kwe-lithium ion ephethe kanye nokukhishwa nakho kuncane. Kodwa-ke, uma ukuminyana kwendawo kuphansi kakhulu, ukuminyana kwamandla ebhethri kuzoncipha futhi izindleko zizonyuka. Ngakho-ke, ukuminyana kwendawo kufanele kucatshangelwe ngokucophelela. Isibalo esilandelayo siyisibonelo sokushaja kwebhethri ye-lithium cobalate ku-6C futhi ishajwa ngo-1C.

Isithombe

(3) Ukungaguquguquki koqweqwe lwe-polar

Ngaphambilini, umngane wabuza, ingabe ukuminyana ngokwengxenye ngokwedlulele ukungahambisani kuzoba nomthelela ebhethrini? Lapha ngendlela, ekusebenzeni kokushaja okusheshayo, okuyinhloko ukuhambisana kwepuleti ye-anode. Uma ukuminyana komhlaba okungalungile kungafani, i-porosity yangaphakathi yezinto eziphilayo izohluka kakhulu ngemva kokugoqa. Umehluko we-porosity uzoholela emehlukweni wokusabalalisa kwamanje kwangaphakathi, okuzothinta ukwakheka nokusebenza kwe-SEI esigabeni sokubunjwa kwebhethri, futhi ekugcineni kuthinte ukusebenza kokushaja okusheshayo kwebhethri.

(4) Ukuminyana kweshidi lesigxobo

Kungani izigxobo kudingeka zihlanganiswe? Enye iwukuthuthukisa amandla athile ebhethri, enye iwukuthuthukisa ukusebenza kwebhethri. I-optimum compaction density iyahlukahluka ngokuya ngezinto zama-electrode. Ngokukhula kokuqina kokuqina, i-porosity yeshidi le-electrode iba yincane, ukusondelana phakathi kwezinhlayiya kusondele, futhi kuncane ukushuba kweshidi le-electrode ngaphansi kokuminyana kwendawo efanayo, ukuze indlela yokufuduka yama-ion we-Lithium ingancishiswa. Uma ukuminyana kokuhlanganiswa kukhulu kakhulu, umphumela wokungena we-electrolyte awumuhle, ongacekela phansi ukwakheka kwezinto ezibonakalayo kanye nokusatshalaliswa kwe-ejenti eqhubayo, futhi inkinga yokujika yakamuva izokwenzeka. Ngokufanayo, ibhethri ye-lithium cobalate ishajwa ku-6C futhi ikhishwe ku-1C, futhi umthelela wokuminyana kokuqina kumthamo othize wokukhipha uboniswa kanje:

Isithombe

05

Ukwakheka ukuguga nabanye

Ngebhethri ye-carbon negative, ukwakheka – ukuguga kuyinqubo eyinhloko yebhethri ye-lithium, ezothinta ikhwalithi ye-SEI. Ugqinsi lwe-SEI alufani noma isakhiwo asizinzile, okuzophazamisa umthamo wokushaja osheshayo nempilo yomjikelezo webhethri.

Ngaphezu kwalezi zici ezimbalwa ezibalulekile ezingenhla, ukukhiqizwa kweseli, ukushaja kanye nesistimu yokukhipha kuzoba nomthelela omkhulu ekusebenzeni kwebhethri ye-lithium. Ngokunwetshwa kwesikhathi sesevisi, izinga lokushajwa kwebhethri kufanele lehliswe ngokumaphakathi, ngaphandle kwalokho i-polarization izoba kubi.

isiphetho

Ingqikithi yokushaja okusheshayo nokushajwa kwamabhethri e-lithium ukuthi i-lithium ion ingashumeka ngokushesha phakathi kwe-anode nezinto ze-cathode. Izakhiwo zezinto ezibonakalayo, idizayini yenqubo kanye nesistimu yokushaja nokukhipha amabhethri konke kuthinta ukusebenza kokushaja okuphezulu kwamanje. Ukuzinza kwesakhiwo se-anode kanye nezinto ze-anode kulungele inqubo ye-delithium esheshayo ngaphandle kokubangela ukuwa kwesakhiwo, i-lithium ions esilinganisweni sokusabalalisa kwezinto iyashesha, ukuze imelane nokushajwa okuphezulu kwamanje. Ngenxa yokungafani phakathi kwejubane lokufuduka kwe-ion kanye nezinga lokudlulisa ama-electron, ukuhlukaniswa kuzokwenzeka kunqubo yokushaja nokukhipha, ngakho ukuhlukaniswa kwe-polar kufanele kuncishiswe ukuze kuvinjwe ukuna kwensimbi ye-lithium futhi kunciphise amandla okuthinta impilo.