Njengoba inani lokushaja kanye nemijikelezo yokukhipha ikhula, umthamo webhethri uzoqhubeka nokubola. Lapho umthamo ubola ufike ku-75% kuya ku-80% womthamo olinganiselwe, ibhethri ye-lithium-ion ibhekwa njengesesimweni sokwehluleka. Izinga lokukhishwa, ukukhuphuka kwezinga lokushisa kwebhethri, nezinga lokushisa le-ambient kunomthelela omkhulu kumthamo wokukhipha amabhethri e-lithium-ion.

Leli phepha lamukela imibandela yokushaja nokukhipha i-voltage engaguquki kanye nokushajwa kwamanje okungashintshi kanye nokushajwa okungaguquki kwamanje kwebhethri. Izinga lokukhishwa, izinga lokushisa lokukhishwa kwebhethri, kanye nezinga lokushisa le-ambient kusetshenziswa ngokulandelana njengokuguquguqukayo kanye nokuhlolwa okujikelezayo kwenziwa ngobuningi, futhi izinga lokuphuma kanye nezinga lokushisa lokukhishwa kwebhethri kuhlaziywa ngaphansi kwezinto ezihlukene ze-cathode. Umthelela wezinga lokushisa, izinga lokushisa elizungezile nezikhathi zomjikelezo kumthamo wokukhipha amabhethri e-lithium-ion.

1. Uhlelo oluyisisekelo lokuhlola lwebhethri

Izinto ezisebenzayo nezingezinhle zihlukile, futhi impilo yomjikelezo iyahlukahluka kakhulu, okuthinta izici zomthamo webhethri. I-Lithium iron phosphate (LFP) kanye ne-nickel-cobalt-manganese ternary materials (NMC) zisetshenziswa kabanzi njengezisetshenziswa ze-cathode zamabhethri esibili e-lithium-ion anezinzuzo zawo ezihlukile. Kungabonakala kuThebula 1 ukuthi umthamo olinganiselwe, amandla kagesi, nezinga lokuphuma kwebhethri le-NMC liphezulu kunalelo lebhethri le-LFP.

Shaja futhi ukhiphe amabhethri e-LFP ne-NMC e-lithium-ion ngokuya ngokushaja okungaguquki kwamandla kagesi kanye nemithetho yokukhipha njalo yamanje, futhi urekhode ukushaja nokukhipha i-voltage enqamukile, izinga lokuphuma, ukukhuphuka kwezinga lokushisa kwebhethri, izinga lokushisa lokuhlola, nokushintsha kwamandla ebhethri. ngesikhathi sokushaja kanye nenqubo yokukhipha Isimo.

2. Umthelela wezinga lokukhipha kumthamo wokuphuma Lungisa izinga lokushisa nemithetho yokushaja kanye nokukhipha, futhi ukhiphe ibhethri le-LFP nebhethri le-NMC ngendlela yamanje engaguquki ngokuya ngamazinga ahlukene okukhipha.

Lungisa izinga lokushisa ngokulandelana: 35, 25, 10, 5, -5, -15°C. Kungabonakala ku-Figure 1 ukuthi ekushiseni okufanayo, ngokukhuphula izinga lokukhipha, umthamo wokukhipha jikelele webhethri ye-LFP ubonisa umkhuba owehlayo. Ngaphansi kwesilinganiso esifanayo sokukhishwa, izinguquko ekushiseni okuphansi zinomthelela omkhulu kumthamo wokukhipha amabhethri e-LFP.

Uma izinga lokushisa lehla ngaphansi kuka-0 ℃, umthamo wokukhipha ubola kakhulu futhi umthamo awubuyiseleki. Kuyaqapheleka ukuthi amabhethri e-LFP akhulisa ukuncishiswa kwamandla okukhipha ngaphansi kwethonya elibili lokushisa eliphansi kanye nezinga elikhulu lokukhipha. Uma kuqhathaniswa namabhethri e-LFP, amabhethri e-NMC azwela kakhulu izinga lokushisa, futhi amandla awo okukhipha ashintsha kakhulu ngezinga lokushisa elizungezile nezinga lokuphuma.

Kungabonwa Emfanekisweni 2 ukuthi ngezinga lokushisa elifanayo, umthamo wokuphuma usuwonke webhethri le-NMC ubonisa inkambiso yokubola kokuqala bese iyakhuphuka. Ngaphansi kwezinga elifanayo lokukhipha, izinga lokushisa eliphansi, liyancipha amandla okukhipha.

Ngokukhuphuka kwezinga lokukhipha, amandla okukhipha amabhethri e-lithium-ion aqhubeka nokwehla. Isizathu siwukuthi ngenxa ye-polarization engathi sína, i-voltage yokukhipha incishiswa ku-voltage yokunqamula ukukhishwa kusengaphambili, okungukuthi, isikhathi sokukhipha sifinyeziwe, ukukhishwa akwanele, futhi i-electrode engalungile Li + ayiwi. Kushunyekiwe ngokuphelele. Uma izinga lokukhishwa kwebhethri liphakathi kuka-1.5 no-3.0, umthamo wokukhulula uqala ukubonisa izimpawu zokululama ngamazinga ahlukahlukene. Njengoba ukusabela kuqhubeka, izinga lokushisa lebhethri ngokwalo lizokhula kakhulu ngokunyuka kwezinga lokukhipha, amandla okunyakaza okushisayo kwe-Li + ayaqiniswa, futhi isivinini sokusabalalisa siyasheshisa, ukuze isivinini sokushumeka se-Li + sisheshiswe futhi amandla okuphuma ayakhuphuka. Kungaphethwa ngokuthi umthelela ombaxambili wezinga elikhulu lokukhipha kanye nokukhuphuka kwezinga lokushisa kwebhethri ngokwalo kubangela into engeyona ye-monotonic yebhethri.

3. Umthelela wokukhuphuka kwezinga lokushisa kwebhethri kumthamo wokuphuma. Amabhethri e-NMC ngokulandelana angaphansi kokuhlolwa kokungu-2.0, 2.5, 3.0, 3.5, 4.0, 4.5C kokungu-30 ℃, futhi ijika lobudlelwano phakathi kwamandla okukhipha kanye nokukhuphuka kwezinga lokushisa kwebhethri le-lithium-ion kuboniswa kuMfanekiso 3. Kubonisiwe.

Kungabonakala kuMfanekiso 3 ukuthi ngaphansi komthamo ofanayo wokukhipha, izinga lokuphuma liphakeme, okubaluleke kakhulu ukukhuphuka kwezinga lokushisa kuyashintsha. Ukuhlaziya izikhathi ezintathu zenqubo yokukhishwa yamanje eqhubekayo ngaphansi kwezinga elifanayo lokukhipha kubonisa ukuthi ukunyuka kwezinga lokushisa ikakhulukazi kusezigabeni zokuqala nezakamuva zokukhishwa.

Okwesine, umthelela wokushisa kwe-ambient kumthamo wokukhipha Izinga lokushisa elingcono kakhulu lokusebenza lamabhethri e-lithium-ion ngu-25-40 ℃. Kusukela ekuqhathanisweni kweThebula 2 kanye neThebula 3, kungabonakala ukuthi lapho izinga lokushisa lingaphansi kuka-5 ° C, izinhlobo ezimbili zamabhethri ziphuma ngokushesha futhi umthamo wokukhipha uyancipha kakhulu.

Ngemva kokuhlolwa kwezinga lokushisa eliphansi, izinga lokushisa eliphezulu labuyiselwa. Ngesikhathi sokushisa okufanayo, umthamo wokukhipha webhethri ye-LFP wehla ngo-137.1mAh, futhi ibhethri ye-NMC yehla ngo-47.8mAh, kodwa ukukhuphuka kwezinga lokushisa nesikhathi sokukhipha akuzange kushintshe. Kungabonakala ukuthi i-LFP inokuqina okuhle kokushisa futhi ibonisa kuphela ukubekezelelana okungalungile emazingeni okushisa aphansi, futhi umthamo webhethri unokuncishiswa okungenakuhlehliswa; kuyilapho amabhethri e-NMC ezwela ekushintsheni kwezinga lokushisa.

Okwesihlanu, umthelela wenani lemijikelezo kumthamo wokukhipha Umfanekiso 4 uwumdwebo wohlelo lwejika lokubola komthamo webhethri le-lithium-ion, futhi umthamo wokukhipha ku-0.8Q urekhodwa njengendawo yokuhluleka kwebhethri. Njengoba inani lokushaja nokukhishwa kwemijikelezo likhuphuka, umthamo wokukhipha uqala ukukhombisa ukwehla.

Ibhethri ye-LFP engu-1600mAh yashajwa futhi yashajwa ku-0.5C futhi yashajwa ngo-0.5C ngokuhlolwa komjikelezo wokushaja. Isamba semijikelezo engu-600 yenziwe, futhi u-80% womthamo webhethri wasetshenziswa njengendlela yokunquma ukuhluleka kwebhethri. Sebenzisa u-100 njengezikhathi zesikhawu ukuze uhlaziye iphesenti lephutha elihlobene lomthamo wokukhipha kanye nokunciphisa umthamo, njengoba kuboniswe kuMfanekiso 5.

Ibhethri le-NMC elingu-2000mAh lashajwa ngo-1.0C laphinde lashajwa ngo-1.0C ngokuhlolwa komjikelezo wokushaja, futhi u-80% womthamo webhethri uthathwe njengomthamo webhethri ekupheleni kwempilo yayo. Thatha izikhathi zokuqala ezingama-700 futhi uhlaziye umthamo wokukhipha kanye nephesenti lephutha elihlobene lokuncishiswa komthamo ngo-100 njengesikhawu, njengoba kuboniswe kuMfanekiso 6.

Umthamo webhethri le-LFP nebhethri le-NMC uma inombolo yemijikelezo ingu-0 umthamo olinganiselwe, kodwa ngokuvamile umthamo wangempela ungaphansi komthamo olinganiselwe, ngakho ngemva kwemijikelezo yokuqala eyi-100, umthamo wokukhipha ubola kakhulu. Ibhethri ye-LFP inokuphila komjikelezo omude, impilo ye-theory izikhathi ezingu-1,000; impilo yethiyori yebhethri le-NMC izikhathi ezingama-300. Ngemva kwenani elifanayo lemijikelezo, umthamo webhethri le-NMC ubola ngokushesha; uma inombolo yemijikelezo ingu-600, umthamo webhethri le-NMC uwohloka eduze komkhawulo wokuhluleka.

6. Isiphetho

Ngokuhlolwa kokushaja nokukhipha amabhethri e-lithium-ion, imingcele emihlanu yezinto ze-cathode, izinga lokuphuma, izinga lokushisa lebhethri elikhuphukayo, izinga lokushisa elizungezile kanye nenombolo yomjikelezo kusetshenziswa njengokuguquguqukayo, kanye nobudlelwano phakathi kwezici ezihlobene namandla kanye nezici ezihlukahlukene ezinethonya buyahlaziywa, futhi okulandelayo kutholakala ekuphetheni:

(1) Phakathi kwebanga lokushisa elilinganiselwe lebhethri, izinga lokushisa eliphezulu elifanele likhuthaza ukuhlukaniswa nokushumeka kwe-Li+. Ikakhulukazi umthamo wokukhipha, izinga lokuphuma likhulu, izinga lokukhiqiza ukushisa likhulu, kanye nokusabela okusobala kwe-electrochemical ngaphakathi kwebhethri ye-lithium-ion.

(2) Ibhethri ye-LFP ibonisa ukuguquguquka okuhle kwezinga lokushisa eliphezulu kanye nezinga lokukhipha ngesikhathi sokushaja nokukhipha; inokubekezelela okungalungile ekushiseni okuphansi, amandla okukhipha abola kakhulu, futhi awakwazi ukubuyiswa ngemva kokushisa.

(3) Ngaphansi kwenombolo efanayo yomjikelezo wokushaja nokukhipha, ibhethri le-LFP linomjikelezo omude wokuphila, futhi umthamo webhethri le-NMC uwohloka ufike ku-80% womthamo olinganiselwe ngokushesha okukhulu. (4) Uma kuqhathaniswa nebhethri ye-LFP, amandla okukhipha ibhethri ye-NMC azwela kakhulu ekushiseni, futhi ngesilinganiso esikhulu sokukhipha, umthamo wokukhipha awuyona i-monotonic futhi ukuphakama kwezinga lokushisa kushintsha kakhulu.