Tasiri da zafi mai zafi na kasuwar motocin lantarki,baturi lithium-ion, a matsayin daya daga cikin mahimman abubuwan motocin lantarki, an ƙarfafa su sosai. Mutane sun himmatu wajen haɓaka rayuwa mai tsayi, babban ƙarfi, ingantaccen batirin lithium-ion mai aminci. Daga cikinsu, attenuation nabaturi lithium-ioniya aiki ya cancanci kulawar kowa da kowa, kawai cikakken fahimtar dalilan da ke haifar da raguwar baturan lithium-ion ko na'ura, don samun damar rubuta magungunan da ya dace don magance matsalar, ƙarfin baturan lithium-ion dalilin da yasa attenuation?
Dalilan lalacewar ƙarfin batir lithium-ion
1.Positive electrode abu
LiCoO2 yana ɗaya daga cikin abubuwan da ake amfani da su na cathode (nau'in 3C ana amfani da su sosai, kuma batura masu ƙarfi suna ɗauke da ternary da lithium iron phosphate). Yayin da adadin hawan hawan keke ya karu, asarar ions lithium mai aiki yana ba da gudummawa ga lalata iya aiki. Bayan zagayowar 200, LiCoO2 bai sami canjin lokaci ba, amma canji a cikin tsarin lamellar, yana haifar da matsaloli a cikin de-embedding Li +.
LiFePO4 yana da kwanciyar hankali na tsari mai kyau, amma Fe3 + a cikin anode yana narkewa kuma ya rage zuwa Fe karfe akan graphite anode, yana haifar da haɓakar anode. Gaba ɗaya Fe3+ narkar da aka hana ta shafi na LiFePO4 barbashi ko zabi na electrolyte.
NCM ternary kayan ① Transition karfe ions a cikin mika mulki karfe oxide cathode abu ne mai sauki narke a high yanayin zafi, don haka yantar a cikin electrolyte ko ajiya a kan korau gefen haddasa iya aiki attenuation; ② Lokacin da ƙarfin lantarki ya fi girma fiye da 4.4V vs. Li +/ Li, canjin tsari na kayan aiki na ternary yana haifar da lalacewar iya aiki; ③ Li-Ni gauraye layuka, wanda ke haifar da toshe tashoshin Li+.
Babban abubuwan da ke haifar da raguwar iya aiki a cikin baturan lithium-ion na tushen LiMnO4 sune 1. lokaci maras canzawa ko sauye-sauyen tsari, irin su Jahn-Teller aberration; da 2. rushewar Mn a cikin electrolyte (kasancewar HF a cikin electrolyte), halayen rashin daidaituwa, ko raguwa a anode.
2.Negative electrode kayan
Ƙirƙirar hazo na lithium a gefen anode na graphite (ɓangaren lithium ya zama "matattu lithium" ko kuma yana haifar da lithium dendrites), a ƙananan yanayin zafi, yaduwar lithium ion yana raguwa cikin sauƙi yana haifar da hazo na lithium, kuma hazo na lithium shima yana yiwuwa ya faru. lokacin da N/P rabo yayi ƙasa da ƙasa.
Maimaita lalacewa da haɓakar fim ɗin SEI a gefen anode yana haifar da raguwar lithium da haɓaka polarization.
Tsarin maimaitawar lithium sakawa / de-lithium cirewa a cikin anode na tushen silicon na iya haifar da haɓaka ƙara cikin sauƙi da gazawar ɓarna na siliki. Don haka, ga silicon anode, yana da mahimmanci musamman don nemo hanyar da za a hana haɓaka ƙarar sa.
3.Electrolyt
Abubuwan da ke cikin electrolyte waɗanda ke ba da gudummawa ga lalacewar iya aiki nabaturi lithium-ionsun hada da:
1. Bazuwar kaushi da electrolytes (mummunan gazawar ko aminci matsaloli kamar gas samar), ga Organic kaushi, lokacin da hadawan abu da iskar shaka m ne mafi girma fiye da 5V vs. Li +/Li ko rage m kasa da 0.8V (daban-daban electrolyte bazuwar ƙarfin lantarki ne. daban), mai sauƙin ruɓewa. Don electrolyte (misali LiPF6), yana da sauƙi don bazuwa a mafi girman zafin jiki (fiye da 55 ℃) saboda rashin kwanciyar hankali;.
2. Yayin da yawan hawan hawan keke ya karu, halayen da ke tsakanin electrolyte da masu amfani da na'urori masu kyau da marasa kyau sun karu, yana sa ƙarfin canja wurin taro ya raunana.
4. Diaphragm
Diaphragm na iya toshe electrons kuma ya cika watsa ions. Koyaya, ikon diaphragm don jigilar Li + yana raguwa lokacin da aka toshe ramukan diaphragm ta samfuran lalata na electrolyte, da sauransu, ko lokacin da diaphragm ya ragu a yanayin zafi mai yawa, ko lokacin da diaphragm ya tsufa. Bugu da kari, samuwar lithium dendrites masu huda diaphragm da ke kaiwa ga gajeriyar da'ira na ciki shine babban dalilin gazawarsa.
5. Tattara ruwa
Dalilin asarar iya aiki saboda mai tarawa gabaɗaya lalatar mai tarawa ne. Ana amfani da Copper azaman mai tarawa mara kyau saboda yana da sauƙin oxidize a babban ƙarfin, yayin da ake amfani da aluminium azaman mai tattarawa mai kyau saboda yana da sauƙin ƙirƙirar allo na lithium-aluminum tare da lithium a ƙaramin ƙarfi. Ƙarƙashin ƙananan ƙarfin lantarki (ƙananan 1.5V da ƙasa, fiye da fitarwa), jan ƙarfe oxidizes zuwa Cu2+ a cikin electrolyte da adibas a kan saman da korau electrode, hana de-embedding na lithium, haifar da iya lalacewa. Kuma a gefen tabbatacce, overcharging nabaturiyana haifar da rami na mai tara aluminium, wanda ke haifar da haɓaka juriya na ciki da lalata iya aiki.
6. Abubuwan caji da fitarwa
Yawan caji da masu haɓaka fitarwa na iya haifar da saurin lalata ƙarfin baturan lithium-ion. Ƙara yawan caji/fitarwa yana nufin cewa rashin daidaituwa na baturi yana ƙaruwa daidai da haka, yana haifar da raguwa a iya aiki. Bugu da ƙari, damuwa mai yaduwa da aka haifar ta hanyar caji da fitarwa a yawan adadin yawan haɓaka yana haifar da asarar kayan aiki na cathode da haɓaka tsufa na baturi.
Game da yawan caji da batura mai yawa, mummunan electrode yana da haɗari ga hazo lithium, ingantacciyar wutar lantarki da ta wuce kima ta hanyar kawar da lithium, kuma bazuwar oxidative na electrolyte (abun da ya faru na samfurori da samar da iskar gas) yana ƙaruwa. Lokacin da batirin ya yi yawa, foil ɗin jan ƙarfe yana ƙoƙarin narke (yana hana lithium de-embedring, ko samar da dendrites na jan karfe kai tsaye), yana haifar da lalacewa ko gazawar baturi.
Nazarin dabarun caji ya nuna cewa lokacin da cajin yanke wutan lantarki ya kasance 4V, yadda ya kamata rage karfin wutar da aka yanke (misali, 3.95V) zai iya inganta rayuwar batirin. Hakanan an nuna cewa saurin cajin baturi zuwa 100% SOC yana lalata sauri fiye da saurin caji zuwa 80% SOC. Bugu da kari, Li et al. gano cewa ko da yake pulsing iya inganta caji yadda ya dace, da ciki juriya na baturi zai tashi sosai, da kuma asarar korau electrode aiki abu ne mai tsanani.
7.Zazzabi
Sakamakon zafin jiki akan iya aiki nabaturi lithium-ionyana da matukar muhimmanci. Lokacin aiki a yanayin zafi mafi girma na tsawon lokaci, ana samun haɓakar halayen gefe a cikin baturin (misali, bazuwar wutar lantarki), yana haifar da asarar ƙarfin da ba za a iya jurewa ba. Lokacin aiki a ƙananan yanayin zafi na tsawon lokaci, jimlar impedance na baturi yana ƙaruwa (haɓakar lantarki yana raguwa, haɓakar SEI yana ƙaruwa, kuma ƙimar halayen electrochemical yana raguwa), kuma hazo lithium daga baturi yana da wuyar faruwa.
Abin da ke sama shine babban dalilin lalacewar ƙarfin baturi na lithium-ion, ta hanyar gabatarwar da ke sama na yi imani kana da fahimtar abubuwan da ke haifar da lalacewar ƙarfin baturi.
Lokacin aikawa: Yuli-24-2023