Dangane da bukatun abokai na rukuni, magana game da fahimtar saurin cajin baturi na lithium:

Hoton

Yi amfani da wannan zane don kwatanta tsarin cajin baturi. Abscissa lokaci ne kuma ordinate shine ƙarfin lantarki. A matakin farko na cajin baturi na lithium, za a yi ƙaramin tsari kafin caji na yanzu, wato CC pre-charge, wanda ke da nufin daidaita abubuwan anode da cathode. Bayan haka, ana iya daidaita baturin zuwa Charge with high current, wato CC Fast Charge, bayan baturin ya tsaya cik. A ƙarshe, yana shiga yanayin cajin wutar lantarki akai-akai (CV). Don baturin lithium, tsarin yana fara yanayin cajin wutar lantarki akai-akai lokacin da ƙarfin lantarki ya kai 4.2V, kuma cajin halin yanzu yana raguwa a hankali har sai cajin ya ƙare lokacin da ƙarfin lantarki ya yi ƙasa da wani ƙima.

A yayin duk aikin, akwai madaidaitan ma’aunin caji don batura daban-daban. Misali, na samfuran 3C, madaidaicin cajin halin yanzu gabaɗaya 0.1C-0.5C ne, yayin da batura masu ƙarfi, daidaitaccen caji gabaɗaya 1C ne. Ana kuma la’akari da ƙarancin cajin halin yanzu don amincin baturin. Don haka, a ce a talakawa lokutan caji mai sauri, shine a nuna sau da yawa sama da daidaitattun cajin yanzu zuwa sau goma.

Wasu mutane sun ce cajin batirin lithium kamar zuba giya ne, da sauri da cika giyar da sauri, amma tare da kumfa mai yawa. Yana da hankali, yana da hankali, amma yana da yawan giya, yana da ƙarfi. Yin caji mai sauri ba kawai yana adana lokacin caji ba, har ma yana lalata baturin kanta. Saboda yanayin polarization a cikin baturi, matsakaicin cajin halin yanzu da zai iya karɓa zai ragu tare da ƙaruwar cajin da zagayowar fitarwa. Lokacin da ci gaba da caji da cajin halin yanzu yana da girma, ƙaddamarwar ion a cikin lantarki yana ƙaruwa kuma polarization yana ƙaruwa, kuma ƙarfin ƙarfin baturi ba zai iya daidaitawa kai tsaye da cajin/makamashi a cikin ma’auni na madaidaiciya ba. A lokaci guda, babban cajin halin yanzu, haɓaka juriya na ciki zai haifar da haɓaka tasirin zafi na Joule (Q = I2Rt), yana kawo halayen gefe, irin su bazuwar amsawar electrolyte, samar da iskar gas da jerin matsaloli, haɗarin haɗari. yana ƙaruwa ba zato ba tsammani, yana da tasiri akan amincin baturi, rayuwar batirin mara ƙarfi za a gajarta sosai.

01

Abun anode

Tsarin saurin caji na baturin lithium shine saurin ƙaura da haɗa Li+ a cikin kayan anode. Girman barbashi na kayan cathode na iya rinjayar lokacin amsawa da kuma yada hanyar ions a cikin tsarin lantarki na baturi. Dangane da binciken, ƙimar haɓakar ion lithium yana ƙaruwa tare da raguwar girman hatsin kayan. Duk da haka, tare da rage kayan barbashi size, za a yi tsanani agglomeration na barbashi a samar da pulping, sakamakon m watsawa. A lokaci guda kuma, nanoparticles za su rage ɗimbin yawa na takardar lantarki, da kuma ƙara wurin hulɗa tare da electrolyte a cikin aiwatar da caji da fitarwa na gefe, yana shafar aikin baturi.

Hanyar da ta fi dacewa ita ce canza ingantaccen kayan lantarki ta hanyar sutura. Alal misali, ƙaddamarwar LFP kanta ba ta da kyau sosai. Rufe saman LFP tare da kayan carbon ko wasu kayan na iya inganta haɓakarsa, wanda ke da amfani don haɓaka aikin caji mai sauri na baturi.

02

Anode kayan

Yin caji da sauri na baturin lithium yana nufin cewa lithium ions na iya fitowa da sauri da kuma “yi iyo” zuwa ga gurɓataccen lantarki, wanda ke buƙatar kayan cathode don samun damar shigar da lithium cikin sauri. Abubuwan anode da ake amfani da su don saurin cajin baturin lithium sun haɗa da kayan carbon, lithium titanate da wasu sabbin kayan.

Don kayan carbon, ions lithium an fi son sanya su cikin graphite ƙarƙashin yanayin caji na al’ada saboda yuwuwar haɗar lithium yayi kama da na hazo lithium. Koyaya, a ƙarƙashin yanayin caji mai sauri ko ƙarancin zafin jiki, ions lithium na iya yin hazo a saman kuma su samar da lithium dendrite. Lokacin da dendrite lithium ya huda SEI, an sami asarar Li+ na biyu kuma an rage ƙarfin baturi. Lokacin da ƙarfen lithium ya kai wani matakin, zai yi girma daga gurɓataccen lantarki zuwa diaphragm, yana haifar da haɗarin gajeriyar kewayawar baturi.

Amma ga LTO, nasa ne na “sifirin sifili” kayan anode mai dauke da oxygen, wanda baya samar da SEI yayin aikin baturi, kuma yana da ƙarfin ɗaure tare da lithium ion, wanda zai iya biyan bukatun cajin sauri da saki. A lokaci guda, saboda SEI ba za a iya samar da shi ba, kayan anode za su tuntuɓi kai tsaye tare da electrolyte, wanda ke inganta yanayin halayen gefe. Matsalar samar da iskar gas ta LTO ba za a iya magance ta ba, kuma za a iya magance ta ta hanyar gyaran fuska.

03

Electrode ruwa

Kamar yadda aka ambata a sama, yayin aiwatar da caji mai sauri, saboda rashin daidaituwar ƙimar ƙaura na lithium ion da adadin canja wurin lantarki, baturin zai sami babban polarization. Don haka don rage mummunan halayen da ke haifar da polarization baturi, ana buƙatar maki uku masu zuwa don haɓaka electrolyte: 1, high dissociation electrolyte gishiri; 2, sauran ƙarfi hade – ƙananan danko; 3, kulawar dubawa – ƙananan ƙwayar cuta.

04

Dangantakar da ke tsakanin fasahar samarwa da cikawa da sauri

Kafin, an yi nazarin buƙatu da tasirin cikawa da sauri daga mahimman abubuwa guda uku, kamar su kayan lantarki masu inganci da mara kyau da ruwan lantarki. Mai zuwa shine tsarin tsarin da ke da tasiri mai girma. Siffofin fasaha na samar da baturi kai tsaye suna shafar juriyar ƙaura na ions lithium a kowane bangare na baturi kafin da bayan kunna batir, don haka sigogin fasaha na shirye-shiryen baturi suna da tasiri mai mahimmanci akan aikin baturin lithium ion.

(1) surutu

Don kaddarorin slurry, a gefe guda, wajibi ne don kiyaye wakili mai gudanarwa a ko’ina. Domin conductive wakili ne a ko’ina rarraba a tsakanin barbashi na aiki abu, a more uniform conductive cibiyar sadarwa za a iya kafa tsakanin aiki abu da kuma aiki abu da kuma mai tara ruwa ruwa, wanda yana da aikin tattara micro current, rage lamba juriya. kuma zai iya inganta yawan motsi na electrons. A daya hannun shi ne don hana over-watsawa na conductive wakili. A cikin tsarin caji da fitarwa, tsarin crystal na anode da kayan cathode za su canza, wanda zai iya haifar da peeling kashe wakili mai gudanarwa, ƙara ƙarfin ciki na baturi, kuma yana shafar aikin.

(2) Matsananciyar bangaranci mai yawa

A ka’idar, batura masu yawa da manyan batura masu ƙarfi ba su dace ba. Lokacin da ƙarancin ƙima da na’urorin lantarki masu kyau da mara kyau ya yi ƙasa, za a iya ƙara saurin watsawar ion lithium, kuma ana iya rage juriyar ƙaura na ion da electron. Ƙarƙashin girman saman shine, mafi ƙarancin ƙarancin wutar lantarki, da kuma canjin tsarin lantarki wanda ya haifar da ci gaba da sakawa da sakin ions na lithium a caji da fitarwa shima ya ragu. Duk da haka, idan girman ƙasa ya yi ƙasa sosai, ƙarfin ƙarfin baturi zai ragu kuma farashin zai ƙaru. Sabili da haka, ya kamata a yi la’akari da yawa a saman. Hoto na gaba shine misalin lithium cobalate baturi yana yin caji a 6C da fitarwa a 1C.

Hoton

(3) Daidaitaccen shafi yanki na Polar

Kafin, wani aboki ya tambaya, shin rashin daidaiton ɗimbin yawa zai yi tasiri akan baturin? Anan ta hanyar, don aikin caji mai sauri, babban shine daidaiton farantin anode. Idan ƙananan ƙarancin ƙasa ba daidai ba ne, porosity na ciki na kayan rayuwa zai bambanta sosai bayan mirgina. Bambance-bambancen porosity zai haifar da bambanci na rarrabawar ciki na ciki, wanda zai shafi samuwa da aikin SEI a cikin tsarin samar da baturi, kuma a ƙarshe ya shafi aikin caji mai sauri na baturi.

(4) Ƙaƙƙarfan ƙima na takardar sanda

Me yasa ake buƙatar dunƙule sanduna? Ɗaya shine inganta takamaiman ƙarfin baturi, ɗayan kuma shine inganta aikin baturi. Madaidaicin madaidaicin ɗimbin yawa ya bambanta da kayan lantarki. Tare da karuwa na compaction yawa, ƙarami da porosity na lantarki takardar, da kusanci tsakanin barbashi, da kuma karami da kauri na lantarki takardar a karkashin wannan surface yawa, don haka ƙaura hanya na Lithium ions za a iya rage. Lokacin da yawan adadin kuzari ya yi girma sosai, tasirin infiltration na electrolyte ba shi da kyau, wanda zai iya lalata tsarin kayan aiki da rarraba wakili mai sarrafawa, kuma matsalar iska daga baya zata faru. Hakazalika, ana cajin baturin lithium cobalate a 6C kuma ana fitar da shi a 1C, kuma ana nuna tasirin ƙarancin ƙarfin fitarwa kamar haka:

Hoton

05

Formation tsufa da sauransu

Don batir mara kyau na carbon, samuwar – tsufa shine babban tsari na baturin lithium, wanda zai shafi ingancin SEI. Kauri na SEI ba daidai ba ne ko tsarin ba shi da kwanciyar hankali, wanda zai shafi saurin caji da rayuwar sake zagayowar baturi.

Baya ga abubuwan da ke sama masu mahimmanci da yawa, samar da tantanin halitta, caji da tsarin fitarwa za su yi tasiri sosai kan aikin baturi na lithium. Tare da tsawaita lokacin sabis, yakamata a rage yawan cajin baturi a matsakaici, in ba haka ba polarization zai tsananta.

ƙarshe

Ma’anar caji mai sauri da fitar da batir lithium shine cewa ion lithium na iya zama cikin sauri cirewa tsakanin kayan anode da cathode. Kayayyakin kayan aiki, ƙirar tsari da caji da tsarin caji na batura duk suna shafar aikin babban caji na yanzu. Tsarin kwanciyar hankali na kayan anode da anode yana dacewa da saurin tsarin delithium ba tare da haifar da rugujewar tsarin ba, ions lithium a cikin adadin rarraba kayan yana da sauri, don jure wa babban caji na yanzu. Saboda rashin daidaituwa tsakanin gudun hijirar ion da ƙimar canja wurin lantarki, polarization zai faru a cikin caji da aiwatar da caji, don haka ya kamata a rage girman polarization don hana hazo na ƙarfe na lithium da rage ƙarfin da zai shafi rayuwa.