Ubusika buyeza, bheka inkambiso yokuhlaziya izinga lokushisa eliphansi lamabhethri e-lithium-ion

Ukusebenza kwamabhethri e-lithium-ion kuthinteka kakhulu izici zabo ze-kinetic. Ngenxa yokuthi i-Li+ idinga ukuchithwa kuqala uma ishunyekwa ku-graphite material, idinga ukusebenzisa inani elithile lamandla futhi ivimbele ukusakazeka kwe-Li+ kugraphite. Ngokuphambene nalokho, lapho i-Li + ikhishwa ku-graphite impahla ibe yisixazululo, inqubo yokuxazulula izokwenzeka kuqala, futhi inqubo yokuxazulula ayidingi ukusetshenziswa kwamandla. I-Li+ ingasusa ngokushesha i-graphite, okuholela ekwamukelweni kwenkokhiso empofu kakhulu yezinto zegraphite. Ekwamukeleni kokukhishwa .

Emazingeni okushisa aphansi, izici ze-kinetic ze-electrode ye-graphite engalungile ziye zaba ngcono futhi ziba zimbi kakhulu. Ngakho-ke, i-electrochemical polarization ye-electrode eyinegethivu iqiniswa kakhulu phakathi nenqubo yokushaja, okungaholela kalula emvuleni ye-lithium yensimbi ebusweni be-electrode eyinegethivu. Ucwaningo lukaChristian von Lüders we-Technical University yaseMunich, eJalimane, lubonise ukuthi ku--2°C, izinga lokushaja lidlula u-C/2, futhi inani lemvula ye-lithium yensimbi lenyuka kakhulu. Isibonelo, ngesilinganiso se-C/2, inani le-lithium plating endaweni ephikisayo ye-electrode limayelana nenkokhiso yonke. Umthamo ongu-5.5% kodwa uzofinyelela ku-9% ngaphansi kokukhuliswa kwe-1C. I-lithium yensimbi enciphayo ingase ithuthuke ngokuqhubekayo futhi ekugcineni ibe i-lithium dendrites, ibhoboze ku-diaphragm futhi ibangele ukujikeleza okufushane kwama-electrode aqondile noma angalungile. Ngakho-ke, kuyadingeka ukugwema ukushaja ibhethri ye-lithium-ion emazingeni okushisa aphansi ngangokunokwenzeka. Uma kufanele ishaje ibhethri ngezinga lokushisa eliphansi, kubalulekile ukukhetha yamanje encane ukuze ishaje ibhethri le-lithium-ion ngangokunokwenzeka futhi igcine ngokugcwele ibhethri le-lithium-ion ngemva kokushaja ukuze uqinisekise I-metallic lithium encibilika ku-electrode engemihle. ingasabela nge-graphite futhi ishumekwe kabusha ku-electrode ye-graphite engalungile.

U-Veronika Zinth nabanye be-Technical University yaseMunich basebenzisa i-neutron diffraction nezinye izindlela zokutadisha ukuziphatha kwe-lithium evolution yamabhethri e-lithium-ion ezingeni lokushisa eliphansi elingu-20°C. I-Neutron diffraction kube yindlela entsha yokuthola eminyakeni yakamuva. Uma kuqhathaniswa ne-XRD, i-neutron diffraction izwela kakhulu ezintweni ezikhanyayo (i-Li, O, N, njll.), ngakho-ke ifaneleka kakhulu ukuhlolwa okungonakali kwamabhethri e-lithium-ion.

Esivivinyweni, i-VeronikaZinth yasebenzisa ibhethri le-NMC111/graphite 18650 ukuze itadishe ukuziphatha kokuvela kwe-lithium kwamabhethri e-lithium-ion emazingeni okushisa aphansi. Ibhethri liyashajwa futhi liyakhishwa ngesikhathi sokuhlolwa ngokwenqubo ekhonjiswe esithombeni esingezansi.

Isibalo esilandelayo sibonisa ukuguqulwa kwesigaba se-electrode engemihle ngaphansi kwama-SoC ahlukene phakathi nomjikelezo wokushaja wesibili ngenani lokushaja elingu-C/30. Kungase kubonakale sengathi ku-30.9% SoC, izigaba ze-electrode engalungile ngokuyinhloko i-LiC12, i-Li1-XC18, kanye nenani elincane le-LiC6 Composition; ngemuva kokuthi i-SoC idlule ama-46%, ukushuba kwe-diffraction ye-LiC12 kuyaqhubeka nokwehla, kuyilapho amandla e-LiC6 eqhubeka nokukhula. Nokho, ngisho nangemva kokuba ukushaja kokugcina sekuqediwe, njengoba kushajwa i-1503mAh kuphela ekushiseni okuphansi (umthamo ungu-1950mAh ekamelweni lokushisa), i-LiC12 ikhona ku-electrode engemihle. Ake sithi ukushaja kwamanje kwehliselwe ku-C/100. Uma kunjalo, ibhethri isengathola umthamo we-1950mAh emazingeni okushisa aphansi, okubonisa ukuthi ukwehla kwamandla amabhethri e-lithium-ion emazingeni okushisa aphansi kubangelwa ikakhulukazi ukuwohloka kwezimo ze-kinetic.

Isibalo esingezansi sibonisa ukuguqulwa kwesigaba se-graphite ku-electrode engalungile ngesikhathi sokushaja ngokwezinga le-C/5 ekushiseni okuphansi kuka -20°C. Ingabona ukuthi ukuguqulwa kwesigaba segraphite kuhluke kakhulu uma kuqhathaniswa nokushaja kwezinga le-C/30. Kungabonakala ngesibalo ukuthi uma i-SoC>40%, amandla esigaba sebhethri i-LiC12 ngaphansi kwezinga lokushaja le-C/5 ehla kancane kakhulu, futhi ukwanda kwamandla esigaba se-LiC6 nakho kuba buthaka kakhulu kunalelo le-C/30. izinga lokushaja. Kubonisa ukuthi ngenani eliphakeme kakhulu lika-C/5, i-LiC12 engaphansi iyaqhubeka nokuhlanganisa i-lithium futhi iguqulelwa ku-LiC6.

Isibalo esingezansi siqhathanisa izinguquko zesigaba se-electrode eyi-graphite engalungile lapho ishaja kumazinga we-C/30 kanye ne-C/5, ngokulandelana. Isibalo sibonisa ukuthi kumanani amabili ahlukene wokushaja, isigaba se-lithium-poor Li1-XC18 sifana kakhulu. Umehluko ubonakala kakhulu ezigabeni ezimbili ze-LiC12 ne-LiC6. Kungabonakala esibalweni ukuthi ukuthambekela koshintsho lwesigaba ku-electrode eyinegethivu kusondele kakhulu esigabeni sokuqala sokushaja ngaphansi kwezilinganiso zokushaja ezimbili. Esigabeni se-LiC12, lapho umthamo wokushaja ufinyelela ku-950mAh (49% SoC), umkhuba oshintshayo uqala ukubonakala uhlukile. Uma kukhulunywa nge-1100mAh (56.4% SoC), isigaba se-LiC12 ngaphansi kokukhulisa okubili siqala ukukhombisa igebe elibalulekile. Uma ishaja ngenani eliphansi le-C/30, ukwehla kwesiteji se-LiC12 kushesha kakhulu, kodwa ukwehla kwesigaba se-LiC12 ngesilinganiso se-C/5 kuhamba kancane kakhulu; okusho ukuthi, izimo ze-kinetic zokufakwa kwe-lithium ku-electrode engalungile ziwohloka emazingeni okushisa aphansi. , Ukuze i-LiC12 iqhubeke nokuhlanganisa i-lithium ukuze ikhiqize isivinini sesigaba se-LiC6 sehlile. Ngokuhambisanayo, isigaba se-LiC6 sikhula ngokushesha okukhulu ngenani eliphansi lika-C/30 kodwa sihamba kancane kakhulu ngesilinganiso esingu-C/5. Lokhu kukhombisa ukuthi ngesilinganiso se-C/5, i-Petite Li eningi ishumekwe esakhiweni sekristalu segraphite, kodwa okujabulisayo ukuthi umthamo wokushaja webhethri (1520.5mAh) ngesilinganiso sokushaja se-C/5 uphakeme kunalowo ose-C. /30 izinga lokushaja. Amandla (1503.5mAh) aphezulu. I-Li eyengeziwe engashumekiwe ku-electrode eyi-graphite engalungile cishe izona endaweni yegraphite ngendlela ye-metallic lithium. Inqubo yokuma ngemva kokuphela kokushaja nayo ifakazela lokhu kusukela ohlangothini—kancane.

Isibalo esilandelayo sibonisa isakhiwo sesigaba se-electrode ye-graphite engalungile ngemva kokushaja nangemva kokushiywa amahora angu-20. Ekupheleni kokushaja, isigaba se-electrode ye-graphite engalungile sihluke kakhulu ngaphansi kwamazinga amabili wokushaja. Ku-C/5, isilinganiso se-LiC12 ku-graphite anode siphezulu, futhi iphesenti le-LiC6 liphansi, kodwa ngemva kokuma amahora angu-20, umehluko phakathi kwakho kokubili usube mncane.

Isithombe esingezansi sibonisa ukuguqulwa kwesigaba se-electrode ye-graphite engalungile phakathi nenqubo yokugcina ye-20h. Ingabona emfanekisweni ukuthi nakuba izigaba zama-electrode amabili aphikisanayo zisahluke kakhulu ekuqaleni, njengoba isikhathi sokugcina sikhula, izinhlobo ezimbili zokushaja Isiteji se-graphite anode ngaphansi kokukhulisa sishintshile kakhulu. I-LiC12 ingaqhubeka nokuguqulelwa ku-LiC6 phakathi nenqubo yokubeka ishelufu, okubonisa ukuthi i-Li izoqhubeka nokushunyekwa ku-graphite phakathi nenqubo yokubeka ishelufu. Le ngxenye ye-Li kungenzeka ibe yi-metallic lithium ehlise ingaphezulu le-electrode eyi-graphite engalungile ngezinga lokushisa eliphansi. Ukuhlaziywa okwengeziwe kubonise ukuthi ekupheleni kokushaja ngesilinganiso se-C/30, izinga le-lithium intercalation ye-electrode eyi-graphite engalungile lalingu-68%. Noma kunjalo, izinga le-lithium intercalation lenyuke laya ku-71% ngemuva kokufakwa kwamasheluli, okuwukunyuka kwama-3%. Ekupheleni kokushaja ngesilinganiso se-C/5, i-lithium yokufaka i-electrode ye-graphite engalungile yayingama-58%, kodwa ngemva kokushiywa amahora angu-20, inyuke yaba ngu-70%, ukwanda okuphelele kwe-12%.

Ucwaningo olungenhla lubonisa ukuthi uma ishaja emazingeni okushisa aphansi, umthamo webhethri uzokwehla ngenxa yokuwohloka kwezimo ze-kinetic. Izophinde inyuse insimbi ye-lithium ebusweni be-electrode engalungile ngenxa yokuncipha kwezinga lokufakwa kwe-lithium ye-graphite. Nokho, ngemva kwesikhathi sokugcina, Le ngxenye ye-metallic lithium ingafakwa ku-graphite futhi; ekusetshenzisweni kwangempela, isikhathi seshalofu sivame ukuba sifushane, futhi asikho isiqinisekiso sokuthi yonke i-lithium yensimbi ingashumeka ku-graphite futhi, ngakho-ke ingabangela i-lithium yensimbi ukuthi iqhubeke nokuba khona ku-electrode engalungile. Indawo yebhethri ye-lithium-ion izothinta umthamo webhethri le-lithium-ion futhi ingase ikhiqize i-lithium dendrites ebeka engozini ukuphepha kwebhethri le-lithium-ion. Ngakho-ke, zama ukugwema ukushaja ibhethri ye-lithium-ion emazingeni okushisa aphansi. Amanje aphansi, futhi ngemva kokusetha, qinisekisa isikhathi esanele seshalofu sokuqeda i-lithium yensimbi ku-electrode ye-graphite engalungile.

Lesi sihloko sibhekisela ikakhulukazi kumadokhumenti alandelayo. Umbiko usetshenziselwa kuphela ukwethula nokubuyekeza imisebenzi yesayensi ehlobene, ukufundisa ekilasini, nocwaningo lwesayensi. Hhayi okokuhweba. Uma unezinkinga ze-copyright, sicela ukhululeke ukuxhumana nathi.

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2.I-Lithium plating kumabhethri e-lithium-ion aphenywa ngokuxegiswa kwamandla kagesi kanye ne-in situ neutron diffraction,Journal of Power Sources 342(2017)17-23, Christian von Lüders, Veronika Zinth, Simon V.Erhard, Patrick J.Osswald, Michael Hofman , uRalph Gilles, u-Andreas Jossen

3.I-Lithium plating kumabhethri e-lithium-ion emazingeni okushisa angaphansi aphenywa yi-in situ neutron diffraction, Journal of Power Sources 271 (2014) 152-159, Veronika Zinth, Christian von Lüders, Michael Hofmann, Johannes Hattendorff, Irmgard Buchberger, Simon Erhard, Joana Rebelo-Kornmeier, Andreas Jossen, Ralph Gilles