Ubusika buyeza, jonga i-low-temperature analysis phenomenon yeebhetri ze-lithium-ion

Ukusebenza kweebhetri ze-lithium-ion kuchaphazeleka kakhulu kwiimpawu zabo zekinetic. Ngenxa yokuba i-Li+ idinga ukuchithwa kuqala xa ifakwe kwizinto zegraphite, kufuneka idle umlinganiselo othile wamandla kwaye ithintele ukusasazwa kweLi + kwigraphite. Ngokuchasene noko, xa i-Li + ikhutshwa kwizinto zegraphite kwisisombululo, inkqubo yokusombulula iya kwenzeka kuqala, kwaye inkqubo yokusombulula ayifuni ukusetyenziswa kwamandla. I-Li + inokususa ngokukhawuleza igraphite, ekhokelela ekwamkelweni kwentlawulo ephantsi kakhulu yezinto zegraphite. Ekukhupheni ukwamkeleka .

Kwiqondo lobushushu eliphantsi, iimpawu zekinetic ze-electrode engalunganga yegraphite ziye zaphucuka kwaye ziba mandundu. Ke ngoko, i-electrochemical polarization ye-electrode engalunganga iqiniswa kakhulu ngexesha lenkqubo yokutshaja, enokuthi iholele ngokulula kwimvula ye-lithium yensimbi kumphezulu we-electrode engalunganga. Uphando olwenziwa nguChristian von Lüders we-Technical University yaseMunich, eJamani, lubonise ukuba kwi--2 ° C, izinga lentlawulo lidlula i-C / 2, kwaye inani le-metal lithium precipitation linyuke kakhulu. Ngokomzekelo, kwizinga le-C / 2, ubungakanani be-lithium plating kwindawo ye-electrode echasayo malunga nentlawulo yonke. I-5.5% yomthamo kodwa iya kufikelela kwi-9% phantsi kokwandiswa kwe-1C. I-lithium yensimbi encitshisiweyo inokukhula ngakumbi kwaye ekugqibeleni ibe yi-lithium dendrites, igqobhoze kwi-diaphragm kwaye ibangele ukujikeleza okufutshane kwee-electrode ezilungileyo kunye nezingalunganga. Ngoko ke, kuyimfuneko ukuphepha ukutshaja ibhetri ye-lithium-ion kumaqondo obushushu aphantsi kangangoko kunokwenzeka. Xa kufuneka uhlawule ibhetri kwiqondo lokushisa eliphantsi, kubalulekile ukuba ukhethe incinci yangoku ukuhlawula ibhetri ye-lithium-ion kangangoko kunokwenzeka kwaye ugcine ngokupheleleyo ibhetri ye-lithium-ion emva kokutshaja ukuqinisekisa ukuba i-metallic lithium ikhutshwe kwi-electrode engalunganga. inokusabela ngegraphite kwaye iphinde ifakwe kwi-electrode yegraphite engalunganga.

UVeronika Zinth kunye nabanye baseYunivesithi yaseMunich basebenzise i-neutron diffraction kunye nezinye iindlela zokufunda ukuziphatha kwe-lithium ye-lithium-ion iibhetri kwiqondo lokushisa eliphantsi -20 ° C. I-neutron diffraction ibe yindlela entsha yokubona kwiminyaka yakutshanje. Xa kuthelekiswa ne-XRD, i-neutron diffraction ivakalelwa ngakumbi kwizinto zokukhanya (i-Li, O, N, njl.), Ngoko ke ifanelekile kakhulu kuvavanyo olungonakalisi lweebhetri ze-lithium-ion.

Kuvavanyo, iVeronikaZinth yasebenzisa ibhetri ye-NMC111/graphite 18650 ukufunda ukuziphatha kwe-lithium evolution yeebhetri ze-lithium-ion kumaqondo obushushu aphantsi. Ibhetri ihlawuliswa kwaye ikhutshwe ngexesha lovavanyo ngokwenkqubo eboniswe kumzobo ongezantsi.

Lo mfanekiso ulandelayo ubonisa utshintsho lwesigaba se-electrode engalunganga phantsi kwee-SoCs ezahlukeneyo ngexesha lomjikelezo wesibini wokutshaja kwi-C / 30 izinga lokutshaja. Kungabonakala ngathi kwi-30.9% ye-SoC, izigaba ze-electrode engalunganga ziyi-LiC12, i-Li1-XC18, kunye nenani elincinci le-LiC6 Composition; emva kokuba i-SoC idlula i-46%, intensity ye-diffraction ye-LiC12 iyaqhubeka nokuhla, ngelixa amandla e-LiC6 eqhubeka nokunyuka. Nangona kunjalo, nasemva kokuba intlawulo yokugqibela igqityiwe, kuba i-1503mAh kuphela ihlawuliswa kwiqondo lokushisa eliphantsi (umthamo ngu-1950mAh kwiqondo lokushisa elingaphakathi), i-LiC12 ikhona kwi-electrode engalunganga. Masithi ukutshaja kwangoku kuncitshiswe ukuya kwi-C/100. Kwimeko apho, ibhetri isenokufumana umthamo we-1950mAh kumaqondo aphantsi, nto leyo ebonisa ukuba ukuhla kwamandla ebhetri ye-lithium-ion kumaqondo aphantsi kakhulu kubangelwa ukuwohloka kweemeko ze-kinetic.

Umfanekiso ongezantsi ubonisa utshintsho lwesigaba segraphite kwi-electrode engalunganga ngexesha lokutshaja ngokwezinga le-C / 5 kwiqondo lokushisa eliphantsi -20 ° C. Iyakwazi ukubona ukuba utshintsho lwesigaba segraphite luhluke kakhulu xa kuthelekiswa nexabiso le-C / 30 lokutshaja. Inokubonwa kumzobo ukuba xa i-SoC> 40%, amandla enqanaba lebhetri ye-LiC12 phantsi kwexabiso le-C / 5 lentlawulo lehla ngokukhawuleza, kwaye ukonyuka kwamandla esigaba se-LiC6 nako kubuthathaka kakhulu kune-C / 30. izinga lentlawulo. Ibonisa ukuba kwinqanaba eliphezulu le-C / 5, i-LiC12 encinci iyaqhubeka i-intercalate lithium kwaye iguqulelwe kwi-LiC6.

Umzobo ongezantsi uthelekisa utshintsho lwesigaba se-electrode ye-graphite engalunganga xa utshaja kwi-C / 30 kunye ne-C / 5 amazinga, ngokulandelanayo. Umzobo ubonisa ukuba kumazinga amabini ahlukeneyo okutshaja, i-lithium-poor phase Li1-XC18 ifana kakhulu. Umahluko ubonakaliswa ikakhulu kwizigaba ezibini ze-LiC12 kunye ne-LiC6. Inokubonwa kumzobo ukuba umzila wokutshintsha kwesigaba kwi-electrode engalunganga isondele kakhulu kwinqanaba lokuqala lokutshaja phantsi kweentlawulo ezimbini zentlawulo. Kwisigaba se-LiC12, xa umthamo wokutshaja ufikelela kwi-950mAh (49% ye-SoC), ukutshintshwa kwendlela iqala ukubonakala ngokuhlukileyo. Xa kufika i-1100mAh (i-56.4% ye-SoC), isigaba se-LiC12 phantsi kwee-magnifications ezimbini siqala ukubonisa i-gap ebalulekileyo. Xa uhlawulisa ngexabiso eliphantsi le-C / 30, ukuhla kwe-LiC12 kwinqanaba likhawuleza kakhulu, kodwa ukuhla kwesigaba se-LiC12 kwizinga le-C / 5 kuncinci kakhulu; oko kukuthi, iimeko ze-kinetic zokufakwa kwe-lithium kwi-electrode engafanelekanga iyancipha kumaqondo aphantsi. , Ukuze i-LiC12 iphinde idibanise i-lithium ukuvelisa isantya sesigaba se-LiC6 sehlile. Ngokuhambelanayo, inqanaba le-LiC6 linyuka ngokukhawuleza kwiqondo eliphantsi le-C/30 kodwa licotha kakhulu kumyinge we-C/5. Oku kubonisa ukuba kwinqanaba le-C / 5, i-petite engaphezulu ifakwe kwi-crystal structure yegraphite, kodwa into enomdla kukuba umthamo webhetri (1520.5mAh) kwi-C / 5 yentlawulo iphezulu kunoko kwi-C. /30 intlawulo yexabiso. Amandla (1503.5mAh) aphezulu. I-Li eyongezelelweyo engafakwanga kwi-electrode yegraphite engalunganga kunokwenzeka ukuba igalelwe kumphezulu wegraphite ngohlobo lwe-metallic lithium. Inkqubo yokuma emva kokuphela kokutshaja iphinda ibonakalise oku ukusuka kwicala-kancinci.

Lo mfanekiso ulandelayo ubonisa ubume besigaba se-electrode yegraphite engalunganga emva kokutshaja nasemva kokushiywa iiyure ezingama-20. Ekupheleni kokutshaja, isigaba se-electrode engalunganga yegraphite yahluke kakhulu phantsi kweereyithi ezimbini zokutshaja. Kwi-C / 5, umlinganiselo we-LiC12 kwi-graphite anode uphezulu, kwaye ipesenti ye-LiC6 iphantsi, kodwa emva kokuma kweeyure ze-20, umehluko phakathi kwezi zibini zincinci.

Umfanekiso ongezantsi ubonisa utshintsho lwesigaba se-electrode yegraphite engalunganga ngexesha lenkqubo yokugcina i-20h. Iyakwazi ukubona kumzobo ukuba nangona izigaba ze-electrode ezimbini ezichasayo zisahluke kakhulu ekuqaleni, njengoko ixesha lokugcinwa landa, iindidi ezimbini zokutshaja Isigaba se-graphite anode phantsi kokukhulisa sitshintshile ngokusondeleyo. I-LiC12 inokuqhubeka iguqulelwa kwi-LiC6 ngexesha lenkqubo yokubeka i-shelf, ebonisa ukuba i-Li iya kuqhubeka ifakwe kwi-graphite ngexesha lenkqubo ye-shelf. Le nxalenye ye-Li inokuba yintsimbi ye-lithium yokunyuka komphezulu we-electrode engalunganga yegraphite kubushushu obuphantsi. Uhlalutyo olongezelelweyo lubonise ukuba ekupheleni kokutshaja kwinqanaba le-C / 30, i-degree ye-lithium intercalation ye-electrode ye-graphite engathandekiyo yayingu-68%. Sekunjalo, idigri ye-lithium intercalation yonyuka ukuya kwi-71% emva kwe-shelf, ukwanda kwe-3%. Ekupheleni kokutshaja kwinqanaba le-C / 5, idigri ye-lithium yokufaka i-electrode ye-graphite engathandekiyo yayingu-58%, kodwa emva kokushiywa kweeyure ezingama-20, yanda ukuya kuma-70%, ukwanda kwe-12%.

Olu phando lungentla lubonisa ukuba xa utshaja kumaqondo obushushu aphantsi, umthamo webhetri uya kuncipha ngenxa yokuwohloka kweemeko zekinetic. Iya kuphinda iqhube isinyithi se-lithium kumphezulu we-electrode engalunganga ngenxa yokuncipha kwesantya sokufakwa kwe-lithium yegraphite. Nangona kunjalo, emva kwexesha lokugcina, Le nxalenye ye-metallic lithium inokufakwa kwigraphite kwakhona; ekusetyenzisweni okwenyani, ixesha leshelufu lihlala lifutshane, kwaye akukho siqinisekiso sokuba yonke i-lithium yesinyithi inokufakwa kwigraphite kwakhona, ngoko kunokubangela ukuba i-lithium yesinyithi iqhubeke ikhona kwi-electrode engalunganga. Umphezulu webhetri ye-lithium-ion uya kuchaphazela amandla ebhetri ye-lithium-ion kwaye unokuvelisa i-lithium dendrites ebeka engozini ukhuseleko lwebhetri ye-lithium-ion. Ngoko ke, zama ukunqanda ukutshaja ibhetri ye-lithium-ion kumaqondo obushushu aphantsi. Ikhoyo ngoku ephantsi, kwaye emva kokumisela, qinisekisa ixesha elaneleyo leshelufu ukuphelisa i-lithium yensimbi kwi-electrode ye-graphite engalunganga.

Eli nqaku libhekisa ikakhulu kula maxwebhu alandelayo. Ingxelo isetyenziselwa kuphela ukwazisa nokuphonononga imisebenzi yenzululwazi enxulumeneyo, ukufundisa eklasini, kunye nophando lwenzululwazi. Ayisetyenziselwa urhwebo. Ukuba unayo nayiphi na imiba ye-copyright, nceda uzive ukhululekile ukuqhagamshelana nathi.

1.Ixabiso lokukwazi ukwenza izinto zegraphite njenge-electrode engalunganga kwi-lithium-ion capacitors, Electrochimica Acta 55 (2010) 3330 - 3335 , SRSivakkumar, JY Nerkar, AG Pandolfo

I-2.I-Lithium plating kwiibhetri ze-lithium-ion iphandwa ngokukhululeka kombane kunye ne-situ neutron diffraction,Ijenali yeMithombo yaMandla 342(2017)17-23, uChristian von Lüders, uVeronika Zinth, uSimon V.Erhard, uPatrick J.Osswald, uMichael Hofman , uRalph Gilles, uAndreas Jossen

I-3.I-Lithium plating kwiibhetri ze-lithium-ion kumaqondo obushushu aphantsi ophandwa 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 U-Erhard, uJoana Rebelo-Kornmeier, u-Andreas Jossen, uRalph Gilles