Nickel-cobalt-manganese ternary zvinhu ndechimwe chezvinhu zvikuru zvebhatiri resimba razvino. Izvo zvinhu zvitatu zvine zvazvinoreva zvakasiyana zvecathode zvinhu, pakati peiyo nickel element ndeyekuvandudza kugona kwebhatiri. Iyo yakakwira iyo nickel yemukati, iyo inokwirisa iyo chaiyo chaiyo yezvinyorwa. NCM811 ine chaiyo inokwana 200mAh/g uye discharge platform inosvika 3.8V, inogona kuitwa bhatiri resimba repamusoro. Nekudaro, dambudziko reNCM811 bhatiri kusachengetedzeka kwakashata uye nekukurumidza kutenderera kwehupenyu kuora. Ndezvipi zvikonzero zvinokanganisa kutenderera kwayo hupenyu nekuchengetedzeka? Nzira yekugadzirisa sei dambudziko iri? Izvi zvinotevera ongororo yakadzama:

NCM811 yakagadzirwa kuita bhatani bhatiri (NCM811 / Li) uye inochinjika paki bhatiri (NCM811 / graphite), uye giramu rayo uye huwandu hwayo hwebhatiri hwakaedzwa zvichiteerana. Soft-pack bhatiri rakakamurwa kuita mapoka mana kune imwechete factor experiment. Iyo parameter inosiyana yaive yakachekwa-kubvisa voltage, yaive 4.1V, 4.2V, 4.3V uye 4.4V, zvichiteerana. Kutanga, bhatiri rakafambiswa kaviri pa 0.05c uyezve pa 0.2C pa 30 ℃. Mushure memazana maviri ekutenderera, iyo yakapfava pack bhatiri kutenderera curve inoratidzwa mumufananidzo uri pazasi:

Zvinogona kuonekwa kubva pamufananidzo kuti pasi pemamiriro ekukwirira-kubvisa magetsi, simba regiramu rezvinhu zvipenyu uye bhatiri zvose zvakakwirira, asi huwandu hwegiramu rebhatiri uye zvinhu zvinokurumidza kuora. Kusiyana neizvi, pazasi-akachekwa-kubvisa voltages (pazasi pe4.2V), huwandu hwebhatiri hunodzikira zvishoma nezvishoma uye hupenyu hwekutenderera hwakareba.

Muchiyedzo ichi, iyo parasitic reaction yakadzidzwa ne isothermal calorimetry uye chimiro uye morphology kuderedzwa kwezvinhu zvecathode panguva yekuchovha bhasikoro zvakadzidzwa neXRD neSEM. Mhedziso ndeiyi inotevera:

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Chekutanga, shanduko yemaitiro haisiriyo chikonzero chikuru chekuderera kwehupenyu hwebhatiri

Mhedzisiro yeXRD neSEM yakaratidza kuti pakanga pasina mutsauko uri pachena mune particle morphology uye atomic chimiro chebhatiri ine electrode uye cut-off voltage ye 4.1V, 4.2V, 4.3V uye 4.4V mushure memazana mazana maviri ekutenderera pa200c. Naizvozvo, kukurumidza kushanduka kwemaitiro ehupenyu panguva yekuchaja nekuburitsa handicho chikonzero chikuru chekudzikira kwehupenyu hwebhatiri. Pane kudaro, kuita kweparasitic painterface pakati peelectrolyte uye twumapenyu twakawanda twezvinhu zvipenyu mudelithium state ndicho chikonzero chikuru chekuderedzwa kwehupenyu hwebhatiri pa0.2V high voltage cycle.

(1) iyo SEM

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A1 uye A2 ndiyo SEM mifananidzo yebhatiri isina kutenderera. B ~ E mifananidzo yeSEM ​​yezvinhu zvakanaka zvemagetsi zvemagetsi mushure me 200cycle pasi pe 0.5C mamiriro uye kuchaja yekucheka-kubvisa voltage ye4.1V/4.2V/4.3V/4.4V, zvichiteerana. Rutivi rworuboshwe imufananidzo weelectronic microscope pasi pekukudza kwakaderera uye rutivi rworudyi mufananidzo wemakorosikopu erekitironi pasi pekukudza kukuru. Sezvinoonekwa kubva pamufananidzo uri pamusoro, hapana mutsauko wakakura muchidimbu morphology uye dhigirii rekuputsika pakati pebhatiri rinotenderera nebhatiri risingatenderere.

(2) XRD mifananidzo

Sezvinoonekwa pamufananidzo uri pamusoro, hapana musiyano uri pachena pakati penhongonya shanu muchimiro nechinzvimbo.

(3) Shanduko yelatisi paramita

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Sezvinoonekwa kubva patafura, zvinotevera pfungwa:

1. Mishonga ye lattice ye-uncycled polar plates inopindirana neiyo yeNCM811 mhenyu yehupfu. Kana iyo cycle cutoff voltage iri 4.1V, iyo lattice inogara haina kunyanya kusiyana kubva kune maviri apfuura, uye C axis inowedzera zvishoma. Iyo lattice constants yeC-axis ine 4.2V, 4.3V uye 4.4V haina kunyanya kusiyana neiyo ye4.1V (0.004 angms), nepo data iri paA-axis yakasiyana chaizvo.

2. Pakanga pasina shanduko yakakosha muNi content mumapoka mashanu.

3. Mahwendefa epolar ane mhepo inotenderera ye4.1V pa44.5 ° inoratidza FWHM yakakura, asi mamwe mapoka ekutonga anoratidza FWHM yakafanana.

Mukuchaja uye kuburitsa bhatiri, iyo C axis ine yakakura shrinkage uye kuwedzera. Kudzikiswa kwehupenyu hwebhatiri kutenderera kwakakwirira hakukonzeri nekushanduka kwechimiro chechinhu chipenyu. Naizvozvo, mapoinzi matatu ari pamusoro anosimbisa kuti shanduko yezvimiro haisiriyo chikonzero chikuru chekudzikira kwehupenyu hwebhatiri.

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Chechipiri, hupenyu hwekutenderera kweNCM811 bhatiri hune hukama nekuita kweparasitic mubhatiri

NCM811 uye graphite inogadzirwa kuita maseru epakeji anochinjika achishandisa ma electrolyte akasiyana. Kusiyana neizvi, 2% VC nePES211 yakawedzerwa kuelectrolyte yemapoka maviri aya, zvakateerana, uye mwero wekugadzirisa kugona kwemapoka maviri aya wakaratidza musiyano mukuru mushure mekutenderera kwebhatiri.

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Zvinoenderana nenhamba iri pamusoro, kana iyo yekucheka-kudzima voltage yebhatiri ine 2% VC iri 4.1V, 4.2V, 4.3V uye 4.4V, chiyero chekuchengetedza bhatiri mushure memakumi manomwe muzana i70%, 98%, 98. % uye 91%, zvichiteerana. Mushure mekutenderera makumi mana chete, chiyero chekuchengetedza bhatiri nePES88 yakawedzera yakaderera kusvika 40%, 211%, 91%, 82%. Zvakakosha, mukuedza kwapfuura, hupenyu hwebhatiri hweNCM82 / graphite uye NCM74 / graphite masisitimu ane PES424 yaive nani pane iyo ine 111% VC. Izvi zvinotungamira kune fungidziro yekuti electrolyte additives ine zvakakosha pahupenyu hwebhatiri mune yakakwira-nickel masisitimu.

Izvo zvinogona zvakare kuoneka kubva pane iri pamusoro data kuti kutenderera hupenyu pasi peyakanyanya voltage yakashata kupfuura iyo iri pasi peyakaderera voltage. Kuburikidza nebasa rakakodzera repolarization, △V uye nguva yekutenderera, nhamba inotevera inogona kuwanikwa:

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Zvinogona kuoneka kuti bhatiri △V idiki kana uchichovha bhasikoro pane yakaderera-kubvisa voltage, asi kana voltage ichikwira pamusoro pe4.3V, △V inowedzera zvakanyanya uye bhatiri polarization inowedzera, iyo inokanganisa zvakanyanya hupenyu hwebhatiri. Zvinogonawo kuonekwa kubva pamufananidzo kuti △V shanduko yeVC nePES211 yakasiyana, iyo inosimbisazve kuti dhigirii uye kukurumidza kwebhatiri polarization zvakasiyana nezvimwe zvakasiyana-siyana zve electrolyte.

Isothermal microcalorimetry yakashandiswa kuongorora iyo parasitic reaction mukana webhatiri. Maparamita akadai sepolarization, entropy uye parasitic kupisa kuyerera akaburitswa kuita hukama hunoshanda neRSOC, sezvakaratidzwa mumufananidzo uri pazasi:

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Pamusoro pe 4.2V, kupisa kweparasite kunoratidzwa kuwedzera kamwe kamwe, nekuti iyo yakanyanya delithium anode pamusoro inobata nyore ne electrolyte pahigh voltage. Izvi zvinotsanangurawo kuti sei kukwira kwechaji uye kubuda kwemagetsi, nekukurumidza chiyero chekuchengetedza bhatiri chinodzikira.

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Iii. NCM811 ine kuchengetedzeka kwakashata

Pasi pemamiriro ekuwedzera tembiricha ambient, kuita kweNCM811 mukuchaja nyika ne electrolyte yakakura kupfuura iyo yeNCM111. Naizvozvo, kushandiswa kweNCM811 kugadzirwa kwebhatiri kwakaoma kupfuudza nyika inomanikidzirwa chitupa.

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Iyo nhamba igraph yezviyero zvekuzvipisa zveNCM811 uye NCM111 pakati pe70 ℃ uye 350 ℃. Huwandu hunoratidza kuti NCM811 inotanga kupisa kusvika pa105 ℃, nepo NCM111 isingasvike 200 ℃. Iyo NCM811 ine mwero wekudziya we1 ℃/min kubva pa200 ℃, nepo NCM111 ine mwero wekudziya we0.05 ℃/min, zvinoreva kuti iyo NCM811/ graphite system inonetsa kuwana inosungirwa kuchengetedza chitupa.

High nickel inogara zvinhu inosungirwa kuve iyo huru zvinhu zveyakakwira simba density bhatiri mune ramangwana. Nzira yekugadzirisa sei dambudziko rekukurumidza kuora kweNCM811 hupenyu hwebhatiri? Chekutanga, iyo particle surface yeNCM811 yakagadziridzwa kuti ivandudze mashandiro ayo. Yechipiri ndeye kushandisa electrolyte iyo inogona kuderedza parasitic reaction yezviviri, kuitira kuti ivandudze kutenderera kwayo hupenyu uye kuchengeteka. Mufananidzo

Kudzvanya kwenguva refu kuona iyo QR kodhi, wedzera lithium π!

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