Ib qho teeb meem ntawm kev rov ua dua tshiab yog tias tus nqi ntawm cov khoom siv nws tus kheej yog tsawg, thiab cov txheej txheem rov ua dua tshiab tsis pheej yig. Lub tshuab tshiab vam tias yuav txhawb nqa rov ua dua tshiab ntawm lithium roj teeb los ntawm kev txo nqi ntxiv thiab siv cov khoom xyaw hauv eco.

Cov txheej txheem kho tshiab tuaj yeem rov qab siv cov khoom siv cathode mus rau nws lub xeev qub, txo cov nqi rov ua dua tshiab. Tsim los ntawm nanoengineers ntawm University of California, San Diego, thev naus laus zis yog ib puag ncig zoo dua li cov kev siv tam sim no. Nws siv cov khoom siv ntsuab ntsuab, txo kev siv hluav taws xob los ntawm 80 mus rau 90 feem pua, thiab txo cov pa roj carbon monoxide emissions los ntawm 75 feem pua.

Cov kws tshawb fawb piav qhia lawv txoj haujlwm hauv ib daim ntawv luam tawm Kaum Ib Hlis 12 hauv Joule.

Cov txheej txheem no yog qhov zoo tshaj plaws rau cathodes ua los ntawm lithium hlau phosphate (LFP). LFP cathode roj teeb yog pheej yig dua li lwm cov roj teeb lithium vim tias lawv tsis siv cov hlau zoo li cobalt lossis npib tsib xee. LFP roj teeb kuj tseem ruaj khov thiab muaj kev nyab xeeb dua. Lawv tau siv dav hauv cov cuab yeej hluav taws xob, tsheb npav hluav taws xob thiab cov phiaj xwm hluav taws xob. Tesla Model 3 kuj tseem siv LFP roj teeb.

Zheng Chen, tus xibfwb ntawm nanoengineering ntawm University of California, San Diego hais tias “Xav txog cov txiaj ntsig no, LFP roj teeb yuav muaj kev sib tw zoo dua li lwm cov roj teeb lithium hauv khw,” said Zheng Chen, tus xibfwb ntawm nanoengineering ntawm University of California, San Diego.

Puas muaj teeb meem? “Nws tsis raug nqi them rov qab cov roj teeb no.” “Nws ntsib teeb meem tib yam li cov yas – cov khoom siv nws tus kheej yog pheej yig, tab sis txoj kev rov ua dua nws tsis pheej yig,” Chen hais.

Kev siv thev naus laus zis tshiab tsim los ntawm Chen thiab nws pab neeg tuaj yeem txo cov nqi no. Lub tshuab ua haujlwm ntawm qhov kub thiab txias (60 txog 80 degrees Celsius) thiab ambient siab, yog li nws siv hluav taws xob tsawg dua li lwm txoj kev. Ntxiv rau, cov tshuaj nws siv, xws li lithium, nitrogen, dej, thiab citric acid, yog pheej yig thiab me me.

Pan Xu, tus kws tshawb fawb tus thawj coj thiab tus kws tshawb fawb tom qab kws kho mob hauv Chen tau hais tias “Txhua txoj kev rov ua dua tshiab tau ua raws li kev nyab xeeb heev, yog li peb tsis xav tau kev ntsuas kev nyab xeeb tshwj xeeb lossis cov cuab yeej tshwj xeeb,” Tias yog vim li cas peb cov nqi roj teeb rov ua dua yog tsawg. ”

Ua ntej, cov kws tshawb fawb tau rov ua dua LFP roj teeb kom txog thaum lawv poob ib nrab ntawm lawv lub peev xwm cia. Tom qab ntawd lawv tau disassembled lub roj teeb, sau nws cov hmoov cathode, thiab soaked nyob rau hauv ib tug daws ntawm lithium ntsev thiab citric acid. Tom ntej no, lawv ntxuav cov tshuaj nrog dej thiab cia cov hmoov qhuav ua ntej cua sov.

Cov kws tshawb fawb tau siv cov hmoov los ua cov cathodes tshiab, uas tau sim hauv cov pob khawm thiab lub hnab ntim. Nws cov electrochemical kev ua tau zoo, tshuaj muaj pes tsawg leeg thiab cov qauv yog rov qab los rau hauv lub xeev qub.

Raws li lub roj teeb txuas ntxiv rov ua dua tshiab, lub cathode tau dhau los ntawm ob qhov kev hloov pauv tseem ceeb uas txo nws txoj kev ua haujlwm. Thawj yog qhov poob ntawm lithium ions, uas tsim voids hauv cov qauv cathode. Qhov thib ob, lwm qhov kev hloov pauv tau tshwm sim thaum cov hlau thiab lithium ions hauv cov qauv siv lead ua pauv qhov chaw. Thaum qhov ntawd tshwm sim, cov ions tsis tuaj yeem hloov rov qab tau yooj yim, yog li cov lithium ions tau daig thiab tsis tuaj yeem hla lub roj teeb.

Txoj kev kho mob tau npaj tseg hauv txoj kev tshawb no thawj zaug ntxiv cov lithium ions, kom cov hlau ions thiab lithium ions tuaj yeem hloov tau yooj yim rov qab mus rau lawv cov haujlwm qub, yog li rov kho cov qauv cathode. Cov kauj ruam thib ob yog siv citric acid, uas ua raws li tus neeg sawv cev txo kom pub electrons rau lwm yam khoom. Nws hloov electrons mus rau cov hlau ions, txo lawv cov nqi zoo. Qhov no txo ​​qis electron repulsion thiab tiv thaiv cov hlau ions rov qab los rau lawv cov haujlwm qub hauv cov qauv siv lead ua, thaum tso lithium ions rov qab mus rau hauv lub voj voog.

Thaum lub zog tag nrho ntawm cov txheej txheem rov ua dua yog tsawg, cov kws tshawb fawb hais tias kev tshawb fawb ntxiv yog xav tau ntawm kev thauj mus los ntawm kev sau, thauj thiab pov tseg ntawm cov roj teeb ntau.

“Qhov kev sib tw tom ntej yog txhawm rau txheeb xyuas seb yuav ua li cas txhawm rau txhim kho cov txheej txheem logistical no.” Chen tau hais tias “Qhov no yuav coj peb cov thev naus laus zis rov ua dua ib kauj ruam los ze dua rau kev thov kev lag luam,” Chen hais.