Cov laj thawj cuam tshuam rau lub peev xwm them ceev ntawm lithium-ion roj teeb
Txhua lub roj teeb lithium muaj qhov zoo tshaj plaws them nqi tam sim no raws li lub xeev tsis sib txawv thiab ib puag ncig tsis zoo. Tom qab ntawd, los ntawm qhov kev xav ntawm cov qauv roj teeb, dab tsi yog yam uas cuam tshuam rau qhov zoo tshaj plaws them nqi.
Cov txheej txheem microscopic ntawm kev them nyiaj
Lithium batteries are known as "rocking chair" batteries, in which charged ions move between positive and negative electrodes to transfer charges to power external circuits or charge from an external power source. In the specific charging process, the external voltage is applied to the two poles of the battery, and the lithium ions are deintercalated from the positive electrode material and enter the electrolyte. At the same time, excess electrons are generated through the positive electrode current collector and move to the negative electrode through the external circuit; lithium ions are in the electrolyte. It moves from the positive electrode to the negative electrode, and passes through the separator to the negative electrode; the SEI film passing through the surface of the negative electrode is embedded in the graphite layered structure of the negative electrode and combines with electrons.
Cov qauv ntawm lub roj teeb, txawm tias electrochemical lossis lub cev, uas cuam tshuam rau kev hloov pauv mus thoob plaws hauv kev ua haujlwm ionic thiab hluav taws xob yuav muaj kev cuam tshuam rau kev them nqi ceev.
Them sai sai, yuav tsum muaj rau txhua feem ntawm lub roj teeb
Rau cov roj teeb, yog tias koj xav txhim kho lub zog ua haujlwm, koj yuav tsum ua haujlwm hnyav rau txhua yam ntawm lub roj teeb tag nrho, suav nrog cov electrodes zoo, tsis zoo electrodes, electrolytes, diaphragms, thiab cov qauv tsim.
zoo electrode
Qhov tseeb, yuav luag txhua yam ntawm cov khoom siv cathode tuaj yeem siv los ua kom ceev -them roj teeb. Cov kev ua yeeb yam tseem ceeb uas yuav tsum tau lees paub suav nrog kev coj ua (txo qis hauv kev tiv thaiv), diffusion (guarantee cov tshuaj tiv thaiv kinetics), lub neej (tsis xav tau piav qhia), kev nyab xeeb (tsis xav tau kev piav qhia), kev ua haujlwm tsim nyog (qhov tshwj xeeb ntawm thaj chaw yuav tsum tsis txhob muaj. loj dhau los txo cov kev cuam tshuam sab thiab ua haujlwm nyab xeeb).
Tau kawg, cov teeb meem yuav daws tau rau txhua yam khoom siv yuav txawv, tab sis peb cov khoom siv cathode tuaj yeem ua tau raws li cov kev cai no los ntawm kev ua kom zoo dua qub, tab sis cov ntaub ntawv sib txawv kuj txawv:
A. Lithium hlau phosphate yuav tsom ntau dua rau kev daws cov teeb meem ntawm hluav taws xob conductivity thiab kub tsis tshua muaj. Cov pa roj carbon txheej, nruab nrab nano-ization (nco ntsoov tias nws yog nruab nrab, tsis yog qhov yooj yim logic ntawm finer yog zoo dua), thiab tsim cov ionic conductors nyob rau saum npoo ntawm hais yog cov feem ntau cov tswv yim.
B. Cov khoom siv hluav taws xob ntawm cov khoom siv ternary nws tus kheej yog qhov zoo, tab sis nws cov reactivity siab dhau lawm, yog li cov khoom siv ternary tsis tshua muaj nano - loj (nano- tshuaj tsis yog tshuaj tua kab mob rau kev txhim kho. Kev ua haujlwm ntawm cov khoom siv, tshwj xeeb tshaj yog nyob rau hauv cov roj teeb, qee zaum muaj kev cuam tshuam ntau heev), thiab kev saib xyuas ntau dua yog them rau kev nyab xeeb thiab inhibition ntawm kev mob tshwm sim (nrog rau electrolyte), tom qab tag nrho, ib qho ntawm cov ntsiab lus tseem ceeb ntawm cov ntaub ntawv ternary tam sim no. yog kev nyab xeeb, thiab tsis ntev los no cov roj teeb kev nyab xeeb tsis ntev los no kuj tseem nyob rau hauv qhov no. muab cov kev xav tau siab dua.
C. Lithium manganate them ntau xim rau lub neej. Tam sim no, muaj ntau lithium manganate series ceev-them roj teeb ntawm lub khw.
tsis zoo electrode
Thaum lub roj teeb lithium-ion raug them, lithium tsiv mus rau qhov tsis zoo electrode. Lub peev xwm loj uas coj los ntawm qhov siab tam sim no ntawm kev them nyiaj ceev yuav ua rau qhov tsis zoo electrode muaj peev xwm ua rau tsis zoo. Nyob rau lub sijhawm no, lub siab ntawm qhov tsis zoo electrode kom sai sai txais lithium yuav nce, thiab cov nyiam ua kom muaj lithium dendrites yuav nce. Yog li ntawd, qhov tsis zoo electrode yuav tsum tsis tsuas yog ua tau raws li cov kev xav tau ntawm lithium diffusion thaum lub sij hawm them ceev ceev Yog li ntawd, qhov teeb meem tseem ceeb ntawm kev them nyiaj ceev ceev yog qhov tso tawm ntawm lithium ions hauv qhov tsis zoo electrode.
A. Tam sim no, cov khoom siv tsis zoo electrode nyob rau hauv kev ua lag luam tseem yog graphite (suav txog li 90 feem pua ntawm cov khoom lag luam). Tsis muaj lwm qhov laj thawj tseem ceeb - pheej yig, thiab kev ua tiav kev ua tau zoo thiab lub zog ntom ntom ntawm graphite yog qhov zoo, thiab qhov tsis zoo kuj tsawg. . Tau kawg, graphite tsis zoo electrode kuj muaj teeb meem. Nws nto yog rhiab heev rau cov electrolyte, thiab intercalation cov tshuaj tiv thaiv ntawm lithium muaj zog directionality. Yog li ntawd, nws yog ib qho tseem ceeb uas yuav tsum tau ua cov graphite nto kho kom zoo dua nws cov qauv kev ruaj ntseg thiab txhawb cov diffusion ntawm lithium ions ntawm lub substrate. kev taw qhia.
B. Cov ntaub ntawv nyuaj carbon thiab mos cov ntaub ntawv kuj tau tsim ntau heev nyob rau hauv xyoo tas los no: cov ntaub ntawv nyuaj carbon muaj siab lithium intercalation muaj peev xwm, thiab muaj micropores nyob rau hauv cov khoom, yog li cov tshuaj tiv thaiv kinetics yog zoo; Thaum cov ntaub ntawv mos cov pa roj carbon zoo sib xws nrog cov electrolytes, MCMB Cov khoom siv kuj yog cov neeg sawv cev zoo heev, tab sis qhov ua tau zoo ntawm cov ntaub ntawv nyuaj thiab cov pa roj carbon monoxide feem ntau qis thiab tus nqi siab (thiab nws tsis muaj kev cia siab heev los ntawm qhov kev xav ntawm kev lag luam. raws li pheej yig li graphite), yog li kev noj tam sim no tsawg dua li ntawm graphite, thiab nws siv ntau dua hauv qee qhov tshwj xeeb ntawm lub roj teeb.
C. Yuav ua li cas txog lithium titanate? Txhawm rau muab nws yooj yim: qhov zoo ntawm cov roj ntsha litity yog cov kev nyab xeeb ntau, thiab qhov tsis txaus ntseeg, thiab tus nqi tsawg heev, thiab tus nqi tau xam los ntawm WH yog siab heev. Yog li ntawd, qhov kev xav ntawm lithium titanate roj teeb yog cov cuab yeej siv tau zoo nrog cov txiaj ntsig zoo hauv qee lub sijhawm, tab sis nws tsis haum rau ntau lub sijhawm nrog kev xav tau siab ntawm tus nqi thiab kev caij nkoj.
D. Silicon anode material is an important development direction. Panasonic's new 18650 battery has begun the commercial process of such materials. However, how to achieve a balance between the performance pursued by nanotechnology and the general micron-scale requirements of the battery industry for materials is still a challenging task.
diaphragm
Rau cov roj teeb fais fab, kev ua haujlwm siab tam sim no muab cov kev xav tau siab dua rau lawv txoj kev nyab xeeb thiab lub neej. Separator txheej tshuab yog inescapable. Ceramic-coated separators tau raug thawb tawm sai sai vim tias lawv muaj kev nyab xeeb siab thiab muaj peev xwm haus cov impurities hauv electrolyte, tshwj xeeb tshaj yog rau kev txhim kho kev nyab xeeb ntawm ternary roj teeb.
Lub hauv paus tseem ceeb tam sim no siv rau cov diaphragms ceramic yog los pleev xim rau saum npoo ntawm cov diaphragms ib txwm muaj nrog alumina hais. Ib txoj hauv kev tshiab yog los coated cov khoom electrolyte fibers ntawm lub diaphragm. Cov diaphragms zoo li no muaj kev tiv thaiv sab hauv thiab kev txhawb zog zoo dua rau lub diaphragm. Zoo heev, thiab nws muaj qhov qis dua los thaiv cov diaphragm pores thaum ua haujlwm.
Cov coated diaphragm muaj kev ruaj ntseg zoo. Txawm hais tias qhov kub thiab txias, nws tsis yooj yim rau shrink thiab deform ua rau luv luv Circuit Court. Jiangsu Qingtao Zog Lub Tuam Txhab, uas yog technically txhawb los ntawm pab pawg neeg tshawb fawb ntawm Academician Nan Cewen, Tsev Kawm Ntawv ntawm Cov Khoom, Tsinghua University, muaj qee cov khoom sawv cev hauv qhov no. Ua haujlwm.
Electrolyte
Cov electrolyte muaj kev cuam tshuam zoo rau kev ua haujlwm ntawm ceev ceev -them lithium- ion roj teeb. Txhawm rau kom muaj kev ruaj ntseg thiab kev nyab xeeb ntawm lub roj teeb nyob rau hauv kev them nyiaj ceev thiab siab tam sim no, cov electrolyte yuav tsum ua raws li cov yam ntxwv hauv qab no: A) nws tsis tuaj yeem decomposed, B) conductivity yuav tsum siab, thiab C) nws yog inert rau qhov zoo thiab tsis zoo. cov ntaub ntawv, thiab tsis tuaj yeem hnov mob lossis yaj.
Yog tias yuav tsum tau ua raws li cov cai no, tus yuam sij yog siv cov khoom siv ntxiv thiab ua haujlwm electrolytes. Piv txwv li, kev nyab xeeb ntawm ternary ceev rechargeable roj teeb yog heev cuam tshuam los ntawm nws, thiab ntau yam additives rau siab kub kuj, nplaim retardant thiab anti- overcharging yuav tsum tau ntxiv rau nws, txhawm rau txhim kho nws txoj kev nyab xeeb rau qee yam. . Qhov ntev - teeb meem sawv ntsug ntawm lithium titanate roj teeb, kub siab flatulence, kuj yuav tsum tau txhim kho los ntawm qhov kub thiab txias ua haujlwm electrolyte.
roj teeb qauv tsim
Ib qho kev ua kom zoo tshaj plaws yog stacked VS winding. Cov electrodes ntawm cov roj teeb stacked yog sib npaug rau ib qho kev sib raug zoo, thiab hom winding yog sib npaug rau kev sib txuas ua ke. Yog li ntawd, lub internal kuj ntawm lub qub yog ntau me me, thiab nws yog ntau haum rau lub hwj chim hom. sijhawm.
Tsis tas li ntawd, koj tuaj yeem ua haujlwm hnyav ntawm cov tabs los daws cov teeb meem sab hauv thiab cov cua sov. Tsis tas li ntawd, kev siv cov khoom siv hluav taws xob hluav taws xob siab, siv cov khoom siv hluav taws xob ntau dua, thiab cov txheej txheem nyias nyias kuj tseem tuaj yeem ua tau.
Hauv kev xaus, cov yam ntxwv uas cuam tshuam rau kev txav mus los hauv lub roj teeb thiab tus nqi ntawm qhov sib cuam tshuam electrode yuav cuam tshuam rau lub peev xwm them ceev ntawm lithium roj teeb.
Lub neej yav tom ntej ntawm kev them nyiaj ceev ceev
Txawm hais tias lub tshuab hluav taws xob ceev ceev ntawm lub tsheb hluav taws xob yog keeb kwm kev taw qhia lossis lub teeb nyem hauv lub lauj kaub, qhov tseeb, muaj kev xav sib txawv thiab tsis muaj qhov xaus. Raws li lwm txoj kev daws teeb meem rau ntau qhov kev ntxhov siab, nws raug txiav txim siab ntawm lub platform nrog roj teeb lub zog ceev thiab tag nrho cov nqi tsheb.
Energy density and fast charging performance, in the same battery, can be said to be incompatible in two directions, and cannot have both. The pursuit of battery energy density is currently the mainstream. When the energy density is high enough, a car has enough power to avoid the so-called "mileage anxiety", and the demand for battery rate charging performance will be reduced; at the same time, if the power is large, if the battery cost per kWh is not low enough, then whether it can be used Ding Kemao's purchase of electricity that is "not anxious" requires consumers to make a choice. Thinking about it this way, fast charging has the value of existence. Another angle is the cost of fast charging facilities, which is of course part of the cost of promoting electrification in the whole society.
Txawm hais tias kev them nyiaj ceev thev naus laus zis tuaj yeem txhawb nqa ntawm qhov loj, leej twg txhim kho sai ntawm lub zog ceev thiab kev them nyiaj ceev ceev, thiab qhov twg ntawm ob lub thev naus laus zis txo tus nqi, tuaj yeem ua lub luag haujlwm txiav txim siab rau yav tom ntej.
