Kev siv cov roj teeb lithium-ion yog txwv nyob rau hauv ib puag ncig uas tsis muaj qhov kub thiab txias, vim tias lawv lub peev xwm tso tawm yuav poob qis heev thiab lawv tsis tuaj yeem them rau qhov kub tsawg. Thaum lub sijhawm them nyiaj qis, qhov tso ntawm lithium ions rau ntawm graphite electrode ntawm lub roj teeb thiab cov lithium plating cov tshuaj tiv thaiv coexist thiab sib tw. Nyob rau hauv qhov kub thiab txias, qhov diffusion ntawm lithium ions nyob rau hauv graphite yog inhibited, thiab cov conductivity ntawm electrolyte txo, ua rau ib tug txo nyob rau hauv insertion tus nqi. Nyob rau saum npoo ntawm graphite, cov tshuaj tiv thaiv lithium plating feem ntau yuav tshwm sim.
Kev tshawb fawb tau pom tias lub roj teeb uas muaj peev xwm ntawm 3500mAh, yog tias ua haujlwm nyob rau hauv ib puag ncig ntawm -10 degree, tom qab tsawg dua 100 them thiab tawm mus, yuav muaj kev poob qis hauv cov roj teeb uas muaj peev xwm mus txog 500mAh, thiab yog qhov pib tawg. Qhov ntawd yog hais tias, nyob rau hauv ib qho chaw ua haujlwm ntawm -10 degree , yog tias lub tsheb fais fab raug them thiab tso tawm ib hnub ib zaug, lub roj teeb yuav tsum tau muab pov tseg thiab hloov nrog ib qho tshiab tom qab peb lub hlis.
Cov laj thawj uas cuam tshuam rau qhov ntsuas kub qis ntawm lithium hlau phosphate roj teeb:
1. Cov qauv zoo electrode
Cov qauv peb-dimensional ntawm cov khoom zoo electrode txwv qhov diffusion tus nqi ntawm lithium hlau phosphate roj teeb, tshwj xeeb tshaj yog nyob rau hauv qis kub. Cov khoom siv electrode sib txawv muaj cov qauv peb sab sib txawv. Tam sim no, cov ntaub ntawv zoo electrode tseem ceeb siv hauv lithium-ion roj teeb rau lub tsheb fais fab yog lithium hlau phosphate, nickel cobalt manganese ternary cov ntaub ntawv, thiab lithium manganese oxide. Lub peev xwm tso tawm ntawm lithium hlau phosphate roj teeb tuaj yeem ncav cuag 67.38% ntawm chav tsev kub ntawm -20 degree, thaum lub roj teeb nickel cobalt manganese ternary tuaj yeem ncav cuag 70.1%.
2. High melting point hnyav
Vim muaj cov kuab tshuaj siab melting point hauv cov kuab tshuaj sib xyaw ntawm electrolyte, viscosity ntawm lithium-ion roj teeb electrolyte nce ntawm qhov kub thiab txias. Thaum qhov ntsuas kub qis dhau lawm, electrolyte solidification tshwm sim, ua rau txo qis hauv kev sib kis ntawm lithium ions hauv electrolyte.
3. Lithium ion diffusion tus nqi
Tus nqi diffusion ntawm lithium ions hauv graphite tsis zoo electrodes txo qis hauv qhov kub thiab txias. Kev nce nqi ntawm kev hloov pauv impedance ntawm lithium-ion roj teeb nyob rau hauv qhov kub thiab txias ib puag ncig ua rau txo qis ntawm lithium ions hauv graphite tsis zoo electrode, uas yog ib qho tseem ceeb cuam tshuam rau qhov kub thiab txias ntawm lithium hlau phosphate roj teeb.
4. SEI daim nyias nyias
Nyob rau hauv ib puag ncig uas tsis kub, SEI zaj duab xis ntawm qhov tsis zoo electrode ntawm lithium hlau phosphate roj teeb thickens, thiab impedance ntawm SEI zaj duab xis nce, ua rau kom txo qis tus nqi ntawm lithium ions hauv SEI zaj duab xis. Thaum kawg, lub polarization tsim thaum lub sij hawm them nyiaj thiab tawm hauv qhov chaw qis qis txo qhov ua tau zoo ntawm kev them nqi thiab tawm.
5. Ntau lawm ib puag ncig
Raws li cov khoom siv thev naus laus zis nrog ntau cov khoom siv tshuaj lom neeg thiab cov txheej txheem nyuaj, lithium hlau phosphate roj teeb muaj qhov yuav tsum tau ua rau kub, av noo, plua plav, thiab lwm yam hauv lawv qhov chaw tsim khoom. Yog tias tsis tswj kom raug, roj teeb zoo yuav hloov pauv.
Cov ntsiab lus: Tam sim no, ntau yam cuam tshuam rau kev ua haujlwm kub ntawm cov roj ntsha lithium hlau phosphate, xws li cov qauv ntawm cov electrode zoo, kev tsiv teb tsaws ntawm lithium ions nyob rau hauv ntau qhov chaw ntawm lub roj teeb, lub thickness thiab tshuaj muaj pes tsawg leeg ntawm SEI zaj duab xis, thiab xaiv cov lithium ntsev thiab cov kuab tshuaj hauv cov electrolyte. Qhov kev ua tau zoo ntawm qhov kub thiab txias txwv tsis pub siv cov roj teeb lithium-ion hauv cov tsheb hluav taws xob, thaj chaw tshwj xeeb, thiab cov cheeb tsam huab cua. Tsim cov roj teeb lithium-ion nrog kev ua tau zoo ntawm qhov kub thiab txias yog qhov xav tau ceev hauv khw.
