Tus yuam sij rau kev tshem tawm dendrite buildup nyob rau hauv lithium -ion roj teeb anodes - exploiting tus kheej - cua kub nyhuv nyob rau hauv lub roj teeb
Rechargeable lithium-ion roj teeb yog lub roj teeb tseem ceeb siv hauv cov khoom siv hluav taws xob, thiab tau dhau los ua lub roj teeb ntawm kev xaiv rau tsheb fais fab thiab daim phiaj siv hluav taws xob cia. Qhov zoo electrode (cathode) yog lithium hlau oxide, thiab qhov tsis zoo electrode (anode) yog graphite. Tab sis cov kws tshawb fawb tsis tau tso tseg rau cov roj teeb lithium hlau uas muaj lub zog ntau dua, thiab tseem tab tom sim nrhiav txoj hauv kev rau cov roj teeb lithium hlau muaj zog dua.
Researchers at the Rensselaer Polytechnic Institute have now found a way to use the thermal energy inside the battery to diffuse dendrites into a smooth layer, or as study leader Nikhil Koratkar, a professor in the Department of Materials Science and Engineering, says, dendrites can "Repair in place" through the self-heating effect of the battery, the paper was published in the journal "Science".
Lub roj teeb yog tsim los ntawm cathode, anode, electrolyte, thiab ib qho cais. Lub separator nyob nruab nrab ntawm ob lub electrodes los tiv thaiv lub roj teeb ntawm luv luv -circuiting vim kev sib cuag. Tsis tas li ntawd, lub pores ntawm lub separator uas muaj cov electrolyte yog ions (them atoms) shuttle ntawm cov electrodes. channel, qhov ntau electrolyte absorbed los ntawm lub separator, lub siab dua ionic conductivity.
Thaum lub roj teeb raug tso tawm, qhov txiaj ntsig zoo ntawm lithium ions ntawm lub anode raug xa mus rau cathode los tsim hluav taws xob; Thaum lub roj teeb raug them, cov lithium ions ntws los ntawm cathode rov qab mus rau lub anode, thiab lub roj teeb nrog lithium hlau raws li cov anode yog nquag rau lithium hlau raws li lub anode thaum lub sij hawm rov qab them nqi thiab tawm. Unevenly deposited los tsim dendrites, cov kev ua kom yuam kev no tuaj yeem nkag mus rau qhov sib cais thiab ncav cuag lub cathode, ua rau lub cell luv thiab ua rau muaj kev phom sij tawg.
Siv graphite raws li cov anode, uas zam qhov teeb meem lithium dendrite, yog qhov kev xaiv roj teeb zoo tshaj plaws tam sim no, tab sis tsis ntev, lawv yuav tsis tuaj yeem khaws cia nrog kev xav tau.
To make lithium metal batteries thrive, the researchers' proposed solution is to use the battery's internal resistive heating to eliminate dendrite buildup. Resistive heating (also known as Joule heating) is a process in which a metallic material resists an electric current and thus generates heat. This "self-heating" effect can occur through the process of charging and discharging.
Therefore, the researchers enhanced the self-heating effect by increasing the current density (charge-discharge rate) of the battery, and found that this process can allow the dendrites to diffuse evenly and smoothly to achieve a "healing" effect. The same results were also obtained in the lithium-sulfur battery experiment. Therefore, when the battery is not in use, the "self-healing" effect of the battery can be achieved by charging and discharging at a high rate for several cycles.
Cov kev tshawb fawb zoo li cog lus. Kev them nyiaj supercharged tuaj yeem rov ua kom lub roj teeb rov zoo, tiv thaiv luv luv los ntawm dendrites, thiab xyuas kom meej tias lub roj teeb muaj kev nyab xeeb dua thiab muaj zog ceev, tab sis qhov no puas tiv thaiv lub roj teeb kom tawg sai? Tej zaum kev tshawb fawb ntxiv yog xav tau los ntawm pab pawg.
