Iinjineli ziye zenza isahluli esizinzisa i-electrolyte yegesi ukwenza iibhetri eziphantsi kobushushu obuphantsi kakhulu zikhuseleke ngakumbi.

Ngokweengxelo zeendaba zangaphandle, iinjineli ze-nano kwiYunivesithi yaseCalifornia eSan Diego ziye zaphuhlisa isahluli sebhetri esinokuthi sisebenze njengesithintelo phakathi kwe-cathode kunye ne-anode ukuthintela i-electrolyte yegesi ekwibhetri ukuba ingaphumi. I-diaphragm entsha ikhusela uxinzelelo lwangaphakathi lwesivunguvungu ukuba luqokelele, ngaloo ndlela lukhusela ibhetri ekudumbeni nasekuqhumeni.

Inkokeli yophando, uZheng Chen, uprofesa we-nanoengineering kwi-Jacobs School of Engineering kwiYunivesithi yaseCalifornia, eSan Diego, wathi: "Ngokubamba i-molecule yegesi, i-membrane inokusebenza njenge-stabilizer ye-electrolytes eguqukayo."

Isahluli esitsha sinokuphucula ukusebenza kwebhetri kumaqondo obushushu asezantsi kakhulu. Iseli yebhetri esebenzisa i-diaphragm inokusebenza kwi-minus 40 ° C, kwaye umthamo unokuba phezulu kwiiyure ze-500 milliampere ngegram, ngelixa ibhetri ye-diaphragm yorhwebo inamandla aphantse abe ngu-zero kule meko. Abaphandi bathi nokuba ishiywe ingasetyenziswanga iinyanga ezimbini, umthamo webhetri usephezulu. Lo msebenzi ubonisa ukuba i-diaphragm inokwandisa ubomi bokugcina. Oku kufunyaniswayo kuvumela abaphandi ukuba bafezekise injongo yabo ngakumbi: ukuvelisa iibhetri ezinokubonelela ngombane kwizithuthi ezikwiindawo ezinomkhenkce, ezifana neziphekepheke, iisathelayithi, neenqanawa ezinzulu elwandle.

Olu phando lusekelwe kuphononongo olwenziwe kwilabhoratri ka-Ying Shirley Meng, unjingalwazi we-nanoengineering kwiYunivesithi yaseCalifornia, eSan Diego. Olu phando lusebenzisa i-electrolyte yerhasi enyibilikisiweyo ukuphuhlisa ibhetri enokugcina ukusebenza kakuhle kwindawo kuthatyathwe i-60°C okokuqala. Phakathi kwazo, i-electrolyte yegesi enyibilikisiweyo yigesi enyibilikayo ngokufaka uxinzelelo kwaye ixhathisa kakhulu kumaqondo obushushu aphantsi kunee-electrolyte zolwelo zemveli.

Kodwa olu hlobo lwe-electrolyte lunesiphako; kulula ukutshintsha ukusuka kulwelo ukuya kwirhasi. U-Chen uthe: "Le ngxaki ngowona mba mkhulu wokhuseleko kule electrolyte." Uxinzelelo kufuneka lwandiswe ukuze udibanise iimolekyuli zolwelo kwaye ugcine i-electrolyte kwindawo yolwelo ukusebenzisa i-electrolyte.

Ilabhoratri kaChen isebenzisana noMeng kunye noTod Pascal, unjingalwazi we-nanoengineering kwiYunivesithi yaseCalifornia, eSan Diego, ukusombulula le ngxaki. Ngokudibanisa ubuchule beengcali ze-computing ezifana ne-Pascal kunye nabaphandi abafana no-Chen kunye ne-Meng, indlela iye yaphuhliswa ukuze idibanise i-electrolyte ephuhliweyo ngaphandle kokufaka uxinzelelo oluninzi ngokukhawuleza. Abasebenzi abakhankanywe ngasentla badibene neZiko loPhando lwezeNzululwazi kunye nezoBunjineli (MRSEC) kwiYunivesithi yaseCalifornia, eSan Diego.

Le ndlela iboleka kwinto ebonakalayo apho iimolekyuli zegesi zijiya ngokuzenzekelayo xa zivaleleke kwiindawo ezincinci ze-nano-scale. Le nto ibizwa ngokuba yi-capillary condensation, enokwenza ukuba igesi ibe lulwelo kuxinzelelo oluphantsi. Iqela lophando lisebenzise le nto ukwenza isahlukanisi sebhetri esinokuzinzisa i-electrolyte kwiibhetri ze-ultra-low, i-electrolyte yegesi engamanzi eyenziwe ngegesi ye-fluoromethane. Abaphandi basebenzise i-crystalline ye-porous material ebizwa ngokuba yi-metal-organic framework (MOF) ukwenza i-membrane. Into ekhethekileyo malunga ne-MOF kukuba igcwele iipores ezincinci, ezinokubamba iimolekyuli zegesi ye-fluoromethane kwaye izidibanise kuxinzelelo oluphantsi. Umzekelo, i-fluoromethane ngokuqhelekileyo iyancipha kwi-30 ° C kwaye inamandla angama-118 psi; kodwa ukuba i-MOF isetyenzisiwe, uxinzelelo lwe-condensation lwe-porous kwiqondo lokushisa elifanayo yi-11 psi kuphela.

U-Chen uthe: "Le MOF inciphisa kakhulu uxinzelelo olufunekayo ukuze i-electrolyte isebenze. Ngoko ke, ibhetri yethu inokubonelela ngomthamo omkhulu wezinga lokushisa eliphantsi ngaphandle kokuthotywa." Abaphandi bavavanya i-MOF-based separator kwibhetri ye-lithium-ion. . Ibhetri ye-lithium-ion iqukethe i-cathode ye-fluorocarbon kunye ne-lithium metal anode. Ingayizalisa ngegesi ye-fluoromethane electrolyte kuxinzelelo lwangaphakathi lwe-70 psi, esezantsi kakhulu kunoxinzelelo olufunekayo ekunyibilikeni kwe-fluoromethane. Ibhetri isenokugcina i-57% yomthamo weqondo lobushushu begumbi kwiminus 40°C. Ngokwahlukileyo, kwiqondo lokushisa elifanayo kunye noxinzelelo, amandla ebhetri ye-diaphragm yorhwebo usebenzisa i-electrolyte yegesi equlethe i-fluoromethane iphantse i-zero.

I-micropores esekwe kwisahluli se-MOF ngundoqo kuba ezi micropores zinokugcina i-electrolyte eninzi ihamba kwibhetri naphantsi koxinzelelo oluncitshisiweyo. I-diaphragm yorhwebo inee-pores ezinkulu kwaye ayikwazi ukugcina i-molecule ye-electrolyte yegesi phantsi koxinzelelo oluncitshisiweyo. Kodwa i-microporosity ayikho kuphela isizathu sokuba i-diaphragm isebenze kakuhle phantsi kwezi meko. I-diaphragm eyenzelwe abaphandi iphinda ivumele i-pores ukuba yenze indlela eqhubekayo ukusuka kwelinye icala ukuya kwelinye, ngaloo ndlela iqinisekisa ukuba i-lithium ion inokuhamba ngokukhululekileyo kwi-diaphragm. Kuvavanyo, i-ionic conductivity yebhetri usebenzisa i-diaphragm entsha kwi-minus 40 ° C iphindwe kashumi kwibhetri esebenzisa i-diaphragm yorhwebo.

Iqela likaChen okwangoku livavanya i-MOF-based separators kwezinye i-electrolytes. U-Chen uthe: "Siye sabona imiphumo efanayo. Ngokusebenzisa le MOF njenge-stabilizer, iamolekyu ezahlukeneyo ze-electrolyte zinokubhengezwa ukuphucula ukhuseleko lwebhetri, kubandakanywa iibhetri ze-lithium zendabuko ezine-electrolyte eziguquguqukayo."