A cewar rahotannin kafofin watsa labaru na kasashen waje, gungun masu bincike a dakin gwaje-gwaje na Brookhaven National Laboratory (Brookhaven National Laboratory) na Ma’aikatar Makamashi ta Amurka (DOE) sun tantance sabbin bayanai game da tsarin mayar da martani na ciki na batirin lithium karfe anode. , Mataki mai mahimmanci don batir abin hawa na lantarki mai rahusa.

Masu binciken baturi a dakin gwaje-gwaje na kasa na Brookhaven (Tsarin Hoto: dakin gwaje-gwaje na kasa na Brookhaven)

Sabuntawar Lithium Anode

Daga wayoyin hannu zuwa motocin lantarki, muna iya ganin al’adar. Duk da cewa batirin lithium ya ba da damar yin amfani da fasahohi da yawa, har yanzu suna fuskantar ƙalubale wajen samar da wutar lantarki ta nesa mai nisa ga motocin lantarki.

Battery500, ƙawancen da masu binciken jami’a ke jagoranta wanda Ma’aikatar Makamashi ta Amurka ta Pacific Northwest National Laboratory (PNNL) da Ma’aikatar Makamashi ta Amurka ke jagoranta, da nufin ƙirƙirar tantanin baturi mai yawan kuzarin 500Wh/kg. A takaice dai, ya ninka ƙarfin ƙarfin ƙarfin batura na yau. Don wannan, ƙawancen yana mai da hankali kan batura waɗanda aka yi da anodes na ƙarfe na lithium.

Batura na ƙarfe na lithium suna amfani da ƙarfe na lithium azaman anode. Sabanin haka, yawancin baturan lithium suna amfani da graphite azaman anode. “Lithium anode yana daya daga cikin mahimman abubuwan da ke haifar da cimma burin ƙarfin makamashi na Battery500,” in ji masu binciken. “Fa’idar ita ce yawan makamashi ya ninka na batir ɗin da ke akwai. Na farko, takamaiman ƙarfin anode yana da girma sosai; na biyu, za ku iya samun batir mafi girma, kuma haɗuwa da su biyun na iya samun ƙarin ƙarfin kuzari.”

Masana kimiyya sun dade sun gane amfanin lithium anodes; a gaskiya, lithium karfe anode ne na farko anode guda biyu zuwa baturi cathode. Duk da haka, saboda rashin “reversibility” na anode, wato, ikon yin caji ta hanyar mayar da martani na electrochemical, masu binciken baturi sun ƙare amfani da graphite anodes maimakon lithium karfe anodes don yin batura lithium.

Yanzu, bayan shekaru da yawa na ci gaba, masu bincike suna da kwarin gwiwa don gane wani nau’in ƙarfe na lithium mai jujjuyawa don tura iyakokin batirin lithium. Makullin shine keɓancewa, ƙaƙƙarfan Layer na kayan abu wanda ke samuwa akan wayoyin baturi a yayin da ake amsawar electrochemical.

“Idan za mu iya fahimtar wannan haɗin gwiwa sosai, zai iya ba da jagoranci mai mahimmanci don ƙirar kayan aiki da kuma samar da lithium anodes mai canzawa,” in ji masu binciken. “Amma fahimtar wannan ƙalubalen ƙalubale ne saboda ƙaramin abu ne mai bakin ciki, kauri kaɗan na nanometer, kuma yana da kula da iska da zafi, don haka sarrafa samfuran yana da wahala.”

Ana ganin wannan haɗin gwiwar a cikin NSLS-II

Don magance waɗannan ƙalubalen da kuma “duba” tsarin sinadarai da tsarin haɗin gwiwar, masu bincike sun yi amfani da National Synchrotron Radiation Light Source II (NSLS-II), wani kayan aiki na DOE Science Office na Brookhaven National Laboratory, wanda ke samar da shi. Hotunan X-haskoki masu haske don yin nazarin abubuwan kaddarorin mahallin akan sikelin atomic.

Bugu da ƙari, yin amfani da ƙarfin ci gaba na nSLS-II, ƙungiyar kuma tana buƙatar amfani da layin katako (tashar gwaji) wanda zai iya gano duk abubuwan da ke cikin dubawa, da kuma amfani da hasken wuta mai ƙarfi (gajeren tsayi) don gano crystalline. da amorphous matakai.

“Kungiyar ilimin sunadarai ta karɓi tsarin tsarin XPD mai yawa, ta yin amfani da dabaru daban-daban guda biyu da aka bayar ta hanyar beamline, X-ray diffraction (XRD) da kuma aikin rarraba (PDF) bincike,” in ji masu binciken. “XRD na iya nazarin matakan crystalline, kuma PDF na iya nazarin matakan amorphous.”

Binciken XRD da PDF ya bayyana sakamako masu ban sha’awa: Lithium hydride (LiH) yana cikin keɓancewa. Shekaru da yawa, masana kimiyya sun yi jayayya game da wanzuwar LiH a cikin haɗin gwiwa, suna haifar da rashin tabbas game da ainihin tsarin amsawa wanda ke haifar da haɗin gwiwa.

“LiH da lithium fluoride (LiF) suna da sifofin crystal iri ɗaya. Da’awarmu game da gano LiH wasu mutane sun yi tambaya game da cewa muna kuskuren LiF don LiH, “in ji mai binciken.

Dangane da rikice-rikicen da ke tattare da binciken da kuma kalubalen fasaha na bambanta LiH daga LiF, ƙungiyar bincike ta yanke shawarar samar da hujjoji masu yawa don kasancewar LiH, ciki har da gudanar da gwaje-gwajen iska.

“Masu bincike sun ce: “LiF yana da kwanciyar hankali a cikin iska, amma LiH ba shi da kwanciyar hankali. Idan muka bijirar da mahaɗin zuwa iska mai laushi, kuma idan adadin fili ya ragu akan lokaci, zamu iya tabbatar da cewa muna ganin LiH, ba LiF ba, kuma LiF ne. Saboda wahalar bambance LiH daga LiF kuma gwajin fallasa iska ba a taɓa yin shi ba, LiH yana yiwuwa a yi kuskure da LiF a cikin rahotannin wallafe-wallafe da yawa, ko kuma ba a lura da shi ba saboda bazuwar LiH a cikin yanayi mai ɗanɗano. ”

Mai binciken ya ci gaba da cewa. “Ayyukan shirye-shiryen samfurin da PNNL ya yi yana da mahimmanci ga wannan binciken. Muna zargin cewa mutane da yawa sun kasa gano LiH saboda samfuran su an fallasa su zuwa yanayi mai ɗanɗano kafin gwajin. ” Idan baku tattara samfuran daidai ba, rufe samfuran da samfuran jigilar kaya, kuna iya rasa LiH. ”

Baya ga tabbatar da wanzuwar LiH, ƙungiyar ta kuma warware wani dogon sirrin da ke kewaye da LiF. An daɗe ana ɗaukar LiF a matsayin ɓangaren fa’ida na keɓancewa, amma babu wanda ya fahimci dalilin. Ƙungiyar ta ƙayyade bambance-bambancen tsarin LiF a cikin haɗin gwiwa da kuma yawancin bambance-bambancen tsarin LiF kanta, kuma sun gano cewa tsohon ya inganta jigilar lithium ions tsakanin anode da cathode.

Masana kimiyyar baturi daga dakin gwaje-gwaje na kasa na Brookhaven, sauran dakunan gwaje-gwaje na kasa, da jami’o’i na ci gaba da ba da hadin kai. Masu binciken sun ce wadannan sakamakon za su samar da jagora mai amfani da ake bukata don bunkasa sinadarin lithium karfen anodes.