Amabhethri e-lithium ion aphinde ashajwe asetshenziswa ukunika amandla izinto eziningi zikagesi ekuphileni kwethu kwansuku zonke, kusukela kuma-laptops kanye namaselula kuya ezimotweni zikagesi. Amabhethri e-lithium ion asemakethe namuhla avame ukuthembela esixazululweni esiwuketshezi, esibizwa ngokuthi i-electrolyte, enkabeni yeseli.

Uma ibhethri lisebenzisa idivayisi, ama-ion e-lithium ahamba esuka ekugcineni okushajwe kabi, noma i-anode, nge-electrolyte ewuketshezi, aye ekugcineni okushajwe kahle, noma i-cathode. Uma ibhethri lishajwa kabusha, ama-ion ageleza ngakolunye uhlangothi esuka ku-cathode, nge-electrolyte, aye ku-anode.

Amabhethri e-lithium ion athembele kuma-electrolyte aketshezi anenkinga enkulu yokuphepha: angasha uma eshajwa kakhulu noma eqhutshwa nge-short circuit. Enye indlela ephephile kune-electrolyte eketshezi ukwakha ibhethri elisebenzisa i-electrolyte eqinile ukuthwala ama-ion e-lithium phakathi kwe-anode ne-cathode.

Kodwa-ke, izifundo zangaphambilini zithole ukuthi i-electrolyte eqinile iholele ekukhuleni okuncane kwensimbi, okubizwa ngokuthi ama-dendrite, okwakuzonqwabelana ku-anode ngenkathi ibhethri lishaja. Lawa ma-dendrite afinyeza ukujikeleza amabhethri kuma-current aphansi, okwenza angasetshenziswa.

Ukukhula kwe-dendrite kuqala emaphutheni amancane ku-electrolyte emngceleni ophakathi kwe-electrolyte ne-anode. Ososayensi eNdiya basanda kuthola indlela yokunciphisa ukukhula kwe-dendrite. Ngokufaka ungqimba oluncane lwensimbi phakathi kwe-electrolyte ne-anode, bangavimba ama-dendrite ukuthi angakhuli abe yi-anode.

Ososayensi bakhethe ukutadisha i-aluminium ne-tungsten njengezinsimbi ezingaba khona ukuze bakhe lolu ngqimba oluncane lwensimbi. Lokhu kungenxa yokuthi i-aluminium noma ingxube ye-tungsten, noma i-alloy, ne-lithium ayihlanganisi i-lithium. Ososayensi babekholelwa ukuthi lokhu kuzonciphisa amathuba okuba kube namaphutha ku-lithium. Uma insimbi ekhethiwe ixubene ne-lithium, amanani amancane e-lithium angangena ongqimbeni lwensimbi ngokuhamba kwesikhathi. Lokhu kuzoshiya uhlobo lwephutha olubizwa ngokuthi i-void ku-lithium lapho i-dendrite ingakheka khona.

Ukuze kuhlolwe ukusebenza kahle kwesendlalelo sensimbi, kwahlanganiswa izinhlobo ezintathu zamabhethri: eyodwa enesendlalelo esincane se-aluminium phakathi kwe-lithium anode kanye ne-electrolyte eqinile, enye enesendlalelo esincane se-tungsten, kanye nenye engenasendlalelo sensimbi.

Ngaphambi kokuhlola amabhethri, ososayensi basebenzise i-microscope enamandla aphezulu, ebizwa ngokuthi i-scanning electron microscope, ukuze babheke eduze umngcele ophakathi kwe-anode ne-electrolyte. Babone izikhala ezincane nezimbobo kusampula engenalo ungqimba lwensimbi, bephawula ukuthi la maphutha kungenzeka abe yizindawo lapho ama-dendrite angakhula khona. Womabili amabhethri anezingqimba ze-aluminium kanye ne-tungsten abukeka ebushelelezi futhi eqhubeka.

Ekuhlolweni kokuqala, ugesi ongaguquki waqhutshwa ngebhethri ngalinye amahora angama-24. Ibhethri elingenayo i-metallic layer short circuit lahluleka phakathi kwamahora ayi-9 okuqala, cishe ngenxa yokukhula kwe-dendrite. Alikho ibhethri eline-aluminium noma i-tungsten elahluleka kulokhu kuhlolwa kokuqala.

Ukuze kutholakale ukuthi yiluphi ungqimba lwensimbi olungcono ekumiseni ukukhula kwe-dendrite, kwenziwa olunye uvivinyo kumasampula e-aluminium kanye ne-tungsten kuphela. Kulolu vivinyo, amabhethri ajikeleziswa ngobuningi bamandla kagesi obukhulayo, aqala ngogesi osetshenziswe ekuhlolweni kwangaphambilini futhi anda ngenani elincane esinyathelweni ngasinye.

Ubuningi bamanje lapho ibhethri lihamba khona kwakucatshangwa ukuthi buyi-current density ebalulekile yokukhula kwe-dendrite. Ibhethri elinesendlalelo se-aluminium lehlulekile ngokuphindwe kathathu kunogesi oqalayo, kanti ibhethri elinesendlalelo se-tungsten lehlulekile ngokuphindwe kahlanu kunogesi oqalayo. Lokhu kuhlola kukhombisa ukuthi i-tungsten iphumelele kakhulu kune-aluminium.

Futhi, ososayensi basebenzise i-scanning electron microscope ukuhlola umngcele phakathi kwe-anode ne-electrolyte. Babona ukuthi izikhala zaqala ukwakheka kungqimba lwensimbi ezingxenyeni ezimbili kwezintathu zobuningi bamanje obubalulekile obulinganiswe ekuhlolweni kwangaphambilini. Kodwa-ke, izikhala zazingekho engxenyeni yesithathu yobuningi bamanje obubalulekile. Lokhu kuqinisekisile ukuthi ukwakheka kwezikhala kuyaqhubeka nokukhula kwe-dendrite.

Ososayensi base beqhuba izibalo zokubala ukuze baqonde ukuthi i-lithium ixhumana kanjani nalezi zinsimbi, besebenzisa lokho esikwaziyo ngendlela i-tungsten ne-aluminium ezisabela ngayo ekushintsheni kwamandla kanye nokushisa. Babonise ukuthi izingqimba ze-aluminium zinamathuba aphezulu okukhula kwezikhala lapho zisebenzisana ne-lithium. Ukusebenzisa lezi zibalo kuzokwenza kube lula ukukhetha olunye uhlobo lwensimbi ukuze luvivinywe esikhathini esizayo.

Lolu cwaningo lukhombisile ukuthi amabhethri e-electrolyte aqinile athembeke kakhulu uma kufakwa ungqimba oluncane lwensimbi phakathi kwe-electrolyte ne-anode. Ososayensi baphinde babonisa ukuthi ukukhetha insimbi eyodwa kunenye, kulokhu i-tungsten esikhundleni se-aluminium, kungenza amabhethri ahlale isikhathi eside nakakhulu. Ukuthuthukisa ukusebenza kwalezi zinhlobo zamabhethri kuzowasondeza esinyathelweni esisodwa sokushintsha amabhethri e-electrolyte ashisayo kakhulu emakethe namuhla.