A cikin ƙananan yanayin zafi, aikin baturin lithium-ion bai dace ba. Lokacin da batir lithium-ion da aka saba amfani da su suna aiki a -10 ° C, matsakaicin cajin su da ƙarfin fitarwa da ƙarfin wutar lantarki za a ragu sosai idan aka kwatanta da yanayin zafi na yau da kullun [6], lokacin da zazzabi ya faɗi zuwa -20 ° C, ƙarfin da ake samu zai ragu. ko da za a rage zuwa 1/3 a dakin da zazzabi 25 ° C, lokacin da fitarwa zafin jiki ne m, wasu lithium baturi ba zai iya ko da caja da fitarwa ayyukan, shigar da "matattu baturi".
1, Halayen batirin lithium-ion a ƙananan yanayin zafi
(1) Macroscopic
Halayen canje-canje na batirin lithium-ion a ƙananan zafin jiki sune kamar haka: tare da ci gaba da rage yawan zafin jiki, juriya na ohmic da juriya na polarization yana karuwa a cikin digiri daban-daban; Fitar wutar lantarki na baturin lithium-ion ya yi ƙasa da na yanayin zafi na al'ada. Lokacin caji da yin caji a ƙananan zafin jiki, ƙarfin ƙarfinsa na aiki yana tashi ko faɗuwa da sauri fiye da haka a yanayin zafi na al'ada, yana haifar da raguwa mai yawa a iyakar ƙarfin aiki da ƙarfinsa.
(2) A bayyane
Canje-canjen aikin batirin lithium-ion a ƙananan zafin jiki sun fi girma saboda tasirin abubuwa masu mahimmanci masu zuwa. Lokacin da yanayin zafin jiki ya kasance ƙasa da -20 ℃, ruwa electrolyte yana ƙarfafawa, dankon sa yana ƙaruwa sosai, kuma ion conductivity yana raguwa. Yaduwar lithium ion a cikin kayan lantarki masu inganci da mara kyau yana jinkirin; Lithium ion yana da wuya a rushewa, kuma watsa shi a cikin fim din SEI yana jinkirin, kuma cajin canja wurin caji yana ƙaruwa. Matsalar lithium dendrite ta shahara musamman a ƙananan zafin jiki.
2, Don warware ƙarancin zafin aikin batirin lithium-ion
Ƙirƙirar sabon tsarin ruwa na electrolytic don saduwa da ƙananan yanayin zafi; Inganta ingantaccen tsarin lantarki da mara kyau don haɓaka saurin watsawa da rage nisan watsawa; Sarrafa tabbatacce da korau m electrolyte dubawa don rage impedance.
(1) Abubuwan da ake buƙata na electrolyte
Gabaɗaya, yin amfani da ƙari na aiki yana ɗaya daga cikin hanyoyin da suka fi dacewa da tattalin arziki don haɓaka ƙarancin yanayin zafi na baturi kuma yana taimakawa ƙirƙirar fim ɗin SEI mai kyau. A halin yanzu, manyan nau'ikan addittu sune abubuwan haɓaka tushen isocyanate, abubuwan sulfur na tushen sulfur, abubuwan ƙara ruwa na ionic da ƙari na gishirin lithium na inorganic.
Alal misali, dimethyl sulfite (DMS) sulfur tushen Additives, tare da dace rage aiki, kuma saboda ta rage kayayyakin da lithium ion dauri ne mai rauni fiye da vinyl sulfate (DTD), rage amfani da kwayoyin Additives zai kara da dubawa impedance, don gina mafi barga da kuma mafi kyau ionic watsin na korau lantarki dubawa fim. Sulfite esters da aka wakilta ta dimethyl sulfite (DMS) suna da babban dielectric akai-akai da kewayon zafin aiki mai faɗi.
(2) Da sauran ƙarfi na electrolyte
Batirin lithium-ion na al'ada electrolyte shine narkar da 1 mol na lithium hexafluorophosphate (LiPF6) a cikin wani gauraye mai ƙarfi, kamar EC, PC, VC, DMC, methyl ethyl carbonate (EMC) ko diethyl carbonate (DEC), inda abun da ke ciki na da sauran ƙarfi, narkewa batu, dielectric akai-akai, danko da kuma dacewa da lithium gishiri zai tsanani rinjayar aiki zafin jiki na baturi. A halin yanzu, kasuwancin lantarki yana da sauƙi don ƙarfafa lokacin da aka yi amfani da shi zuwa yanayin ƙananan zafin jiki na -20 ℃ da ƙasa, ƙananan dielectric akai-akai yana sa gishirin lithium yana da wuya a rabu, kuma danko yana da girma don yin juriya na ciki da ƙananan baturi. ƙarfin lantarki dandamali. Batirin lithium-ion na iya samun mafi kyawun ƙarancin zafin jiki ta hanyar haɓaka rabon ƙarfi na yanzu, kamar ta haɓaka ƙirar lantarki (EC: PC: EMC = 1: 2: 7) ta yadda TiO2 (B) / graphene korau electrode yana da A. iya aiki na ~ 240 mA h g-1 a -20 ℃ da 0.1 A g-1 halin yanzu yawa. Ko haɓaka sabbin kaushi mai ƙarancin zafin jiki. Rashin aikin batir lithium-ion a ƙananan zafin jiki yana da alaƙa da jinkirin lalatawar Li+ yayin aiwatar da saka Li+ a cikin kayan lantarki. Abubuwan da ke da ƙarancin ɗauri mai ƙarfi tsakanin Li+ da ƙwayoyin ƙarfi, kamar 1, 3-dioxopentylene (DIOX), ana iya zaɓar su, kuma ana amfani da nanoscale lithium titanate azaman kayan lantarki don haɗa gwajin baturi don ramawa ga raguwar haɓakar yaduwa na kayan lantarki a yanayin zafi mara nauyi, don cimma kyakkyawan aiki mai ƙarancin zafi.
(3) gishirin lithium
A halin yanzu, LiPF6 ion na kasuwanci yana da babban ƙarfin aiki, babban buƙatun danshi a cikin muhalli, rashin kwanciyar hankali na thermal, da munanan iskar gas kamar HF a cikin maganin ruwa suna da sauƙin haifar da haɗarin aminci. Fim ɗin mai ƙarfi mai ƙarfi wanda lithium difluoroxalate borate (LiODFB) ya samar ya tsaya tsayin daka kuma yana da mafi ƙarancin yanayin zafin jiki da ƙimar ƙimar girma. Wannan saboda LiODFB yana da fa'idodin duka lithium dioxalate borate (LiBOB) da LiBF4.
3. Takaitawa
Ƙarƙashin yanayin zafi na baturan lithium-ion zai shafi abubuwa da yawa kamar kayan lantarki da electrolytes. Cikakkun ci gaba daga ra'ayoyi da yawa kamar kayan lantarki da lantarki na iya haɓaka aikace-aikace da haɓaka batirin lithium-ion, kuma yanayin aikace-aikacen batirin lithium yana da kyau, amma fasahar tana buƙatar haɓakawa da haɓakawa cikin ƙarin bincike.
Lokacin aikawa: Yuli-27-2023