Mabhatiri eLithium-ion ari kunyanya kukura akananga kune simba rakawanda. Pakupisa kwemumba, zvinhu zve silicon-based negative electrode zvinosanganiswa ne lithium kuti zvigadzire lithium-rich product Li3.75Si phase, ine simba rakati re 3572 mAh/g, iro rakakwirira kupfuura simba re theoretical specific electrode re graphite negative 372 mAh/g. Zvisinei, panguva yekuchaja nekuburitsa zvinhu zve silicon-based negative electrode, shanduko yeSi neLi3.75Si inogona kuwedzera huwandu hwemagetsi (anenge 300%), izvo zvinotungamira mukugadzirwa kwe electrode neupfu uye kuumbwa kweSEI film nguva dzose, uye pakupedzisira kukonzera kuti simba ridzike nekukurumidza. Indasitiri iyi inonyanya kuvandudza mashandiro e silicon-based negative electrode zvinhu uye kugadzikana kwemabhatiri e silicon kuburikidza ne nano-size, carbon coating, pore formation nedzimwe tekinoroji.
Zvinhu zvekabhoni zvine conductivity yakanaka, mutengo wakaderera, uye manyuko akawanda. Zvinogona kuvandudza conductivity uye kugadzikana kwepamusoro kwezvinhu zvakagadzirwa nesilicon. Zvinonyanya kushandiswa sezvinhu zvinovandudza mashandiro ema electrodes asina kunaka akavakirwa pasilicon. Zvinhu zveSilicon-carbon ndizvo zvinonyanya kushandiswa pakukura kwema electrodes asina kunaka akavakirwa pasilicon. Carbon coating inogona kuvandudza kugadzikana kwepamusoro kwezvinhu zvakagadzirwa nesilicon, asi kugona kwayo kudzivirira kuwedzera kwehuwandu hwesilicon kwakajairika uye hakugone kugadzirisa dambudziko rekuwedzera kwehuwandu hwesilicon. Nokudaro, kuti zvinhu zvakagadzirwa nesilicon zvivandudzwe kugadzikana, zvivakwa zvine maburi zvinofanirwa kuvakwa. Ball milling inzira yeindasitiri yekugadzira nanomaterials. Zvimwe zvinowedzerwa zvakasiyana kana zvikamu zvezvinhu zvinogona kuwedzerwa kune slurry inowanikwa ne ball milling zvichienderana nezvinodiwa zvemagadzirirwo e composite material. Slurry inopararira zvakaenzana kuburikidza nemaslurry akasiyana-siyana uye inoomeswa nespray. Munguva yekuomesa nekukurumidza, nanoparticles nezvimwe zvikamu zviri muslurry zvinoumba hunhu hwemaburi ane maburi. Pepa iri rinoshandisa tekinoroji yeindasitiri uye ine hushamwari kune nharaunda ye ball milling uye spray drying kugadzira zvinhu zvakagadzirwa nesilicon zvine maburi.
Kushanda kwezvinhu zvakagadzirwa nesilicon kunogonawo kuvandudzwa nekutonga morphology uye kugoverwa kwezvinhu zvakagadzirwa nesilicon nanomaterials. Parizvino, zvinhu zvakagadzirwa nesilicon zvine maitiro akasiyana-siyana uye maitiro ekugovera zvakagadzirwa, zvakaita sesilicon nanorods, porous graphite embedded nanosilicon, nanosilicon yakagoverwa mucarbon spheres, silicon/graphene array porous structures, nezvimwewo. Pachiyero chimwe chete, zvichienzaniswa ne nanoparticles, nanosheets dzinogona kudzvinyirira zviri nani dambudziko rekupwanya rinokonzerwa nekuwedzera kwevhoriyamu, uye zvinhu zvine huwandu hwakawanda hwekumanikidzana. Kuunganidzwa kwakashata kwema nanosheets kunogonawo kuumba chimiro chine maburi. Kuti ubatanidze boka rekuchinjana kwe silicon negative electrode. Ipa nzvimbo ye buffer yekuwedzera kwevhoriyamu yezvinhu zvesilicon. Kuunzwa kwema carbon nanotubes (CNTs) hakungogone chete kuvandudza conductivity yezvinhu, asiwo kukurudzira kuumbwa kwezviumbwa zvine maburi zvechinhu nekuda kwehunhu hwayo hwe one-dimensional morphological. Hapana mishumo pamusoro pezvivakwa zvine maburi zvakagadzirwa nesilicon nanosheets neCNTs. Pepa iri rinoshandisa nzira dzekugadzira bhora, kukuya nekupararira, kuomesa nekusasa, kugadzira carbon pre-coating uye calcination, uye rinounza zvinhu zvinosimudzira tumaburi mugadziriro yekugadzira zvinhu zvine tumaburi zvine silicon-based negative electrode zvinoumbwa nekuzviunganidza kwesilicon nanosheets neCNTs. Maitiro ekugadzirira ari nyore, ane hushamwari nezvakatipoteredza, uye hapana marara kana marara anogadzirwa. Kune mishumo yakawanda yemabhuku pamusoro pe carbon coating yezvinhu zvine silicon, asi hapana hurukuro dzakadzama pamusoro pemhedzisiro ye coating. Pepa iri rinoshandisa asphalt senzvimbo ye carbon kuti riongorore mhedzisiro yenzira mbiri dze carbon coating, liquid phase coating uye solid phase coating, pamhedzisiro ye coating uye mashandiro e silicon-based negative electrode zvinhu.
1 Kuedza
1.1 Kugadzirira zvinhu
Kugadzirwa kwezvinhu zvine silicon-carbon composite zvinosanganisa matanho mashanu: kugaya bhora, kukuya nekupararira, kuomesa ne spray, carbon pre-coating uye carbonization. Kutanga, yera 500 g ye silicon powder yekutanga (yepamba, 99.99% purity), wedzera 2000 g ye isopropanol, uye gadzira wet ball milling nekumhanya kwe 2000 r/min kwemaawa makumi maviri nemana kuti uwane nano-scale silicon slurry. Silicon slurry inowanikwa inotamisirwa mutangi rekutamisa dispersion, uye zvinhu zvinowedzerwa zvichienderana nehuwandu hwe silicon: graphite (inogadzirwa muShanghai, bhatiri grade): carbon nanotubes (inogadzirwa muTianjin, bhatiri grade): polyvinyl pyrrolidone (inogadzirwa muTianjin, analytical grade) = 40:60:1.5:2. Isopropanol inoshandiswa kugadzirisa zviri mukati makasimba, uye zviri mukati makasimba zvakagadzirirwa kuva 15%. Kukuya nekupararira kunoitwa nekumhanya kwekupararira kwe3500 r/min kwemaawa mana. Rimwe boka remaslurry pasina kuwedzera CNTs rinoenzaniswa, uye zvimwe zvinhu zvakafanana. Slurry yakapararira inozoendeswa kutangi rekudyisa rinopfapfaidza, uye kuomesa kwespray kunoitirwa mumhepo yakachengetedzwa nenitrogen, tembiricha yekupinda nekubuda iri 180 ne90 °C, zvichiteerana. Zvadaro mhando mbiri dze carbon coating dzakaenzaniswa, solid phase coating uye liquid phase coating. Nzira ye solid phase coating ndeiyi: spray-dried powder inosanganiswa ne20% asphalt powder (yakagadzirwa muKorea, D50 iri 5 μm), yakasanganiswa mumuchina wekusanganisa kwemaminitsi gumi, uye mixing speed ndeye 2000 r/min kuti pave ne pre-coated powder. Liquid phase coating method ndeiyi: spray-dried powder inowedzerwa kune xylene solution (yakagadzirwa muTianjin, analytical grade) ine 20% asphalt yakanyungudutswa mupowder ine solid content ye55%, uye vacuum yakasanganiswa zvakaenzana. Bika muovheni ine vacuum pa 85℃ kwemaawa mana, woisa mumuchina wekusanganisa, kumhanya kwekusanganisa i2000 r/min, uye nguva yekusanganisa imaminitsi gumi kuti uwane upfu hwakaputirwa kare. Pakupedzisira, upfu hwakaputirwa kare hwakaiswa mu calcined muchoto chinotenderera pasi pemhepo ine nitrogen pakupisa kwe5°C/min. Pakutanga hwakachengetwa pakupisa kwakafanana kwe550°C kwemaawa maviri, wobva waramba uchipisa kusvika 800°C wochengetwa pakupisa kwakafanana kwemaawa maviri, wozotonhodzwa zviri pamutemo kusvika pasi pe100°C wozoburitswa kuti uwane silicon-carbon composite material.
1.2 Nzira dzekugadzirisa hunhu
Kugoverwa kwehukuru hwezvinhu izvi kwakaongororwa uchishandisa muchina wekuyedza hukuru hwezvinhu (Mastersizer 2000 version, yakagadzirwa muUK). Upfu hwakawanikwa padanho rega rega hwakaedzwa nekutarisa electron microscopy (Regulus8220, yakagadzirwa muJapan) kuti vaongorore chimiro nehukuru hweupfu. Chimiro chechikamu chezvinhu chakaongororwa uchishandisa X-ray powder diffraction analyzer (D8 ADVANCE, yakagadzirwa muGermany), uye kuumbwa kwezvinhu izvi kwakaongororwa uchishandisa energy spectrum analyzer. Zvinhu zvakagadzirwa nesilicon-carbon zvakawanikwa zvakashandiswa kugadzira bhatani rehafu yesero remuenzaniso weCR2032, uye chiyero chehukuru hwesilicon-carbon: SP: CNT: CMC: SBR chaive 92:2:2:1.5:2.5. Electrode yecounter isimbi ye lithium sheet, electrolyte i electrolyte yekutengeserana (modhi 1901, yakagadzirwa muKorea), Celgard 2320 diaphragm inoshandiswa, huwandu hwechaji nevoltage yekuburitsa i 0.005-1.5 V, chaji nevoltage yekuburitsa i 0.1 C (1C = 1A), uye discharge cut-off current i 0.05 C.
Kuti tiongorore mashandiro ezvinhu zvakagadzirwa nesilicon-carbon, bhatiri diki rakapfava rakaiswa laminated 408595 rakagadzirwa. Electrode iyi inoshandisa NCM811 (yakagadzirwa muHunan, bhatiri remhando yepamusoro), uye graphite yeelectrode isina kunaka yakasanganiswa ne 8% silicon-carbon material. Fomura ye electrode ine 96% NCM811, 1.2% polyvinylidene fluoride (PVDF), 2% conductive agent SP, 0.8% CNT, uye NMP inoshandiswa se dispersant; fomura ye electrode isina kunaka ndeye 96% composite negative electrode material, 1.3% CMC, 1.5% SBR 1.2% CNT, uye mvura inoshandiswa se dispersant. Mushure mekusanganisa, kufukidza, kutenderedza, kucheka, lamination, tab welding, kurongedza, kubika, liquid injection, formation uye capacity division, 408595 laminated small soft pack batterys dzine 3 Ah dzakagadzirwa. Kushanda kwemuchina we0.2C, 0.5C, 1C, 2C ne3C pamwe nekushanda kwemuchina we0.5C charge ne1C discharge kwakaedzwa. Voltage yekuchaja ne discharge yaive 2.8-4.2 V, constant current ne constant voltage charging, uye cut-off current yaive 0.5C.
2 Mhedzisiro neKukurukurirana
Upfu hwekutanga hwesilicon hwakaonekwa nekushandisa scanning electron microscopy (SEM). Upfu hwesilicon hwakanga husina kurongeka nehukuru hwechimedu husingasviki 2μm, sezvakaratidzwa muMufananidzo 1(a). Mushure mekugayiwa kwebhora, saizi yeupfu hwesilicon yakaderedzwa zvakanyanya kusvika pa100 nm [Mufananidzo 1(b)]. Bvunzo yehukuru hwechimedu yakaratidza kuti D50 yeupfu hwesilicon mushure mekugayiwa kwebhora yaive 110 nm uye D90 yaive 175 nm. Kuongorora kwakanyatsojeka kwechimiro cheupfu hwesilicon mushure mekugayiwa kwebhora kunoratidza chimiro chakapwanyika (kuumbwa kwechimiro chakapwanyika kuchasimbiswa zvakare kubva kuSEM yakachinjika gare gare). Nokudaro, data reD90 rakawanikwa kubva kubvunzo yehukuru hwechimedu rinofanira kunge riri kureba kwenanosheet. Pamwe chete nemhedzisiro yeSEM, zvinogona kutongwa kuti saizi yenanosheet yakawanikwa idiki pane kukosha kwakakosha kwe150 nm yekuputsika kweupfu hwesilicon panguva yekuchaja nekubudisa mune kanenge dhigiri rimwe chete. Kuumbwa kwechimiro che "flaky morphology" kunonyanya kukonzerwa nekusiyana kwesimba rekuparadzanisa kwe "crystal planes" ye "crystal silicon", iyo pakati payo "111} plane ye "silicon" ine simba rekuparadzanisa rakaderera pane "100} uye "110} crystal planes". Nokudaro, iyi "crystal plane" inotetepa zviri nyore nekugayiwa kwebhora, uye pakupedzisira inoumba "flaky structure". Chimiro che "flaky structure" chinobatsira pakuunganidzwa kwe "looks structures", chinochengetedza nzvimbo ye "expansion" ye "boost", uye chinovandudza kugadzikana kwezvinhu.
Slurry ine nano-silicon, CNT uye graphite yakapfapfaidzwa, uye upfu usati wapfapfaidzwa uye mushure mekupfapfaidzwa hwakaongororwa neSEM. Mhedzisiro yacho inoratidzwa muMufananidzo 2. Graphite matrix yakawedzerwa usati wapfapfaidzwa chimiro chakajairika cheflake chine saizi ye5 kusvika 20 μm [Mufananidzo 2(a)]. Kuyedzwa kwehukuru hweparticle distribution yegraphite kunoratidza kuti D50 i15μm. Upfu hwakawanikwa mushure mekupfapfaidzwa hune chimiro chespherical [Mufananidzo 2(b)], uye zvinogona kuonekwa kuti graphite yakaputirwa ne coating layer mushure mekupfapfaidzwa. D50 yeupfu mushure mekupfapfaidzwa i26.2 μm. Hunhu hwe morphological hwezvikamu zvechipiri hwakaonekwa neSEM, zvichiratidza hunhu hwechimiro chakasununguka chine porous chakaunganidzwa ne nanomaterials [Mufananidzo 2(c)]. Chimiro chine porous chinoumbwa nesilicon nanosheets neCNTs zvakabatana [Mufananidzo 2(d)], uye nzvimbo chaiyo yebvunzo (BET) yakakwira kusvika 53.3 m2/g. Saka, mushure mekupfapfaidza, ma silicon nanosheets neCNTs zvinozviunganidza zvega kuti zvigadzire chimiro chine maburi.
Chikamu chine maburi chakagadziriswa ne liquid carbon coating, uye mushure mekuwedzera carbon coating precursor pitch uye carbonization, SEM yakaonekwa. Mhedzisiro yacho inoratidzwa muMufananidzo 3. Mushure me carbon pre-coating, pamusoro pezvikamu zvechipiri zvinova zvakatsetseka, ne coating layer yakajeka, uye coating yacho yapera, sezvakaratidzwa muMifananidzo 3(a) na (b). Mushure me carbonization, chikamu che coating chepamusoro chinoramba chiri mumamiriro akanaka e coating [Mufananidzo 3(c)]. Pamusoro pezvo, mufananidzo weSEM unoratidza strip-shaped nanoparticles [Mufananidzo 3(d)], iyo inoenderana nehunhu hwe nanosheets, zvichisimbisa kuumbwa kwe silicon nanosheets mushure mekugayiwa kwebhora. Pamusoro pezvo, Mufananidzo 3(d) unoratidza kuti kune fillers pakati pemamwe nanosheets. Izvi zvinonyanya kukonzerwa nekushandiswa kwe liquid phase coating method. Asphalt solution inopinda muzvinhu, kuitira kuti pamusoro pe internal silicon nanosheets iwane carbon coating protective layer. Saka, nekushandisa liquid phase coating, pamusoro pekuwana secondary particle coating effect, double carbon coating effect ye primary particle coating inogonawo kuwanikwa. Carbonized powder yakaedzwa neBET, uye mhedzisiro yekuedzwa yaive 22.3 m2/g.
Upfu hwakakangwa hwakaongororwa kuburikidza ne cross-sectional energy spectrum analysis (EDS), uye mhedzisiro yacho inoratidzwa muMufananidzo 4(a). Core ine saizi ye micron chikamu che C, chinoenderana ne graphite matrix, uye coating yekunze ine silicon ne oxygen. Kuti tiongorore zvakanyanya chimiro che silicon, bvunzo ye X-ray diffraction (XRD) yakaitwa, uye mhedzisiro yacho inoratidzwa muMufananidzo 4(b). Chinhu ichi chakanyanya kuumbwa ne graphite ne single-crystal silicon, isina hunhu hwe silicon oxide, zvichiratidza kuti chikamu che oxygen che energy spectrum test chinobva mukuoxidation yechisikigo ye silicon surface. Chinhu chakagadzirwa ne silicon-carbon chakanyorwa se S1.
Zvinhu zvakagadzirwa nesilicon-carbon S1 zvakaongororwa kugadzira hafu yemasero uye kuyedzwa kwekuburitsa charge. Curve yekutanga yekuburitsa charge inoratidzwa muMufananidzo 5. Kugona kwayo kunodzora i1000.8 mAh/g, uye kushanda kwechikamu chekutanga kwakakwira kusvika 93.9%, iyo iri pamusoro pekushanda kwekutanga kwezvinhu zvakawanda zvakagadzirwa nesilicon pasina pre-lithiation yakataurwa mumabhuku. Kushanda kwekutanga kwakakwira kunoratidza kuti zvinhu zvakagadzirwa nesilicon-carbon zvine kugadzikana kwakanyanya. Kuti zvionekwe kuti mhedzisiro yechimiro chine porous, conductive network uye carbon coating iri pakugara kwezvinhu zvesilicon-carbon, mhando mbiri dzezvinhu zvesilicon-carbon zvakagadzirwa pasina kuwedzera CNT uye pasina primary carbon coating.
Maumbirwo eupfu hwakakangwa hwezvinhu zvakagadzirwa nesilicon-carbon pasina kuwedzera CNT anoratidzwa muMufananidzo 6. Mushure mekuputirwa kwechikamu chemvura uye carbonization, layer yekuputira inogona kuonekwa zvakajeka pamusoro pezvikamu zvechipiri muMufananidzo 6(a). SEM yechikamu chechinhu chakakangwa inoratidzwa muMufananidzo 6(b). Kuunganidzwa kwema silicon nanosheets kune hunhu hwemaburi, uye bvunzo yeBET ndeye 16.6 m2/g. Zvisinei, zvichienzaniswa nechiitiko cheCNT [sezvakaratidzwa muMufananidzo 3(d), bvunzo yeBET yeupfu hwayo hwakakangwa ndeye 22.3 m2/g], huwandu hwemukati hwe nano-silicon stacking hwakakwira, zvichiratidza kuti kuwedzerwa kweCNT kunogona kukurudzira kuumbwa kwechimiro chine maburi. Pamusoro pezvo, chinhu chacho hachina network ye conductive yemativi matatu yakagadzirwa neCNT. Chinhu chakakangwa chesilicon-carbon chakanyorwa seS2.
Hunhu hwechimiro che silicon-carbon composite material yakagadzirwa ne solid-phase carbon coating hunoratidzwa muMufananidzo 7. Mushure me carbonization, pane ganda repamusoro rinoonekwa, sezvakaratidzwa muMufananidzo 7(a). Mufananidzo 7(b) unoratidza kuti kune nanoparticles dzakaita se strip muchikamu chemuchinjikwa, zvinoenderana nehunhu hwechimiro che nanosheets. Kuunganidzwa kwe nanosheets kunoumba chimiro chine maburi. Hapana chinonyatsojeka pamusoro pe nanosheets dzemukati, zvichiratidza kuti solid-phase carbon coating inongogadzira ganda repamusoro rine maburi, uye hapana ganda repamusoro re silicon nanosheets. Iyi silicon-carbon composite material yakanyorwa seS3.
Bvunzo ye "half-cell charge" uye "discharge" yemhando yemabhatani yakaitwa paS2 neS3. Kugona kwacho uye kushanda kwekutanga kweS2 kwaive 1120.2 mAh/g uye 84.8%, zvichiteerana, uye kugona kwacho uye kushanda kwekutanga kweS3 kwaive 882.5 mAh/g uye 82.9%, zvichiteerana. Kugona kwacho uye kushanda kwekutanga kwe "solid-phase coated S3 sample" kwaive kwakaderera, zvichiratidza kuti "carbon coating" yechimiro chine maburi chete ndiyo yakaitwa, uye "carbon coating" yemukati me silicon nanosheets haina kuitwa, izvo zvaisagona kupa simba rakazara kune simba racho rechinhu chakavakirwa pasilicon uye zvaisagona kudzivirira pamusoro pechinhu chakavakirwa pasilicon. Kushanda kwekutanga kweS2 sample isina CNT kwaive kwakadererawo pane kwe "silicon-carbon composite material" ine CNT, zvichiratidza kuti zvichibva pa "coating layer" yakanaka, "conductive network" uye "porous structure" yepamusoro inobatsira pakuvandudza kushanda kwe "charge" uye kuburitsa simba rechinhu chakagadzirwa nesilicon-carbon.
Chinhu cheS1 silicon-carbon chakashandiswa kugadzira bhatiri diki rakapfava kuti riongorore mashandiro emuchina uye mashandiro emuchina. Mutsetse wemuchina wekuburitsa unoratidzwa muMufananidzo 8(a). Kugona kwemuchina wekuburitsa 0.2C, 0.5C, 1C, 2C ne3C nde2.970, 2.999, 2.920, 2.176 ne1.021 Ah, zvichiteerana. Mutsetse wemuchina wekuburitsa 1C wakakwira kusvika 98.3%, asi mutsetse wemuchina wekuburitsa 2C unodzikira kusvika 73.3%, uye mutsetse wemuchina wekuburitsa 3C unodzikira zvakanyanya kusvika 34.4%. Kuti ubatanidzwe muboka rekuchinjana electrode resilicon negative, ndapota wedzera WeChat: shimobang. Panyaya yemutsetse wemuchina wekuchaja, mutsetse wemuchina wekuchaja we0.2C, 0.5C, 1C, 2C ne3C ndewe3.186, 3.182, 3.081, 2.686 ne2.289 Ah, zvichiteerana. Mwero wekuchaja we1C uri 96.7%, uye mwero wekuchaja we2C uchiri kusvika 84.3%. Zvisinei, tichitarisa curve yekuchaja iri muMufananidzo 8(b), puratifomu yekuchaja ye2C yakakura zvakanyanya kupfuura puratifomu yekuchaja ye1C, uye kugona kwayo kuchaja kwevoltage isingachinji kunotora chikamu chikuru (55%), zvichiratidza kuti polarization yebhatiri rinochajwa re2C yatove yakakura kwazvo. Chinhu chesilicon-carbon chine mashandiro akanaka ekuchaja uye kuburitsa pa1C, asi hunhu hwechigadzirwa chacho hunofanira kuvandudzwa zvakanyanya kuti chiwane mashandiro epamusoro. Sezvakaratidzwa muMufananidzo 9, mushure me450 cycles, mwero wekuchengetedza kugona ndeye 78%, zvichiratidza mashandiro akanaka ekutenderera.
Mamiriro epamusoro pe electrode isati yatanga uye yapera yakaongororwa neSEM, uye mhedzisiro yacho inoratidzwa muMufananidzo 10. Kutenderera kusati kwatanga, pamusoro pe graphite nezvinhu zve silicon-carbon zvakajeka [Mufananidzo 10(a)]; mushure mekutenderera, jira rekufukidza rinogadzirwa pachena pamusoro [Mufananidzo 10(b)], inova firimu gobvu reSEI. Kuoma kwefirimu reSEI Kushandiswa kwe lithium inoshanda kwakanyanya, izvo zvisingakodzeri mashandiro ekutenderera. Naizvozvo, kukurudzira kuumbwa kwefirimu reSEI rakatsetseka (senge kugadzirwa kwefirimu reSEI rekugadzira, kuwedzera zvinowedzera zve electrolyte zvakakodzera, nezvimwewo) kunogona kuvandudza mashandiro ekutenderera. Kuonekwa kweSEM kwezvikamu zve silicon-carbon mushure mekutenderera [Mufananidzo 10(c)] kunoratidza kuti silicon nanoparticles yekutanga yakaita sestrip yave coarser uye chimiro cheporous chabviswa zvakanyanya. Izvi zvinonyanya kukonzerwa nekuwedzera kwevhoriyamu uye kudzikira kwezvinhu zve silicon-carbon panguva yekutenderera. Nokudaro, chimiro cheporous chinofanira kuwedzerwa kuti chipe nzvimbo yakakwana ye buffer yekuwedzera kwevhoriyamu yezvinhu zvakagadzirwa ne silicon.
3 Mhedziso
Zvichibva pakuwedzera kwehuwandu, kufambisa simba zvisina kunaka uye kugadzikana kwakashata kwenzvimbo yezvinhu zve silicon-based negative electrode, bepa iri rinoita kuvandudzwa kwakanangwa, kubva pakuumbwa kwema silicon nanosheets, kuvaka porous structure, kuvaka conductive network uye complete carbon coating yezvikamu zvese zvechipiri, kuvandudza kugadzikana kwezvinhu zve silicon-based negative electrode zvese. Kuunganidzwa kwema silicon nanosheets kunogona kuumba porous structure. Kuunzwa kweCNT kuchasimudzira kuumbwa kweporous structure. Silicon-carbon composite material yakagadzirwa ne liquid phase coating ine double carbon coating effect pane yakagadzirwa ne solid phase coating, uye inoratidza kugona kwakanyanya uye kushanda kwekutanga. Pamusoro pezvo, kushanda kwekutanga kwe silicon-carbon composite material ine CNT kwakakwira kupfuura kusina CNT, izvo zvinonyanya kukonzerwa nekukwanisa kwakakwirira kwe porous structure kuderedza kuwedzera kwe volume yezvinhu zve silicon-based. Kuunzwa kweCNT kuchavaka three-dimensional conductive network, kunatsiridza conductivity yezvinhu zve silicon-based, uye kuratidza kushanda kwakanaka pa 1C; uye zvinhu zvinoratidza kushanda kwakanaka kwe cycle. Zvisinei, chimiro chine maburi echinhu ichi chinofanira kusimbiswa zvakanyanya kuti chipe nzvimbo yakakwana yekuwedzera huwandu hwesilicon, uye kukurudzira kuumbwa kwechinhu chakatsetseka.uye firimu reSEI rakakora kuti riwedzere kuvandudza mashandiro echinhu chakagadzirwa nesilicon-carbon.
Isu tinopawo zvigadzirwa zve graphite ne silicon carbide zvine hutsanana hwakanyanya, izvo zvinoshandiswa zvakanyanya mukugadzirisa wafer senge oxidation, diffusion, uye annealing.
Gamuchirai vatengi vanobva kumativi ese epasi kuti vatishanyire kuti tikurukure zvakawanda!
https://www.vet-china.com/
Nguva yekutumira: Mbudzi-13-2024