Kedu ihe bụ electrolyte na batrị lithium?
electrolyte
Electrolyte dị na batrị lithium{0}ion bụ ihe na-ebu ion na batrị ahụ. Ọ na-abụkarị nnu lithium, ihe mgbaze organic na ihe mgbakwunye, dị ka egosiri na foto 7-4. Electrolyte na-arụ ọrụ dị oke mkpa n'ime ion n'etiti electrodes ziri ezi na nke na-adịghị mma nke batrị lithium-, na-ahụta uru ya dị ka voltaji dị elu na ike dị elu. A na-akwadokarị electrolytes n'okpuru ọnọdụ ndị akọwapụtara yana n'ọ̀tụ̀tụ̀ dị iche iche sitere na ihe mgbaze organic dị ọcha dị elu{8}, nnu lithium, na ihe mgbakwunye ndị dị mkpa. Mgbe ihe electrode na-ekpebi njupụta ike batrị, electrolyte na-ekpebi n'ụzọ doro anya ndụ okirikiri ya, arụmọrụ dị elu na nke dị ala, yana nchekwa. Ihe mejupụtara nke electrolyte na-anọgide na-agbanwe agbanwe; ihe ọhụrụ na-adabere na mmepe nke nnu lithium ọhụrụ na ihe mgbakwunye, yana nghọta miri emi nke usoro kemịkalụ interfacial na usoro dị na batrị lithium-ion.
Enwere ọtụtụ ụdị nnu lithium, dị ka egosiri na foto 7-5, mana ole na ole ka a na-eji na batrị lithium-ion dị na azụmaahịa. Ezigbo nnu lithium kwesịrị inwe ihe ndị a:
1) ogo mkpakọrịta dị ala, na-agbaze ngwa ngwa na ihe mgbaze organic, na-eme ka nrụpụta ion dị elu nke electrolyte.
2) Anions na antioxidant na ibelata nguzogide; ngwaahịa mbelata na-enyere aka guzobe ihe nkiri SEI siri ike, dị ala{1}.
3) Nkwụsi ike kemịkalụ dị mma, na-enweghị ime mmeghachi omume na-emerụ ahụ na ihe elektrọd, electrolytes, ma ọ bụ nkewa.
4) Usoro nkwadebe dị mfe, ọnụ ala dị ala, enweghị- na-egbu egbu na mmetọ{2} n'efu.
LiPF6 bụ nnu lithium a na-ejikarị eme ihe. Ọ bụ ezie na ihe onwunwe ya n'otu n'otu abụghị ihe kachasị pụta ìhè, ọ na-egosipụta arụmọrụ zuru oke na carbonate mix electrolytes. LiPF6 nwere uru isi ndị a:
1) Solubility dabara adaba yana ion conductivity dị elu n'ime ihe mgbaze na-abụghị{1}.
2) Ọ nwere ike na-etolite a anụ passivation film n'elu aluminum foil ugbu a na-anakọta.
3) Ọ synergistically na-etolite a kwụsiri ike SEI film na graphite electrode elu na carbonate solvents.
Agbanyeghị, LiPF6 nwere nkwụsi ike ọkụ na-adịghị mma yana ọ na-enwekarị mmeghachi omume ire ere. Ihe ndị na-emepụta nwere ike imebi ihe nkiri SEI na elu electrode, gbazee ihe ndị na-arụ ọrụ nke ọma na electrode na-eduga n'ike n'ike n'oge ịgba ígwè.
LiBF bụkwa ihe mgbakwunye nnu lithium a na-ejikarị. Tụnyere LiPF6, LiBF nwere oke okpomoku na-arụ ọrụ sara mbara, nkwụsi ike dị elu{2}okpomọkụ dị elu, yana arụmọrụ dị ala- dị elu. LiBF nwere ihe nrụpụta dị elu, windo electrochemical sara mbara yana nkwụsi ike dị mma. Uru kachasị ya bụ na ihe nkiri ya - imepụta ihe, ebe ọ nwere ike itinye aka na nhazi ihe nkiri SEI.
N'usoro, LiDFOB nwere ọkara-molecule nke LiBOB na LiBF, na-ejikọta uru dị na ihe nkiri dị mma{1}}ịmepụta njirimara LiBOB na ezigbo arụmọrụ dị ala{2} nke LiBF4. E jiri ya tụnyere LiBOB, LiDFOB nwere oke solubility dị na linear carbonate solvents na elu electrolyte conductivity. Okpomọkụ ya dị elu{5} na obere- arụmọrụ dị mma karịa LiPF4, yana ọ nwere ndakọrịta dị mma na batrị cathode, na-eme ihe nkiri passivation n'elu elu foil aluminom ma na-egbochi oxidation electrolyte.
Ndị otu CF₃SO₂ dị na nhazi LiTFSI nwere mmetụta eletrọn siri ike{0}mwepu, nke na-eme ka mwepu nke ụgwọ ọjọọ ahụ ka njọ ma na-ebelata njikọta ion, na-ebute nnukwu solubility nke nnu. Ọzọkwa, LiTFSI nwere eletriki eletrik dị elu, okpomọkụ dị elu nke ire ere, na ọ dịghị mfe hydrolyzed; Otú ọ dị, ọ ga-emebisị ndị na-anakọta aluminom dị ugbu a na voltaji karịa 3.7V.
Atọm fluorine dị na molekul LiFSI nwere ihe nrụpụta elektrọn siri ike{0}, nke na-ewepụ ụgwọ na-adịghị mma na N, na-ebute mkpakọrịta ion adịghị ike yana ikesa Li+ dị mfe, si otú a na-eduga n'ịdị elu.
LiPO2F2 na-egosipụta ezigbo arụmọrụ dị ala{2} ma na-emekwa ka arụmọrụ dị elu - okpomọkụ nke electrolyte dị elu. Dị ka mgbakwunye, ọ nwere ike ịmepụta ihe nkiri SEI bara ụba na LixPOyFz na LiF na elu electrode na-adịghị mma, nke na-enyere aka belata nkwụsị nke batrị ma melite arụmọrụ batrị. Agbanyeghị, LiPO2F2 na-atakwa ahụhụ site na obere solubility.
Isi akụrụngwa nkemmiri mmiri electrolytebụ ihe mgbaze organic, nke na-agbaze nnu lithium ma na-enye ihe na-ebu maka ion lithium. Ezigbo ihe mgbaze organic maka lithium{1}ion batrị electrolyte kwesịrị izute ọnọdụ ndị a:
1) Dielectric dị elu na ike mgbaze maka nnu lithium.
2) Ebe mgbaze dị ala na ebe a na-esi esi elu, na-ejigide ọnọdụ mmiri mmiri n'elu oke okpomọkụ.
3) Viscosity dị ala, na-eme njem lithium{1}}ion.
4) Ezigbo nkwụsi ike nke kemịkal, anaghị emebi usoro electrode dị mma na nke na-adịghị mma ma ọ bụ gbarie ihe ndị dị mma na nke na-adịghị mma.
5) Ebe ọkụ ọkụ dị elu, ezigbo nchekwa, ọnụ ala dị ala, anaghị - na-egbu egbu na adịghị emetọ ya -.
A na-ekewakarị ihe mgbaze mmiri ara ehi a na-ejikarị na lithium -ion batrị electrolytes ka ọ bụrụ carbonate solvents na organic ether solvents, dị ka egosiri na foto 7-6. Iji nweta nnukwu batrị lithium-ion batrị dị elu -, a na-ejikarị ihe mgbaze agwakọta nwere ihe mgbaze abụọ ma ọ bụ karịa, na-enye ha ohere imeju ibe ha wee rụpụta arụmọrụ zuru oke. E gosipụtara njirimara anụ ahụ nke ihe mgbaze carbonate nkịtị na tebụl 7-1.
Tebụl 7-1 Njirimara anụ ahụ nke ihe mgbaze Carbonate nkịtị
| Organic mgbaze | Ọdịda Dielectric Constant | Ebe mgbaze/ ogo | Ebe esi esi/ ogo | Ọnụ ego viscosity |
|---|---|---|---|---|
| Ethylene Carbonate (EC) | 89.6 | 37 | 243 | 1.86 |
| Propylene Carbonate (PC) | 64.4 | -55 | 240 | 2.53 |
| Dimethyl Carbonate (DMC) | 0.59 | 2 | 91 | 0.59 |
| Diethyl Carbonate (DEC) | 2.8 | -43 | 126 | 0.75 |
| Ethyl Methyl Carbonate (EMC) | 3.0 | -53 | 108 | 0.65 |
Organic ether mgbaze tumadi gụnyere yinye ethers dị ka 1,2-dimethoxypropane (DMP), dimethoxymethane (DMM), na ethylene glycol dimethyl ether (DME), na cyclic ethers dị ka tetrahydrofuran (THF) na 2-methyltetrahydro-THF2. Maka agbụ ether mgbaze, ogologo carbon carbon, ka ahụ kemịkal kwụsie ike, ma elu viscosity na ala nke lithium-ion Mbugharị ọnụego. Ethylene glycol dimethyl ether nwere ike ịmepụta chelate kwụsiri ike (LiPF6 · DME) na lithium hexafluorophosphate, na-egosipụta ike mgbaze siri ike maka nnu lithium ma na-ebute ihe nrụpụta electrolyte dị elu. Agbanyeghị, DME enweghị nkwụsi ike kemịkalụ na-adịghị mma na enweghị ike imepụta ihe nkiri ngafe kwụsiri ike n'elu ihe elektrọd adịghị mma.
Ihe mgbaze Carbonate gụnyere cyclic carbonates dị ka propylene carbonate (PC) na ethylene carbonate (EC), na yinye carbonates dị ka dimethyl carbonate (DMC), diethyl carbonate (DEC), na methyl ethyl carbonate (EMC). Cyclic carbonates nwere dielectric dị elu mgbe niile, na-eme ka nnu lithium na-agbaze karịa, mana ha nwekwara nnukwu viscosity, na-ebute ọnụ ọgụgụ mbugharị lithium dị ala{1}}. Chain carbonates nwere obere dielectric mgbe niile na ike lithium nnu solubility, ma obere viscosity na ezi flowability, na-eme ka lithium{3} ion Mbugharị.
Ụdị ire ọkụ - ihe mgbakwunye retardant maka lithium{1}}ion electrolytes ka egosiri na foto 7-7. Ihe mgbakwunye, nke ejiri obere obere, nwere mmetụta dị egwu yana usoro akụ na ụba yana bara uru maka ịkwalite arụmọrụ nke batrị lithium{5}}. Site n'ịgbakwụnye ntakịrị ihe mgbakwunye na batrị ion electrolyte -, enwere ike imeziwanye njirimara arụmọrụ batrị ụfọdụ, dị ka ike ntụgharị, ndakọrịta electrode/electrolyte, arụmọrụ okirikiri, arụmọrụ ọnụego, na arụmọrụ nchekwa, na-arụ ọrụ dị mkpa na batrị lithium{8}}. Ihe mgbakwunye batrị lithium-ion kacha mma kwesịrị ịnwe njirimara anọ ndị a:
1) Akwa solubility na organic solvents.
2) Obere ego nwere ike imeziwanye otu njirimara arụmọrụ ma ọ bụ karịa.
3) Enweghị mmeghachi omume n'akụkụ na-emerụ ahụ yana akụrụngwa batrị ndị ọzọ na-emetụta arụmọrụ batrị.
4) Ọnụ ego dị ala, anaghị egbu egbu ma ọ bụ obere nsi.
Dabere na ọrụ ha, enwere ike kewaa ihe mgbakwunye n'ime ihe mgbakwunye na-eduzi, ihe mgbakwunye nchekwa ngafe, ihe mgbakwunye ire ọkụ, ihe nkiri SEI{0}} ihe mgbakwunye, ihe nchekwa ihe cathode, LiPF6 stabilizers, na mgbakwunye ọrụ ndị ọzọ.
Ihe mgbakwunye na-arụ ọrụ na-eme ka arụmọrụ nke batrị lithium{0}ion dị elu site na ijikọ ya na ion electrolyte, na-akwalite mgbasa nnu lithium, yana ịba ụba electrolyte conductivity. N'ihi na ihe mgbakwunye conductive na-arụ ọrụ site na mmeghachi omume nhazi, a na-akpọkwa ha ihe mgbakwunye ligand, a na-ekewa ha na ligand anionic, cationic ligands, na ndị na-anọpụ iche na-adabere na ion mmekọrịta.
Ihe mgbakwunye nchekwa nfefe na-enye nchebe karịrị ụgwọ ma ọ bụ kwalite nnabata nfefe. A na-ekewa ha na-arụ ọrụ n'ime ihe mgbakwunye redox na ihe mgbakwunye monomer. Ugbu a, ihe mgbakwunye redox bụ usoro anisole, nke nwere ikike redox dị elu yana ezigbo solubility. Ihe mgbakwunye monomer na-enweta mmeghachi omume polymerization n'okpuru nnukwu voltaji, na-ahapụ gas, na polymer na-ekpuchi elu ihe cathode, na-akwụsị ịchaji. Ihe mgbakwunye monomer na-agụnyekarị ogige aromatic dị ka xylene na phenylcyclohexane.
Ihe mgbakwunye ire ere na-arụ ọrụ site n'ịwelite ebe mgbanye nke electrolyte ma ọ bụ kwụsịtụ mmeghachi omume radical free nke na-egbochi ire ọkụ. Egosiri ụdị ha na eserese 7{2}}8. Ịgbakwunye ihe ndị na-ere ọkụ bụ otu n'ime ụzọ dị mkpa isi belata ire ọkụ nke electrolyte, gbasaa oke okpomọkụ nke batrị lithium-ion na-arụ ọrụ, ma melite arụmọrụ ha. Usoro eji eme ihe mgbakwunye ire ere bụ ụzọ abụọ:
1) Site n'ịmepụta mkpuchi mkpuchi n'etiti oge gas na akụkụ nke condensed, ha na-egbochi combustion na ma akụkụ nke condensed na gas.
2) Ha na-ejide radicals n'efu n'oge usoro mmeghachi omume combustion, na-akwụsị mmeghachi omume n'efu nke na-egbochi mmeghachi omume combustion n'etiti usoro gas.
