Lithium battery hta electrolyte gaw hpa rai ta?
wan n-gun, wan lum shara
Lithium-ion hta lawm ai electrolyte gaw battery kata na ion ni hpe htaw ai re. Dai hpe madung hku nna lithium sau, organic solvents, hte additives ni hte hpawng de da ai, sumla 7-4 hta madun da ai. Ndai electrolyte gaw lithium-ion battery a kaja ai hte n kaja ai electrode ni a lapran ion ni hpe galaw ai hta ahkyak ai lit nga ai, dai gaw shi a akyu ni rai nga ai voltage kaba ai hte n-gun kaba ai zawn re ai akyu ni hpe hkam la lu ai. Electrolytes ni hpe masat da ai masa lam ni a npu e, n-gun ja ai{8}}} n-gun rawng ai organic solvents, lithium sau, hte ra kadawn ai additives ni kaw na, laksan shadawn shadang ni hta lajang da ai. Electrode arung arai ni gaw battery a n-gun n-gun hpe dawdan ya ai raitim, electrolyte gaw shi a cycle prat, nbung katsi ai hte n-gun n law ai, shim lum ai lam ni hpe madung hku nna dawdan ya ai. Electrolyte a madung npawt nhpang gaw grai n galai shai ai sha naw rai nga ai; hpaji ningnan ni gaw madung hku nna, n-nan ai lithium sau hte additives ni hpe gyin shalat ai hta nga ai, dai zawn sha, lithium-ion battery ni hta lawm ai interfacial chemical process ni hte ladat ni hpe grau sung ai hku chye na ai lam ni hta mung lawm nga ai.
Lithium sau amyu myu nga ai, sumla 7-5 hta madun da ai zawn, raitim, hpaga lam hta lu mai ai lithium-ion battery ni hta grai n law ai. Kaja dik ai lithium sau hta lawu na atsam marai ni nga ra ai:
.
2) antioxidant hte shayawm ai hpe ninghkap lu ai ni; shayawm ai arung arai ni gaw, ngang grin ai, n-gun n law ai- hpe n-gun jaw ai SEI sumla hkrung langai hpe hpaw shabawn na matu loi ai.
3) Kaja ai chemical stability, electrode arung arai, electrolytes, shing nrai garan ginhka ai ni hte n kaja ai maga de n-gun n rawng ai sha.
4) Simple hkyen lajang ai lam, manu n law ai, n-gun n jaw ai, n-gun n jaw ai hte n san seng ai lam n nga ai-lawn.
LiPF6 gaw grau nna jai lang ai lithium sau re. Shi a langai hkrai a atsam marai ni gaw shi a laklai dik htum n re ai sha, carbonate kayau ai hka htung electrolytes ni hta grai kaja ai bungli galaw lu ai lam hpe madun dan nga ai. LiPF6 hta lawu na madung akyu ni nga ai:
.
2) aluminum foil ya na mahkawng da ai ni a ntsa e ngang grin ai passivation film langai mi hpe hpaw mai ai.
3).
Raitim, LiPF6 gaw n kaja ai thermal stability nga ai rai nna, decomposition reactions byin chye ai. Byproducts ni gaw electrode ntsa kaw na SEI film hpe hkra machyi shangun nna, kaja ai electrode active components ni hpe yeng seng kau ya lu ai, cycle jawn ai shaloi n-gun yawm wa shangun lu ai.
LiBF gaw law malawng lang ai lithium sau hpe mung lang ai. LiPF6 hte shingdaw yu yang, LiBF gaw grau dam lada ai bungli galaw ai nbung n-gun, grau kaja ai{2}} n-gun grau tsaw ai, hte grau kaja ai npu n-gun{3}} aten ladaw hpe galaw lu ai. li Shi a kaba dik ai akyu gaw SEI sumla hkrung a hkrang shapraw ai lam hta hkrak shang lawm lu ai majaw, shi a sumla hkrung- hkrang bung ai lam ni hta nga ai.
Hkrang hku yu yang, LiDFOB gaw LiBOB hte LiBF a daw mi-molecules ni hte hpawng de da ai rai nna, LiBOB a kaja ai sumla hkrung a kaja ai sumla hkrung a akyu ni hte LiBF4 a kaja ai n-gun yawm ai- aten ladaw hpe kayau kaya galaw ai. LiBOB hte shingdaw yu yang, LiDFOB gaw linear carbonate hka htung ni hta hka n-gun grau law ai hte electrolyte galaw ai lam grau law ai. Shi a tsaw dik htum- aten ladaw hte npu n-gun n-gun n-gun n-gun n-gun n-gun gaw LiPF4 hta grau kaja ai, battery cathode hte grai htap htuk ai, aluminum foil ntsa kaw passivation film langai mi hpe hpaw ya ai hte electrolyte oxidation hpe pat shingdang ya ai.
LiTFSI structure hta CF₃SO€ hpung ni gaw n-gun ja ai electron- hte rau shapraw ai akyu nga ai, dai gaw negative charge a delocalization hpe grau sawng shangun nna, ion association pairing hpe shayawm kau ya ai majaw, sau grai law hkra hka lim mat ai. Dai hta n-ga, LiTFSI gaw wan n-gun grai law ai, thermal decomposition nbung katsi ai lam grai law ai, loi loi hte hydrolyze n galaw ai; rai tim, 3.7V jan ai voltage ni hta aluminum current mahkawng da ai ni hpe grai hkra machyi shangun na re.
LiFSI molecule hta na fluorine atom ni hta n-gun ja ai electron- hpe lu da ai majaw, N hta n kaja ai charge hpe delocalize galaw ai majaw, ion ion association hte Li+ hpe loi loi hte garan ginhka kau lu ai majaw, n-gun kaba ai conductivity de du wa ai.
LiPO2F2 gaw kaja ai low- aten ladaw hpe madun dan nna, electrolyte a tsaw ai- aten ladaw hpe mung grau kaja hkra galaw ya ai. Additive hku nna, LixPOyFz hte LiF law ai SEI sumla hkrung hpe n kaja ai electrode ntsa kaw hpaw ya lu ai, dai gaw battery interfacial impedance hpe shayawm ya lu nna, battery cycle hpe grau kaja hkra galaw ya lu ai. Raitim, LiPO2F2 hta mung, hka n-gun n law ai.
Dai 1 a madung daw gaw .hting n tsawm ai wan jakgaw, lithium sau ni hpe htum kau nna, lithium ions ni a matu htaw sa ai lam hpe jaw ya ai organic solvent re. Lithium-ion battery electrolyte a matu kaja dik ai organic solvent hpe lawu na masa ni hpe hkan sa ra ai:
1) Lithium sau ni a matu grai tsaw ai dielectric n galai shai ai hte n-gun ja ai hku garan mat ai.
.
3) Hpyen n-gun n law ai, lithium-ion htaw sa ai lam hpe n-gun jaw ai.
4) Kaja ai chemical stability, kaja ai hte n kaja ai electrode hkrang hpe n jahten kau ai (sh) kaja ai hte n kaja ai electrode arung arai ni hpe n jahten kau ai.
5) Flash point law ai, shim lum ai, manu n law ai, non{1}}toxic hte non{2}} n san seng ai.
Lithium-ion a battery electrolytes ni hta lang ai shinggyim masha ni a shinggyim hkum hkrang n-gun dat ni hpe madung hku nna carbonate hka hte organic ether solvent ni hpe garan nna, sumla 7-6 hta madun da ai. N-gun ja ai{3}}}} a n-gun rawng ai lithium battery electrolyte hpe lu la na matu, n-gun rawng ai hka n-gun hpe n-gun rawng ai hka n-gun lahkawng (sh) dai hta jan ai hka n-gun rawng ai hka htung hpe lang nna, langai hte langai hpe madi shadaw ya lu nna, grau kaja ai bungli yawng hpe lu la na matu ahkang jaw ai. Carbonate hka htung ni a hkum hkrang atsam ni hpe Table 7-1 hta madun da ai.
Table 7-1 hte bung ai Carbonate Solvents ni a hkum hkrang arung arai ni
| Organic Laknak | Relative Dielectric Constant | Point/℃shaw la ai | Boiling Point/ degree | Viscosity Coefficient |
|---|---|---|---|---|
| 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 hparan ladat ni gaw madung hku nna 1,2{4}dimethoxypropane (DMP), dimethoxymethane (DMM), hte ethylene glycon dimethyl ether (DME) zawn re ai chain ether ni hpe lawm ai. Chain ether solvents ni a matu, carbon chain galu wa yang, chemical stability grau kaja wa na re, raitim, n-gun grau law wa nna, lithium-ion htawt sit ai lam yawm wa ai. Ethylene glycon dimethyl ether gaw, n-gun n rawng ai chelate (LiPF6·DME) hpe lithium hexafalophosphate hte hpaw ya lu ai, lithium sau ni a matu n-gun ja ai n-gun hpe madun dan ai hte, electrolyte n-gun grai law ai majaw, n-gun ja ai n-gun hpe shapraw ya lu ai. Raitim, DME gaw n kaja ai chemical stability nga ai rai nna, n kaja ai electrode n-gun a ntsa e ngang grin ai passivation film n mai byin ai.
Carbonate hka ja ai tsi ni hta, n-gun n rawng ai carbonate (PC) hte ethylene carbonate (EC) zawn re ai cyclic carbonate ni lawm nna, n-gun rawng ai carbonate (DMC), diethyl carbonate (DEC), hte methyl ethyl carbonate (EMC) zawn re ai carbonate ni lawm ai. Cyclic carbonate ni gaw dielectric constant grai law ai majaw, lithium sau ni hpe grau hka lim shangun ai, raitim, shanhte hta n-gun grai ja ai majaw, lithium-ion htawt sit ai lam yawm wa ai. Chain carbonates ni gaw n-gun n law ai hte n-gun kya ai lithium sau hka n-gun nga ai, raitim, n-gun n law ai hte hka lwi ai lam kaja ai, lithium-ion htawt sit ai lam hpe loi ai hku galaw ya ai.
Lithium-ion electrolytes ni a matu wan n-gun n rawng ai wan n-gun n-gun n-gun n-gun n-gun n-gun n-gun n-gun n-gun hpe madun da ai. Kaji kajaw sha jai lang ai additives ni gaw, ahkyak ai akyu ni nga ai rai nna, lithium-ion battery ni a bungli galaw ai lam hpe grau kaja hkra galaw na matu, sut masa hte tatut galaw mai ai ladat langai rai nga ai. Lithium-ion battery ni a electrolyte hta additives kaji mi hpe jat bang ai hku nna, battery galaw ai lam nkau mi hpe laksan hku nna gram lajang mai ai, ga shadawn, bai nhtang mai ai atsam, electrode/electrolyte hte htuk manu ai lam, cycle a bungli galaw ai lam, hte shim lum ai lam ni hpe galaw ai, lithium-ion battery ni hta ahkyak ai lit nga ai. Kaja dik ai lithium-ion battery electrolyte additive gaw lawu na atsam marai mali hpe madu ra ai:
1) Organic solvent ni hta hka n-gun ja ai.
2) Kaji ai gumhpraw gaw bungli galaw ai lam langai (sh) law law hpe grai kaja hkra galaw ya lu ai.
3) Battery bungli hpe hkra machyi shangun ai kaga battery ni hte n kaja ai maga de bai htang ai lam n nga ai.
.
Shanhte a bungli hpe madung tawn nna, additives ni hpe conductive additives, overcharge makawp maga ai additives ni, wan n-gun n-gun shayawm ai tsi ni, SEI sumla hkrung- hkrang shapraw ai additives ni, cathode arung arai ni hpe makawp maga ya ai, LiPF6 stabilizers, hte kaga bungli galaw ai lam ni hpe garan ginhka mai ai.
Addive additives ni gaw, electrolyte ions ni hte matut mahkai nna, lithium sau htum mat ai hpe n-gun jaw ai, electrolyte conductivity hpe jat ya ai hku nna, lithium-ion battery ni a rate hpe grau kaja hkra galaw ya ai. Hpa majaw nga yang, conductive additives ni gaw coordination reactions hku nna bungli galaw ai majaw, shanhte hpe ligand additives ngu nna mung shamying ma ai, dai ni hpe anionic ligand, cationic ligand, hte neutral ligands ni hku nna garan ginhka ai.
Overcharge makawp maga ai additives ni gaw, n-gun ja ai hpe makawp maga ya ai (sh) grai law hkra hkam sharang lu ai atsam hpe jat ya ai. Dai ni hpe redox additives hte monomer additives ni hku nna bungli galaw ai hku garan ginhka da ai. Ya aten hta, redox additives ni gaw madung hku nna anisole series ni rai nna, dai ni gaw redox atsam grai law ai hte kaja ai hka lim ai lam ni nga ai. Monome additives ni gaw, n-gun kaba ai voltage npu hta polymerization reactions ni hpe hkam la nna, gases ni hpe shapraw ai, polymer gaw cathode a arai ntsa hpe coat galaw nna, charge galaw ai hpe jahkring kau ai. Monomer additives ni gaw madung hku nna xylene hte phenylcyclohexan zawn re ai manam pyaw ai baw ni hpe bang da ai.
Flame retardant additives ni gaw, wan hkru ai lam hpe pat shingdang ai free radical chain reaction hpe jahkring kau ai hku nna (sh) wan hkru ai lam hpe jahkring kau ai hku nna bungli galaw nga ai. Shanhte a amyu ni hpe sumla 7-8 hta madun da ai. Wan n-gun shayawm ai tsi ni hpe jat bang ai gaw, electrolyte a wan n-gun hpe shayawm ya lu ai ahkyak ai ladat langai rai nna, lithium-ion battery ni a bungli galaw ai n-gun hpe jat ya lu ai, shanhte a bungli hpe grau kaja hkra galaw lu ai. Wan n-gun shayawm ai additives ni a action a ladat ni gaw madung hku nna lahkawng rai nga ai:
1) Gas phase hte condensed phase lapran na insulating layer hpe galaw ai hku nna, shanhte gaw condensed hte gas phases lahkawng yan hta wan hkru ai lam hpe pat shingdang ya ai.
2) Shanhte gaw wan hkru ai lam galaw ai aten hta free radicals ni hpe rim la nna, wan hkru ai lam hpe pat shingdang ai free radical chain reaction hpe jahkring kau ya ai.
