Nea ɛkyerɛ sɛ lithium-ion batere electrolyte?

◆Dɛn ne nsu mu electrolytes?

◆Nnianim Asɛm a Ɛfa Electrolytes a Ɛyɛ Den Ho

Electrolyte, ade a ɛho nhia a ɛwɔlithium-ion batere ahorow, di dwuma titiriw wɔ battery no charge-discharge cycles mu.

Ɛnyɛ sɛ ɛyɛ nea ɛyɛ lithium ions a ɛkɔ yiye ne current a ɛkɔ nko, na mmom ɛwɔ ɛlɛtrɔnik insulation su ahorow a ɛbɛma ɛlɛtrɔnik a ɛsen tẽẽ wɔ electrode a ɛyɛ papa ne nea enye ntam no ano yiye. Sɛ yɛbɛka no sɛnkyerɛnne kwan so a, electrolyte no te sɛ "mogya" a ɛwɔ lithium-ion battery mu, na ɛhwɛ ma nkitahodi a ɛda electrode nneɛma a ɛyɛ papa ne nea enye no ntam, na ɛnam so ma ɛma charge-discharge nhyehyɛe no nyinaa kɔ so yiye.

Ɛsɛ sɛ electrolyte a eye ma lithium-ion battery di ahwehwɛde anum a edidi so yi ho dwuma:

Ɛnam sɛ batere ahoɔden dodoɔ ne ahoɔden dodoɔ a wɔhwehwɛ no kɔ soro bere nyinaa nti, batere mfiridwuma renya nkɔsoɔ ntɛmntɛm, na electrode nneɛma anya nkɔsoɔ kɛseɛ. Nea ɛne eyi bɔ abira no, electrolyte nhyehyɛe ahorow a wɔayɛ no aka akyi. Mprempren, wobetumi akyekyɛ lithium-ion battery electrolytes nkɔso mu wɔ ɔkwan a ɛtrɛw so ayɛ no ahorow abiɛsa: electrolytes a ɛnyɛ -nsu mu solvent, nsu electrolytes, ne solid-state electrolytes.

Ɛnyɛ-nsuo a wɔde yɛ aduru electrolyte

 

Electrolytes a ɛnyɛ -aqueous solvent electrolytes a ɛwɔ lithium-ion battery mu no kyerɛ electrolyte nhyehyɛe a nsu nni mu, a nea ɛyɛ solvents, solutes (mpɛn pii no lithium nkyene), ne nneɛma a wɔde ka ho titiriw na ɛyɛ. Saa nnuru a ɛnyɛ -nsuo yi taa yɛ organic solvents, sen sɛ ɛbɛyɛ nsuo mu solvents, sɛdeɛ ɛbɛyɛ a wɔbɛkwati nsuo a wɔde electrolysis anaasɛ electrode nneɛma a wɔde yɛ adwuma bɔne. Lithium nkyene ne nneɛma titiriw a ɛde lithium-ion kɔ, nnuru a wɔde siw ano yɛ adwuma sɛ nea ɛpete, ɛpete, na ɛboa lithium nkyene, na nneɛma a wɔde ka ho no yɛ adwuma titiriw de ma anyinam ahoɔden adwumayɛ anaa ahobammɔ a ɛwɔ lithium-ion batere mu no tu mpɔn.

Electrolytes a wɔtɔn (kyerɛ sɛ, nsu electrolytes) a wɔde di dwuma wɔ lithium-ion battery mu no yɛ lithium nkyene biako anaa nea ɛboro saa a wɔapete wɔ organic solvents abien anaa nea ɛboro saa mu titiriw; electrolytes a wɔde aduru biako a wɔde yɛ aduru ayɛ no ho yɛ na koraa. Nea enti a wɔde nnuru pii di dwuma ne sɛ wiase ankasa-wiase batere wɔ ahwehwɛde ahorow, a ɛbɔ abira mpo, a ɛyɛ den sɛ wobedi ho dwuma denam aduru biako a wɔde di dwuma so. Sɛ nhwɛso no, ebia electrolytes behia nsu a ɛkɔ soro bere a ɛwɔ dielectric constant a ɛkorɔn nso; enti wɔtaa de nnuru a wɔde siw ano a ɛsono nea ɛwɔ nipadua mu nneɛma mu di dwuma bom, na ɛda su ahorow adi bere koro mu. Bio nso, mpɛn pii no wɔmfa lithium nkyene nni dwuma bere koro mu efisɛ lithium nkyene a wɔpaw no sua, na ɛnyɛ mmerɛw sɛ wobehu mfaso a ɛwɔ so.

Ɛsɛ sɛ organic solvents a eye no nya nneɛma atitiriw a edidi so yi: Nea edi kan no, wohia dielectric constant a ɛkorɔn na ama wɔahwɛ ahu sɛ lithium nkyene no bɛpete yiye; nea ɛto so abien no, ɛsɛ sɛ wonya ɔhyew a ɛba fam ne nsu a ɛbobɔ kɛse na ama wɔatrɛw ɔhyew a ɛwɔ anyinam ahoɔden a wɔde yɛ adwuma no mu; nea ɛto so abiɛsa no, nsunsuanso a ɛba fam boa ma lithium ions a ɛwɔ aduru no mu no tu kɔ baabi foforo yiye; na awiei koraa no, ɛsɛ sɛ saa nnuru a wɔde siw ano yi bo nyɛ den na awuduru nni mu (sɛ ɛbɛyɛ yiye a, ɛnyɛ awuduru). Carbonate nnuru, sɛ ɛyɛ organic solvents a edi kan na wɔde di dwuma kɛse wɔ lithium-ion battery adwumayɛ mu no mu biako, di gyinabea titiriw wɔ battery electrolytes mu.

Mprempren, saa aduru yi titiriw ne nhyehyɛe abien: cyclic ne chain. Table a ɛwɔ aseɛ ha yi bɔ honam fam nsusuiɛ a ɛfa ho a ɛfa nnuru dodoɔ bi a ɛnyɛ -nsuo, electrolytes, ne organic solvents dodoɔ bi a wɔtaa de di dwuma ho no mua.

Mprempren, wɔde alkyl carbonate aduru di dwuma kɛse wɔ electrolytes mu. Saa solvents yi wɔ oxidation resistance pa na ɛda stability a ɛkyɛn so adi wɔ voltage tebea a ɛkorɔn mu. Wonim carbonate a ɛkyinkyini te sɛ ethylene carbonate ne propylene carbonate sɛ ɛwɔ dielectric constant a ɛkɔ soro, a ɛkyerɛ sɛ ebetumi apete lithium nkyene yiye; nanso esiane tumi a emu yɛ den a ɛwɔ molecule ahorow ntam nti, saa nnuru yi wɔ nsu a ɛyɛ den kɛse, na ɛma lithium ions a ɛwɔ mu no nkɔ brɛoo. Nea ɛne eyi bɔ abira no, nkɔnsɔnkɔnsɔn carbonate te sɛ dimethyl carbonate ne diethyl carbonate, bere a ɛwɔ ntini a ɛba fam no, nso wɔ dielectric constants a ɛba fam koraa, na ɛma lithium nkyene ntumi nsɛe no yiye koraa. Enti, sɛnea ɛbɛyɛ na wɔasiesie solution nhyehyɛe ahorow a ɛwɔ ionic conductivity a ɛkorɔn no, wɔtaa fra solvents ahorow ahorow, te sɛ PC+DEC anaa EC+DMC a wɔaka abom. Lithium nkyene, sɛ lithium ions fibea a ɛwɔ electrolyte no mu no, di dwuma titiriw wɔ lithium-ion ion akwantu mu bere a wɔrebɔ lithium-ion batere ahorow no charge na wɔayi afi mu. Wɔn adwumayɛ nya lithium-ion batere no afã horow pii so nkɛntɛnso tẽẽ, a ahoɔden dodow, tumi a ɛyɛ den, adwumayɛ ahoɔden a ɛkɔ akyiri, kyinhyia nkwa nna, ne ahobammɔ ka ho. Mprempren, wɔ aduruyɛdan mu nhwehwɛmu ne mfiridwuma mu nneyɛe mu no, wɔtaa paw lithium nkyene a ɛwɔ anionic radii akɛse ne redox a ɛyɛ den kɛse. Wobetumi agyina nnuru a ɛwɔ mu so akyekyɛ lithium nkyene mu akuw abien: lithium nkyene a ɛnyɛ abɔde mu de ne lithium nkyene a ɛnyɛ abɔde mu de. Wɔayɛ lithium nkyene pii a ɛnyɛ abɔde mu nneɛma, a LiPF6, LiClO4, LIBF, ne LIASF ka ho. Nea ɛne eyi bɔ abira no, wɔyɛ lithium nkyene a wɔtaa de di dwuma wɔ lithium-ion batere mu denam ɛlɛtrɔnik-akuw a ɛtwe ɛlɛtrɔnik a wɔde ka lithium nkyene a ɛnyɛ nkwaboaa yi anion ho, te sɛ lithium dioxalato-borate (LiBOB), lithium difluorooxalato-borate ([iODFB]), lithium difluorosulfonylimide (LiFSI), ne lithium ditrifluoromethylsulfonylimide (LTFSI).Ase hɔ pon no kyerɛ abɔde mu nneɛma a ɛfata a ɛwɔ lithium nkyene pii a wɔtaa de di dwuma wɔ lithium-ion batere mu.

Nneɛma a wɔde ka ho yɛ nneɛma a wɔde ka electrolyte no ho wɔ dodow a ɛba fam (mpɛn pii no ɛnboro 10% wɔ ne kɛse mu) a ɛwɔ dwumadi pɔtee bi na ebetumi ama batere no anyinam ahoɔden su atu mpɔn kɛse. Wobetumi agyina wɔn dwumadi so akyekyɛ saa nneɛma a wɔde ka ho yi mu akuwakuw pii: nneɛma a wɔde ka ho a ɛma film-yɛ, nneɛma a ogya ntumi nhyew, ne nneɛma a wɔde ka ho de siw ahoɔden a ɛboro so ano. Bio nso, nneɛma bi wɔ hɔ a wɔde ka ho a wɔde ma nsuo a ɛkɔ nsuo mu no yɛ kɛseɛ, ɛma adwumayɛ yɛ yie wɔ tebea a ɛba fam-ɔhyeɛ mu, anaasɛ wɔhwɛ dodoɔ kakraa bi ne HF dodoɔ a ɛwɔ electrolyte solution no mu.