Elektrokemija ultramikroporoznih ogljikov v Li-S akumulatorjih

magistrsko delo

Anže Zalar (Author), Robert Dominko (Mentor), Marjan Marinšek (Thesis defence commission member), Boštjan Genorio (Thesis defence commission member)

Abstract

Li–S akumulatorji v zadnjem času vse bolj pridobivajo na svoji veljavi. Glavni vzrok za vse večji pomen teh sistemov je v njihovi visoki energijski gostoti in specifični kapaciteti. Žveplo je tudi eden izmed elementov, ki so v naravi zelo zastopani. Njegova cena je zato nižja in posledično je privlačen za uporabo v akumulatorjih. Pri klasičnih sistemih z etri se pojavlja več problemov. Med njimi je sigurno največji migracija polisulfidnih zvrsti. Temu pojavu se lahko izognemo z uporabo ultramikroporoznega ogljikovega kompozita z velikostjo por manj kot 0,7 nm. S tem močno omejimo stik med elektrolitom in žveplom, ki predstavlja naš aktivni material znotraj por ultramikroporoznega ogljikovega kompozita. Posledično lahko v tovrstnih sistemih uporabljamo tudi karbonate, ki jih sicer ne bi morali. Z oblikovanjem zaščitnega filma na površini por kompozita v začetnih ciklih delovanja akumulatorja bi se dalo stik še dodatno zmanjšati in s tem preprečiti kontinuirno izgubo žvepla zaradi migracije polisulfidov. Sistem je mogoče optimizirati z uporabo različno debelih nanosov za katodni material, različnih elektrolitov in z uporabo različnih napetostnih oken delovanja akumulatorja. Sklepamo lahko, da je možno z elektrokemijskimi eksperimenti preko uravnavanja teh parametrov oblikovati akumulator, ki nam bo zagotavljal kar se da stabilno in efektivno delovanje preko večjega števila ciklov.

Keywords

elektrokemija;Li-S akumulatorji;ultramikropore;ultramikroporozni ogljik;karbonati;zaščitni film;magistrska dela;

Data

Language:	Slovenian
Year of publishing:	2021
Typology:	2.09 - Master's Thesis
Organization:	UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher:	[A. Zalar]
UDC:	621.355(043.2)
COBISS:	69580035
Views:	261
Downloads:	47
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Electrochemistry of ultramicroporous carbons in Li- S batteries
Secondary abstract:	Li–S batteries are experiencing a large increase in their research lately. The main reason for this efforts is their high energy density and specific capacity. Sulphur is also very abundant and thus enables a reduced cost for usage in batteries. In Li–S batteries with eter based electrolytes we can easily discover the polysulphide shuttle effect which represents the biggest problem in such systems. It can be smoothly avoided with the use of ultramicroporous carbons with pore size less than 0,7 nm. If we use such composites, we can disable the contact between our electrolyte and active sulphur material within the pores of the carbon composite. This actually means we can also use carbonate based electrolytes which are meant to be useless in combination with bigger pore sizes. With the design of a cathode electrolyte interphase at the surface of the pores, we can further decrease the contact and therefore the loss of active sulphur due to the polysulphide shuttle effect. We can perform the optimization through different parameters. The most common ones are: changing of electrode thickness, use of different electrolytes and use of different voltage cutoffs. We can conclude that through this optimization process we can create a stable and effective battery for longer cycling.
Secondary keywords:	Li-S battery;ultramicropores;carbonates;cathode electrolyte interphase;
Type (COBISS):	Master's thesis/paper
Study programme:	1000376
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Kemijsko inženirstvo
Pages:	51 str.
ID:	13040642