magistrsko delo
Povzetek
Podnebni in strateški cilji Evropske skupnosti zahtevajo postopen, a odločen umik
neobnovljivih energentov. Prav tako je cilj, da obstoječe pogonske agregate
zamenjamo z učinkovitejšimi in okolju prijaznejšimi. Termični motorji, na primer motorji
z notranjim izgorevanjem, poleg ogljikovega dioksida v okolje prispevajo še znaten
delež dušikovih oksidov ter prašnih delcev.
Kemijsko energijo moramo na ekološko nesporen način pretvoriti v električno energijo,
ki jo nadalje z velikim izkoristkom uporabimo za pogon vozil. S transportom energentov
po plinovodih do uporabnikov, kjer pretvorimo kemijsko energijo v električno, se
izognemo preobremenjevanju električnega omrežja ter omogočimo hitro polnjenje
zaloge goriva.
Gorivne celice omogočajo učinkovito pretvorbo kemijske energije v električno. Gorivne
celice s trdnim elektrolitom (angl.: Solid Oxide Fuel Cells – SOFC) oziroma
visokotemperaturne gorivne celice imajo med različnimi izvedbami celic največji
izkoristek in njihovo delovanje je najmanj občutljivo na kakovost goriv.
Gorivne celice s trdnim elektrolitom so najpogosteje zložek keramičnih plasti anode,
trdnega elektrolita in katode ter kovinskega prevodnika, ki povezuje posamezne plasti.
Na katodi poteka redukcija kisika v kisikove anione, ki potujejo skozi trdni elektrolit do
anode, kjer poteče reakcija med kisikovimi anioni in vodikom. Običajno so debeline
plasti anode, trdnega elektrolita in katode okrog 10 mikrometrov, plasti kovine so
milimetrske debeline.
Gorivne celice s trdnim elektrolitom sem pripravil v obliki večplastnih struktur. Anodo
sem pripravil kot večplastno strukturo s postopkom nalivanja suspenzije zmesi prahov
nikljevega oksida in cirkonijevega oksida, modificiranega z itrijevim oksidom (YSZ), in
laminacijo posameznih plasti do želene debeline. Preostale elemente gorivne celice,
trdni elektrolit YSZ, katodo lantanov stroncijev kobaltit ferit in zaščitno plast cerijev
oksid, dopiran z gadolinijevim oksidom, sem nanesel s sitotiskom. Zložke sem sintral
v peči do temperature 1200 °C na zraku. Na podlagi mikrostrukturne analize z vrstičnim
elektronskim mikroskopom sem zaključil, da med posameznimi plastmi ni prišlo do
opaznih interakcij oziroma do pojava razpok.
Ključne besede
gorivne celice;gorivne celice s trdnim elektrolitom (SOFC);elektrolit;anoda;katoda;
Podatki
Jezik: |
Slovenski jezik |
Leto izida: |
2024 |
Tipologija: |
2.09 - Magistrsko delo |
Organizacija: |
UL NTF - Naravoslovnotehniška fakulteta |
Založnik: |
[Ž. Bertalanič] |
UDK: |
669 |
COBISS: |
193678339
|
Št. ogledov: |
12 |
Št. prenosov: |
3 |
Ocena: |
0 (0 glasov) |
Metapodatki: |
|
Ostali podatki
Sekundarni jezik: |
Angleški jezik |
Sekundarni naslov: |
solid oxide fuel cells |
Sekundarni povzetek: |
The climate and strategic goals of the European Union require a gradual yet decisive
transition away from non-renewable energy sources. Existing power units should be
replaced with more efficient and environmentally friendly alternatives. Thermal
engines, for example internal combustion engines, contribute a significant amount of
nitrogen oxides and particulate matter to the environment in addition to carbon dioxide.
We should convert chemical energy into electrical energy in an ecologically
indisputable manner and use it with high efficiency to power the vehicles. By
transporting energy carriers through pipelines to the point of use, where chemical
energy is converted into electrical energy, we avoid overloading the electrical grid and
enable rapid fuel replenishment.
Fuel cells enable the effective conversion of chemical energy into electrical energy.
Solid oxide fuel cells (SOFCs) or high-temperature fuel cells have the highest efficiency
among versatile cell designs, and their operation is the least sensitive to fuel quality.
Solid oxide fuel cells most frequently consist of a composite of ceramic layers for the
anode, solid electrolyte, and cathode, along with a metal conductor that connects the
individual layers. At the cathode, oxygen is reduced to oxide anions, which travel
through the solid electrolyte to the anode, where a reaction occurs between the oxide
anions and hydrogen. Typically, the thicknesses of the anode, solid electrolyte, and
cathode layers are around 10 micrometers, and the metal layers are about millimeter
thick.
I prepared fuel cells with a solid electrolyte in the form of multilayer structures. The
anode was formed by tape-casting the suspension of a powder mixture of nickel oxide
and zirconium oxide stabilized with yttrium oxide (YSZ) into sheets and laminating
them to the desired thickness. The remaining elements of the fuel cell, the YSZ solid
electrolyte, the lanthanum strontium cobaltite ferrite cathode and the protective layer
of cerium oxide doped with gadolinium oxide were screen printed. The multilayer
structure was sintered at a temperature of 1200 °C in air. The scanning electron
microscopy analysis revealed that there were no noticeable interactions between
individual layers or the appearance of cracks between individual layers. |
Sekundarne ključne besede: |
fuel cells;solid oxide fuel cell (SOFC);electrolyte;anode;cathode; |
Vrsta dela (COBISS): |
Magistrsko delo/naloga |
Študijski program: |
0 |
Komentar na gradivo: |
Univ. v Ljubljani, Naravoslovnotehniška fak., Oddelek za materiale in metalurgijo |
Strani: |
XXIV, 49 str. |
ID: |
23502053 |