Recycling of Li-Ion batteries based on NMC cathodes

Magistrsko delo obravnava osnove delovanja litij-ionskih tehnologij, ki se uporabljajo v električnih vozilih. Zaradi zahtev po prehodu na bolj zelene tehnologije gre v prihodnosti pričakovati rast števila vozil na električni pogon, posledično pa se bo povečala količina odpadnih akumulatorjev. Po izteku življenjske dobe celic v obliki akumulatorja se te lahko uporabijo za shranjevanje presežkov električne energije v omrežjih, na ta način se jim doba nekoliko podaljša in je izkoriščenost večja. Vsak izdelek pa enkrat konča kot odpadek, s katerim je treba ravnati pravilno, da se zmanjšajo škodljivi vplivi na okolje in človeka, hkrati pa lahko po predelavi predstavlja tudi koristen vir dragocenih surovin. V delo so vključeni trenutni zakonski okviri na področju zbiranja in reciklaže odpadnih baterij in akumulatorjev v Evropi in Sloveniji z napovedmi sprememb v prihodnje. Li-ion akumulatorji s svojimi komponentami v različnih fazah življenjskega cikla prinašajo tudi določene nevarnosti. V ekstremnih primerih lahko pride do pregrevanja, iskrenja, pojava plamenov in tudi eksplozije, vendar je ob pravilnem ravnanju in številnih varnostnih komponentah verjetnost za takšen pojav izjemno majhna. Odstopanje od pravilnega ravnanja pa pomeni razstavljanje celic akumulatorja, ki je začetni korak reciklaže. Z reciklažo se lahko ukvarja le strokovnjak, ki upošteva dodatne ukrepe za zagotavljanje varnosti in je za takšno delo usposobljen. V postopek reciklaže sodi zbiranje odpadnih litij-ionskih akumulatorjev, ki mu sledita razvrščanje in mehansko ločevanje komponent, v nadaljevanju pa se z različnimi pirometalurškimi in hidrometalurškimi procesi izvajata še ločitev in pridobivanje kritičnih kovin, ki so sestavni del akumulatorjev sodobnih tehnologij. Eksperimentalni del sem izvajal na Li-ion akumulatorju z NMC katodo. Za izbiro primernega postopka reciklaže je ključnega pomena poznavanje natančne sestave akumulatorja, zato sem na komponentah opravil različne analize. Z analizo SEM-EDS sem določil osnovne materiale v anodnem in katodnem kompozitu. Poudarek je predvsem na reciklaži katodnih materialov, zato sem sestavo aktivnega katodnega materiala natančneje potrdil še z analizo FAAS. Opravil sem tudi analizo TGA-MS in v zaključni fazi s hidrometalurškimi procesi opravil še ekstrakcijo elementov Li, Ni, Mn in Co iz NMC katodnega materiala.This thesis discusses the basics of operation of lithium-ion technologies used in electric vehicles. Due to increasing demands for transition to greener technologies, the number of electric vehicles is expected to rise in the future, and as a result the amount of battery waste will also increase. After ceasing the operation of cells in the form of a vehicle battery, they can be used to store surplus electricity from the grid, thus prolonging their life expectancy and using them more effectively. Each product once ends up in the form of waste that needs to be handled properly so that its harmful effects are diminished as much as possible. At the same time, after recycling, they can also present a source of valuable raw materials. This thesis also includes the current legal framework in the field of collection and recycling of waste batteries in Europe and Slovenia with forecasts of changes in future periods. Li-Ion batteries and their components can pose certain dangers in different stages of their life cycle. In extreme cases, overheating, appearance of sparks, flames and even explosions can occur, but with proper handling and inclusion of multiple safety measures that probability is extremely low. Disassembly of battery cells is one of the initial steps of recycling. It presents a certain deviation from proper handling since it includes taking the battery apart. Therefore, recycling should be done by a professional who takes additional safety measures and is qualified for such work. The recycling process also includes the collection of waste lithium-ion batteries, which is followed by sorting and mechanical separation of the components. Recycling is concluded by using various pyrometallurgical and hydrometallurgical processes to separate and extract critical metals, which are an integral part of modern-technology batteries. The experimental part of this thesis was performed on a Li-Ion battery with a NMC cathode. To choose the recycling process properly, it is crucial to know the exact composition of the examined battery, therefore I performed various analyses of the components. Using SEM-EDS analysis, I determined the basic materials present in anode and cathode powder. Since the emphasis is mainly on effectively recycling the cathode materials, I confirmed the composition of the active cathode material with FAAS and conducted a TGA-MS analysis. In the final stage I also performed an extraction of cathode powder elements Li, Ni, Mn, and Co by employing various hydrometallurgical processes