3D-tulostetut litium-ioniseula adsorbentit litiumin talteenottoon Li-ion akkujen kierrätysprosessien raffinaateista

Lithium is used widely in batteries to power various electronic devices. A sharp increase in demand is being driven by the increasing production of consumer electronics, and more recently, the production of electric vehicles and grid battery storages. The rising number of end-of-life batteries has resulted in the emergence of recycling processes for the recovery of various valuable metals including lithium from them. However, the recovery of lithium in these processes is often incomplete, leaving behind a battery raffinate with lithium contents of 1400 – 2000 mg/L, with a sodium to lithium ratio of 10 – 100. The recovery of the remaining lithium is challenging due to both its low concentration, which limits the effectiveness of precipitation, and the significantly higher sodium content present in the raffinate. The purpose of this thesis was to develop a highly selective and 3D-printable adsorbent for the recovery of lithium from raffinates. Ion sieves are specialized inorganic adsorbents, which usually consist of manganese or titanium oxides to achieve good performance or a more dissolution-resistant structure respectively. In this thesis, a combined titanium-manganese ion sieve adsorbent is synthesized and 3D-printed with the purpose of achieving competitive performance with a resistant structure. The results show the synthesized adsorbent to be extremely selective for lithium, while also providing improved dissolution resistance compared to manganese-based ion sieves. The adsorption process was shown to prefer high pH values, and to be highly endothermic, with large increases in performance achieved in temperature-controlled column application.