Preparation of Li4SiO4 from lithium-ion battery cathode waste and diamond wire saw silicon powder using a two-step process

Li4SiO4 materials have excellent high-temperature CO2 adsorption properties. In this thesis, Li4SiO4 was produced by a two-step process by using Li+ from waste lithium-ion battery cathodes as a partial lithium source. The diamond wire saw silicon powder generated by the photovoltaic industry, was used as the silicon source. The reduction melting process of LiMeO2 (Me = Ni, Co, or Mn) in the battery cathode material was analyzed, and the effect of the Li: Si molar ratio in the melting system on the reduction of metal oxides was investigated. The effects of roasting temperature and roasting time on the adsorption properties of Mn-doped Li4SiO4 were also studied. The results showed that the maximum adsorption capacity of Mn-doped Li4SiO4 reached 29.44 wt.% under a pure CO2 atmosphere, which was about 2.6 times higher than that of pure Li4SiO4. The saturated adsorption capacity reached 34.2 wt.%. This study achieved the resource utilization of solid waste and may reduced the preparation costs of Li4SiO4 adsorbent, which may promote carbon capture technologies.