Original Article:
Recovery and regeneration of lithium cobalt oxide from spent lithium-ion batteries through a low-temperature ammonium sulfate roasting approach
Yiqi Tang, et al.
Journal of Power Sources, 2020, 474, 228596.
10.1016/j.jpowsour.2020.228596
Lithium cobalt oxide (LiCoO2) is most widely used in portable electronic devices due to its relatively high specific energy density and good cycle performance. Currently, many efforts are devoted to the recycling of spent LiCoO2-based lithium-ion batteries (LIBs). This study proposes a molten ammonium sulfate ((NH4)2SO4) low-temperature roasting method for the recovery and regeneration of LiCoO2 from spent LIBs at 400 °C. The results show that the (NH4)2SO4-assisted roasting method provides a facile, energy-saving, and environmentally friendly method to recycle and regenerate spent LiCoO2-based lithium-ion batteries. The flow chart of the recovery and regeneration process achieved by the ammonium sulfate roasting method is shown in the figure.
The characteristics of ammonium sulfate roasting method
> (NH4)2SO4 has a relatively low melting point (230-280 °C) and high chemical reducibility. Thus, the use of (NH4)2SO4 significantly lowers the operating temperature to 400 °C, thereby increasing extraction yields while reducing energy consumption.
> During sulfation, LiCoO2 is reduced to Co2+ by (NH4)2SO4 assisted roasting and then converted to Li2Co(SO4)2/CoSO4 and Li2SO4.
The proposed reactions involved the (NH4)2SO4 sulfation roasting are represented as follows:
1) 2/3LiCoO2+(NH4)2SO4→2/3CoSO4+1/3Li2SO4+1/9N2(g) +16/9NH3(g)+4/3H2O(g)
2) CoO+(NH4)2SO4→CoSO4+2NH3(g)+H2O(g)
> (NH4)2SO4 can be used as a reducing agent and a sulfating agent to achieve sulfation of LiCoO2 without introducing metal ions. In addition, liquid (NH4)2SO4 can improve the kinetics of sulfation at relatively low operating temperatures.
Chemicals Related in the Paper:
| Catalog Number | Product Name | Structure | CAS Number | Price |
|---|---|---|---|---|
| ACM12190793 | Cobalt lithium oxide |  |
12190-79-3 | Price |
| ACM7783202 | Ammonium sulfate |  |
7783-20-2 | Price |
