| Title |
Reduction Behavior of Black Mass Recovered from NCM-based Spent Lithium-ion Batteries by CO Gas |
| Authors |
이상엽(Sang-Yeop Lee) ; 황재호(Jae-Ho Hwang) ; 이소영(So-Yeong Lee) ; 손호상(Ho-Sang Sohn) |
| DOI |
https://doi.org/10.3365/KJMM.2025.63.10.820 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Lithium-ion battery; Recycling; Reduction roasting; Boudouard reaction; Black mass |
| Abstract |
The cathode active materials of lithium-ion batteries (LIBs) contain critical metals including Ni,
Co, Mn, and Li. Since these metals are only produced in a few countries, it is necessary to recover them from
spent lithium-ion batteries. The concentrated electrode materials of lithium-ion batteries are referred to as
black mass (B/M), which contains a large amount of carbon used as the anode material, along with metal
oxides used in the cathode. In this study, the effect of roasting temperature in an Ar+CO gas atmosphere on
the reduction behavior of NCM (LiNixCoyMn1-x-yO2)-based black mass powder and the recovery of Li was
investigated. In the thermogravimetric analysis, the CO2 concentration increased sharply from about 430 oC
to a maximum value and then decreased, during which a weight gain due to the formation of Li2CO3 was also
observed. Above approximately 700 oC, the concentration of CO increased due to the reaction of CO2 with the
C in the B/M due to the Boudouard reaction. In the isothermal roasting in an Ar+CO 50 vol.% atmosphere,
the weight of the sample decreased significantly above 696 oC, and the final weight loss amount also increased
with increasing temperature. Most of the significant weight loss is thought to be due to the Boudouard
reaction. Li2CO3 was generated regardless of temperature. Above 696 oC, most of the Ni and Co oxides were
reduced to metals, and above 900 oC, some of the MnO was also reduced and is thought to have been dissolved
in the Ni-Co alloy. At temperatures above 696 oC, where the NiO was fully reduced, the recoveries rate of
lithium was approximately 90 % with no significant difference. |