NMC532 direct recycling(molten-salt-based method (MSDR) )

Categories:
Categories:
Unit processes/End-of-life treatment/Material recycling
Location:
CN - China
Reference year: 2021 -
Description

To upcycle the degraded NMC532 (Li1-xNi0.5Mn0.3Co0.2O2) into Ni66-NMC, 0.2 mol of the degraded NMC532 cathode powder (?20 g, a mixture of NMC532, carbon black, and polymer binder) was mixed with 0.2 mol Ni0.83Mn0.09Co0.08(OH)2, 0.5 mol LiOH, and 0.1 mol Li2SO4 and transferred into a crucible. LiOH was in excess (excess % = (1.5 ? x)/(1 + x)) to facilitate complete re-lithiation, which is a self-saturated process according to the literature.1 The crucible used for the reaction was loosely covered by a lid to allow air intake during the synthesis but avoid excess evaporation of Li salts. The material mixture was heated to 900℃ at aram pin g r a t e o f ?10℃ min-1 and held at 900℃ for 5 h and then at 860℃ for 15h in air before slow cooling at a rate of 2℃ min-1 to 300℃. The carbon black and the poly merbinder were burned away during the high-temperature MSDR process. After that, the mixture was allowed to cool down naturally. The obtained powders were recovered from the crucible, ground in an agate mortar, and washed using deionized water to separate the material from the water-soluble Li salts, which could be recycled after water evaporation and reused. The Ni66-NMC powder was collected by centrifugation and dried at 70℃ in air before being thermally treated at 700℃ for 4 h in air. T h e powder was ground again to pass through a 400-mesh sieve and then stored in a humidity-controlled storage chamber before further tests. To upcycle the degraded NMC532 into Ni80-NMC via MSDR, 0.2 mol of the degraded NMC532 cathode powder (?20 g) was mixed with 0.3 mol Ni(OH)2, 0.625 mol LiOH, and 0.125 mol Li2SO4 and transferred into a crucible. The experimental procedures were the same as those for the Ni66-NMC, except the sintering temperature was lowered to 780℃. Users of this LCA dataset should ensure that they account for the specific inputs and outputs associated with the MSDR process when conducting life cycle assessments. It is crucial to include the amounts of Ni, Mn, and Co added during the recycling process, as well as the energy consumption and emissions during the disassembly and recovery stages. Additionally, the environmental benefits of the water-soluble Li salts recovery should be considered. The MSDR method is a high-temperature process, and the effects of carbon black and polymer binder combustion on the overall environmental impact must be evaluated. Finally, the changes in sintering temperature between Ni66-NMC and Ni80-NMC recycling should be reflected in the analysis to accurately represent their respective impacts.

Process type
Unit
LCI modeling approach
Unknown
Multifunctional modeling
NONE
Format
ILCD
Aggregation type
NOT_APPLICABLE
Data provider
TianGong
Review status
Internal
Cost
Free
Contact
Tiangong LCI Data Working Group