TY - JOUR
T1 - Single-Step Recovery of Divalent Mn Component from LiMn2O4Cathode Material at Hydrothermal Conditions as an Mn-Citrate Complex
AU - Zheng, Qingxin
AU - Shibazaki, Kensuke
AU - Ogawa, Tetsufumi
AU - Watanabe, Masaru
N1 - Funding Information:
This work was supported by the Japan Science and Technology Agency (JST)-Mirai program (Grant No. JP18077450) and the Japan Society for the Promotion of Science (JSPS) KAKENHI (Grant No. JP21K12302).
Publisher Copyright:
© 2021 American Chemical Society. All rights reserved.
PY - 2021/8/23
Y1 - 2021/8/23
N2 - As one of the most important lithium-ion battery cathode materials for electric vehicles, LiMn2O4 (LMO) cathode material was used as the feedstock of metal recovery in this study. Through a hydrothermal treatment with citric acid (0.3 mol/L), Li and Mn ions were completely leached from a commercial LMO cathode material at 120 °C for 2 min. More importantly, simultaneously with complete leaching of Li and Mn ions from LMO, the Mn component was precipitated and separated as a Mn-citrate complex by adjusting the parameters such as citric acid concentration and holding time. This process avoided the use of high-concentration acids, alkalis, and reductants, and skipped the second separation step, thereby realizing the direct recovery of the Mn component from LMO cathode materials via a green and single-step route. The Mn-citrate complex was identified to be pure C6H8MnO8 or Mn(C6H6O7)H2O, in which Mn existed as in a divalent state. Furthermore, the morphology of the Mn-citrate complex was characterized, and a mechanism was proposed to explain the reactions during this one-step hydrothermal process. Even though the research is just at the initial stage, the Mn-citrate complex reported here is expected to open a new path to the organic acid leaching step of traditional hydrometallurgy and the Mn separation process.
AB - As one of the most important lithium-ion battery cathode materials for electric vehicles, LiMn2O4 (LMO) cathode material was used as the feedstock of metal recovery in this study. Through a hydrothermal treatment with citric acid (0.3 mol/L), Li and Mn ions were completely leached from a commercial LMO cathode material at 120 °C for 2 min. More importantly, simultaneously with complete leaching of Li and Mn ions from LMO, the Mn component was precipitated and separated as a Mn-citrate complex by adjusting the parameters such as citric acid concentration and holding time. This process avoided the use of high-concentration acids, alkalis, and reductants, and skipped the second separation step, thereby realizing the direct recovery of the Mn component from LMO cathode materials via a green and single-step route. The Mn-citrate complex was identified to be pure C6H8MnO8 or Mn(C6H6O7)H2O, in which Mn existed as in a divalent state. Furthermore, the morphology of the Mn-citrate complex was characterized, and a mechanism was proposed to explain the reactions during this one-step hydrothermal process. Even though the research is just at the initial stage, the Mn-citrate complex reported here is expected to open a new path to the organic acid leaching step of traditional hydrometallurgy and the Mn separation process.
KW - Citric acid
KW - Hydrothermal treatment
KW - LiMnO
KW - Lithium-ion battery
KW - Mn recovery
KW - Mn-citrate complex
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U2 - 10.1021/acssuschemeng.1c03459
DO - 10.1021/acssuschemeng.1c03459
M3 - Article
AN - SCOPUS:85113895678
SN - 2168-0485
VL - 9
SP - 10970
EP - 10976
JO - ACS Sustainable Chemistry and Engineering
JF - ACS Sustainable Chemistry and Engineering
IS - 33
ER -
