Hydrothermal leaching of LiCoO2 with sulfuric acid, nitric acid, and citric acid

Tatsuya Aikawa, Masaru Watanabe, Taku M. Aida, Richard L. Smith

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


Spent lithium ion batteries are a secondary resource of metals. To recover Li and Co ions into water, hydrothermal reactions were performed to leach cobalt and lithium from LiCoO2 at 150-300°C for 10-60 min with 0.4 M of various acids. Sulfuric acid, nitric acid, and citric acid were introduced as leaching reagents. For 0.4 M of citric acid aqueous solution, over 90% of Li and Co ions could be leached at 150°C within 10 min. Reduction of cobalt ion (Co3+ to Co2+) is considered to be necessary for dissolution of Co ion into water solution and citric acid acted reductant. Formation of Co citrate, which was detected by UV-vis spectroscopy, was the reason why citric acid was effective for leaching LiCoO2 with hydrothermal water.

Original languageEnglish
Pages (from-to)313-318
Number of pages6
Journalkagaku kogaku ronbunshu
Issue number4
Publication statusPublished - 2017 Jan 1


  • Acid Leaching
  • Citric Acid
  • Hydrothermal
  • Lithium Ion Battery
  • Nitric Acid
  • Recycle
  • Sulfuric Acid

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)

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