Repurposing of fruit peel waste as a green reductant for recycling of spent lithium-ion batteries

The development of environmentally benign hydrometallurgical processes to treat spent lithium-ion batteries (LIBs) is a critical aspect of the electronic-waste circular economy. Herein, as an alternative to the highly explosive H2O2, discarded orange peel powder (OP) is valorized as a green reductan...

Full description

Saved in:
Bibliographic Details
Main Authors: Wu, Zhuoran, Soh, Tanto, Chan, Jun Jie, Meng, Shize, Meyer, Daniel, Srinivasan, Madhavi, Tay, Chor Yong
Other Authors: School of Materials Science and Engineering
Format: Article
Language:English
Published: 2021
Subjects:
Online Access:https://hdl.handle.net/10356/148822
Tags: Add Tag
No Tags, Be the first to tag this record!
Institution: Nanyang Technological University
Language: English
Description
Summary:The development of environmentally benign hydrometallurgical processes to treat spent lithium-ion batteries (LIBs) is a critical aspect of the electronic-waste circular economy. Herein, as an alternative to the highly explosive H2O2, discarded orange peel powder (OP) is valorized as a green reductant for the leaching of industrially produced LIBs scraps in citric acid (H3Cit) lixiviant. The reductive potential of the cellulose- and antioxidant-rich OP was validated using the 3,5-dinitrosalicylic acid and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic) acid assays. Leaching parameters such as OP concentration (200 mg), processing temperature (100 °C), H3Cit concentration (1.5 M), reaction duration (4 h), and slurry density (25 g/mL) were systematically optimized to achieve 80-99% leaching efficiencies of Ni, Mn, Co, and Li from the LIB "black mass". Importantly, solid side-streams generated by the OP-enabled leaching displayed negligible cytotoxicity in three different human cell lines, suggesting that the process is environmentally safe. As a proof of concept, Co(OH)2 was selectively recovered from the green lixiviant and subsequently utilized to fabricate new batches of LiCoO2 (LCO) coin cell batteries. Galvanostatic charge-discharge test revealed that the regenerated batteries exhibited initial charge and discharge values of 120 and 103 mAh/g, respectively, which is comparable to the performance of commercial LCO batteries. The use of fruit peel waste to recover valuable metals from spent LIBs is an effective, ecofriendly, and sustainable strategy to minimize the environmental footprint of both waste types.