Sustainable Hydrometallurgical Recovery of Valuable Elements from Spent Nickel–Metal Hydride HEV Batteries

Abstract

In the present study, the recovery of valuable metals from a Panasonic Prismatic Module 6.5 Ah NiMH 7.2 V plastic casing hybrid electric vehicle (HEV) battery has been investigated, processing the anode and cathode electrodes separately. The study focuses on the recovery of the most valuable compounds, i.e., nickel, cobalt and rare earth elements (REE). Most of the REE (La, Ce, Nd, Pr and Y) were found in the anode active material (33% by mass), whereas only a small amount of Y was found in the cathode material. The electrodes were leached in sulfuric acid and in hydrochloric acid, respectively, under different conditions. The results indicated that the dissolution kinetics of nickel could be slow as a result of slow dissolution kinetics of nickel oxide. At leaching in sulfuric acid, light rare earths were found to reprecipitate increasingly with increasing temperature and sulfuric acid concentration. Following the leaching, the separation of REE from the sulfuric acid leach liquor by precipitation as NaREE (SO4)2·H2O and from the hydrochloric acid leach solution as REE2(C2O4)3·xH2O were investigated. By adding sodium ions, the REE could be precipitated as NaREE (SO4)2·H2O with little loss of Co and Ni. By using a stoichiometric oxalic acid excess of 300%, the REE could be precipitated as oxalates while avoiding nickel and cobalt co-precipitation. By using nanofiltration it was possible to recover hydrochloric acid after leaching the anode material.

A Fast Metals Recovery Method for the Synthesis of Lithium Nickel Cobalt Aluminum Oxide Material from Cathode Waste

“…The inorganic acids present a satisfactory performance during leaching and achieve higher efficiency of metal extraction than organic acids [29]. Techniques that are used to prepare the final products from the leaching filtrate include solvent extraction [10,[30][31][32][33], electrochemical techniques [34][35][36], selective precipitation [21,[37][38][39][40], and co-precipitation [41][42][43]. Among these, co-precipitation is the most efficient technique for the recovery of more than one metal (mixed metal) due to a higher level of homogeneity and spherical/sphere-like products [44].…”

Leaching Mechanisms of Industrial Powders of Spent Nickel Metal Hydride Batteries in a Pilot‐Scale Reactor

“…Hydrometallurgical processes are the main alternative for recycling NiMH batteries, in which battery powders are generally leached in a mineral acid, such as HCl (around 40 % of the recent literature) or H 2 SO 4 (about 60 %) . To a minor extent, a few researchers have studied the use of HNO 3 , carboxylic acids, or ascorbic acid as leaching agents, but these have not been considered in this study.…”

“…Hydrometallurgical processes are the main alternative for recycling NiMH batteries, in which battery powders are generally leachedi namineral acid, such as HCl [13,[16][17][18][19][20][21][22][23] (around 40 %o f the recentl iterature)o rH 2 SO 4 (about 60 %). [2, 3, 28-32, 10, 12, 14, 18, 24-27] In view of as ustainable recycling process, the leaching mechanisms of nickel and rare-earth elements (REEs) contained within industrial samples of spent nickel metal hydride battery powders were investigated in HCl and H 2 SO 4 ,u nder mild temperature( 25-60 8C) and pH (3-5.5).…”

Recovery of Rare Earth Oxide from Waste NiMH Batteries by Simple Wet Chemical Valorization Process

“…Korkmaz [17]. Korkmaz et al also reported a HCl acid leaching and oxalic acid precipitation route for the recovery of REM from waste NiMH batteries [18]. Innocenzi and Vegliò reported REM recovery by H 2 SO 4 leaching followed by a (REM) 2 SO 4 precipitation route using NaOH [19].…”