Lithium and Cobalt Recovery from LiCoO₂ Using Oxalate Chemistry: Scale-Up and Techno-Economic Analysis

Abstract

Currently, approximately 59% of spent lithium-ion batteries (LIBs) contain a lithium cobalt oxide (LiCoO 2 ) cathode. Both lithium (Li) and cobalt (Co) are critical metals, and the efficient recycling of LiCoO 2 cathodes through an environmentally benign process is essential for a stable Li and Co economy. In this work, a closed-loop recycling process utilizing oxalic acid (H 2 C 2 O 4 ) and hydrogen peroxide (H 2 O 2 ) was scaled-up to operate at a solid-to-liquid (S/L) ratio of 38 g/L. The H 2 C 2 O 4 process was operated at 100 °C with Li 2 CO 3 and Co(OH) 2 as the final products, whereas in the presence of H 2 O 2 , the metal extraction was operated at 75 °C. After the metal recovery, the H 2 C 2 O 4 was efficiently recycled using an ion exchange process. A techno-economic analysis was performed to compare the oxalate process with the H 2 SO 4 process operating at 65 °C and S/L = 100 g/L. The H 2 C 2 O 4 and H 2 C 2 O 4 + H 2 O 2 processes with 90% recycling of oxalate are equal in cost with the H 2 SO 4 process on a per kilogram LiCoO 2 production basis. An important difference is that the H 2 C 2 O 4 + H 2 O 2 process produces 50% less waste than the H 2 SO 4 + H 2 O 2 process. The H 2 C 2 O 4 and H 2 C 2 O 4 + H 2 O 2 processes provide the opportunity to recycle oxalate in order to create a closed-loop, economical, and environmentally friendly process for recovering critical metals such as Li and Co from LiCoO 2 . The oxalate process offers similar advantages for recycling other valuable metals from ore processing and waste streams.

A Review of Recovering Lithium and Cobalt from Spent LiCoO2 Lithium‐Ion Batteries Cathode

“…Sodium hydroxide (NaOH) plays a role in adjusting the pH value precipitating Co(OH) 2 from the solution. Verma extracted lithium and cobalt by using K 2 CO 3 and NaOH [92] . The recovery efficiencies reached >90 % of Li and 97 % Co with a high purity of 99.5 %.…”

“…[91] Oxalic acid (OA) is an efficient reagent by which Li is leached into solution, whereas Co is precipitated out in the recycling process. [92] Oxalic acid dissolution behaviors on spent LiCoO 2 cathode are depicted in Figure 4, manifesting oxalic acid as an efficient reagent to separate and recover Li and Co. [38] The leaching reactions using oxalate as leachant and precipitant may be represented as follows: [77]…”

Clean Process for Selective Recovery of Lithium Carbonate from Waste Lithium-Bearing Aluminum Electrolyte Slag

“…The demand for lithium batteries has witnessed a significant surge in recent years, propelled by the rapid growth in production and sales of mobile smart terminals, compact power equipment, and new energy vehicles. − This leads to intensified competition for global lithium resources and an increased price of lithium salt. As of October 31, 2022, the prevailing price of battery-grade lithium carbonate had risen to $79,383.7/ton. , Because of demand for lithium resources and commercial opportunity, researchers have directed their focus toward recycling of spent lithium-ion batteries − and using low-grade raw materials (low-grade lithium ore smelting − and saline brine lithium − ) in metallurgical processes.…”

A Review of Sodium Oxalate Solubility in Water

“…The solubility of disodium oxalate is not only of interest to industries that use it but is also an input to alternative analyses for reagent selection. For instance, recent hydrometallurgical process development teams chose to use dipotassium oxalate as a reagent instead of disodium oxalate because of the higher solubility of dipotassium oxalate. , …”

“…For instance, recent hydrometallurgical process development teams chose to use dipotassium oxalate as a reagent instead of disodium oxalate because of the higher solubility of dipotassium oxalate. 14,15 The impetus for the present study is to better understand oxalate behavior in alkaline nuclear waste at sites such as Hanford and Savannah River in the United States. The Hanford Site maintains an inventory of nuclear waste constituents in a database called the Tank Waste Inventory Network System.…”