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.