Development of a Process for Recovering Nickel and Cobalt Sulfate from Used Lithium-Ion Batteries

DOWA ECO-SYSTEM CO., LTD. (Location: Tokyo, Capital: 1 billion yen, President: Yasuharu Yanai) has developed a process for recovering nickel and cobalt sulfate from used lithium-ion batteries (hereafter, LIBs) and has commenced demonstration tests for direct sales to cathode material manufacturers.

Amidst the anticipated increase in the volume of used LIBs generated, the company aims for a stable supply of rare metals through the establishment of an integrated recycling process encompassing the safe treatment of used LIBs to the refining of raw materials, and the advancement of recovery technologies.

Background

LIBs, which are expected to play a significant role in the efficient use of energy towards the realization of a decarbonized society, are seeing expanding adoption in various fields such as electronic devices, automobiles (HV/EVs), and residential applications. On the other hand, rare metals like lithium, cobalt, and nickel, essential for LIB cathode materials, are unevenly distributed in terms of reserves and production among specific countries. Their circulation volume is smaller compared to common metals, and an intensification of international competition for their acquisition is anticipated with future demand increases. Therefore, recycling from used LIBs, in addition to natural resources, is being called for.

Overview of the New Recovery Process

The company has a leading track record in Japan for recovering black mass, a raw material for cathode materials, from used LIBs safely processed at its own waste treatment facilities. Previously, lithium contained in black mass was recovered as lithium carbonate, and its applicability for cathode material use has been confirmed through demonstration experiments.

With the recent development of a process to recover nickel and cobalt sulfate from black mass, an integrated recycling process has been established for the recovery of the main rare metals (lithium, nickel, and cobalt) contained in LIBs. This enables the recovery of all rare metals from used LIBs, for which recovery targets are set by the European Battery Regulation by 2030. The nickel and cobalt sulfate recovered by this process are currently undergoing sample supply and performance evaluation by cathode material manufacturers.

This process was established through the collaboration of the black mass recovery technology held by our company and the refining technology held by DOWA ELECTRONICS CO., LTD. (Location: Tokyo, Capital: 1 billion yen, President: Takehiko Suzuki), also a DOWA group company. Patent applications are currently being filed for the integrated recycling process.

Nickel and Cobalt Sulfate

Overall Diagram of the Demonstration Plant

Future Outlook

Moving forward, alongside verifying the operational stability and quality of the demonstration plant, we will proceed with scale-up for future production increases by advancing evaluations through sample provision to cathode material manufacturers. We are also considering deployment to overseas bases of our group, not only domestically.

Company Profile of DOWA ECO-SYSTEM CO., LTD.

1. Headquarters: 4-14-1 Sotokanda, Chiyoda-ku, Tokyo

2. Established: October 2006

3. Capital: 1 billion yen

4. Representative: Representative Director and President Yasuharu Yanai

5. Number of Employees: Approximately 3,700 (Consolidated DOWA ECO-SYSTEM, as of end of March 2026)

6. Shareholder: DOWA HOLDINGS CO., LTD. 100%

7. Business Activities: Environmental and Recycling Business (Resource Recycling, Waste Treatment, Soil Remediation, Logistics, Consulting)