― Post–Tokyo Battery Summit Tour in Osaka ―
Following the 13th Tokyo Battery Summit, Michel Siemon, a speaker in the recycling session, visited battery recycling facilities in Osaka under the coordination of IRuniverse to gain firsthand insights into Japan’s recycling practices. The tour included two sites: Metal Do, a specialist in rare metal recycling, and the Japan Recycling Center.
This first article focuses on the visit to Metal Do’s Nishiyodogawa facility.
Nishiyodogawa Facility: A Hub for LIB Recycling
While Metal Do’s headquarters is located in Osaka Minami, the visit focused on its Nishiyodogawa facility, guided by Mr. Kitaoka (Domestic Sales Department) and Mr. Tajiri (Site Leader).
This site serves as a key operational base for sorting and shredding lithium-ion batteries (LIBs) and producing black powder.
The tour began with the battery intake and sorting process. Here, batteries containing valuable metals are collected from:
- Manufacturing scrap and offcuts
- Aerospace components
- Electronic materials
The facility processes approximately 150–200 tons per month.
Understanding Battery Structure: Cells and Foils
An initial briefing covered the fundamental structure of lithium-ion batteries. Collected batteries include:
- Cylindrical cells
- Prismatic EV batteries
- Laptop batteries
Among these, EV batteries account for the largest share.

Each battery consists of “cells” containing: Cathode, Anode, and Separator. A key component is the foil, the metal sheet that supports the electrode materials:
- Cathode foil: Aluminum (Al) + active materials (e.g., NCM)
- Anode foil: Copper (Cu) + carbon
The cathode material is the primary source of black powder.
Black Powder Generation Process
Recovered batteries are composed of “cells” that include the cathode, anode, and separator. In this case, since the feedstock consists of production scrap, no electrolyte is present.
A key component within the cell is the foil, the metal sheet that supports the electrode materials. The cathode and anode are separated by an insulating layer and wound into a structure—commonly referred to as a “jelly roll” in cylindrical batteries.
The cathode contains aluminum foil and active materials such as NCM (nickel, cobalt, manganese), which form the primary source of black powder. In contrast, the anode consists of copper and carbon.
- Cathode: Aluminum foil (Al) + active materials (e.g., NCM)
- Anode: Copper foil (Cu) + carbon
In some recycling processes, batteries are not disassembled into individual components but are instead treated through thermal processing or shredding. This produces what is known as “black mass.”
In general, black powder derived from the cathode contains fewer impurities and is therefore considered higher in quality.

Shredding Process: Dry Recycling Technology
The tour continued to the shredding facility, where cathode foil is processed to separate aluminum from active material.
The process includes:
- Feeding foil into the system
- Three-stage crushing (final stage: hammer mill)
- Airflow transport of fine particles
- Sieving based on particle size
Because aluminum particles are larger and black powder is finer, separation is achieved through mesh size differences.
Technology Comparison: Wet vs Dry Processing
During the visit, Michel Siemon provided insights into Primobius’ technology.
Metal Do’s foil-based approach, Primobius technology allows:
- Processing of full cells or modules
- Simplified pre-treatment
- Reduced labor requirements
Unlike Metal Do’s foil-based approach, Primobius technology allows:
- Processing of full cells or modules
- Simplified pre-treatment
- Reduced labor requirements
“In our wet process, entire cells or modules can be fed directly into the system, eliminating manual separation.”
Battery Discharge Practices in Japan
Mr. Kitaoka also outlined three common discharge methods used in Japan:
- Thermal treatment (burning off electrolyte)
- Wet discharge (in water)
- Nitrogen atmosphere processing
Michel noted that Primobius systems also incorporate nitrogen stages, highlighting technical overlap between regions.
Production Capacity and Operational Strategy
The Nishiyodogawa facility produces:
- ~70 tons/month of black powder
- From ~80 tons of cathode foil input
- Operating on a single daily shift
This reflects a demand-driven operation model, avoiding overcapacity and excessive capital investment.
Strategic Focus: Cathode Specialization vs Full Processing
Metal Do has deliberately chosen to focus on cathode material processing.
Advantages:
- High cost efficiency
- Simplified operations
Limitations:
- Cannot process full battery cells or modules
In contrast, full black mass processing systems:
- Handle diverse battery types
- Require higher capital investment
Mr. Kitaoka commented:
“Demand for full black mass processing systems may increase in the future.”

Toward Future Collaboration
At the conclusion of the visit, Metal Do invited Michel to visit its Osaka headquarters to further explore its broader business, including:
- Titanium
- Rare earths
- Superalloy scrap
Michel responded:
“We would be happy to welcome you in Germany and show you our hydrometallurgical facilities.”
This exchange highlighted the potential for deeper Japan–Europe collaboration in battery recycling technologies.
As EV battery volumes rise globally, the convergence of these technologies may shape the future of resource circularity.
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