(From left: Mr. Tajiri, Mr. Kitaoka, Mr. Michel)
― 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 to gain firsthand insights into Japan’s recycling practices. The visit was coordinated by IRuniverse (Sugihara). The tour covered two sites: Metal Do, a specialist in rare metal recycling, and the Japan Recycling Center.
This article (Part 1) focuses on the visit to Metal Do’s Nishiyodogawa facility.
Nishiyodogawa Facility: A Battery Recycling Hub
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).
The facility serves as a key operational base for:
- Sorting lithium-ion batteries (LIBs)
- Producing black powder (black mass precursor)
The tour began with the battery intake and sorting process, where valuable metals are recovered from:
- Electrode sheets and wound electrodes (jelly rolls)
- Battery production scrap
- Electronic components
The facility processes approximately 200 tons per month on average.
Understanding Battery Structure: Cells and Foils
The visit started with an overview of lithium-ion battery structure.
Recovered batteries include:
- Cylindrical batteries
- Prismatic batteries (for EVs)
- Pouch-type batteries (smartphones, laptops, etc.)
Among these, automotive batteries account for the largest volume, while EV batteries yield the highest amount of recoverable rare metals.
Inside each battery are “cells” composed of:
- Cathode
- Anode
- Separator
(Note: As the facility mainly handles production scrap, electrolytes are typically not present.)
A key component is the foil, the metal sheet supporting the electrode materials. The cathode and anode are separated by an insulator and wound together into a structure known as a jelly roll.
- Cathode: Aluminum foil (Al) + active materials (e.g., NCM: nickel, cobalt, manganese)
- Anode: Copper foil (Cu) + carbon
The cathode material is the primary source of black powder.
Black Powder and Black Mass
In some recycling processes, batteries are shredded or thermally treated without separating cathode and anode materials beforehand. The resulting mixed powder is known as black mass.
By contrast, when cathode materials are processed separately—as in Metal Do’s approach—the resulting black powder is higher in purity, with fewer impurities and higher concentrations of valuable metals.
Shredding Process: Dry Recycling Technology
The next stage of the tour focused on the shredding facility.
Here, cathode foil is processed to separate aluminum from active material (the precursor to black powder).
The process involves:
- 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 while black powder is finer, separation is achieved through mesh size differences.
Technology Comparison: Wet vs Dry Processing
During the visit, Michel Siemon shared insights into Primobius’ approach.
Metal Do’s process is characterized by:
- Processing of cathode foil only
- Focus on production scrap
- No electrolyte content → high safety
In contrast, Primobius technology enables processing of entire cells or modules.
“In our wet process, we can feed whole cells into the system, eliminating the need for manual separation,” said Siemon.
This approach simplifies pre-treatment and reduces labor requirements.
Battery Discharge Approaches in Japan
While Metal Do also handles batteries containing electrolytes, discharge processing is outsourced to partner companies for black mass production.
According to Mr. Kitaoka, the main discharge methods used in Japan include:
- Thermal treatment (e.g., rotary kiln or drying furnace)
- Coarse crushing under nitrogen atmosphere
- Saltwater discharge
Regarding the necessity of discharge, Michel Siemon commented:
“Whether discharge is required depends on the process. In some cases, full discharge is not necessary. With systems such as APEX, reducing the state of charge to around 30% is sufficient.”
He also highlighted safety aspects:
“In our process, shredding is conducted in water, which significantly reduces the risk of explosion. We also incorporate nitrogen atmosphere stages within our system.”
Production Capacity and Operational Strategy
Michel also inquired about production capacity.
The Nishiyodogawa facility produces:
- Approximately 70 tons of black powder per month
- Using around 80 tons of cathode foil input
- Operating on a single daily shift
This reflects a demand-driven operational model, avoiding overinvestment while maintaining efficiency.
Strategic Focus: Cathode Specialization
Metal Do has deliberately focused its investment on cathode material processing.
Advantages:
- High cost efficiency
- Simplified processing
Limitations:
- Cannot process full battery cells or modules
In contrast, full black mass processing systems:
- Can handle various battery types
- Require higher capital investment
Mr. Kitaoka noted:
“Demand for full black mass processing technologies may increase in the future.”
Toward Future Collaboration
At the conclusion of the visit, Metal Do proposed a future visit to its logistics centers:
- A secondary yard handling nickel-based materials
- A primary processing site for titanium and superalloys
Michel responded:
“We would be delighted to welcome you in Germany and show you our hydrometallurgical facilities.”
This exchange highlighted the growing potential for Japan–Europe collaboration in battery recycling technologies.
Related Article：Pre-Summit Interview―Primobius CEO Michel Siemon: Scaling Industrial Battery Recycling from Europe to Japan.
（IRuniverse R.S.）
